Prevalence of paranasal sinus opacifications on whole-body MRI in healthy children and adolescents: A population-based study

BackgroundWhole-body (WB) magnetic resonance imaging (MRI) is increasingly being used in children and often includes the paranasal sinuses.PurposeTo examine the prevalence of paranasal sinus opacifications by age and over time, as seen on WB-MRI.Material and MethodsProspective, population-based, bi-center study including healthy volunteers aged 6-18 years, undergoing WB-MRI (1.5 T) for research purposes only during 2018-2020, of whom 88 had a follow-up after a mean of 88 days. Paranasal sinuses and mastoid complexes were assessed separately for symmetry, presence of a nasal septal spur, bullous or inverted conchae, mucosal thickness, and presence/thickness of fluid levels. Opacification was graded on a scale of 0-3, as none/<2 mm, <33%, 33%-65%, and 66%-100% and according to the Lund-Mackay scoring system.ResultsA total of 171 volunteers (85 boys; mean age=11.9 ± 3.3 years) were included. On a 0-3 scale, 120/171 (70.2%) participants had opacification grade ≥1 in at least one paranasal sinus (67.8%) or mastoid air cell (6.4%). Corresponding findings for each sinus pair separately were 51.4% of the maxillary, 39.2% of the ethmoid, 23.4% of the sphenoid, and 4.7% of the frontal sinuses. Mean Lund-Mackay score for the initial scans was 2.85, with 47/171 (27.5%) scoring ≥4; 40.9% had a score of 0 or 1. In the majority, the grade of opacification remained stable over time.ConclusionThe prevalence of paranasal sinus opacifications in healthy 6-18-year-olds is high, with nearly one-third having a Lund-Mackay score ≥4, which, in a clinical setting, supports a diagnosis of rhinosinusitis.