Quantitative assessment of multi-phase contrast-enhanced CT features in hepatic epithelioid hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEH) is a rare vascular malignancy with imaging features often overlapping with hepatic metastatic tumors (HMTs), leading to frequent misdiagnosis. Current diagnostic reliance on qualitative imaging signs lacks specificity, while biopsy-the gold standard-is invasive and impractical for multifocal lesions. The study aimed to assess the diagnostic performance of multi-phase contrast-enhanced computed tomography (CECT) in differentiating HEH from HMT.

This retrospective comparative study included 33 patients (mean age: 42.06 years; male: 27.27%) with histologically confirmed HEH and 36 patients (mean age: 64.22 years; male: 66.67%) with HMT between January 2017 and July 2024. Only non-coalescent hepatic lesions at the time of the initial emergence were analyzed to avoid confounding imaging features. Quantitative parameters including contrast enhancement ratio (CER), lesion-to-liver contrast ratio (LLC), arterial phase related absolute and relative percentage washout (APW_arterial and RPW_arterial), portal phase related absolute and relative percentage washout (APW_portal and RPW_portal) derived from multiphase hepatic CECT were evaluated and compared between HEH and HMT. Receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic performance of these parameters.

The study found that APW_arterial, APW_portal and RPW_portal were significantly lower in HEH compared to HMT (P=0.01, P=0.001 and P=0.001, respectively). According to the ROC curve, APW_portal and RPW_portal showed moderate diagnostic significance with the area under the curve (AUC) values of 0.729 and 0.728, respectively. The cut-off values for APW_portal and RPW_portal were -17.08% and -6.90%, respectively.

Multiphase CECT-derived parameters, particularly APW_portal and RPW_portal, demonstrate potential value in differentiating HEH from HMT.