Portal Vein Thrombosis: Imaging the Spectrum of Disease With an Emphasis on MRI Features

Development and validation of an integrated model for the diagnosis of liver cirrhosis with portal vein thrombosis combined with endoscopic characters and blood biochemistry data: a retrospective propensity score matching (PSM) cohort study

BACKGROUND

Liver cirrhosis complicated by portal vein thrombosis (PVT) is a fatal complication with no specific manifestations but often misdiagnosed, it crucially increases the mortality worldwide. This study aimed to identify risk factors and establish a predictive model for diagnosis of venous thrombosis clinical by routine blood tests and endoscopic characteristics.

METHODS

Patients from Gansu Provincial Hospital from October 2019 to December 2023 were enrolled. The retrospective modelling cohort was screened by propensity score matching (PSM) at a 1:1 ratio from the baseline characteristics before endoscopic diagnosis. Variables were collected from blood test and endoscopic signs using machine learning method (ML). Logistic regression determined risk factors. The predictive performance was evaluated by receiver operation curve (ROC), calibration curve, clinical decision analysis (DCA) and influence curve (CIC). Furthermore, external cohort was used for validation, an online nomogram was established.

RESULTS

A total of 1,058 patients were enrolled, and 470 patients were included after PSM 1: 1. The model identified 7 factors, including splenectomy, blood urea nitrogen (BUN), serum sodium, activated partial thromboplastin time (APTT), thrombin time (TT), D-dimer, and degree of oesophageal varices. The area under the curve (AUC) was 0.907 (95% CI, 0.877-0.931). The calibration curve, decision and clinical impact curves showed the model demonstrated a good predictive accuracy and clinical benefits. The validation got an AUC of 0.890 (95% CI, 0.831-0.934), A nomogram tool was finally established for application.

CONCLUSION

Blood test combined endoscopic characters could preliminarily predict the liver cirrhosis with portal vein thrombosis for cirrhotic patients undergoing endoscopic examination.

Portal Vein Thrombosis in Patients Without Cirrhosis: Current Practical Approaches and Treatment Strategies

Portal vein thrombosis in non-cirrhotic individuals, although uncommon, is an increasingly explored condition that affects mainly young people, consequently representing a significant disease burden. Reports primarily including western European populations have recently shed light regarding the pathophysiology, risk factors, natural history, treatment, and prognosis of this entity. Underlying predisposing conditions are documented in ~70% of cases, encompassing local risk factors, inherited and acquired thrombophilia, cancer, and systemic inflammatory conditions. Non-cirrhotic portal vein thrombosis can cause significant portal hypertension in the acute setting, but, more frequently, significant portal hypertension-related complications arise when the condition becomes chronic and portosystemic collaterals develop, increasing the risk for variceal bleeding and ascites. The diagnostic approach to screen for underlying thrombophilia remains a challenge, and recommendations in this regard, although scarce and backed by scarce evidence, have changed notably in the last years, leaning toward a universal screen in patients who develop this condition without a clear provoking factor. Recently, studies have shown that long-term anticoagulation may be appropriate even in the absence of clear provoking factors or underlying thrombophilia. Future studies should address which patients may benefit from this approach, which patients may not need it, and what the most appropriate strategies are to approach patients who do not recover portal vein patency with anticoagulation to further prevent portal hypertension-related complications.

An exploration of radiological signs in post-intervention liver complications

The advent and progression of radiological techniques in the past few decades have revolutionized the diagnostic and therapeutic landscape for liver diseases. These minimally invasive interventions, ranging from biopsies to complex therapeutic procedures like transjugular intrahepatic portosystemic shunt placement and transarterial embolization, offer substantial benefits for the treatment of patients with liver diseases. They provide accurate tissue diagnosis, allow real-time visualization, and render targeted treatment for hepatic lesions with enhanced precision. Despite their advantages, these procedures are not without risks, with the potential for complications that can significantly impact patient outcomes. It is imperative for radiologists to recognize the signs of these complications promptly to mitigate further health deterioration. Ultrasound, CT, and MRI are widely utilized examinations for monitoring the complications. This article presents an overarching review of the most commonly encountered hepatobiliary complications post-radiological interventions, emphasizing their imaging characteristics to improve patient post-procedure management.

Thrombosed massive portal vein aneurysm in an adolescent boy

Portal vein aneurysm is a rare vascular disorder, particularly in the pediatric population, with relatively few cases reported in the literature. The most frequent complication of portal vein aneurysm is thrombosis, which may lead to diagnostic uncertainty as it can resemble a tumor. Therefore, it is important to recognize this entity and its imaging features for accurate diagnosis. We present a case of a portal vein aneurysm in an adolescent boy, complicated with thrombosis, and report radiological findings, treatment, and short-term follow-up.

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

Current concepts in the management of non-cirrhotic non-malignant portal vein thrombosis

Non-cirrhotic non-malignant portal vein thrombosis (NCPVT) is an uncommon condition characterised by thrombosis of the portal vein, with or without extension into other mesenteric veins, in the absence of cirrhosis or intra-abdominal malignancy. Complications can include intestinal infarction, variceal bleeding and portal biliopathy. In this article, we address current concepts in the management of NCPVT including identification of risk factors, classification and treatment, and review the latest evidence on medical and interventional management options.

Refining MRI-based criteria for portal vein invasion in hepatocellular carcinoma: improving sensitivity beyond portal vein tumor thrombosis

PURPOSE

To investigate the imaging features indicating portal vein invasion (PVI) of hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced MRI and to create more accurate diagnostic criteria than the presence of portal vein tumor thrombosis (PVTT) on MRI.

METHODS

This retrospective study included patients with surgically resected HCC larger than 5 cm, and the presence of PVI was investigated. On MRI, we evaluated the image findings of portal vein occlusion, the parenchymal signal change caused by hemodynamic alterations of the portal vein, and their combination showing the highest odds ratio (OR) to define the diagnostic criteria for radiological PVI detection (rPVI criteria). The diagnostic performance and recurrence-free survival were compared between the rPVI criteria and the presence of PVTT using McNemar's test and Kaplan-Meier method, respectively. Interobserver agreement was evaluated using Cohen's weighted ĸ statistics.

RESULTS

Of 189 enrolled patients, 25 (13.2%) had PVI on histology. To diagnose PVI on MRI, either peripheral wedge-shaped arterial peritumoral hyperemia with an abrupt cut-off of a portal vein or the presence of PVTT had the highest OR (41.67, p < 0.001). The sensitivity of PVI was significantly increased under this diagnostic criterion (64.0% to 88.0%; p = 0.031) with comparable accuracy (95.2% vs. 94.7%; p > 0.999). In terms of recurrence-free survival, the patient group with rPVI was significantly worse (p = 0.017) compared with the patients without rPVI. Interobserver agreement of radiologic findings was substantial (ĸ = 0.64).

CONCLUSION

Diagnostic criteria for radiologically PVI detection increase the sensitivity more than the only presence of PVTT.

Intestinal Obstruction as Initial Presentation of Idiopathic Portal and Mesenteric Venous Thrombosis: Diagnosis, Management, and Literature Review

It is quite common for portal vein thrombosis to occur in subjects who present predisposing conditions such as cirrhosis, hepatobiliary malignancies, infectious or inflammatory abdominal diseases, or hematologic disorders. The incidence of idiopathic portal vein thrombosis in non-cirrhotic patients remains low, and despite the intensive workup that is performed in these cases, in up to 25% of cases, there is no identifiable cause. If portal vein thrombosis is untreated, complications arise and include portal hypertension, cavernous transformation of the portal vein, gastroesophageal and even small intestinal varices, septic thrombosis, or intestinal ischemia. However, intestinal ischemia develops as a consequence of arterial thrombosis or embolism, and the thrombosis of the mesenteric vein accounts for about 10% of cases of intestinal ischemia. Although acute superior mesenteric vein thrombosis can cause acute intestinal ischemia, its chronic form is less likely to cause acute intestinal ischemia, considering the possibility of developing collateral drainage. Ileus due to mesenteric venous thrombosis is rare, and only a small number of cases have been reported to date. Most patients experience a distinct episode of acute abdominal pain due to ischemia, and in the second phase, they develop an obstruction/ileus. Acute superior mesenteric venous thrombosis is a rare condition that is still associated with a high mortality rate. The management of such cases of superior mesenteric venous thrombosis is clinically challenging due to their insidious onset and rapid development. A prompt and accurate diagnosis followed by a timely surgical treatment is important to save patient lives, improve the patient survival rate, and conserve as much of the patient's bowel as possible, thus leading to fewer sequelae.

Understanding the role of radiologists in complex treatment decisions for patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver and represents a significant global health burden. Management of HCC can be challenging due to multiple factors, including variable expectations for treatment outcomes. Several treatment options are available, each with specific eligibility and ineligibility criteria, and are provided by a multidisciplinary team of specialists. Radiologists should be aware of the types of treatment options available, as well as the criteria guiding the development of individualized treatment plans. This awareness enables radiologists to contribute effectively to patient-centered multidisciplinary tumor boards for HCC and play a central role in reassessing care plans when the treatment response is deemed inadequate. This comprehensive review aims to equip radiologists with an overview of HCC staging systems, treatment options, and eligibility criteria. The review also discusses the significance of imaging in HCC diagnosis, treatment planning, and monitoring treatment response. Furthermore, we highlight the crucial branch points in the treatment decision-making process that depend on radiological interpretation.

Diagnostic Prediction of portal vein thrombosis in chronic cirrhosis patients using data-driven precision medicine model

BACKGROUND

Portal vein thrombosis (PVT) is a significant issue in cirrhotic patients, necessitating early detection. This study aims to develop a data-driven predictive model for PVT diagnosis in chronic hepatitis liver cirrhosis patients.

METHODS

We employed data from a total of 816 chronic cirrhosis patients with PVT, divided into the Lanzhou cohort (n = 468) for training and the Jilin cohort (n = 348) for validation. This dataset encompassed a wide range of variables, including general characteristics, blood parameters, ultrasonography findings and cirrhosis grading. To build our predictive model, we employed a sophisticated stacking approach, which included Support Vector Machine (SVM), Naïve Bayes and Quadratic Discriminant Analysis (QDA).

RESULTS

In the Lanzhou cohort, SVM and Naïve Bayes classifiers effectively classified PVT cases from non-PVT cases, among the top features of which seven were shared: Portal Velocity (PV), Prothrombin Time (PT), Portal Vein Diameter (PVD), Prothrombin Time Activity (PTA), Activated Partial Thromboplastin Time (APTT), age and Child-Pugh score (CPS). The QDA model, trained based on the seven shared features on the Lanzhou cohort and validated on the Jilin cohort, demonstrated significant differentiation between PVT and non-PVT cases (AUROC = 0.73 and AUROC = 0.86, respectively). Subsequently, comparative analysis showed that our QDA model outperformed several other machine learning methods.

CONCLUSION

Our study presents a comprehensive data-driven model for PVT diagnosis in cirrhotic patients, enhancing clinical decision-making. The SVM-Naïve Bayes-QDA model offers a precise approach to managing PVT in this population.

The Portal Vein: A Comprehensive Review

Radiologists are familiar with the appearances of a normal portal vein; variations in its anatomy are commonplace and require careful consideration due to the implications for surgery. These alterations in portal vein anatomy have characteristic appearances that are clearly depicted on CT, MR, and US images. Similarly, there are numerous congenital and acquired disorders of the portal vein that are deleterious to its function and can be diagnosed by using imaging alone. Some of these conditions have subtle imaging features, and some are conspicuous at imaging but poorly understood or underrecognized. The authors examine imaging appearances of the portal vein, first by outlining the classic and variant anatomy and then by describing each of the disorders that impact portal vein function. The imaging appearances of portal vein abnormalities discussed in this review include (a) occlusion from and differentiation between bland thrombus and tumor in vein and the changes associated with resultant hepatic artery buffer response changes, cavernous transformation of the portal vein, and portal biliopathy; (b) ascending thrombophlebitis of the portal vein (pylephlebitis); (c) portal hypertension and its causes and sequelae; (d) the newly described disease entity portosinusoidal vascular disorder; and (e) intra- and extrahepatic shunts of the portal system, both congenital and acquired (including Abernethy malformations), and the associated risks. Current understanding of the pathophysiologic processes of each of these disorders is considered to aid the approach to reporting. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Modified Appleby procedure for locally advanced pancreatic carcinoma: A primer for the radiologist

Pancreatic ductal adenocarcinoma (PDAC) is the most prevalent pancreatic neoplasm accounting for more than 90% of pancreatic malignancies. Surgical resection with adequate lymphadenectomy remains the only available curative strategy for patients with PDAC. Despite improvements in both chemotherapy regimen and surgical care, body/neck PDAC still conveys a poor prognosis because of the vicinity of major vascular structures, including celiac trunk, which favors insidious disease spread at the time of diagnosis. Body/neck PDAC involving the celiac trunk is considered locally advanced PDAC in most guidelines and therefore not eligible for upfront resection. However, a more aggressive surgical approach (i.e., distal pancreatectomy with splenectomy and en-bloc celiac trunk resection [DP-CAR]) was recently proposed to offer hope for cure in selected patients with locally advanced body/neck PDAC responsive to induction therapy at the cost of higher morbidity. The so-called "modified Appleby procedure" is highly demanding and requires optimal preoperative staging as well as appropriate patient preparation for surgery (i.e., preoperative arterial embolization). Herein, we review current evidence regarding DP-CAR indications and outcomes as well as the critical role of diagnostic and interventional radiology in patient preparation before DP-CAR, and early identification and management of DP-CAR complications.

Congenital extrahepatic portosystemic shunt masquerading as chronic portal vein thrombosis: A case report

INTRODUCTION AND IMPORTANCE

Congenital extra hepatic portosystemic shunt (CEPS) is a rare vascular malformation in which splanchnic and portal blood is shunted into the systemic circulation eluding the liver. Type 1 CEPS is sometimes difficult to differentiate from pathologies such as chronic portal veinthrombosis as the portal vein may not be visualized in either entities.

CASE PRESENTATION

A 3-year-old male child with a week of abdominal pain was diagnosed with chronic portal vein thrombosis in an out-of-hospital setting. Repeat abdominal ultrasound was done at our institution and we were able to visualize termination of the portal vein to the suprarenal infra-hepatic inferior vena cava with an end to side pattern and a focal hypoechoic hepatic lesion at segment eight of the liver. There was no evidence of cavernous transformation or sign of portal hypertension. Subsequently, tri-phasic computed tomography revealed similar findings, with the portal vein terminating at the suprarenal inferior vena cava. The focal hepatic lesion showed peripheral contrast enhancement in the arterial phase and appeared as a central non-enhancing area with evidence of homogeneous enhancement on the subsequent sequences.

CLINICAL DISCUSSION

Type 1 CEPS can be easily confused with chronic portal vein thrombosis as the portal vein may not be visible and the hepatic artery shows compensatory enlargement in both entities. However, portal vein thrombosis is usually associated with underlying predisposing factors and can result in the development of secondary signs of portal hypertension and cavernous transformation which are critical to distinguish it from CEPS.

CONCLUSION

Chronic portal vein thrombosis is a great mimicker that should be distinguished from CEPS on ultrasound. A meticulous scan with color flow is helpful to scrutinize vascular anatomy, identify findings associated with CEPS such as hepatic lesions, and exclude signs of chronic portal vein thrombosis.

Prevalence of portal vein and splanchnic venous thrombosis in dogs with chronic hepatitis

OBJECTIVES

Alterations in haemostasis have been described in dogs and humans with chronic hepatitis. Portal vein thrombosis is a recognised complication of chronic hepatitis in humans; however, its prevalence in dogs with chronic hepatitis has not been reported. We aimed to estimate the prevalence of, and describe clinical and laboratory data of dogs with chronic hepatitis and portal vein thrombosis and splanchnic venous thrombosis.

MATERIALS AND METHODS

Retrospective cross-sectional study. Medical records of dogs admitted to a veterinary teaching hospital between 2009 and 2019 were reviewed. Dogs were included if chronic hepatitis was histopathologically confirmed, and if diagnostic imaging or necropsy indicated the presence of thrombosis. Clinical and laboratory data (i.e. haematology, biochemistry, coagulation panels) were recorded. Descriptive statistics were used to characterise dogs with and without thrombosis.

RESULTS

Records from 136 dogs with chronic hepatitis were identified. Three of these dogs, 2.2% (95% confidence interval: 0.8 to 6.3%) all females, were diagnosed with portal vein thrombosis. Five dogs in total, (3.7%; 95% confidence interval: 1.6 to 8.3%), including three with portal vein thrombosis, all females, were diagnosed with splanchnic venous thrombosis. Dogs with portal vein and splanchnic venous thrombosis often had hyperbilirubinaemia, increased serum gamma-glutamyl transferase activity, and decreased plasma antithrombin 3 activity. They also had relatively high alternative Child-Pugh scores for dogs (median 6 out of 13).

CLINICAL SIGNIFICANCE

Portal vein and splanchnic venous thrombosis are potentially serious complications that were identified in a relatively low proportion of dogs with chronic hepatitis.

Portal vein thrombosis in cirrhosis: A literature review

Portal Vein Thrombosis (PVT), a common complication of advanced liver disease, is defined as an obstruction of the portal vein due to thrombus formation that can extend to the superior mesenteric and splenic veins. It was believed that PVT occurred predominantly due to prothrombotic potential. However, recent studies have shown that decreased blood flow related to portal hypertension appears to increase PVT risk as per Virchow's triad. It is well known that there is a higher incidence of PVTs in cirrhosis with a higher MELD and Child Pugh score. The controversy for management of PVTs in cirrhotics lies in the individualized assessment of risks versus benefits of anticoagulation, since these patients have a complex hemostatic profile with both bleeding and procoagulant propensities. In this review, we will systematically compile the etiology, pathophysiology, clinical features, and management of portal vein thrombosis in cirrhosis.

Liver involvement in patients with COVID-19 infection: A comprehensive overview of diagnostic imaging features

During the first wave of the pandemic, coronavirus disease 2019 (COVID-19) infection has been considered mainly as a pulmonary infection. However, different clinical and radiological manifestations were observed over time, including involvement of abdominal organs. Nowadays, the liver is considered one of the main affected abdominal organs. Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs. After clinical assessment, radiology plays a key role in the evaluation of liver involvement. Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate liver involvement. US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection, in particular liver steatosis and portal-vein thrombosis. CT and MRI are used as second- and third-line techniques, respectively, considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization. This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage.

Portal vein thrombosis on unenhanced MRI: a case series

Portal vein thrombosis (PVT) is usually diagnosed on contrast-enhanced CT, MRI or Doppler ultrasound. However, for patients with contraindications to intravenous contrast, its diagnosis is challenging. In these patients, PVT can be detected on unenhanced MRI using T2, T1 and diffusion-weighted imaging. These sequences may also help differentiate between bland PVT, portal pyemia and tumour thrombus. This case series aims to highlight the various appearances of PVT on unenhanced MRI.

The Role of Imaging in Portal Vein Thrombosis: From the Diagnosis to the Interventional Radiological Management

PURPOSE

To illustrate diagnostic and interventional imaging for the characterization and treatment of portal vein thrombosis (PVT).

INTRODUCTION

The broad spectrum of congenital and acquired PVT manifestations is illustrated, with a focus on the pediatric population; diagnostic and interventional imaging techniques are described.

DESCRIPTION

PVT frequently presents as an incidental finding at imaging in the screening for liver diseases or for other unrelated reasons. PVT can be classified based on: extension (intrahepatic, extrahepatic, involving the spleno-mesenteric tract, etc.); degree (partial or complete); onset (acute or chronic); and with or without cavernomatous transformation. This comprehensive review relies on the experience gained from a large series of congenital and acquired PVT in a referral center for pediatric and adult liver transplantation. Diagnostic and interventional imaging techniques are described, including: color-Doppler and contrast-enhanced Ultrasound; CT and MR angiography; retrograde portography; percutaneous transhepatic, transplenic, and transmesenteric portography; transjugular intrahepatic portosystemic shunt creation. Pre- and post-operative imaging assessment of the surgical meso-rex bypass is discussed. The description is enriched with an original series of pictorial imaging findings.

CONCLUSION

PVT is a clinical condition associated with significant morbidity and mortality. Diagnostic and interventional imaging plays a crucial role in both conservative and operative management.

Portal Interventions in the Setting of Venous Thrombosis or Occlusion

Portal vein thrombosis most commonly occurs as a complication of liver cirrhosis and can result in worsening symptoms of portal hypertension, which often can be challenging to treat with conventional decompression therapies. In addition, because complete portal vein thrombosis is associated with higher posttransplant morbidity and mortality, it is regarded as a relative contraindication to liver transplant. Often, the diagnosis of portal vein thrombosis is incidental; hence, imaging remains the mainstay for diagnosing this complication and is used to guide subsequent treatment. Although anticoagulation is the initial approach used to treat acute portal vein thrombosis, endovascular and/or surgical interventions may be necessary when there is concern for impending bowel ischemia. Treatment of chronic portal vein thrombosis is primarily aimed at alleviating the symptoms of portal hypertension and improving the chance of candidacy for liver transplant. Awareness of the portal venous anatomy to differentiate it from the periportal collaterals is key during recanalization of a chronically occluded portal vein. The authors provide an overview of the pathophysiology, acute and chronic imaging findings, and management of portal vein thrombosis, with a specific focus on endovascular management, as well as a summary of the current related literature. An invited commentary by Lopera and Yamaguchi is available online. ©RSNA, 2022.

Portal Vein Thrombosis in Cirrhosis

Patients with cirrhosis of the liver are at high risk of developing portal vein thrombosis (PVT), which has a complex, multifactorial cause. The condition may present with a myriad of symptoms and can occasionally cause severe complications. Contrast-enhanced computed tomography (CT) is the gold standard for the diagnosis of PVT. There are uncertainties regarding the effect on PVT and its treatment outcome in patients with cirrhosis. The main challenge for managing PVT in cirrhosis is analyzing the risk of hemorrhage compared to the risk of thrombus extension leading to complications. All current knowledge regarding non-tumor PVT in cirrhosis, including epidemiology, risk factors, classification, clinical presentation, diagnosis, impact on natural history, and treatment, is discussed in the present article.

Ultrasonographic evaluation of patients with abnormal liver function tests in the emergency department

Ultrasonography is often the initial modality used to evaluate patients found to have abnormal liver function tests (LFTs) in the emergency department. While an assessment for biliary ductal dilatation and obstruction remains one of the main questions to answer, radiologists should also be aware of the ultrasonographic appearance of other conditions that can cause abnormal LFTs. This may be crucial for the management and disposition of patients in the emergency department. This article reviews the ultrasonographic features of diseases that may cause abnormal LFTs.

Young boy with a long history of splenomegaly and cytopenia

A 15-year-old boy was admitted with a history of cytopenia (white blood cell count 3.170/μm, platelets 90.000/μm) associated with splenomegaly, found during investigations for recurrent mild jaundice due to Gilbert's syndrome.He was in good general health, without systemic symptoms; therefore, the leading causes of asymptomatic splenomegaly were excluded. Coagulation, liver tests and abdomen ultrasound (US) were normal, showing a hepatopetal portal flow to the colour-Doppler. There was no sign of haemolysis on haematology investigations. The C reactive protein, immune globulins levels and erythrocyte sedimentation rate were normal, excluding both an infective and an immune regulation disorder. We excluded the haematological malignancy and lymphoproliferative disorders through a peripheral blood smear and a bone marrow biopsy.His history was remarkable for neonatal sepsis, which required umbilical venous catheter during hospitalisation in a neonatal intensive care unit (NICU). The patient follow-up was interrupted for a while, probably due to his good health condition.At age 17 years, the child accessed our emergency department. for a minor trauma to the limbs, and his physical examination was unremarkable, except for the splenomegaly. We repeated the abdomen US, with colour flow Doppler (figure 1).

Clinical Applications of 4D Flow MRI in the Portal Venous System

Evaluation of the hemodynamics in the portal venous system plays an essential role in many hepatic pathologies. Changes in portal flow and vessel morphology are often indicative of disease.Routinely used imaging modalities, such as CT, ultrasound, invasive angiography, and MRI, often focus on either hemodynamics or anatomical imaging. In contrast, 4D flow MRI facilitiates a more comprehensive understanding of pathophysiological mechanisms by simultaneously and noninvasively acquiring time-resolved flow and anatomical information in a 3D imaging volume.Though promising, 4D flow MRI in the portal venous system is especially challenging due to small vessel calibers, slow flow velocities, and breathing motion. In this review article, we will discuss how to account for these challenges when planning and conducting 4D flow MRI acquisitions in the upper abdomen. We will address patient preparation, sequence acquisition, postprocessing, quality control, and analysis of 4D flow data.In the second part of this article, we will review potential clinical applications of 4D flow MRI in the portal venous system. The most promising area for clinical utilization is the diagnosis and grading of liver cirrhosis and its complications. Relevant parameters acquired by 4D flow MRI include the detection of reduced or reversed flow in the portal venous system, characterization of portosystemic collaterals, and impaired response to a meal challenge. In patients with cirrhosis, 4D flow MRI has the potential to address the major unmet need of noninvasive detection of gastroesophageal varices at high risk for bleeding. This could replace many unnecessary, purely diagnostic, and invasive esophagogastroduodenoscopy procedures, thereby improving patient compliance with follow-up. Moreover, 4D flow MRI offers unique insights and added value for surgical planning and follow-up of multiple hepatic interventions, including transjugular intrahepatic portosystemic shunts, liver transplantation, and hepatic disease in children. Lastly, we will discuss the path to clinical implementation and remaining challenges.

Hepatic pseudolesions caused by alterations in intrahepatic hemodynamics

Hepatic pseudolesion may occur in contrast-enhanced computed tomography and magnetic resonance imaging due to the unique haemodynamic characteristics of the liver. The concept of hepatic arterial buffer response (HABR) has become mainstream for the understanding of the mechanism of the reciprocal effect between hepatic arterial and portal venous flow. And HABR is thought to be significantly related to the occurrence of the abnormal imaging findings on arterial phase of contrast enhanced images, such as hepatic arterial-portal vein shunt and transient hepatic attenuation difference, which mimic hypervascular tumor and may cause clinical problems. Third inflow to the liver also cause hepatic pseudolesion, and some of the cases may show histopathologic change such as focal hyperplasia, focal fatty liver, and focal sparing of fatty liver, and called pseudotumor. To understand these phenomena might be valuable for interpreting the liver imaging findings.

Portal Vein Thrombosis: Diagnosis and Endovascular Management

BACKGROUND

 Portal vein thrombosis (PVT) is a rare but severe entity that can cause clinically significant sequela such as worsening portal hypertension or mesenteric ischemia. Those cases refractory to medical management may be referred for endovascular intervention. Several technical considerations have been described in the literature, but a cohesive comparison of these multiple techniques is lacking.

METHODS

 The purpose of this article is to review the diagnosis and endovascular management of PVT, including areas in which further research is warranted.

RESULTS

 Cases of PVT can be readily diagnosed using ultrasound, computed tomography, or magnetic resonance imaging. Treatment often begins with systemic anticoagulation and endovascular interventions may be used in selected cases. Determining the optimal approach to accessing the portal venous system depends on the underlying disease and chronicity of the thrombus and the degree of occlusion. Once access to the portal venous system is established, catheter-directed therapy may be performed to achieve recanalization.

CONCLUSION

 Despite the heterogeneity in patient presentation, cases of PVT can be readily diagnosed across several imaging modalities. Strategizing interventional approaches involves evaluation of the underlying disease and the chronicity of the thrombus.

KEY POINTS

  · This review will enable interventionalists to establish a framework for treating portal vein thrombosis by identifying patient risk factors and thrombus characteristics that determine patient management.. · The unique risks and benefits for transhepatic, transsplenic, and transmesenteric approaches for establishing portal venous access will be discussed.. · Advantages and complications of thrombolysis, thrombectomy, and transjugular intrahepatic portosystemic shunt creation for treating portal vein thrombosis will be reviewed in detail based on our extensive institutional experience..

CITATION FORMAT

· Ju C, Li X, Gadani S et al. Portal Vein Thrombosis: Diagnosis and Endovascular Management. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1642-0990.

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.

A unique case of bleeding from esophageal varices as the first sign of essential thrombocythemia

Upper gastrointestinal bleeding (UGIB) is a common cause of hospital admission and variceal hemorrhage is responsible for many UGIB cases. Esophageal and gastric varices are caused by portal hypertension (PHT), mostly due to liver cirrhosis. Portal vein thrombosis (PVT) is an important cause of non-cirrhotic PHT and can be associated with several diseases, including myeloproliferative disorders such as essential thrombocythemia (ET). PVT may become apparent due to complications of PHT, including variceal bleeding (VB). We report the case of a 43-year-old male admitted with esophageal VB. Etiologic work-up for chronic liver disease was negative and abdominal magnetic resonance imaging revealed chronic PVT with cavernous transformation and a non-cirrhotic liver. JAK2 mutation was found, and the bone-marrow biopsy was consistent with ET, without peripheral blood alterations. This is a unique case of ET diagnosed in a variceal bleeding setting, remembering the necessity for high clinical suspicion.

Current knowledge and management of portal vein thrombosis in cirrhosis

Portal vein thrombosis (PVT) is an increasingly recognised complication of cirrhosis whose incidence increases in parallel with the severity of cirrhosis. Several risk factors have been associated with the occurrence and progression of PVT. Although the negative effect of complete PVT on the surgical outcome of liver transplant recipients is clear, its impact on cirrhosis progression remains uncertain. Treatment options include anticoagulants and interventional thrombolytic therapies, which are chosen almost on a case-by-case basis depending on the characteristics of the patient and the thrombus. In this manuscript, we review current knowledge regarding the epidemiology, risk factors, diagnosis and classification, natural history, clinical consequences and treatment of non-neoplastic PVT in cirrhosis.

Magnetic Resonance Imaging of Liver Transplant

MR imaging increasingly has been adopted for follow-up imaging post-liver transplantation and for diagnosis of its complications. These include vascular and biliary complications as well as post-transplant malignancies. Interpretation of postoperative MR imaging should take into account the surgical technique and expected post-transplant changes. Contrast-enhanced MR imaging has high sensitivity for identification of vascular complications. MR cholangiopancreatography on the other hand is the most accurate noninvasive method for evaluation of biliary complications.

Pfortaderthrombosen – therapeutische Möglichkeiten

Die Pfortaderthrombose ist eine seltene Erkrankung, die eine Thrombose im Zustromgebiet der Pfortader in die Leber beschreibt bzw. in der Leber selbst in den entsprechenden Pfortaderästen lokalisiert ist. Oftmals liegt bereits eine chronische Lebererkrankung bzw. ein Malignom der Leber selbst oder unmittelbar benachbart liegender Organe vor; die Pfortaderthrombose kann aber auch bei Patienten auftreten, die keine entsprechende Vorerkrankung haben. Bei jeder neu diagnostizierten Pfortaderthrombose gilt es zu entscheiden, ob unmittelbar oder im Verlauf eine radiologisch-interventionelle Rekanalisation vorgenommen wird oder ein rein konservativer Therapieversuch mit Antikoagulanzien erfolgt. Aber auch chirurgische Verfahren, wie eine Shuntanlage oder die Notwendigkeit einer Lebertransplantation, müssen hierbei berücksichtigt werden. Für diesen Therapiealgorithmus ist die Kontaktaufnahme mit einem entsprechenden Zentrum sinnvoll. Die Therapieentscheidung muss die Ursache der Pfortaderthrombose und die Begleiterkrankungen adäquat berücksichtigen.

Advances in diagnosis and treatment of portal venous thrombosis

Portal vein thrombosis (PVT) is one of the common complications of liver cirrhosis, which can further increase portal vein pressure and aggravate liver function decompensation. However, due to the insidious onset and atypical symptoms, the importance of PVT has been neglected in clinical work for quite a long time. With the development of clinical diagnostic technology, the detection rate of PVT has increased year by year. At present, the well-established treatment methods for PVT include anticoagulant therapy, interventional therapy, and surgical treatment. However, the optimal choice for PVT treatment remains unclear. In this paper, we briefly review the recent progress in the diagnosis and treatment of PVT in order to provide a theoretical reference for the refined clinical management of patients with PVT.

Vascular disorders of the gallbladder and bile ducts: Imaging findings

Vascular disorders of the gallbladder and biliary tree are many and varied. In the acute setting, the clinical presentation of vascular conditions such as hemorrhagic cholecystitis and gangrenous cholecystitis are non-specific and rely on imaging for diagnosis and triaging for emergent surgery. These hemorrhagic and ischemic complications of acute cholecystitis are uncommon but potentially fatal. Hemorrhage into the gallbladder and biliary tree, from other causes, may itself result in acute cholecystitis. Knowledge of vascular anatomy of the gallbladder and biliary tree is essential for surgeons to prevent significant operative bleeding complications, particularly in laparoscopic cholecystectomy. The unique venous drainage of the gallbladder and biliary tree, with their connections to the portal venous system, lends itself to less well-recognised vascular phenomena such as gallbladder varices, portal biliopathy, and gallbladder bed perfusion abnormalities.

The ABCD of portal vein thrombosis: a systematic approach

Portal vein thrombosis refers to complete or partial obstruction of the portal venous system, in the intrahepatic or extrahepatic venous tract or even in the splenic or superior mesenteric veins. This common and potentially fatal condition can develop in various clinical contexts, especially those of liver cirrhosis, hepatocellular carcinoma, and other solid tumors. Certain characteristics, such as the time since the onset of the thrombus (acute or chronic), its biology (hematic or tumoral), the presence of collateral vessels, and the magnetic resonance imaging aspects, are important components of a thorough, careful analysis, as well as informing decisions regarding the appropriate therapeutic strategy. Here, we present a brief review of the anatomy of the portal venous system and a systematic approach to analyzing the condition, using a mnemonic (ABCD, for age, biology, collaterals, and diffusion). We discuss the various imaging methods and illustrate our discussion with images selected from the case files archived at our facility.

Venous thrombosis of the liver: current and emerging concepts in management

Venous thrombosis within the hepatic vasculature is associated with a distinct array of risk factors, characteristics, and potential complication. As such, it entails unique management considerations and strategies relative to the more common categories of venous thromboembolic disease. Although broadly divided into thrombosis of the afferent vasculature (the portal venous system) and efferent vasculature (the hepatic venous system), presentations and management strategies within these groupings are heterogeneous. Management decisions are influenced by a variety of factors including the chronicity, extent, and etiology of thrombosis. In this review we examine both portal vein thrombosis and hepatic vein thrombosis (and the associated Budd-Chiari Syndrome). We consider those factors which most impact presentation and most influence treatment. In so doing, we see how the particulars of specific cases introduce nuance into clinical decisions. At the same time we attempt to organize our understanding of such cases to help facilitate a more systematic approach. Critically, we must recognize that although increasing evidence is emerging to help guide our management strategies, the available data remain limited and largely retrospective. Indeed, current paradigms are based largely on observational experiences and expert consensus. As new and more rigorous studies emerge, treatment strategies are likely to be continually refined, and paradigm shifts are sure to occur.

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.

Rare Hematological Disease of Paroxysmal Nocturnal Hemoglobinuria With Profound Implications for a Gastroenterologist: A Case Report and Literature Review

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare type of thrombophilia and hematopoietic stem cell disorder characterized by mutation of the X-linked PIG-A gene. Patients with PNH present either with clinical features of intravascular hemolysis or thrombosis. Visceral vein thrombosis is associated with increased mortality risk. Here, we present an extremely rare case of a young man presenting with extensive thrombosis of multiple visceral veins from PNH.

How to Best Detect Portal Vein Tumor Thrombosis in Patients with Hepatocellular Carcinoma Meeting the Milan Criteria: Gadoxetic Acid-Enhanced MRI versus Contrast-Enhanced CT

INTRODUCTION

The detection of portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC) meeting the Milan criteria is of critical importance as PVTT is known to be a contraindication to transplantation and an indicator of a dismal prognosis.

OBJECTIVE

To determine which modality may best detect PVTT, we compared the diagnostic performance of gadoxetic acid-enhanced MRI (GA-MRI) and contrast-enhanced CT (CECT) in HCC patients meeting the Milan criteria.

METHODS

We retrospectively enrolled 310 patients with HCCs meeting the Milan criteria who underwent both GA-MRI and CECT between June 2007 and May 2017. Among them, 44 patients were demonstrated to have PVTT while 266 patients had no PVTT. Two radiologists then assessed GA-MRI and CECT images for the presence of PVTT on a 5-point scale as well as vessel expansion, continuity with tumors, and enhancement on both modalities, as well as T2 hyperintensity and diffusion restriction on GA-MRI. The McNemar test was used to compare sensitivity and specificity of GA-MRI and CECT for the detection of PVTT, and Fisher's exact test was used to compare their imaging features.

RESULTS

GA-MRI showed higher sensitivity values than CECT in detecting PVTT (reviewer 1, 93.2% [41/44] vs. 77.3% [34/44]; reviewer 2, 88.6% [39/44] vs. 70.5% [31/44]) (both p = 0.039). Specificity of GA-MRI and CECT demonstrated no difference (reviewer 1, 95.5% [254/266] vs. 95.1% [253/266]; reviewer 2, 97.0% [258/266] vs. 97.4% [259/266]) (both p > 0.999). Continuity with tumors and enhancement were more frequently observed on GA-MRI than on CECT (p < 0.050, both reviewers).

CONCLUSION

GA-MRI detected PVTT more often than CECT in HCC patients meeting the Milan criteria and better depicted PVTT in continuity with tumors and those showing enhancement than CECT.

Imaging and implications of tumor thrombus in abdominal malignancies: reviewing the basics

Extension of tumor tissue within a vein is a recognized prognostic factor in abdominal malignancy because of its influence on tumor staging and selection of therapeutic management. With the advent of newer surgical techniques, and variable treatment strategies, imaging plays a crucial role in categorizing patients according to the tumor resectability and vascular reconstruction techniques during surgery. Understanding the clinical impact of tumor thrombus increases the awareness of the radiologist about the key findings in tumor staging and decision-making of surgical approach. Ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) can be used individually and in combination to accurately assess the tumor thrombus. In our pictorial review, we will discuss the imaging findings and clinical consequences of tumor thrombosis in abdominal malignancies, including hepatocellular carcinoma, pancreatic neuroendocrine tumor, renal cancer, and adrenal cortical carcinoma.

Diffuse Large B-Cell Lymphoma in the Portal Vein

Tumor thrombus in the portal vein without any liver parenchymal abnormality is extremely rare. In the liver, the primary tumor most frequently presenting with intravascular tumor thrombi is hepatocellular carcinoma and lymphoma is rarely considered. Even though thrombosis occurs quite often in lymphoma, cases of tumor thrombus are rare and cases of tumor thrombus in the portal vein are even rarer. Only four cases of lymphoma with portal vein tumor thrombosis have been reported to date and all cases were the result of direct extensions of a dominant nodal or extra-nodal mass. To our knowledge, there has been no report on diffuse large B-cell lymphoma (DLBCL) presenting only within the lumen of the portal vein and not intravascular B-cell lymphoma. We present the first case of DLBCL presenting only within the lumen of the portal vein in an immunocompetent patient.

Imaging of Acute Hepatobiliary Dysfunction

Abdominal pain is a common cause for emergency department visits in the United States, and biliary tract disease is the fifth most common cause of hospital admission. Common causes of acute hepatobiliary include gallstones and its associated complications and multiple other hepatobiliary etiologies, including infectious, inflammatory, vascular, and neoplastic causes. Postoperative complications of the biliary tract can result in an acute abdomen. Imaging of the hepatobiliary tree is integral in the diagnostic evaluation of acute hepatobiliary dysfunction, and imaging of the biliary tree requires a multimodality approach utilizing ultrasound, computed tomography, nuclear medicine, and MR imaging.

Current knowledge in pathophysiology and management of Budd-Chiari syndrome and non-cirrhotic non-tumoral splanchnic vein thrombosis

Budd-Chiari syndrome and non-cirrhotic non-tumoral portal vein thrombosis are 2 rare disorders, with several similarities that are categorized under the term splanchnic vein thrombosis. Both disorders are frequently associated with an underlying prothrombotic disorder. They can cause severe portal hypertension and usually affect young patients, negatively influencing life expectancy when the diagnosis and treatment are not performed at an early stage. Yet, they have specific features that require individual consideration. The current review will focus on the available knowledge on pathophysiology, diagnosis and management of both entities.

Hepatic disorders associated with exogenous sex steroids: MR imaging findings

OBJECTIVE

To describe the MRI findings of the effects of exogenous sex steroids on the liver.

FINDINGS

Estrogens, progesterone and synthetic testosterone are exogenous sex steroids that may result in a variety of liver diseases, including tumour formation and vascular disorders. These hormones are mainly administered in the form of the oral contraceptive pill (OCP) and anabolic steroids. Both are implicated in hepatic adenoma formation. The HNF-1α-mutated and inflammatory adenoma subgroups are more commonly seen in association with the OCP whereas there is an increased incidence of the β-catenin positive subtype with anabolic steroid use. Furthermore, anabolic steroids are associated with hepatocellular carcinoma resulting from malignant transformation of β-catenin positive adenomas. The oral contraceptive pill may also induce vascular disorders within the liver, some of which are related to the prothrombotic effect of the hormones, such as hepatic and portal vein thrombosis. Other hepatic vascular abnormalities resulting from exogenous sex steroids include veno-occlusive disease and peliosis hepatis.

Abdominal and pelvic imaging findings associated with sex hormone abnormalities

Hormones are substances that serve as chemical communication between cells. They are unique biological molecules that affect multiple organ systems and play a key role in maintaining homoeostasis. In this role, they are usually produced from a single organ and have defined target organs. However, hormones can affect non-target organs as well. As such, biochemical and hormonal abnormalities can be associated with anatomic changes in multiple target as well as non-target organs. Hormone-related changes may take the form of an organ parenchymal abnormality, benign neoplasm, or even malignancy. Given the multifocal action of hormones, the observed imaging findings may be remote from the site of production, and may actually be multi-organ in nature. Anatomic findings related to hormone level abnormalities and/or laboratory biomarker changes may be identified with imaging. The purpose of this image-rich review is to sensitize radiologists to imaging findings in the abdomen and pelvis that may occur in the context of hormone abnormalities, focusing primarily on sex hormones and their influence on these organs.