Objective: To observe the effect of imaging techniques on the diagnostic pattern of sinusitis in primary care.
Design: A multicentre survey.
Setting: 14 health centres with varying facilities for clinical imaging.
Subjects: 446 adult patients with a suspicion of acute maxillary sinusitis. Ultrasound or radiography facilities existed in 337 cases while 109 could only be judged clinically. MAIN outcome measures--The use of ultrasound, radiography, laboratory tests, irrigation and control visits. The final number of patients with sinusitis in different facility groups.
Results: When available, ultrasound was used in 82-92% and radiography in 6-32% of cases. The ultrasound finding showed mucosal thickening or was difficult to interpret in every third case; one half of these were interpreted as sinusitis and the rest were considered healthy. In total, sinusitis was diagnosed in 84-88% when ultrasound or radiography only could be used, and in 77% when both techniques were available (p < 0.01). Simultaneously the general practitioners' confidence in the correctness of their diagnosis increased from 39% to 66%.
Conclusion: When possible, ultrasound is widely used in diagnosing sinusitis in Finnish primary care. The use of ultrasound slightly diminished the numbers of sinusitis diagnoses but the techniques of using and interpreting ultrasound findings need to be improved.