Validity of B-Mode Ultrasonography in Diagnosis of Paranasal Sinusitis

Background: Accurate diagnosis of sinusitis is difficult on the basis of clinical examination only because the signs and symptoms of sinusitis are non specific. A simple, rapid, and readily available method for diagnosing sinusitis in primary care would increase the accuracy of the diagnosis and thus reduce unnecessary antibiotic treatment. Aim of Work: The aim of this study was to determine the validity of B- mode sonography in the diagnosis of sinusitis, compared with plain radiography with the use of sinus CT as a gold standard. Patients and Methods: Twenty patients with paranasal sinusitis were enrolled in this prospective study. Plain-film radiography of the sinuses (Standard Water s -occipitomental-view) was done for each patient and also a real time B-mode ultrasound to evaluate the maxillary, frontal, and ethmoidal sinuses. The maxillary and frontal sinuses were examined with traditional sonographic techniques. The ethmoid sinus scanned with transglobe technique. All Patients were referred for CT evaluation.The standard CT technique was used which includes thin section (3 to 5 mm thickness) axial and direct coronal scans. Results: The diagnosis of sinusitis was made if an airfluid level, total opacity or mucosal thickening was detected. Plain X-ray, was more sensitive (98.13%) for detection of the mucosal thickening in the sinuses than ultrasound (62.96%), while the specificity was higher by ultrasound (87.12%), than by plain X-ray (33.33%) . On testing the sensitivity and specificity to detect the sinus polyp it was found, that both methods were equally sensitive and specific (sensitivity was 66.66% by both methods while specificity was 96.07% by plain X-ray and 97.22% by ultrasound). To detect fluid level in the sinuses it was found that plain X-ray was more sensitive (50% vs 33.33%) and specific (92.13% vs 81.%) than ultrasound. So in general, it was found that plain X-ray was more sensitive than ultrasound (71.9% vs 54.31%) while ultrasound was more specific (88.6% vs 73.84%) method in detection of sinusitis. Conclusion: This study shows that B-mode ultrasonography compared by computed tomography, is a useful method in the diagnosis of paranasal sinusitis, with higher specificity (88.60%) and lower sensitivity (54.31%) than plain radiography and its over all accuracy is (77.22%).