SALIVARY GLAND SONOELASTOGRAPHY: TO DO OR NOT TO DO?

Abstract

Background Sonoelastography (SEG) is a non-invasive, relatively new imaging modality that maps the elastic properties through stiffness of soft tissue. Pathological conditions such as inflammation and neoplasia can change tissue elasticity; as a result, when used in the major salivary glands, this non-invasive modality may provide information that could be useful for diagnosis. Objective Two preliminary studies are presented; both assess the diagnostic utility of SEG: the first in primary Sjogren's syndrome (pSS) and the second concerns major salivary gland tumors. Methods and materials The first study included fifteen patients with pSS that underwent SEG of the major salivary glands before starting pilocarpine treatment versus diffused sialadenitis and normal glands. The second study included nineteen benign and malignant tumors, just before ultrasound-guided needle aspiration for cytology and excisional biopsy. Quantitative indices of the shear elastic modulus were compared with cytological and histopathological results. Elastography was scored on color-scaled elastograms. Results Mean elasticity/stiffness values for pSS were not significantly different from those of diffused sialadenitis and normal salivary gland tissue. As for salivary gland tumors, scores showed clustering according to pathological condition. For example, pleomorphic adenomas were firmer than Warthin's and adenoid cystic carcinoma was firmer than polymorphus adenocarcinoma. Conclusions SEG did not show a diagnostic advantage in regard to the assessment of pSS. Nevertheless, it might serve as a tool in the evaluation of benign and malignant major salivary glands tumors. Our studies should be continued to confirm these preliminary observations.