Paranasal sinus opacification‐to‐pneumatization ratio applied as a rapid and validated clinician assessment

BackgroundThe utility of clinician‐applied instruments, particularly the Lund‐Mackay score, in the assessment of paranasal sinus computed tomography (CT) in chronic rhinosinusitis (CRS) remains incompletely defined. The purpose of this study was to determine if a new approach to the evaluation of sinus CT could accurately predict the extent of opacification while remaining simple for clinician use.MethodsTwenty‐four sinus CT scans were measured for the percent of sinus opacification using three‐dimensional (3D) volumetric analyses. The same scans were also evaluated using the Lund‐Mackay score to measure opacification and the Assessment of Pneumatization of the Paranasal Sinuses (APPS) score to measure total sinus volume (TSV). Correlation analysis was performed for the Lund‐Mackay to APPS score ratio as a predictor of percent opacification. Validation analysis was also performed to determine the optimal orientation for Lund‐Mackay scoring, which has not previously been described.ResultsThe Lund‐Mackay to APPS score ratio was very strongly correlated with the percentage of sinus opacification measured by 3D volumetric analysis (r = 0.862, r2 = 0.743, p < 0.001). Lund‐Mackay scoring was not statistically different between axial‐only, coronal‐only, or triplanar groups for interrater (p = 0.379) and intrarater reliability (p = 0.312).ConclusionThe Lund‐Mackay score is validated for rater reliability in multiple orientations. Using the APPS score as a measure of TSV, the Lund‐Mackay‐to‐APPS ratio very strongly correlates with the percentage of sinus opacification by 3D volumetric analysis. Further study will be required to determine if this ratio is predictive of symptom severity.