Relative value of MR imaging as compared with CT in the diagnosis of inflammatory paranasal sinus disease

PURPOSE: To evaluate the relative value of magnetic resonance (MR) imaging versus computed tomography (CT) in the diagnosis of inflammatory paranasal sinus disease. MATERIALS AND METHODS: In 30 patients suspected of having or known to have inflammation of the paranasal sinuses, both coronal CT and coronal CT and c oronal T1-weighted, three-dimensional, gradient-echo MR imaging of the para nasal sinuses were performed. Visualization of anatomic details, kind and e xtent of inflammatory disease, and artifacts from dental work were scored. The scores were compared by using the Wilcoxon matched pairs signed rank te st. Interexamination agreement between the two methods was calculated by us ing a kappa analysis. RESULTS: Most bone structures of the infundibular complex were significantl y better visualized at CT than at MR imaging. Orbital and brain anatomy wer e visualized better at MR imaging than at CT. No artifacts from dental work occurred in diagnostically relevant regions at MR imaging. There was a sub stantial to almost perfect agreement between CT and MR imaging for every ki nd and extent of the disease expect for mucosal thickening in the maxillary and frontal sinuses, in the nasal cavity, and in the infundibulum. CONCLUSION: CT is superior to MR imaging in the depiction of fine bony deta ils and anatomic variants and thus is superior to MR imaging in helping pla n functional endoscopic sinus surgery. However, there are patient groups in which MR imaging can be used as a primary tool in screening for sinusitis.