ABSTRACT

Conclusion:

Multi-phase helical CT showed a pattern of strong enhancement in early phase scanning with a decrease in the delayed phase for the Warthin tumor. Although all non-Warthin parotid tumors showed a slower enhancement pattern, an increase in enhancement in delayed phase images might be sugges-tive of a pleomorphic adenoma. These enhancement patterns can be helpful in the differential diagnosis of parotid gland tumors.

Results:

There were twelve pleomorphic adenomas, five malignant tumors, and two Warthin tumors. At visual assessment five pleomorphic adenomas, one Warthin tumor and two malignant tumors showed homogeneous enhancement in the early phase. Heterogeneous enhancement with intratumoral low attenu-ation was seen in two pleomorphic adenomas, one Warthin tumor, and three malignant tumors. In early phase scans tumoral mean CT numbers were highest for the Warthin tumor. Pleomorphic adenomas and malignant tumors showed a slower contrast enhancement pattern. In delayed phase scans mean CT numbers were highest for pleomorphic adenomas. The resultant ER was highest for the Warthin tumor

Materials and Methods:

A total of 19 patients were enrolled in this study. Multi-phase axial CT images were obtained before and 30, 90, 180, and 360 s after the contrast material injection. A late enhanced axial image was also ob-tained 25 min after the contrast material injection. The images were evaluated by two radiologists for lesion enhancement degree and pattern. For quantitative assessment density numbers measured in the early (30 s delay) and delayed (25 min delay) phases were compared. The tumoral enhancement ratio (ER) was also calculated by using the function ER=Subscript/CTlate. The histopatholo-gic diagnosis was confirmed at surgical resection in all patients

Purpose:

To perform multi-phase dynamic helical computed tomography (CT) in patients with parotid gland tumors and to describe their enhancement cha-racteristics