Abstract: Objective To evaluate the value of the time-intensity curve(TIC) of contrast-enhanced ultrasound(CEUS) in differentiation of malignant from benign lymph nodes of the head and neck. Methods Eighty-five patients with enlarged cervical lymph nodes(85 lesions) were examined with CEUS. Of 85 nodes, 36 benign and 49 malignant lesions were proved histopathologically. Region of interest(ROI) was placed in whole lymph nodes, the most evident enhanced area of the cortex, the weakest enhanced area of the cortex, medulla-hilar area, and soft tissue next to the node, respectively. Eight TIC parameters(basic intensity, peak intensity, wash in slope, arrival time, time to peak, rise time, time from peak to one half, and mean transit time) were compared between malignant and benign nodes. Finally the malignant lymph nodes were evaluated by the ROC curve drawn with the rise time, and meanwhile the cut off value was obtained. Results The rise time of ROI that was placed on the most evidently enhanced area of the cortex of cervical lymph nodes was significantly shorter in malignant than benign lesions(P=0.041). Conclusion The rise time value obtained from most evidently enhanced areas of the lymph node cortex could help differentiate malignant from benign nodes of the head and neck.

Key words: lymph nodes, head and neck, ultrasonic diagnosis, contrast-enhanced ultrasound, time-intensity curve