Multiple arterial-phase MRI with gadoxetic acid improves diagnosis of hepatocellular carcinoma ≤3.0 cm.

Background And Aims: Multiple arterial-phase magnetic resonance imaging (MA-MRI) was introduced to overcome the limitations of gadoxetic acid-enhanced MRI, but its clinical impacts on hepatocellular carcinoma (HCC) diagnosis have not been well assessed. We investigated whether MA-MRI with gadoxetic acid could improve the diagnosis of HCC ≤3.0 cm in comparison with single arterial-phase MRI (SA-MRI).

Methods: This retrospective study included 397 patients from two tertiary institutions who underwent gadoxetic acid-enhanced MRI (243 patients with 271 lesions in cohort-1 underwent SA-MRI, and 154 patients with 166 lesions in cohort-2 underwent MA-MRI). The patients had 437 hepatic lesions ≤3.0 cm with pathologic confirmation. The arterial-phase image quality and diagnostic performance of SA-MRI and MA-MRI were analysed and compared. To minimize the effects of selection bias because of potential confounding between the two groups, propensity score-matching was additionally performed.

Results: MA-MRI showed a significantly higher percentage of optimal arterial-phase timing (94.2% vs. 74.5%, p < .001) and lower incidence of inadequate examinations (1.3% vs. 5.8%, p = .034) than SA-MRI. MA-MRI had a significantly higher non-rim arterial-phase hyperenhancement (APHE) detection rate (94.9% vs. 85.5%, p = .005) and sensitivity for diagnosing HCC (87.4% vs. 70.0%, p < .001) than SA-MRI, but no significant difference in specificity (92.9% vs. 93.1%, p = .966). In 123 pairs of propensity score-matched patients, MA-MRI had significantly higher sensitivity (89.1% vs. 74.5%, p = .006) than SA-MRI with equal specificity (92.3% vs. 92.3%, p > .999).

Conclusions: Compared with SA-MRI, MA-MRI with gadoxetic acid can detect more non-rim APHE and significantly improve sensitivity for diagnosing HCC ≤3.0 cm, without a significant decrease in specificity.