Enhancement patterns and pseudo-washout of hepatic haemangiomas on gadoxetate disodium-enhanced liver MRI.

OBJECTIVES

To compare the enhancement patterns and prevalence of pseudo-washout between rapidly and slowly enhancing hepatic haemangiomas on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD) and healthy liver (HL).

METHODS

On gadoxetate disodium-enhanced MRI, the extent of intralesional arterial enhancement >50 % and ≤ 50 % of lesions was defined as rapid and slow enhancement, respectively. The enhancement patterns and presence of pseudo-washout during the portal venous phase (PVP) and transitional phase (TP) of 74 hepatic haemangiomas were retrospectively evaluated in the CLD and HL groups. Sequential changes of signal-to-noise ratio (SNR) were measured in unenhanced phase, PVP and TP.

RESULTS

Irrespective of hepatic health status, pseudo-washout in TP was significantly more common in the rapidly enhancing haemangiomas (p ≤ 0.026). In both groups, rapidly enhancing haemangiomas showed complete or progressive incomplete enhancement in PVP, which either lasted or transformed to pseudo-washout in TP, whereas slowly enhancing haemangiomas showed progressive incomplete enhancement in PVP and TP. SNR of hepatic parenchyma continued to rise until TP, whereas that of portal vein and haemangioma falls in TP.

CONCLUSIONS

Regardless of CLD, pseudo-washout in TP was more common in rapidly than in slowly enhancing haemangiomas, with enhancement patterns differing in the two subgroups.

KEY POINTS

On gadoxetate disodium-enhanced MRI, some hepatic haemangiomas show pseudo-washout in transitional phase. Regardless of chronic liver disease, pseudo-washout is significantly more common in rapidly enhancing haemangiomas. Rapidly enhancing haemangiomas show complete or progressive incomplete enhancement or pseudo-washout in TP. Slowly enhancing haemangiomas show progressive incomplete enhancement in portal venous phase and TP.