Learning Objectives: In this presentation the registrants will understand: 1) the indications for CT and MR in sinonasal disease; 2) the appearances and features of benign and malignant disease of the paranasal sinuses on MR and CT; 3) the MR and CT features of more common and some uncommon disorders of the skull base and sinonasal regions; 4) the postoperative appearance of sinonasal disease and strategies for following these cases and distinguishing them from recurrent disease.