Incidental findings in MRI of the paranasal sinuses in adults: a population-based study (HUNT MRI)

Background Diagnostic imaging of the head is used with increasing frequency, and often includes the paranasal sinuses, where incidental opacifications are found. To determine the clinical relevance of such findings can be challenging, and for the patient such incidental findings can give rise to concern if they are over-reported. Studies of incidental findings in the paranasal sinuses have been conducted mostly in patients referred for diagnostic imaging, hence the prevalence in the general population is not known. The purpose of this study was to determine the prevalence and size of incidental opacification in the paranasal sinuses in a non-selected adult population using magnetic resonance imaging (MRI) without medical indication, and to relate the results to sex and season. Methods Randomly and independent of medical history, 982 participants (518 women) with a mean age of 58.5 years (range, 50–66) underwent MRI of the head as part of a large public health survey in Norway. The MRIs included 3D T1 weighted volume data and 2D axial T2 weighted image (WI). Opacifications, indicating mucosal thickenings, polyps, retention cysts, or fluid, were recorded if measuring more than 1 mm. Results Opacifications were found in 66% of the participants. Mucosal thickenings were found in 49%, commonly in the maxillary sinuses (29%) where 25% had opacifications that were less than 4 mm in size. Other opacifications occurred in the anterior ethmoid (23%), posterior ethmoid (21%), frontal sinus (9%), and sphenoid (8%). Polyps and retention cysts were also found mainly in the maxillary sinuses in 32%. Fluid was observed in 6% of the MRIs. Mucosal thickening was observed more frequently in men than in women (P <0.05). No seasonal variation was found. Conclusions In this large non-selected sample, incidental opacification in the paranasal sinuses was seen in two out of three participants, and mucosal thickening was seen in one out of two. Fluid was rare. Knowledge of incidental opacification is important because it can affect clinical practice

Paranasal sinus opacification in headache sufferers: A population-based imaging study (the HUNT study-MRI).

Background: The association between headache and paranasal sinus disease is still unclear. Because of symptom overlap, the two conditions are not easily studied on the basis of symptoms alone. The aim of the present study was to investigate whether paranasal sinus opacification on magnetic resonance imaging (MRI) was associated with migraine, tension-type headache (TTH) or unclassified headache. Methods: This was a cross-sectional study of 844 randomly selected participants (442 women, age range 50–65 years, mean age 57.7 years). Based on 14 headache questions, participants were allocated to four mutually exclusive groups: migraine, TTH, unclassified headache or headache free. On MRI, opacifications as mucosal thickening, polyps/retention cysts and fluid in the five paired sinuses were measured and recorded if ≥1 mm. For each participant, opacification thickness was summed for each sinus and, in addition, a total sum of all sinuses was calculated. Opacification in each sinus was compared between headache-free participants and the headache groups using non-parametric tests, and the total sum was compared by logistical regression. Results: No significant association was found between paranasal sinus opacification and headache in general, nor when headache was differentiated into migraine, TTH and unclassified headache. This was also true in separate analyses of mucosal thickening and fluid and of opacification from each paranasal sinus. Conclusion Migraine:, TTH and unclassified headache were found not to be associated with an increased degree of paranasal sinus opacification at MRI