MR Imaging of Parotid Tumors: Typical Lesion Characteristics in MR Imaging Improve Discrimination between Benign and Malignant Disease

Abstract

BACKGROUND AND PURPOSE:The surgical approach to parotid tumors is different for benign and malignant neoplasms, but the clinical symptoms do not correlate well with histology. Difficulties in tumor classification also arise in imaging modalities, in which sonography has the lowest and MR imaging, the highest accuracy. The purpose of this study was to review our experience using conventional MR imaging of the neck in the evaluation of parotid tumors and to evaluate which MR imaging findings are best able to predict malignant histology.

Comparative Study of Ct and Mri in Evaluation of Suprahyoid Neck Masses

“…On MR performed, subsequently well-defined lesions of intermediate signal intensity showing mild homogeneous enhancement and restriction on DW1-ADC mapping sequences were detected. Similar findings were described in the imaging of salivary gland tumours by A. Christe et al (13) CT and MR both demonstrated the relationship of mass to carotid artery and IJV in cases of vagal schwannoma and carotid body paraganglioma. Ultimately, the arterial velocity flow voids on T2W1 sequence helped confirm paragangliomas.…”

Metastases to the parotid nodes: CT and MR imaging findings

“…Previous radiologic literature has described a tendency for metastases to the parotid nodes to be multifocal. 12,13 In contrast, dermatologic and otolaryngologic studies have reported that metastases to the parotid nodes usually appear as solitary parotid masses. 10,14 Indeed, the In our study, metastases to the parotid nodes were most frequently noted in the parotid tail, followed by the pretragal area in the superficial lobe, which corresponds well to the distribution of the parotid lymph nodes.…”

An Unusual Presentation of Mucoepidermoid Carcinoma of the Parotid Gland

“…A helpful MR imaging feature of high grade tumors is low signal intensity on T2 weighted images which is believed to reflect the highcellularity of tumor cells [6,7]. Furthermore, the identification of perineural spread is also predictive of high grade tumors [7]. In contrast to low grade lesions which are reported to demonstrate higher signal intensity on T2 weighted images due to the presence of mucin secreting cells [6].…”

“…MR imaging should be considered preoperatively as it is more sensitive in evaluating tumor components and is particularly useful in evaluating for perineural invasion, an important prognostic indicator. A helpful MR imaging feature of high grade tumors is low signal intensity on T2 weighted images which is believed to reflect the highcellularity of tumor cells [6,7]. Furthermore, the identification of perineural spread is also predictive of high grade tumors [7].…”