Determination of the "incidental" Lund score for the staging of chronic rhinosinusitis

OBJECTIVE: Determine normative values for the Lund score for computed tomographic (CT) scans of the paranasal sinuses. METHODS: Patients undergoing CT of the paranasal sinus region for nonsinusitis causes were evaluated and staged according to the Lund-MacKay system. Complete and near complete Lund scores were computed from these scans and the frequencies of incidental paranasal abnormalities were tabulated. RESULTS: A total of 199 patients who underwent CT scans of the internal auditory canals, pituitary, or orbits demonstrated adequate visualization of the paranasal sinuses. In 91 patients, the imaging was sufficient to compute a complete Lund score with a mean of 4.26 (95% Cl, 3.43 to 5. 10). In 130 patients, all sinuses were adequately imaged except for the ostiomeatal complex. For this near complete group, the mean prorated Lund score was 4.26 (95% Cl, 3.55 to 4.97). Both of these scores differed significantly from an expected score of zero (P < 0.00 1). CONCLUSIONS: The Lund score in the general population is not 0. A Lund score ranging from 0 to 5 may be considered within an incidentally "normal" range, and should be factored into clinical decision-making.