Ultrasound contrast media in the study of salivary gland tumors.

BACKGROUND The aims of the present study were: to assess standard ultrasound and color-Doppler patterns for the study and characterization of salivary gland tumors; to define the improvement in the color-Doppler ultrasound image after injection of a signal amplifier (Levovist); to compare morphological and vascular aspects of the neoplasm with data obtained during postoperative histopathological analysis. MATERIALS AND METHODS We used color-Doppler ultrasound before and after injection of the contrast medium to study 56 patients (32 males and 24 females) between the ages of 28 and 77 years old, presenting nodular pathology of the salivary glands. Only patients with less than optimal results of the basic color-Doppler examination (grade of vascularization 0-1) were included in the study. The data were then compared with the final histological results. RESULTS According to B-mode ultrasonography, all neoplasms were hypoechogenous; 8 showed irregular margins and, of these, 6 were carcinomas. We did not obtain significant data regarding size and echostructure. In 10 cases, we observed the presence of multiple locoregional formations in the lymph nodes. Patients were selected on the basis of unsatisfactory color-Doppler examination results; following injection of the contrast medium, we were able to visualize an increased number of vascular signals in 40 out of 56 patients, compared to the basic examination. This enabled us to better assess the vascular map of the neoplasms, as well as more easily trace the vascular blood flow and perform a better extrapolation of the quantitative and semi-quantitative data. This study demonstrated the importance of the vascular pattern, which is predictive of a malignant lesion when it is high-grade with multiple vascular poles and irregular vascular distribution. Furthermore, certain semi-quantitative parameters proved to be important, particularly the velocity of the systolic peak (SP), the cut-off of which was approximately 25 cm/s. The resistance index (RI) and pulsality index (PI) did not prove significant and showed overlapping values. CONCLUSION We observed that the contrast medium was useful in characterizing lesions, of the salivary glands by allowing for a more precise vascular map of the lesions, as well as greater diagnostic accuracy in tracing the vascular blood flow and calculating quantitative and semiquantitative data.