Major and ancillary magnetic resonance features of LI-RADS to assess HCC: an overview and update

Abstract

Liver Imaging Reporting and Data System (LI-RADS) is a system for interpreting and reporting of imaging features on multidetector computed tomography (MDCT) and magnetic resonance (MR) studies in patients at risk for hepatocellular carcinoma (HCC). American College of Radiology (ACR) sustained the spread of LI-RADS to homogenizing the interpreting and reporting data of HCC patients. Diagnosis of HCC is due to the presence of major imaging features. Major features are imaging data used to categorize LI-RADS-3, LI-RADS-4, and LI-RADS-5 and include arterial-phase hyperenhancement, tumor diameter, washout appearance, capsule appearance and threshold growth. Ancillary are features that can be used to modify the LI-RADS classification. Ancillary features supporting malignancy (diffusion restriction, moderate T2 hyperintensity, T1 hypointensity on hapatospecifc phase) can be used to upgrade category by one or more categories, but not beyond LI-RADS-4. Our purpose is reporting an overview and update of major and ancillary MR imaging features in assessment of HCC.

Keywords: HCC; LI-RADS; Magnetic resonance imaging.

Fig. 1

Included and excluded studies in systematic review

Fig. 2

Man 73 years old with typical HCC on VI hepatic segment. The HCC is hyperintense (arrow) on T2-W sequences (a), shows (arrows) restrict diffusion (b: b50 s/mm², c: b800 s/mm²). After contrast medium injection, the nodule is hypervascular (arrow) on arterial phase (d), with wash-out appearance (arrow) on portal phase (e) and capsule appearance (arrow) on equilibrium phase (f) of contrast study with Gd-BT-DO3A

Fig. 3

Woman 73 years old with atypical HCC on VII-VIII hepatic segment. The HCC is hyperintense (arrow) on T2-W sequences (a) and hypointense (arrow) on T1-W sequences (b: out-of-phase). During arterial phase (c), it is not hypervascular (arrow), while there is wash-out appearance (arrow) and capsule appearance (arrow) on portal phase (d), on equilibrium phase (e) and hepatospecific phase (f) of contrast study

Fig. 4

Woman 44 years old with multiple nodules of HCC. The nodules are hyperintense (arrow) on T2-W sequences (a), hypointense (arrow) on T1-W sequences (b: in-of-phase; c: out-of-phase), hypervascular (arrow) on arterial phase (d), with wash-out and capsule appearance (arrow) on portal phase (e) and hypointense signal (arrow) on hepatospecific phase (f) of contrast study with EOB-GD-DTPA

Fig. 5

Man 74 years old with HCC on II hepatic segment. The HCC is hyperintense (arrow) on T2-W sequence (a), isointense (arrow) on T1-W (b: in-of-phase) with peripheral fat suppression (arrow) on T1-out of phase (c). During arterial phase of contrast study (d) with EOB-GD-DTPA, the HCC shows hyperenhancement (arrow), with wash-out and capsule appearance (arrow) on portal phase (e). During hepatospecific phase (f) of contrast study the HCC is hypointense (arrow)

Fig. 6

The same patient of Fig. 5. Restricted diffusion. The nodule (arrow) shows hyperintense signal on b0 s/mm² (a), on b 500 s/mm² (b) and on b 800 s/mm²(c)