The timing phase affected the inconsistency of APHE subtypes of liver observations in patients at risk for HCC on the multi-hepatic arterial phase imaging

OBJECTIVE

To investigate whether liver observations in patients at risk for hepatocellular carcinoma (HCC) display inconsistent arterial phase hyperenhancement (APHE) subtypes on the multi-hepatic arterial phase imaging (mHAP) and to further investigate factors affecting inconsistent APHE subtype of observations on mHAP imaging.

METHODS

From April 2018 to June 2021, a total of 141 patients at high risk of HCC with 238 liver observations who underwent mHAP MRI acquisitions were consecutively included in this retrospective study. Two experienced radiologists reviewed individual arterial phase imaging independently and assessed the enhancement pattern of each liver observation according to LI-RADS. Another two experienced radiologists identified and recorded the genuine timing phase of each phase independently. When a disagreement appeared between the two radiologists, another expert participated in the discussion to get a final decision. A separate descriptive analysis was used for all observations scored APHE by the radiologists. The Kappa coefficient was used to determine the agreement between the two radiologists. Univariate analysis was performed to investigate the factors affecting inconsistent APHE subtype of liver observations on mHAP imaging.

RESULTS

The interobserver agreement was substantial to almost perfect agreement on the assessment of timing phase (κ = 0.712-0.887) and evaluation of APHE subtype (κ = 0.795-0.901). A total of 87.8% (209/238) of the observations showed consistent nonrim APHE and 10.2% (24/238) of the observations showed consistent rim APHE on mHAP imaging. A total of 2.1% (5/238) of the liver observations were considered inconsistent APHE subtypes, and all progressed nonrim to rim on mHAP imaging. 87.9% (124/141) of the mHAP acquisitions were all arterial phases and 12.1% (17/141) of the mHAP acquisitions obtained both the arterial phase and portal venous phase. Univariate analysis was performed and found that the timing phase of mHAP imaging affected the consistency of APHE subtype of liver observations. When considering the timing phase and excluding the portal venous phase acquired by mHAP imaging, none of the liver observations showed inconsistent APHE subtypes on mHAP imaging.

CONCLUSION

The timing phase which mHAP acquisition contained portal venous phase affected the inconsistency of APHE subtype of liver observations on mHAP imaging. When evaluating the APHE subtype of liver observations, it's necessary to assess the timing of each phase acquired by the mHAP technique at first.

Preoperative prediction of pathologic grade of HCC on gadobenate dimeglumine-enhanced dynamic MRI

PURPOSE

To evaluate the value of gadobenate dimeglumine-enhanced MRI in predicting the pathologic grade of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Patients with pathologically proven HCC who underwent preoperative gadobenate dimeglumine-enhanced dynamic MRI were included. Two radiologists blinded to pathology results evaluated images in consensus. Lesions were evaluated quantitatively in terms of ratio of enhancement (RE), and qualitatively based on image features related to tumor aggressiveness. Logistic regression and ROC analyses were used to determine the value of these parameters to predict pathologic grade.

RESULTS

In total, 221 patients (194 males, 27 females, aged 52.9 ± 11.7 years) with 49 poorly differentiated HCCs and 172 well/moderately differentiated HCCs were evaluated. Features significantly related to poorer pathologic grade at univariate analysis included lower RE in the early arterial phase (EAP) (p = 0.001), nonsmooth margins (p = 0.001), absence of capsule (p < 0.001), arterial peritumoral hyperenhancement (p < 0.001), higher AFP (p = 0.004), multiple tumors (p = 0.026), and larger tumor size (p = 0.028). At multivariate analysis, lower RE (EAP) (OR = 0.144, p = 0.002), absence of capsule (OR = 0.281, p = 0.004), and arterial peritumoral hyperenhancement (OR = 4.117, p < 0.001) were independent predictive factors for poorer pathologic grade. ROC analysis showed lower RE (EAP) was predictive of poorer pathologic grade (AUC = 0.667). AUC increased to 0.797 when combined with absence of capsule and presence of peritumoral hyperenhancement.

CONCLUSIONS

Lower RE (EAP), absence of capsule, and arterial peritumoral hyperenhancement were predictive biomarkers for poorer pathologic grade of HCC on gadobenate dimeglumine-enhanced dynamic MRI.

KEY POINTS

• Gadobenate dimeglumine-enhanced dynamic MRI was a useful quantitative biomarker for preoperative prediction of pathologic grade in patients with HCC. • Lower RE in the early arterial phase, absence of capsule, and arterial peritumoral hyperenhancement were potential imaging indicators for preoperative prediction of poorer pathologic grade of HCC on gadobenate dimeglumine-enhanced MRI. • A lower RE in the early arterial phase was effective at predicting poorer pathologic grade of HCCs but prediction is improved when combined with absence of capsule and presence of peritumoral hyperenhancement.