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

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.

[Budd-Chiari syndrome, review and illustration]

Budd-Chiari syndrome is a rare vascular disorder characterized by obstruction of the hepatic venous outflow. Various diseases causing coagulopathy play a role in aetiology, such as myeloproliferative disorders. Acute vascular occlusion may lead to acute phlebitis with fever. The classic triad of acute liver failure may be present with ascites, hepatomegaly, and abdominal pain. However, subacute courses of disease were also observed. Because of the variable symptoms and severity extent, depending on the acuity of the course and the extent of the affected vessels, diagnosis is often difficult. Sonography, as a ubiquitously available and cost-effective diagnostic tool, plays a leading role. Doppler ultrasonography can be used to visualize hemodynamics in particular. In acute thrombotic occlusion, the affected hepatic veins usually cannot or only partially be visualized. In non-occluding thrombi, turbulent flow patterns may develop in the area of venous outflow obstruction, and flow velocity is then increased in the area of stenosis. Contrast enhanced ultrasound offers even better specificity of diagnosis. Computed tomography and magnetic resonance imaging can directly visualize thrombi and the cause of obstruction. Once the diagnosis is confirmed, anticoagulation must be initiated, but therapy of the underlying disease must also be started. If symptom-controlling measures are not sufficient, angioplasty/stenting to reopen short-segment stenoses or implantation of a TIPSS device may be considered. Liver transplantation remains ultima ratio. As studies on the precision of diagnostic methods are controversial, the characteristics of imaging for BCS are therefore summarized in this review on the basis of several illustrating case reports.

Contrast enhanced ultrasound versus multiphasic contrast enhanced computed tomography in evaluation of gallbladder lesions

AIM

To compare the diagnostic performance of contrast enhanced ultrasound (CEUS) and multiphasic contrast enhanced computed tomography (CECT) in differentiating benign and malignant gallbladder (GB) lesions.

METHODS

This prospective ethical review board approved study comprised consecutive patients with GB lesions who underwent CEUS and multiphasic CECT at a tertiary care referral center. The enhancement patterns at CEUS and CT were compared. The quantitative CEUS parameters including arrival time (AT), AT in liver, time to peak enhancement, and washout time (WT) were assessed. The diagnostic performance of CEUS and CT features was calculated using receiver operating characteristic analysis. A subgroup analysis was performed for patients with GB wall thickening. Multivariate analysis was performed to identify features significantly associated with malignancy.

RESULTS

Over the study period, 30 patients (mean age, 52.8 ± 12.2 years, 17 females) with GB lesions were evaluated. Benign and malignant diseases were present in 13 and 17 patients, respectively. There was excellent agreement between CEUS and CT findings. Among the quantitative CEUS features, only WT was significantly associated with malignancy in the overall group (p < 0.001) and wall thickening subgroup (p = 0.007). WT within 53.5 s and 51.5 s had sensitivity of 88.2% and 81.8% and specificity of 84.5% and 100% in diagnosing malignant lesions in the overall group (AUC 0.900) and the wall thickening subgroup (area under curve, AUC 0.927), respectively. At multivariate analysis, features that were significantly associated with malignant lesions in the overall group were disruption of GB wall (CEUS), intralesional non-enhancing areas (CEUS), liver involvement (CEUS or CT), and arterial phase hyperenhancement (CT) in the overall group and disruption of GB wall (CEUS), WT (CEUS), and liver involvement (CEUS or CT) in the wall thickening subgroup.

CONCLUSION

CEUS is a useful adjunct to CT in evaluation of GB lesions. Its utilization in patients with GB wall thickening may improve detection of malignancy.