Evaluation of topography and vascularization of cervical paragangliomas by magnetic resonance imaging and color duplex sonography

The management of cervical paragangliomas (PGs) depends on their specific type and their relation to adjacent vessels. The purpose of this study was to evaluate the potential of magnetic resonance imaging (MRI) and color duplex sonography (CDS) to classify PGs according to topography and vascularization. Sixteen patients harboring 22 PGs were studied retrospectively. With digital subtraction angiography as reference, the topographic relation of the tumors to the carotid arteries and the internal jugular vein and the patterns of vascularization were assessed. On MRI and CDS the typical feature of 15 carotid PGs was splaying of the carotid bifurcation, with the external carotid displaced anteriorly and the internal carotid artery and internal jugular vein located posteriorly. In five vagal PGs both modalities showed unidirectional anterior displacement of the external and internal carotid arteries. Two jugular PGs were found to extend within the lumen of the internal jugular vein. CDS completely depicted carotid body tumors but failed to delineate the high cervical portion of vagal and jugular PGs. MRI allowed us to assess the entire extent of all PGs. Nineteen lesions showed flow voids corresponding to abundant flow signal on CDS; three carotid body tumors appeared hypovascular on CDS and MRI. On CDS, intratumoral flow was directed cranially in carotid and inferiorly in vagal and jugular PGs. CDS and MRI are suitable for classification of cervical PGs as carotid, vagal or jugular PGs based on the topographic relation to the carotid arteries and internal jugular vein. Visualization of the intrinsic tumor vasculature proved an additional distinguishing criterion on CDS.