Imaging description

Pathologically, the term nutmeg liver refers to the speckled appearance of the cut liver in chronic venous congestion, due to dilated and congested red central veins surrounded by paler, unaffected liver tissue (resembling a grated nutmeg kernel) [1]. Radiologically, the term refers to the distinctive pattern of diffuse reticular heterogeneous enhancement seen in the arterial and early portal venous phases of enhancement at CT or MRI in patients with venous congestion (Figures 13.1–13.4), due either to Budd-Chiari syndrome or cardiac or pericardial disease with elevated right heart pressure [2–5]. The terms mosaic perfusion and shattered glass have also been used to describe to this distinctive hepatic enhancement pattern.

Importance

Nutmeg liver detected at CT or MRI suggests either Budd-Chiari syndrome or heart disease. Recognition of passive hepatic congestion on CT or MRI may help explain liver function abnormalities in patients with heart failure [3] and may be an important clue to the diagnosis of constrictive pericarditis, which might otherwise go unrecognized [6]. Rarely, nutmeg liver can progress to cardiac cirrhosis [1].

Typical clinical scenario

Nutmeg liver is most frequently seen in right heart failure, and this diagnosis may be suggested by ancillary imaging findings such as retrograde hepatic venous opacification, hepatomegaly, cardiomegaly, pleural effusions, ascites, and periportal edema [3, 4]. Pericardial disease may be suggested by pericardial effusion, thickening, or calcification [4, 6]. Nutmeg liver is seen primarily in the subacute and chronic phases of Budd- Chiari syndrome [2, 7], when it may be accompanied by non-visualization or narrowing of the hepatic veins and intrahepatic inferior vena cava, caudate lobe hypertrophy, peripheral atrophy, and intrahepatic collateral veins [8].