Objeative:

To analyze the contrast-enhanced ultrasonography (CEUS) characteristic

s of hepatic neuroendocrine neoplasm (hNEN) and to investigate its clinical values of CEUS in predicting pathological grading of hNEN.

Methods:

From Sep. 2009 to Sep. 2017

images of CEUS were analyzed retrospectively in 34 cases of hNEN confirmed by pathology and imaging in Zhongshan Hospital

Fudan University. The CEUS characteristics including enhancement time

enhancement pattern

manifestations of peak time

washout degree of enhancement and wash in-wash out model of lesions were observed by two ultrasound doctors who had at least five-year working experience. These 34 cases were divided into 3 grades（G1

G2 and G3）according to World Health Organization 2010 classification of gastroenteropancreatic NEN. The differences in CEUS characteristics among deifferent grades were compared.

Results:

The average time to start

time to peak and time to decline were (16.24.7)

(22.05.5) and (42.923.4) s respectively. Two patterns of enhancement were observed during the enhancement progression: global enhancement and centripetal enhancement. Of the 34 hNEN cases

79.4% (27/34) of lesions showed global enhancement and 20.6% (7/34) of lesions showed centripetal enhancement. As for the manifestations of peak time

61.8% (21/34) of lesions showed homogenously enhanced pattern

while 26.5% (9/34) of lesions showed inhomogenously enhanced pattern and 11.8% (4/34) of lesions showed rim-like enhanced pattern. The enhancement of all lesions washed out at portal venous phase with different degree. Of the 34 hNEN cases

32.3% (11/34) of leisons showed mild washout and 67.7% (23/34) of lesions showed remarkable washout. All lesions showed remarkable washout at delay phase. Compared with liver parenchyma

52.9% (18/34) of hNEN lesions showed fast in and fast out

38.3% (13/34) of hNEN lesions showed synchronous in and fast out and 8.8% (3/34) of hNEN lesions showed slow in and fast out. A greater percentage of fast in and fast out was found in G2 lesions (76.2%

16/21) than in G3 lesions (15.4%

2/13)

with statistical significance (

P

＜0.05）.

Conclusion:

CEUS can provide useful information in diagnosing hNEN. The wash in-wash out model of CEUS may preoperatively predict the pathological grading of hNEN.