Comparative study of contrast enhanced ultrasound versus contrast enhanced MRI in hepatic epithelioid hemangioendothelioma

Abstract

Objective To analyze and compare the imaging characteristics of contrast-enhanced ultrasound (CEUS) and contrast enhanced magnetic resonance imaging (CEMRI) in diagnosing hepatic epithelioid hemangioendothelioma (HEHE) for improving radiological diagnostic accuracy. Methods The imaging characteristics of CEUS and dynamic CEMRI in 17 patients with histopathological diagnosis of HEHE on specimens obtained after surgical resection or fine needle biopsy were retrospectively analyzed and compared. Results On CEUS, 20 lesions in 13 patients demonstrated different enhancement patterns in the arterial phase: 13 lesions (65.0%) displayed gross enhancement and 7 lesions (35.0%) displayed a rim-like enhancement. Synchronous enhancement was observed in 17 lesions (85.0%) and rapid enhancement was observed in 3 lesions (15.0%). All these 20 lesions manifested as a hypoechoic mass in the portal venous and delayed phases. Other characteristics included speculated enhancement in the inner margin of the lesions and a vessel . On CEMRI, 45 lesions (71.4%) manifested slight enhancement in the arterial phase and continuous enhancement in the portal venous and delayed phases. The remaining 18 lesions (28.6%) manifested no enhancement in the arterial phase but progressive enhancement in the portal venous and delayed phases. 47 lesions (74.6%) displayed a rim-like enhancement and 16 lesions (25.4%) displayed gross enhancement. Other imaging characteristics included a halo , a lollipop sign, a capsular retraction or a vessel . Conclusions On CEUS, characteristic manifestations of HEHE were synchronous enhancement with a quick wash-out. At peak time, the enhancement degree was equal to the normal liver parenchyma. On CEMRI, the main radiological feature of HEHE was a rim-like enhancement. In the arterial phase, the enhancement degree was not high and there was either a continuous enhancement or a progressive enhancement in the portal venous and delayed phases. Furthermore, HEHE lesions always occurred under the liver capsule and showed a capsular retraction , a halo , a lollipop sign or a vessel . The combination of CEUS and CEMRI helped to improve the diagnostic rate and contributed to selection of clinical treatment. Key words: Hepatic epithelioid hemangioendothelioma; Contrast-enhanced ultrasound; Contrast-enhanced magnetic resonance imaging