Perfusion characteristics of parotid gland tumors evaluated by contrast-enhanced ultrasound.

Purpose: Contrast enhanced ultrasound (CE-US) is a promising imaging modality for non-invasive analysis of parotid gland lesions because their vascularisation differs from normal gland tissue. This clinical study should further investigate CE-US as a diagnostic tool for parotid gland tumors.

Materials And Methods: 39 patients underwent CE-US measurements after intravenous application of a contrast agent (SonoVue, Bracco, Italy) before surgical tumor resection. Time-intensity curves gradients were calculated and parameters of intratumoral microcirculation were analysed. The vascularisation parameters were compared among the different tumor entities as defined per definitive histological diagnosis.

Results: Histological analyses revealed 17 pleomorphic adenoma, 15 cystadenolymphoma and 7 malignoma. A significant difference of area below intensity time curve (AUC) and mean transit time (MTT) was measured in the malignant lesions compared to benign tumors (p<0.05). A significant difference of AUC and maximum of signal increase (ΔSImax) for pleomorphic adenoma versus cystadenolymphoma was found (p<0.05).

Conclusion: CE-US seems to be a quantitative and independent method for the assessment of malign and benign parotid gland tumors. Further studies and clinical experience will have to validate this method as a reliable diagnostic tool that facilitates preoperative planning.