Evaluation of benign parotid gland tumors with superb microvascular imaging and shear wave elastography

Aim of the study: This study aimed to examine the role of superb microvascular imaging and shear wave elastography for the pre-surgical evaluation of common parotid tumors. Material and methods: This single-center prospective study included 37 patients with parotid gland lesions. After institutional review board approval, grayscale, shear wave elastography and superb microvascular imaging ultrasound examinations were performed prior to biopsy or operation. The diagnosis of the lesions was based on cytological/pathological evaluation after the ultrasound examinations. Pleomorphic adenomas and Warthin tumors were compared using the Mann-Whitney U test. A receiver operating characteristic curve analysis was performed to obtain a cut-off value. A multivariate regression analysis was carried out. Results: The mean age of the patients (11 female, 26 male) was 48.2 ± 18. The shear wave elastography parameters of the lesions were not significantly different between pleomorphic adenomas and Warthin tumors, while the vascular index obtained by using superb microvascular imaging was significantly different (p = 0.012). The mean vascular index was 2.9 ± 3.1 in pleomorphic adenomas, and 9.5 ± 9.5 in Warthin tumors. A cut-off value of 4.05 for the vascular index discriminated pleomorphic adenoma and Warthin tumors with 68% sensitivity and 72% specificity (the area under the curve was 0.768). Conclusion: Superb microvascular imaging is a novel ultrasound imaging technique which is useful for the discrimination of pleomorphic adenomas and Warthin tumors.