Brief Article
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World J Gastroenterol. Apr 7, 2013; 19(13): 2087-2091
Published online Apr 7, 2013. doi: 10.3748/wjg.v19.i13.2087
Contrast-enhanced ultrasonographic findings of hepatic paragonimiasis
Qiang Lu, Wen-Wu Ling, Lin Ma, Zi-Xing Huang, Chang-Li Lu, Yan Luo
Qiang Lu, Department of Ultrasound, Chinese Evidence-Based Medicine Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China
Wen-Wu Ling, Lin Ma, Yan Luo, Department of Ultrasound, West China Hospital of Sichuan University, Sichuan University, Chengdu 610041, Sichuan Province, China
Zi-Xing Huang, Department of Radiology, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China
Chang-Li Lu, Department of Pathology, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China
Author contributions: Lu Q, Ling WW, Ma L, Huang ZX, Lu CL and Luo Y designed and revised the manuscript; Lu Q wrote the manuscript.
Supported by Science and Technology Department of Sichuan Province, China, No. 2011FZ0016; National Natural Science Foundation of China, No. 81101060, No. 30870715 and No. 81071163
Correspondence to: Dr. Yan Luo, Department of Ultrasound, West China Hospital of Sichuan University, Sichuan University, No. 37, Guoxuexiang, Chengdu 610041, Sichuan Province, China. luoyand@126.com
Telephone: +86-28-85423192 Fax: +86-28-85422192
Received: December 18, 2012
Revised: January 28, 2013
Accepted: February 5, 2013
Published online: April 7, 2013
Abstract

AIM: To investigate the features of hepatic paragonimiasis on contrast-enhanced ultrasound (CEUS) imaging.

METHODS: Fifteen patients with hepatic paragonimiasis who were admitted to our hospital between March 2008 and August 2012 were enrolled to this study. The conventional ultrasound and CEUS examinations were performed with a Philips IU22 scanner with a 1-5-MHz convex transducer. After conventional ultrasound scanning was completed, the CEUS study was performed. Pulse inversion harmonic imaging was used for CEUS. A bolus injection of 2.4 mL of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue) was administered. CEUS features were retrospectively reviewed and correlated with pathological findings.

RESULTS: In total, 16 lesions were detected on CEUS. The mean size of the lesions was 4.4 ± 1.6 cm (range, 1.7-6.6 cm). Subcapsular location was found in 12 lesions (75%). All the lesions were hypoechoic. Six lesions (37.5%) were of mixed content, seven (43.8%) were solid with small cystic areas, and the other three (18.8%) were completely solid. Ten lesions (62.5%) were rim enhanced with irregular tract-like nonenhanced internal areas. Transient wedge-shaped hyperenhancement of the surrounding liver parenchyma was seen in seven lesions (43.8%). Areas with hyper- or iso-enhancement in the arterial phase showed contrast wash-out and appeared hypoenhanced in the late phase. The main pathological findings included: (1) coagulative or liquefactive necrosis within the lesion, infiltration of a large number of eosinophils with the formation of chronic eosinophilic abscesses and sporadic distribution of Charcot-Leyden crystals; and (2) hyperplasia of granulomatous and fibrous tissue around the lesion.

CONCLUSION: Subcapsular location, hypoechogenicity, rim enhancement and tract-like nonenhanced areas could be seen as the main CEUS features of hepatic paragonimiasis.

Keywords: Paragonimiasis, Liver, Infection, Contrast-enhanced ultrasonography

Core tip: We retrospectively investigated the contrast-enhanced sonographic features of hepatic paragonimiasis. Hepatic paragonimiasis has its own features on contrast-enhanced ultrasound. Knowledge of these findings is helpful in differentiating hypoechoic lesions in the liver. When a subcapsular hypoechoic lesion with irregular tract-like non-enhancing necrosis is presented in non-cirrhotic liver, the diagnosis of hepatic paragonimiasis should be suspected.