MRI in preoperative evaluation of chronic paranasal sinusitis - a comparison with CT

MRI in preoperative evaluation of chronic paranasal sinusitis - a compariso n with CT. Purpose: To determine the value of MRI in the preoperative evalu ation of chronic paranasal sinusitis and to compare the results with CT and intraoperative findings. Method/Materials: 42 patients with clinical signs of chronic parnasal sinusitis underwent MRI after CT evaluation on one day , with subsequent functional endoscopic sinus surgery on the next day. Coro nary CT was obtained with 5-mm slices and table-feed in the prone position, while MRI was performed in the supine position with coronary T-2-TSE+ pd a nd coronary and transverse HASTE, each with 5-mm slice thickness. Aquisitio n time in MRI was less than 8 minutes. Two radiologists reviewed the CT and MRI scans for signs of sinusitis and detection of anatomical landmarks. Th e results were correlated with the intraoperative findings. Results: MRI of fered no artifacts of dental work and showed more often high quality pictur es than CT. CT and MRI demonstrated a good correlation in the detection of mucosal pathologies (kappa =0.46-0.87) and anatomic variants (kappa =0.55-0 .86). All important anatomical structures could be evaluated sufficiently w ith MRI for preoperative management. Both diagnostic tools showed an unsati sfactory correlation with intraoperative findings in the ethmoidal complex and maxillary sinus (tau=-0.08-0.3). Conclusions: MRI is a fast and reliabl e alternative to preoperative CT in examining paranasal sinuses and offers a good visualization of mucosal changes. CT and MRI both give an unreliable representation of the ethmoidal complex.