Budd-Chiari syndrome: a prospective analysis of hepatic vein obstruction on ultrasonography, multidetector-row computed tomography and MR imaging

Porto-sinusoidal Vascular Disease: Classification and Clinical Relevance

Non-cirrhotic portal hypertension (NCPH) is a well-recognized clinico-pathological entity, which is associated with clinical signs and symptoms, imaging, and endoscopic features of portal hypertension (PHT), in absence of cirrhosis. In patients with NCPH without known risk factors of PHT or extrahepatic portal vein thrombosis, the condition is called idiopathic non-cirrhotic portal hypertension (INCPH). There are multiple infectious, immune related causes, systemic diseases, drug and toxin exposures, haematological disorders, and metabolic risk factors that have been associated with this INCPH. However, the causal pathogenesis is still unclear. The Vascular liver disorders interest group group recently proposed porto-sinusoidal vascular disease (PSVD) as a syndromic entity, which provides definite histopathological criteria for diagnosis of NCPH (table 1). The three classical histo-morphological lesions specific for PSVD include obliterative portal venopathy, nodular regenerative hyperplasia, and incomplete septal fibrosis. The PSVD definition includes patients with portal vein thrombosis, PVT, and even those without PHT, thus broadening the scope of diagnosis to include patients who may have presented early, prior to haemodynamic changes consistent with PHT. However, this new diagnosis has pros and cons. The cons include mandating invasive liver biopsy to assess the PSVD histological triad in all patients with NCPH, an erstwhile clinical diagnosis in Asian patients. In addition, the natural history of the subclinical forms of PSVD without PHT and linear progression to develop PHT is unknown yet. In this review, we discuss the diagnosis and treatment of INCPH/PSVD, fallacies and strengths of the old and new schema, pathobiology of this disease, and clinical correlates in an Asian context. Although formulation of standardised diagnostic criteria is useful for comparison of clinical cohorts with INCPH/PSVD, prospective clinical validation in global cohorts is necessary to avoid misclassification of vascular disorders of the liver.

Imaging of hepato-pancreato-biliary emergencies in patients with cancer

Hepato-pancreato-biliary (HPB) emergencies in patients with cancer encompass an extensive array of various conditions, including primary malignancies that require prompt treatment, associated severe complications, and life-threatening consequences arising from treatment. In patients with cancer, the liver can be affected by chemotherapy-induced hepatotoxicity, veno-occlusive disease, Budd-Chiari syndrome, liver hemorrhage, and other complications arising from cancer therapy with all these complications requiring timely diagnosis and prompt treament. Cholecystitis induced by systemic anticancer therapies can result in severe conquences if not promptly identified and treated. The application of immunotherapy in cancer therapy is associated with cholangitis. Hemobilia, often caused by medical interventions, may require arterial embolization in patients with severe bleeding and hemodynamic instability. Malignant biliary obstruction in patients with biliary cancers may necessitate palliative strategies such as biliary stenting. In pancreatic cancer, patients often miss surgical treatment due to advanced disease stages or distant metastases, leading to potential emergencies at different treatment phases. This comprehensive review underscores the complexities of diagnostic and treatment roles of medical imaging in managing HPB emergencies in patients with cancer. It illustrates the crucial role of imaging techniques, including magnetic resonance imaging, computed tomography and ultrasound, in diagnosing and managing these conditions for timely intervention. It provides essential insights into the critical nature of early diagnosis and intervention in cancer-related HPB emergencies, ultimately impacting patient outcomes and survival rates.

Budd-Chiari syndrome in myeloproliferative neoplasms: A review of literature

Myeloproliferative neoplasms (MPNs) are defined as clonal disorders of the hematopoietic stem cell in which an exaggerated production of terminally differentiated myeloid cells occurs. Classical, Philadelphia-negative MPNs, i.e., polycythemia vera, essential thrombocythemia and primary myelofibrosis, exhibit a propensity towards the development of thrombotic complications that can occur in unusual sites, e.g., portal, splanchnic or hepatic veins, the placenta or cerebral sinuses. The pathogenesis of thrombotic events in MPNs is complex and requires an intricate mechanism involving endothelial injury, stasis, elevated leukocyte adhesion, integrins, neutrophil extracellular traps, somatic mutations (e.g., the V617F point mutation in the JAK2 gene), microparticles, circulating endothelial cells, and other factors, to name a few. Herein, we review the available data on Budd-Chiari syndrome in Philadelphia-negative MPNs, with a particular focus on its epidemiology, pathogenesis, histopathology, risk factors, classification, clinical presentation, diagnosis, and management.

Evaluation of dangerous collateral vessels and thrombus in Budd-Chiari syndrome patients with inferior vena cava obstruction

PURPOSE

To evaluate the diagnostic accuracy of preoperative imaging in defining inferior vena cava (IVC) obstruction characteristics, in identifying the presence of a thrombus and dangerous venous collateral. The other goal is to explore the clinical implication of these data in the designing the treatment strategy in Budd-Chiari patients.

METHODS

This study included 112 patients with IVC obstruction who underwent endovascular treatment between July 2009 and June 2019. Two radiologists independently assessed MSCT and/or MRI imaging data with a 5-point scale to evaluate the diagnostic accuracies relating to obstructive characteristics, dangerous collateral vessels, and thrombus within IVC.

RESULTS

The diagnostic sensitivities for obstructive characteristics, as determined by the two independent assessors, ranged from 81.25 to 100%. The areas under the receiver operating characteristic curve (ROC) for judging thrombus ranged from 0.87 to 0.975 for the two assessors. Inter-assessor agreement was substantial or excellent with regards to diagnostic accuracy (κ = 0.745-0.927). Twelve cases involving dangerous collateral vessels were identified in the MSCT group of 82 patients (κ = 1); six were identified by digital subtraction venography (DSV) imaging. Eight cases involving dangerous collateral vessels were reported in the MRI group of 32 patients (κ = 1); three were identified by DSV imaging.

CONCLUSION

Preoperative MSCT and MRI can accurately reveal the obstructive characteristics and risk factors of patients with IVC obstruction and can therefore be used to guide interventional planning so as to minimize complications.

Comparison of long-term outcomes of balloon angioplasty with or without stent placement for hepatic vein type Budd-Chiari syndrome

PURPOSE

To compare percutaneous transluminal balloon angioplasty (PTBA) alone with PTBA plus stent placement for Budd-Chiari syndrome (BCS) patients with short-segmental obstruction of hepatic vein.

METHODS

Between May 2001 and December 2010, 91 hepatic vein type BCS patients (mean age, 32.8 ± 10.8; M:F ratio 50:41) were included and divided into two groups (PTBA alone, as group A, n = 48; PTBA plus stent, as group B, n = 43). The incidence of restenosis, long-term patency, and survival were evaluated.

RESULTS

All 91 patients were successfully treated with hepatic vein recanalization. During follow-up period (median 161 months, range: 84-234), group B had a significantly higher proportion of hepatic vein restenosis (56%, 24/43) than group A (33%, 16/48; P < 0.05). Cumulative primary patency rates at 1, 5, 10, 15 years were 96%, 81%, 69%, 65% and 91%, 60%, 47%, 47% in group A and group B, respectively (log-rank P < 0.05). Secondary technical success rates of target hepatic vein were 93% and 57% in group A and group B, respectively (P < 0.05). Clinical complete response rates were 94% and 86% in group A and group B, respectively (P > 0.05). The 15-year cumulative survival rates were 98% and 95% in group A and group B, respectively (P > 0.05). Major procedure-related complications occurred in 3 (3%) patients (1 in group A, 2 in group B).

CONCLUSIONS

Hepatic vein recanalization is safe and efficient for hepatic vein type BCS patients with hepatic vein short segmental obstruction. Restenosis after hepatic vein stenting is more common and difficult to manage than that after hepatic vein balloon angioplasty alone.

Contrast-Enhanced Ultrasound is a Useful Adjunct to Doppler Ultrasound in the Initial Assessment of Patients Suspected of Budd Chiari Syndrome

BACKGROUND

Doppler is the screening modality of choice for assessment of patients suspected of Budd Chiari syndrome (BCS). The aim of this study was to compare the diagnostic value of contrast enhanced ultrasound (CEUS) with Doppler in the initial evaluation of patients with BCS.

METHODS

This was a retrospective study of patients with suspicion of BCS who underwent CEUS of the hepatic veins and inferior vena cava between July 2017 and April 2019. CEUS was performed using Sonovue. All patients underwent Doppler evaluation of the hepatic veins and inferior vena cava. The final diagnosis of BCS was based on transvenous or percutaneous digital subtraction venography. The diagnostic accuracy of CEUS was compared with Doppler.

RESULTS

A total of 19 patients (median age, 30 years; 11 males) were evaluated with CEUS and Doppler. A final diagnosis of BCS was established on digital subtraction venography in 15 patients. CEUS was found to have a 100% sensitivity and 75% specificity. The sensitivity and specificity of Doppler was 100% and 25%. The diagnostic accuracies of CEUS and Doppler were 94.74% and 84.29%, respectively.

CONCLUSION

CEUS is a useful adjunct to the Doppler in the initial assessment of patients with BCS. However, further prospective studies must confirm our preliminary observations.

Inferior vena cava-syndrome

Inferior vena cava syndrome (IVCS) is caused by agenesis, compression, invasion, or thrombosis of the IVC, or may be associated with Budd-Chiari syndrome. Its incidence and prevalence are unknown. Benign IVCS is separated from malignant IVCS. Both cover a wide clinical spectrum reaching from asymptomatic to highly symptomatic cases correlated to the underlying cause, the acuity, the extent of the venous obstruction, and the recruitment and development of venous collateral circuits. Imaging is necessary to determine the underlying cause of IVCS and to guide clinical decisions. Interventional therapy has changed the therapeutic approach in symptomatic patients. This article provides an overview over IVCS and focuses on interventional therapeutic methods and results.

Changes and significance of hydrodynamic parameters in Budd-Chiari syndrome with obstruction of the inferior vena cava prior to and after interventional therapy

In recent years, the role of computational fluid dynamics for Budd-Chiari syndrome evaluation has become the focus of certain studies. The purpose of the present study was to evaluate the role of computational fluid dynamics in Budd-Chiari syndrome with obstruction of the inferior vena cava (IVC). Magnetic resonance venous angiography was used to obtain original IVC and hepatic venous blood flow images from patients with Budd-Chiari syndrome. The computational fluid dynamics method was used to establish a three-dimensional model and simulate the blood flow velocity, wall shear stress and wall pressure. The results revealed that the hemodynamic parameters of Budd-Chiari syndrome were successfully simulated by computational fluid dynamics. The hemodynamic parameters of the IVC stenosis varied with the cardiac cycle. Vascular flow velocity (pre-operative, 1.64±0.10 m/sec; post-operative, 0.34±0.14 m/sec; t=34.97, P<0.001) and wall shear stress (pre-operative, 25.69±2.85 Pa; post-operative, 3.51±1.70 Pa; t=29.86, P<0.001) at the area of stenosis decreased after interventional therapy and the wall pressure increased (pre-operative, -119.33±251.50 Pa; post-operative, 1,128.42±207.70 Pa; t=17.10, P<0.001). In conclusion, the computational fluid dynamics method was able to effectively simulate the hemodynamic parameters of Budd-Chiari syndrome with obstruction of the IVC and may provide an effective quantitative method for the evaluation of vascular function post-treatment.

Ultrasonography in pediatric Budd-Chiari syndrome

Budd-Chiari syndrome is a vascular pathology of the liver, commonly seen in adults and uncommon in children. Most children with Budd-Chiari syndrome present with ascites, and an etiology is found in only about 50%. Ultrasonography (US) with color Doppler is the main modality used in the diagnosis. US imaging additionally guides radiologic interventions and follow-up after recanalization or shunt procedure. In this pictorial review, we illustrate the findings in pediatric Budd-Chiari syndrome as seen on B-mode and color Doppler US and describe the role of US in guiding percutaneous radiologic interventions, with a brief description of the role of US contrast agent and sonoelastography in this setting.

Diagnostic accuracy of Doppler ultrasound, CT and MRI in Budd Chiari syndrome: systematic review and meta-analysis

OBJECTIVE

To evaluate the sensitivity, specificity, and diagnostic odds ratio (DOR) of Doppler ultrasound, CT, and MRI in the diagnosis of Budd Chiari syndrome (BCS).

METHODS

We performed a literature search in PubMed, Embase, and Scopus to identify articles reporting the diagnostic accuracy of Doppler ultrasound, CT, and MRI (either alone or in combination) for BCS using catheter venography or surgery as the reference standard. The quality of the included articles was assessed by using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

11 studies were found eligible for inclusion. Pooled sensitivities and specificities of Doppler ultrasound were 89% [95% confidence interval (CI), 81-94%, I2 = 24.7%] and 68% (95% CI, 3-99%, I2 = 95.2%), respectively. Regarding CT, the pooled sensitivities and specificities were 89% (95% CI, 77-95%, I2 = 78.6%) and 72% (95% CI, 21-96%, I2 = 91.4%), respectively. The pooled sensitivities and specificities of MRI were 93% (95% CI, 89-96%, I2 = 10.6%) and 55% (95% CI, 5-96%, I2 = 87.6%), respectively. The pooled DOR for Doppler ultrasound, CT, and MRI were 10.19 (95% CI: 1.5, 69.2), 14.57 (95% CI: 1.13, 187.37), and 20.42 (95% CI: 1.78, 234.65), respectively. The higher DOR of MRI than that of Doppler ultrasound and CT shows the better discriminatory power. The area under the curve for MRI was 90.8% compared with 88.4% for CT and 86.6% for Doppler ultrasound.

CONCLUSION

Doppler ultrasound, CT and MRI had high overall diagnostic accuracy for diagnosis of BCS, but substantial heterogeneity was found. Prospective studies are needed to investigate diagnostic performance of these imaging modalities.

ADVANCES IN KNOWLEDGE

MRI and CT have the highest meta-analytic sensitivity and specificity, respectively for the diagnosis of BCS. Also, MRI has the highest area under curve for the diagnosis of BCS.

ACG Clinical Guideline: Disorders of the Hepatic and Mesenteric Circulation

Disorders of the mesenteric, portal, and hepatic veins and mesenteric and hepatic arteries have important clinical consequences and may lead to acute liver failure, chronic liver disease, noncirrhotic portal hypertension, cirrhosis, and hepatocellular carcinoma. Although literature in the field of vascular liver disorders is scant, these disorders are common in clinical practice, and general practitioners, gastroenterologists, and hepatologists may benefit from expert guidance and recommendations for management of these conditions. These guidelines represent the official practice recommendations of the American College of Gastroenterology. Key concept statements based on author expert opinion and review of literature and specific recommendations based on PICO/GRADE analysis have been developed to aid in the management of vascular liver disorders. These recommendations and guidelines should be tailored to individual patients and circumstances in routine clinical practice.

Budd-Chiari syndrome: imaging review

Budd-Chiari syndrome (BCS), also known as hepatic venous outflow tract obstruction includes a group of conditions characterized by obstruction to the outflow of blood from the liver secondary to involvement of one or more hepatic veins (HVs), inferior vena cava (IVC) or the right atrium. There are a number of conditions that lead to BCS-ranging from hypercoagulable states to malignancies. In up to 25% patients, no underlying disorder is identified. Diagnosis of BCS is based on a combination of clinical and imaging features. A major part of the literature in BCS has been devoted to interventions; however, a detailed description of various imaging manifestations of BCS is lacking. In this review, we highlight the importance of various imaging modalities in the diagnosis of BCS.

Doppler ultrasound in the diagnosis of Budd-Chiari syndrome in children after split liver transplantation

PURPOSE

To assess the capabilities of a velocity ratio>3 for the diagnosis of Budd-Chiari syndrome (BCS) in children after split liver transplantation using Doppler ultrasonography (DUS).

MATERIALS AND METHODS

A total of 28 children who underwent liver transplantation using a split procedure were included. There were 11boys and 17girls with a mean age of 3.8years (range: 0.7-12years). Velocity ratio between blood velocity upstream of the anastomosis and that at the level of the inferior vena cava anastomosis was calculated. Sensitivity, specificity and accuracy of DUS for the diagnosis of BCS were estimated using a velocity ratio>3.

RESULTS

Eight children (8/28; 29%) had BCS and 20 (20/28; 71%) did not have BCS using the standard of reference. A velocity ratio>3 on DUS yielded 88% sensitivity (95% CI: 53-98%), 80% specificity (95% CI: 58-92%) and 82% accuracy (95% CI: 64-92%) for the diagnosis of BCS.

CONCLUSION

A velocity ratio>3 on DUS is a reliable finding for the diagnosis of BCS in children after split liver transplantation.

Angioplasty for Budd-Chiari Syndrome in a Child with 26-Year Follow-up

Budd-Chiari syndrome (BCS) is a rare but life-threatening disease. If not treated promptly, it is almost always lethal with progressive liver failure, severe nutritional depletion, and renal failure at the late stage. We report the successful treatment of a 5-year-old boy with BCS due to a stenosis of the inferior vena cava (IVC) with a 26-year follow-up. We performed a percutaneous transluminal angioplasty, which resulted in a great improvement of BCS and the disappearance of ascites. Restenosis occurred at 25 years after the initial angioplasty, for which balloon angioplasty was repeatedly performed. The IVC was patent at 1-year follow-up after the second angioplasty.

Magnetic Resonance Venography Findings of Obstructed Hepatic Veins and the Inferior Vena Cava in Patients with Budd-Chiari Syndrome

Objective

This study aimed to illustrate the magnetic resonance venography (MRV) manifestations of obstructed hepatic veins (HVs), the inferior vena cava (IVC), and accessory hepatic veins (AHVs) in patients with Budd-Chiari syndrome (BCS) and to evaluate the visualization capacity of MRV in the diagnosis of BCS.

Materials and Methods

Fifty-two patients with chronic BCS were included in this study. All patients were examined via MRV performed with a 3T system following injections of gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) or Gd-ethoxibenzyl-DTPA. HV and IVC lesions were classified, and their characteristics were described. HV cord-like occlusions detected via MRV were compared using ultrasonography (US). Digital subtraction angiography (DSA) was performed as a contrast in the MRV detection of IVC lesions. The HVs draining collaterals, mainly AHVs, were carefully observed. HV lesions were classified as segmental stenosis, segmental occlusion, membranous stenosis, membranous occlusion, cord-like occlusion, or non-visualized. Except for patent IVCs, IVC lesions were classified as segmental occlusion, segmental stenosis, membranous occlusion, membranous stenosis, and hepatomegaly-induced stenosis.

Results

All patients (52/52, 100%) showed HV lesions of different degrees. MRV was inferior to US in detecting cord-like occlusions (6 vs. 19, χ² = 11.077, p < 0.001). Dilated AHVs, including 50 (50/52, 96.2%) caudate lobe veins and 37 (37/52, 71.2%) inferior HV and AHV lesions, were well-detected. There were no significant differences in detecting segmental lesions and thrombosis between MRV and DSA (χ² = 0.000, p1 = 1.000, p2 = 1.000). The capacity of MRV to detect membranous lesions was inferior to that of DSA (7 vs. 15, χ² = 6.125, p = 0.013).

Conclusion

In patients with BCS, MRV can clearly display the lesions in HVs and the IVC, as well as in AHVs, and it has diagnostic and therapeutic value.

Imaging manifestations of Behcet's disease: Key considerations and major features

Behcet's disease is an autoimmune disease most commonly seen in the Middle East. Although primarily known with painful oral and genital ulcers, it can lead to vasculitis. Therefore, several associated complications such as thrombotic syndromes, aneurysmal arterial disease may arise. In many cases, it might be difficult to make the diagnosis purely based on clinical grounds; however, imaging plays an important role for both diagnosis and assessment of the disease's complications. We provide a comprehensive review of the most notable imaging findings of Behcet's disease.

Working Subgroup for Clinical Practice Guideline for Aberrant Portal Hemodynamics. Diagnosis and treatment guidelines for aberrant portal hemodynamics: The Aberrant Portal Hemodynamics Study Group supported by the Ministry of Health, Labor and Welfare of Japan

Idiopathic portal hypertension (IPH), causing aberrant portal hemodynamics, is a disease with an as yet unidentified cause and no established treatment protocol. The Japanese research group on IPH in Japan was set up in 1975 by the Ministry of Health, Labor and Welfare. Extrahepatic portal obstruction and Budd-Chiari syndrome (BCS) have since been added to the group's research subjects. The aims of the research group are to accurately evaluate the current status of the three diseases in Japan, elucidate their etiology and pathogenesis, and develop new treatments. Due to the long-term efforts of the Japanese research group, aberrant portal hemodynamics has been investigated in a variety of aspects, from epidemiological and pathological studies to molecular biology analyses. As a result, it has been shown that there are abnormal genes in the liver, specific for IPH. In addition, pathological findings of BCS were internationally compared and the difference in findings between Japan and Europe (or North America) has been clarified. Furthermore, it was found that complication rates of hepatocellular carcinoma in BCS were higher in Japan. Based on the research, "Diagnosis and treatment of aberrant portal hemodynamics (2001)", including diagnostic criteria for aberrant portal hemodynamics, was published in 2001. In 2013, it was revised to "Diagnosis and treatment guidelines for aberrant portal hemodynamics (2013)" after the incorporation of diagnosis and treatment in accordance with its current status.

Budd-Chiari syndrome: Focus on surgical treatment

Budd-Chiari syndrome (BCS) is caused by an obstruction in the hepatic venous outflow tract at various levels from small hepatic veins to the inferior vena cava (IVC) due to thrombosis or fibrous sequelae. This rare disease mainly affects young adults. Risk factors have been identified and patients often have multiple risk factors. Myeloproliferative diseases of atypical presentation account for nearly 50% of patients in Europe and North America countries. Multistep management is required for such patients. Interventional revascularization and transjugular intrahepatic portosystemic shunt procedure are indicated after initial anticoagulation therapy, whereas IVC plasty using a patch graft is indicated for obstruction of the IVC. Liver transplantation (LT) is usually indicated as a treatment for liver failure despite various treatments. The outcomes of LT are good, with a 5-year survival after LT of nearly 70%.

Diagnostic efficacy of single-pass abdominal multidetector-row CT: prospective evaluation of a low dose protocol

OBJECTIVE

To evaluate the diagnostic efficacy of single-pass contrast-enhanced multidetector CT (CE-MDCT) performed with a low-radiation high-contrast (LR-HC) dose protocol in selected patients with non-traumatic acute bowel disease.

METHODS

65 (32 males, 33 females; aged 20-67 years) consecutive patients with non-traumatic acute bowel disease underwent single-pass CE-MDCT performed 70-100 s after i.v. bolus injection of a non-ionic iodinated contrast medium (CM) (370 mgI ml^-1). In 46 (70%) patients with a clinical and/or ultrasonographic suspicion of inflammatory bowel disease, up to 1.2-1.4 l of a 7% polyethylene-glycol solution was orally administered 45-60 mins prior to the CT examination. Patients were then divided into two groups according to age: Group A (20-44 years; n = 34) and Group B (45-70 years; n = 31). Noise index (NI) and CM dose were selected as follows: Group A (NI = 15; 2.5 ml kg^-1) and Group B (NI = 12.5; 2 ml kg^-1). All patients of Group A underwent thyroid functional tests at 4-6 weeks. Final diagnoses were obtained by open (n = 12) or laparoscopic surgery (n = 4), endoscopy w/without biopsy (n = 24) and clinical (n = 19) and/or instrumental (ultrasonography) (n = 6) follow-up at 11 ± 4 months (range 6-18 mo.). Statistical analysis was performed by χ² and Student's t-test for categorical and continuous variables, respectively.

RESULTS

Sensitivity and specificity were 91.3 vs 95.4% (p = 0.905) and 90.9 vs 88.8% (p = 0.998) with an overall diagnostic accuracy of 91.1 vs 93.5% (p = 0.756), whereas the radiation (in millisievert) and CM dose (in millilitre) were 7.5 ± 2.8 mSv and 155 ± 30 ml for Group A and 14.1 ± 5.3 mSv and 130 ± 24 ml for Group B (p < 0.001), respectively. No patients of Group A showed laboratory signs of thyrotoxicosis at follow-up.

CONCLUSION

The LR-HC has proved to be a safe and a dose-effective protocol in the evaluation of selected young patients with non-traumatic acute bowel disease. Advances in knowledge: (1) As reaching the highest diagnostic benefit to risk ratio (AHARA) appears to be the current principle of MDCT imaging, an increased amount of iodinated CM (0.7-0.9 gI ml^-1) can be safely administered to young patients (<40 years) with normal thyroid and renal function to compensate for the lower image quality resulting from low-dose CT protocols performed with the standard filter back-projection algorithm. Such an approach will result in a significant reduction of the radiation dose, which could be otherwise achieved only using iterative reconstruction algorithms combined with either low tube voltage and/or low tube current protocols. (2) An optimal scan delay (T_delay) for a venous phase caudocranial acquisition can be calculated by the following formula: T_delay = CI + 25 - T_SD, where CI is the duration of the contrast injection, 25 is the average of the sum of abdominal aortic and peak hepatic arrival times and T_SD is the scan duration. With such an approach, the radiation exposure resulting from bolus tracking, albeit performed with low-dose scans, can be spared in patients with normal transit times.

Redefining Budd-Chiari syndrome: A systematic review

AIM: To re-examine whether hepatic vein thrombosis (HVT) (classical Budd-Chiari syndrome) and hepatic vena cava-Budd Chiari syndrome (HVC-BCS) are the same disorder.

METHODS: A systematic review of observational studies conducted in adult subjects with primary BCS, hepatic vein outflow tract obstruction, membranous obstruction of the inferior vena cava (IVC), obliterative hepatocavopathy, or HVT during the period of January 2000 until February 2015 was conducted using the following databases: Cochrane Library, CINAHL, MEDLINE, PubMed and Scopus.

RESULTS: Of 1299 articles identified, 26 were included in this study. Classical BCS is more common in women with a pure hepatic vein obstruction (49%-74%). HVC-BCS is more common in men with the obstruction often located in both the inferior vena cava and hepatic veins (14%-84%). Classical BCS presents with acute abdominal pain, ascites, and hepatomegaly. HVC-BCS presents with chronic abdominal pain and abdominal wall varices. Myeloproliferative neoplasms (MPN) are the most common etiology of classical BCS (16%-62%) with the JAK2V617-F mutation found in 26%-52%. In HVC-BCS, MPN are found in 4%-5%, and the JAK2V617-F mutation in 2%-5%. Classical BCS responds well to medical management alone and 1^st line management of HVC-BCS involves percutaneous recanalization, with few managed with medical management alone.

CONCLUSION: Systematic review of recent data suggests that classical BCS and HVC-BCS may be two clinically different disorders that involve the disruption of hepatic venous outflow.

Budd-Chiari syndrome: an update on imaging features

Budd-Chiari syndrome (BCS) is a rare cause of portal hypertension and liver failure. This condition is characterized by an impaired hepatic venous drainage. The diagnosis of BCS is based on imaging, which helps initiate treatment. Imaging findings can be categorized into direct and indirect signs. Direct signs are the hallmarks of BCS and consist of visualization of obstructive lesions of the hepatic veins or the upper portion of the inferior vena cava. Indirect signs, which are secondary to venous obstruction, correspond to intra- and extrahepatic collateral circulation, perfusion abnormalities, dysmorphy and signs of portal hypertension.

Budd-Chiari Syndrome: an unnoticed diagnosis

Budd–Chiari syndrome (BCS) encompasses a group of disorders caused by the obstruction to the hepatic venous outflow at the level of the small or large hepatic veins, the inferior vena cava, or any combination thereof. Clinical manifestation of the subacute form is characterized by supramesocolic abdominal discomfort, abdominal distension, fever, and lower limbs edema. Imaging work-up with hepatic Doppler ultrasound and abdominal computed tomography (CT) enables the diagnosis in the majority of cases. Treatment comprises long-term anticoagulation associated with measures that attempt to re-establish the flow in the thrombosed vessel (thrombolysis or angioplasty) or through the venous blood flow bypasses (transjugular intrahepatic portosystemic shunt or surgical bypass); however, the outcome is often dismal. The authors report the case of a 37-year-old woman presenting a 2-month history of dyspeptic complaints and abdominal distention. Fever was present at the beginning of symptoms. The laboratory work-up disclosed mild hepatic dysfunction, and the ultrasound showed evidence of chronic liver disease. Despite a thorough etiologic investigation, diagnosis was missed and, therefore, management could not be directed towards the physiopathogenetic process. The outcome was characterized by portal hypertension and esophageal varices bleeding. The patient died and the autopsy findings were characteristic of BCS, although an abdominal CT, close to death, had showed signs consistent with this diagnosis. The authors highlight the importance of knowledge of this entity, the diagnostic methods, and the multidisciplinary approach. BCS should be considered whenever investigating etiology for chronic or acute hepatopathy.