Extracellular contrast agent-enhanced MRI: 15-min delayed phase may improve the diagnostic performance for hepatocellular carcinoma in patients with chronic liver disease.

OBJECTIVES

To determine the value of a 15-min delayed phase in extracellular contrast agent (ECA)-enhanced magnetic resonance imaging (MRI) for evaluation of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

METHODS

Between 2014 and 2015, 103 patients with chronic liver disease underwent ECA-enhanced MRI; 133 lesions consisting of 107 HCCs, 23 benign lesions and three non-HCC malignancies were identified with pathological or clinical diagnosis. MRI images were reviewed by two abdominal radiologists independently using the European Association for the Study of the Liver (EASL) and Liver Imaging Reporting and Data System (LI-RADS) criteria. Imaging features observed in the 15-min delayed phase were recorded.

RESULTS

Of 107 HCCs, three or four additional HCCs were diagnosed according to the EASL criteria by adding the 15-min delayed phase, increasing sensitivity (Reviewer 1, from 69.2-72.0 % [P = 0.072]; Reviewer 2, from 75.7-79.4 % [P = 0.041]). Reviewers 1 and 2 upgraded one and four HCCs from LR-4 to LR-5 based on the LI-RADS, respectively. Among 23 benign lesions, no additional findings were observed in the 15-min delayed phase.

CONCLUSIONS

Including the 15-min delayed phase in ECA-enhanced MRI may improve the diagnostic performance for HCC in patients with chronic liver disease.

KEY POINTS

• Additional acquisition of 15-min delayed phase (FDP) requires approximately 20 s. • About 5 % of HCCs show washout or capsule appearance only in FDP. • Including FDP improves the sensitivity of extracellular contrast agent-enhanced MRI for HCC. • These results are applicable only to patients with chronic liver disease.