Assessment of contrast-enhanced ultrasonography in diagnosis and preoperative localization of insulinoma.
OBJECTIVE
This study was to evaluate the value of contrast-enhanced ultrasonography (CEUS) in the diagnosis and preoperative localization of insulinoma and explore the enhancement patterns of the tumors.


METHODS
Unenhanced and contrast-enhanced ultrasonographic examinations of 31 patients who underwent resection of insulinomas were retrospectively reviewed. The diagnosis sensitivity and localization specificity of CEUS for insulinomas were determined. Results of unenhanced ultrasonography and CEUS were compared by Chi-square test.


RESULTS
Unenhanced ultrasonography could display 9 of 37 (24.3%) surgically verified insulinomas in 31 patients, while the diagnosis sensitivity and localization specificity of preoperative CEUS was 33 (89.2%) and 32 (86.5%) of the 37 tumors, respectively. In contrast to the unenhanced ultrasonography, the improvement of CEUS in the diagnosis and preoperative localization of insulinomas was significant (p<0.0001). The enhancement pattern of insulinoma on CEUS was fast wash-in and slow wash-out. All the tumors were homogeneous hypervascularity in the earlier arterial phase, while the tumors still displayed hyperenhancing pattern in the late phase.


CONCLUSIONS
Our study demonstrates the great potential of CEUS in the diagnosis and preoperative localization of insulinomas. Since CEUS is a convenient, inexpensive, effective and non-invasive modality, the study supports the use of CEUS as a primary tool in the evaluation of patients with insulinomas.
Department of Ultrasound, Chinese People's Liberation Army General Hospital, 28 Fuxing Road, Beijing 100853, PR China. alc301@126.com
Lichun
L
An
Wenxiu
W
Li
Ke-chun
KC
Yao
Rong
R
Liu
Faqin
F
Lv
Jie
J
Tang
Sunxin
S
Zhang
D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D007340:Insulinoma / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D010743:Phospholipids; D011300:Preoperative Care / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride