Magnetic resonance imaging of the cirrhotic liver: An update

Table 1 Summary of a wide-spectrum of lesions in cirrhotic liver and their imaging appearances on magnetic resonance imaging

Imaging sequences	RNs	Siderotic nodules (RNs or LGDNs)	LGDNs1	AP Shunts2	HGDNs	HCCs
T1-weighted images	Iso- or hyperintense3	Hypointense4	Iso- or hyperintense	Isointense	Iso- or slightly hyperintense	Ranging from hypo- to hyperintense
T2-weighted images	Iso- or hypointense	Hypointense	Iso- or hypointense	Isointense	Isointense	Iso- to mildly hyperintense
DWI	Isointense	Hypointense	Iso- or hypointense	Isointense	Isointense	Iso- to hyperintense5
Post-Gadolinium Dynamic images (arterial and delayed images)	Iso-enhancement on the hepatic arterial phase, and no delayed washout	Iso-enhancement on the hepatic arterial phase, and no delayed washout	Iso-enhancement on the hepatic arterial phase, and no delayed washout	Hyper-enhancement on the arterial phase, and no show delayed washout6	Usually hyper-enhancement on the arterial phase and can be mistaken for HCC. These nodules do not show delayed washout	Usually hyper-enhancement on the arterial phase and delayed washout (hypointense), with or without pseudocapsule enhancement7
Hepatobiliary phase images	Iso- to slightly hyperintense	Hypointense	Iso- to slightly hyperintense	Isointense	Isointense	Hypointense8

¹RNs and LGDNs tend to be indistinguishable on MRI;

²AP shunts might be indistinguishable from HGNDs and small, early HCCs. Relying on additional features and short-term follow-up can help in making this distinction;

³The exact cause for this hyperintensity is believed to be due to the presence of binding proteins;

⁴These nodules show lower signal intensity on longer TE T1-weighted GRE sequences, due to susceptibility artifact;

⁵Usually hyperintense, especially if > 2 cm;

⁶AP shuns are usually easy to differentiate from other hypervascular lesions when they show a triangular or linear configuration. When AP shunts show round configuration, they can be indistinguishable from HGDNs and HCCs;

⁷HCCs ≤ 1.5 cm are frequently isointense on T1- and T2-weighted images and are detected only on the arterial phase. Early stage HCC, especially tumors ≤ 2 cm, may also appear isointense, or less likely, hypointense on the arterial phase;

⁸Some HCCs may appear isointense or hyperintense on the hepatobiliary phase; especially well-differentiated and moderately-differentiated HCCs. LGDNs: Low-grade dysplastic nodules; AP: Arterio-portal; HGDNs: High-grade dysplastic nodules; HCCs: Hepatocellular carcinomas; RNs: Regenerative nodules; DWI: Diffusion weighted images.