Magnetic resonance imaging of paranasal sinus tumors for craniofacial resection

Computerized tomography (CT) has been shown to be 78% accurate with respect to anatomic extent of tumor when correlated with operative findings and histology in patients undergoing craniofacial resection. To determine whether preoperative evaluation could be improved by the combination of CT and magnetic resonance imaging (MRI), 26 patients with tumor of the paranasal sinuses had undergone MRI before surgery in addition to CT. Ten patients also received Gadolinium-DTPA as a contrast-enhancement agent during MRI. The radical approach offered by craniofacial resection allows accurate evaluation of imaging techniques and when these are compared with histologic findings, a 94% correlation is found. The use of Gadolinium further improves the accuracy of tumor delineation to 98%. Despite the intrinsic disadvantage of absent bone detail, MRI demonstrates the extent of tumor better than CT and can distinguish it from inflammed mucosa, retained secretions, and normal mucosa provided the correct sequences are used.