Diagnostic performances of adding transition and hepatobiliary phase to washout in gadoxetic acid-enhanced MRI for subcentimeter hepatocellular carcinoma

Abstract

Objective: To compare the diagnostic performances of washout (WO) criteria confined to portal venous phase (PVP), extended to transition phase (TP) or hepatobiliary phase (HBP) for subcentimeter hepatocellular carcinoma (HCC) using gadoxetic acid-enhanced MRI.

Materials and methods: Two hundred patients (mean age, 53.4 ± 10.4 years) who were scanned with 1.5-T gadoxetic acid-enhanced MRI were included. Arterial phase hyperenhancement and signal intensity on PVP, TP and HBP images were evaluated. Three WO criteria were established: WO confined to the PVP, WO extended to the TP and WO extended to the HBP.

Assessment: Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy with 95% confidence interval were calculated for WO confined to the PVP and WO extended to the TP or HBP, and generalized estimating equation was used to compare sensitivity, specificity, PPV, NPV and accuracy.

Results: A total of 200 surgically confirmed subcentimeter hepatic nodules (171 HCCs and 29 non-HCCs) were included. For solitary subcentimeter HCCs, WO extended to the TP showed significantly higher sensitivity and accuracy than WO confined to the PVP (70.80% vs. 49.64%, P < 0.05; 71.52% vs. 55.70%, P < 0.001) and AFP (70.80% vs. 51.09%, P < 0.05; 71.52% vs. 55.70%, P < 0.05), but no significant difference in specificity (76.19% vs. 95.24%, P > 0.05; 76.19% vs. 85.71%, P > 0.05). Extending WO to the HBP achieved significantly higher sensitivity (78.10% vs. 49.64%, P < 0.001; 78.10% vs. 70.80%, P < 0.05) and accuracy (75.32% vs. 55.70%, P < 0.001; 75.32% vs. 71.52%, P < 0.05) compared to WO confined to the PVP and WO extended to the TP, but lower specificity (57.14%% vs. 95.24%, P < 0.05) compared to WO confined to the PVP. The combination of AFP with WO confined to the PVP, WO extended to the TP, or WO extended to the HBP yielded significantly higher sensitivities and accuracies compared to each MRI washout criterion alone (all P < 0.001).

Conclusion: WO extending to TP rather than HBP may be a preferred alternative for diagnosing subcentimeter HCC, and the supplement of AFP may improve sensitivity and accuracy.

Keywords: Gadoxetic acid; Hepatobiliary phase; Hepatocellular carcinoma; Magnetic resonance imaging; Subcentimeter; Transition phase.

Fig. 1

Flow chart of the patient’s selection. HCC, hepatocellular carcinoma; ICC, intrahepatic cholangiocarcinoma, cHCC-ICC, combined hepatocellular carcinoma-intrahepatic cholangiocarcinoma; MALT, mucosa-associated lymphoid tissue

Fig. 2

Subcentimeter hepatocellular carcinoma (HCC) with washout appearance in transitional and hepatobiliary phase in a 78-year-old man with chronic hepatitis B. Arterial phase (a) shows nonrim hyperenhancement (hyperintensity) of a 5 mm nodule (arrow) in hepatic segment VIII, and the nodule shows isointensity in portal venous phase (b), whereas it shows hypointensity in transitional (c) and hepatobiliary phase (d). Axial T2-weighted images (repetition time msec/echo time msec, 4087.9/106; e and f) show a 5 mm nodule in hepatic segment VIII (e) and a 40 mm lesion in hepatic segment V (f) with mild hyperintensity, and both lesions were surgically confirmed HCCs

Fig. 3

Subcentimeter hepatocellular carcinoma (HCC) with washout appearance in hepatobiliary phase in a 53-year-old woman with chronic hepatitis B. Precontrast T1-weighted image shows hypointensity of a 7 mm nodule in hepatic segment VII (arrow), and the nodule shows nonrim hyperenhancement in arterial phase (b) and slight hyperintensity in portal venous (c) and transitional phase (d), whereas it shows hypointensity in hepatobiliary phase (e). Axial T2-weighted images (repetition time msec/echo time msec, 4087.9/106; f) shows mild hyperintensity of the nodule

Fig. 4

A decision tree for the use of AFP as the primary gatekeeper before MRI. If AFP is elevated (≥ 20 ng/mL), washout in the transitional phase (TP) is the best trade-off between sensitivity and specificity with high positive predictive value (PPV) and accuracy. If AFP is normal (< 20 ng/mL), washout in the portal venous phase (PVP) or hepatobiliary phase (HBP) is recommended, depending on the diagnostic cut-offs used

Fig. 5

Mucosa-associated lymphoid tissue lymphoma with washout appearance in portal venous phase in a 40-year-old man with chronic hepatitis B. Precontrast T1-weighted image shows hypointensity of an 8.6 mm nodule in hepatic segment V (arrow), and the nodule shows nonrim hyperenhancement in arterial phase (b) and hypointensity in portal venous (c), transitional (d) and hepatobiliary phase (e). Axial T2-weighted image (repetition time msec/echo time msec, 4087.9/106; f) shows mild hyperintensity of the nodule