Prospective evaluation of Quasistatic Ultrasound Elastography (USE) compared with Baseline US for parotid gland lesions: preliminary results of elasticity contrast index (ECI) evaluation.

Abstract

To assess the diagnostic value of elasticity contrast index (ECI) elastography, in comparison with conventionalultrasound for the differentiation of benign and malignant parotid lesions. Sixty-three consecutivepatients with parotid gland tumors, treated surgically at a single tertiary center were enrolled. Ultrasound evaluation consistedof B-mode, color-Doppler and quasistatic ultrasound elastography (USE), conducted with the ECI technique. For each lesionthe echogenicity, margins, vascularization, and capsulation were considered to determine benign or malignant lesions. Histologywas considered the gold standard. Using conventional parameters, the observer suggested malignant lesions in20 cases and benign lesions in 43 cases (accuracy: 61.8%). ECI>3.5 alone was the most accurate parameter (accuracy: 90.5%),with sensitivity of 93.7% and specificity of 89.4%. However, when combined with the other US criteria, no statistically significantdiagnostic accuracy improvement was achieved. Our results show that USE with ECI index measurementcan help to discriminate preoperatively benign from malignant lesions, with the exception of pleomorphic adenoma which isstiff. We suggest that USE can be used as an additional tool to conventional US evaluation of salivary gland lesions.