Comparison of MRI and triphasic dynamic contrast enhanced multislice spiral CT in the differentiation of benign-malignant for parotid masses

Abstract

Objectives: To compare accuracy of magnetic resonance imaging (MRI) and triphasic dynamic contrast enhanced multislice spiral CT (MSCT) in the differentiation of benign-malignant for parotid masses.Methods: Thirty-nine patients (mean age 55 years) with parotid masses were evaluated, prospectively. T1, T2 and fatsuppressed T2-weighted images and fat-suppressed T1- weighted postcontrast images were obtained for neck MRG. After post-contrast whole neck examination at 30 seconds, images only at the level of the parotid mass were obtained at 90 seconds and at 5 minutes in the neck CT examination in an MSCT unit. Magnetic resonance imaging and triphasic MSCT diagnosis was compared with histopathology.Results: The masses comprised 32 benign and 7 malignant. The accuracy, sensitivity, specifity, positive and negative predictive values of MRI were 86%, 71%, 89%, 83% and 93%; and of triphasic MSCT were 82%, 71%, 85%, 83% and 96%, respectively. Youden’s index was 0.60 for MRI and 0.56 for triphasic MSCT.Conclusion: Both non-contrast MRI and triphasic dynamic contrast enhanced MSCT may be valuable modalitity in the differentiation of benign-malignant for parotid masses. In the method selection, some factors as patient comfort and cooperation, ionizan radiation, the presence of ferromagnetic device, cost-effectivity and accesible of modality should be considered.

Keywords

• parotid tumor
• magnetic resonance imaging
• computed tomography