To explore the value of ¹⁸F-fluorodexyglucose (FDG) PET/CT combined with integrated contrast-enhanced CT on the diagnosis of hepatic epithelioid hemangioendothelioma(HEH).

Six patients (2 males, 4 females, age: (41.0±5.6) years) histopathologically confirmed to be HEH in Qingdao Central Hospital between November 2013 and November 2018 were retrospectively analyzed. All patients underwent ¹⁸F-FDG PET/CT dual-phase imaging and three-phase dynamic enhanced scanning with integrated CT. Characteristics of ¹⁸F-FDG PET/CT and contrast-enhanced CT images were classified and analyzed.

All 6 patients had multi-lesions (30 lesions in total). The capsule retraction sign was found in 16.7% (5/30) lesions, target sign was found in 33.3% (10/30) lesions, and " lollipop sign" was found in 13.3% (4/30) lesions. There were three ways of enhancement showed by CT: mild progressive enhancement, delayed enhancement, and black target sign/white target sign in the portal phase. Among the 30 lesions, 66.7% (20/30) had higher ¹⁸F-FDG uptake than liver parenchyma, with maximum standardized uptake value (SUV_max) of 4.18±0.64 during routine imaging and 4.23±0.70 during delayed imaging, and the retention index was 0.65(-1.88, 4.60). The rest 33.3% (10/30) showed similar ¹⁸F-FDG uptake to liver parenchyma, with SUV_max of 2.75±0.52 during routine imaging, and 2.78±0.55 during delayed imaging. The uptake of ¹⁸F-FDG increased with time in 22 lesions and decreased in 8 lesions. In the metabolically heterogeneous lesions, the relatively high-metabolization site was also the site with higher peak enhancement; in the lesions with uniform metabolism, the CT enhancement was also uniform. Bilateral pulmonary metastases were found in 2/6 patients.

¹⁸F-FDG PET/CT dual-phase imaging combined with CT three-phase dynamic enhanced scanning is helpful in accurate diagnosis of HEH and could show extrahepatic metastases.

Hemangioendothelioma, epithelioid; Liver; Positron-emission tomography; Tomography, X-ray computed; Deoxyglucose