Postprandial reversal of the portal venous flow in a patient with liver cirrhosis

Clinical Relevance of Retrograde Inferior Vena Cava or Hepatic Vein Opacification During Contrast-Enhanced CT

OBJECTIVE

The purpose of this investigation was to explore the clinical relevance of retrograde inferior vena cava or hepatic vein opacification during contrast-enhanced CT.

MATERIALS AND METHODS

We retrospectively identified 127 patients who underwent contemporaneous contrast-enhanced CT of the chest or abdomen and echocardiography. On CT, the presence of retrograde inferior vena cava or hepatic vein opacification and the rate of IV contrast injection (> 3 mL/sec, high; < or = 3 mL/sec, low) were recorded. On echocardiography, the presence of tricuspid regurgitation, pulmonary hypertension, or right ventricular systolic dysfunction was recorded.

RESULTS

Retrograde inferior vena cava or hepatic vein opacification was more common in studies performed with a high rather than a low contrast injection rate (28/56 vs 6/71 patients, respectively; p < 0.01). This finding was 31% sensitive (5/16) and 98% specific (54/55) for right-sided heart disease at low contrast injection rates, and 81% sensitive (17/21) and 69% specific (24/35) at high injection rates. Multivariate logistic regression models showed that high injection rate, tricuspid regurgitation, pulmonary hypertension, and right ventricular systolic dysfunction were independent predictors of retrograde inferior vena cava or hepatic vein opacification (p < 0.05 for each).

CONCLUSION

Retrograde opacification of the inferior vena cava or hepatic veins on CT is a specific but insensitive sign of right-sided heart disease at low contrast injection rates, but the usefulness of this classic sign decreases with high injection rates. This realization is important because many centers increasingly use high-injection-rate CT.

CT Signs of Hepatofugal Portal Venous Flow in Patients with Cirrhosis

OBJECTIVE

We investigated whether CT signs can be used to predict hepatofugal flow in the main portal vein in patients with cirrhosis.

MATERIALS AND METHODS

We retrospectively identified 36 patients with cirrhosis, 18 with hepatopetal and 18 with hepatofugal flow in the main portal vein, who underwent contemporaneous abdominal sonography and CT. Two independent observers evaluated the following features on the randomized CT studies: diameter of the portal, splenic, and superior mesenteric veins; spleen size; and the presence of ascites, varices, or arterial phase portal venous enhancement. These data were correlated with the flow direction seen on sonography.

RESULTS

A small main portal vein was the only sign significantly (p </= 0.05) predictive of hepatofugal flow by univariate and multivariate analyses. Observers 1 and 2 recorded a portal vein diameter of less than 1 cm in eight (44%) and seven (39%) of the 18 patients with hepatofugal flow compared with one (6%) and none of the 18 patients with hepatopetal flow, respectively (p < 0.02). Receiver operating characteristic analysis using the size of the portal vein to predict flow direction revealed an area under the curve of 0.83 for observer 1 and 0.74 for observer 2.

CONCLUSION

A diameter of less than 1 cm for the main portal vein is highly specific, although not sensitive, for hepatofugal portal venous flow in patients with cirrhosis. This sign may be useful when sonography is limited, or this sign may prompt sonographic assessment in patients not known to have hepatofugal flow.

Doppler ultrasound in the evaluation of cirrhotic patients: the prevalence of intrahepatic arteriovenous shunting, and implications for diagnosis of hepatocellular carcinoma

To establish the prevalence and significance of Doppler-detected hepatic arteriovenous shunting (AVS) in patients with compensated cirrhosis, 115 patients (mean age 55.4 +/- 12.47 SD y) were prospectively screened using real-time ultrasound with pulsed Doppler at 2.5 MHz to detect focal liver lesions and quantify AVS. Focal masses were biopsied and correlated with the US findings. All other patients had clinical follow-up and imaging for at least 12 months. AVS occurred in 28 of 115 (24.3%), and in 18 of 20 proven malignancies (90%) including 11 of 13 cases of hepatocellular carcinoma (85%). However, 9 of 28 (32%) AVS (mean Doppler shift 2.73 +/- 1.51 [SD] kHz [range 0.6-5.41 kHz], n = 9) were in regions of fatty infiltration (4) or isolated (5), unassociated with malignancy. At a prevalence of 17.9% malignancy (11.3% due to hepatocellular carcinoma), specificity for malignancy increased with shunt velocity, from 76% (for mass alone), to 94.8% for mass with AVS, 96.8% for a mass with AVS of 1.75-2.4 kHz, and 100% for a mass with AVS > 2.4 kHz. Doppler US is useful in characterizing liver lesions in cirrhotic patients: the majority of malignant hepatic lesions are associated with AVS and specificity for malignancy increases with shunt velocity. However, isolated AVS or AVS associated with focal fat may be detected in 7.8% of compensated cirrhotics.