Liver Function Assessment Using Parenchyma-Specific Contrast-Enhanced Ultrasonography

An Optimal Prognostic Model Based on Multiparameter Ultrasound for Acute-on-Chronic Liver Failure

OBJECTIVE

Acute-on-chronic liver failure (ACLF) is associated with a considerably high mortality, and accurate prognosis prediction is critical to navigate intervention decisions and improve clinical outcomes. The objective of this study was to establish a better prognostic model for ACLF based on multiparameter ultrasound in combination with clinical features.

METHODS

A total of 149 patients with ACLF were prospectively enrolled and underwent conventional ultrasound, 2-D shear wave elastography (SWE), attenuation imaging, color Doppler sonography, superb microvascular imaging and contrast-enhanced ultrasound (CEUS). Univariate and multivariate analyses were performed to identify independent ultrasound signatures for the prognosis of ACLF, which, when integrated with clinical characteristics, were used to establish a prognostic model.

RESULTS

Hepatic perfusion features of CEUS differed significantly between the poor and good prognosis groups, among which the time interval (TI) between peak portal vein (PV) velocity and liver parenchyma (LP) enhancement, TI(PV, LP), was independently associated with the prognosis of ACLF. A prediction model comprising TI(PV, LP) and the international normalized ratio was established, and the area under the curve (AUC) was 0.851, which is greater than those of the Model for End-stage Liver Disease (0.785), fall time of LP model (0.754), 2-D SWE nomogram (0.708) and TI(PV, LP) (0.352). Furthermore, the performance of the model was verified in an independent validation cohort (AUC = 0.920).

CONCLUSION

The newly developed model performs better than existing tested models; thus, it has potential as a better non-invasive model for predicting the prognosis of patients with ACLF. A future multicenter, large-sample study is required to validate the performance of this model.

Successful Diagnosis of a Longstanding Giant Amoebic Liver Abscess Using Contrast-Enhanced Ultrasonography (CEUS): A Case Report in a Western Country

BACKGROUND E. histolytica liver abscess results from extra-intestinal diffusion of amebiasis, which is responsible for up 100 000 deaths per annum, placing it second only to malaria in mortality. Currently, the criterion standard for the diagnosis of liver abscesses is ultrasound, but CEUS (contrast-enhanced ultrasound) is emerging as a more accurate method for liver study, and it could be more accurate than ultrasound and non-invasive compared to CT. CASE REPORT A white man (59 years old) with a 2-day history of dyspnea, acute abdominal pain in right upper quadrant, and raised inflammatory markers was admitted to a second-level Emergency Department in Rome (Italy). He reported several trips to tropical areas many years before, during which he ingested non-potable water and became infected with Entamoeba histolytica. This was treated medically with success. After administration of antibiotics (meropenem and metronidazole), a liver CEUS (contrast-enhanced ultrasonography) with administration of SonoVue (sulphur hexafluoride microbubbles) confirmed a giant liver abscess (15×16 cm). One day later, CT-guided drainage was performed without complications and the patient was discharged on the 25th post-procedure day, with improved blood results. CONCLUSIONS Acute abdominal pain can be caused by a variety of diseases, but a diagnosis of parasitic abscess should not be overlooked in non-endemic Western countries. CEUS is a new, promising, and more accurate technique that can be utilized to recognize liver abnormalities, including abscesses; however, retrospective population-wide studies are necessary to define the differential diagnoses.

Washout Ratio in the Hepatic Vein Measured by Contrast-Enhanced Ultrasonography to Distinguish Between Inflammatory and Noninflammatory Hepatic Disorders in Dogs

Background

Perflubutane microbubbles, a second‐generation ultrasound contrast agent, are phagocytized by Kupffer cells. This characteristic may be useful to differentiate diffuse hepatic diseases in dogs.

Hypothesis/objectives

To determine whether the washout ratio in the hepatic vein (HV) measured by contrast‐enhanced ultrasonography (CEUS) can distinguish between inflammatory and noninflammatory hepatic disorders in dogs.

Animals

Forty‐one client‐owned dogs with hepatic disorders including 14 with hepatitis, 7 with primary hypoplasia of the portal vein (PHPV), 9 with congenital portosystemic shunt (cPSS), and 11 with other hepatopathy were enrolled. Six dogs without hepatic disease also were evaluated as healthy controls.

Methods

Dogs with hepatic disorders were prospectively included. Contrast‐enhanced ultrasonography of the HV was performed for 2 minutes. Washout ratio was defined as the attenuation rate from peak intensity to the intensity at the end of the CEUS study.

Results

Washout ratio in the hepatitis group (median, 18.0%; range, 2.0–37.0%) was significantly lower than that of the PHPV (median, 52.2%; range, 11.5–86.3%), cPSS (median, 60.0%; range, 28.6–77.4%), other hepatopathy (median, 70.5%; range, 26.6–88.4%), and normal (median, 78.0%; range, 60.7–91.7%) groups. The area under the receiver operating characteristic curve for hepatitis was 0.960, with a 95% confidence interval (CI) of 0.853–0.990. Washout ratio ≤37.1% resulted in a sensitivity of 100% (95% CI, 78.5–100%) and specificity of 85.2% (95% CI, 67.5–94.1%) for the prediction of hepatitis.

Conclusions and Clinical Importance

Washout ratio can distinguish hepatitis from the other noninflammatory disorders with high accuracy. This result might reflect impaired Kupffer cell phagocytosis in dogs with hepatitis.

Contrast-enhanced ultrasonography of the hepatic vein in normal dogs

Contrast-enhanced ultrasonography (CEUS) of the hepatic vein can assess intrahepatic hemodynamic changes and has been studied as a noninvasive method to assess the severity of portal hypertension and hepatic fibrosis in humans. However, few reports have described its usefulness in veterinary medicine. The purpose of this study was to characterize CEUS findings of the hepatic vein in normal dogs and assess the repeatability of this method both in a conscious group (n=6) and a sedated group (n=6). Sonazoid^® (0.01 ml/kg) was used as a contrast agent, and scanning of the hepatic vein was performed for 2 min. Time-intensity curves were generated from regions of interest in the hepatic vein. Four perfusion parameters were measured for quantitative analysis: hepatic vein arrival time (HVAT), time to peak (TTP), time to peak phase (TTPP) and wash-out ratio (WR). CEUS examinations were performed three times in each dog. The median (range) values of HVAT, TTP, TTPP and WR in the conscious group were 13.5 sec (9–22 sec), 12.5 sec (6–24 sec), 8 sec (6–13 sec) and 78.0% (60.7–91.7%), respectively. Median (range) values of HVAT, TTP, TTPP and WR in the sedated group were 12 sec (8–17 sec), 12.5 sec (9–17 sec), 9 sec (7–13 sec) and 84.1% (63.0–94.4%), respectively. The coefficients of variation of these parameters in the conscious and sedated groups were 7.6–29.7% and 11.8–14.8%, respectively.