Objective:

To explore the correlations between contrast-enhanced ultrasound (CEUS) features of pancreatic neuroendocrine neoplasm (pNEN) and their pathological grades.

Methods:

In this retrospective study

49 cases of operation o

r biopsy and histopathological proven pNEN lesions were included. Ultrasound and CEUS examinations were performed preoperatively. Using histopathological results as final gold standard

imaging features of ultrasound and CEUS were analyzed and compared among neuroendocrine tumor (NET) G1

NET G2

NET G3 or neuroendocrine carcinoma (NEC) groups.

Results:

Final histopathological results included 15 cases of NET G1

23 cases of NET G2 and 11 cases of NET G3/NEC. During the arterial phase of CEUS

most NET G1 were homogeneously enhanced (11/15

73.3%)

while most NET G3/NEC lesions were heterogeneously enhanced (8/11

72.7%;

P

＜0.05). As for the enhancement degree

the majority of NET G1

NET G2

NET G3/NEC lesions were hyper or iso-enhanced during the arterial phase. During the venous phase

most NET G1 lesions showed hyper or iso-enhancement (14/15

93.3%)

meanwhile 44.1% of the NET G2 and NET G3/NEC lesions showed hypo-enhancement. Most NET G1 lesions were hyper- enhanced or iso-enhanced during the late phase (13/15

86.7%)

meanwhile 67.6% (23/34) of the NET G2 and NET G3/NEC lesions were hypo-enhanced.

Conclusion:

CEUS enhancement features of pNEN related to their pathological grades. Homogeneous hyper- or iso-enhancement during the late phase of CEUS might indicate the possible diagnosis of NET G1.