The value of the occipitomental (Waters') view in diagnosis of sinusitis: A comparative study with computed tomography

AIM: Sinus X-rays are still frequently used in the evaluation of paranasal sinusitis, Many radiology departments nowadays provide the referring doctors with a single Waters' projection. Our purpose was to evaluate the diagnostic accuracy of a single Waters' view vs high resolution computed tomography (CT) in the diagnosis of paranasal sinusitis. SUBJECTS AND METHODS: A total of 134 patients with suspected paranasal sinusitis underwent a Waters' view X-ray and high resolution CT on the same day, The radiographs were evaluated independently by nine experienced radiologists, who observed each sinus separately. Sensitivity; specificity, accuracy, positive and negative predictive values were calculated for each sinus and for each observer, using the CT findings as a 'gold standard', RESULTS: The weighted mean sensitivity for diagnosis of any abnormality in the maxillary sinus was 67.7%, specificity 87.6%, accuracy 78.6%, positive predictive value 82.5% and negative predictive value 76.9%. For this sinus the variation between observers was small, however, the sensitivity for diagnosis of any disease in the frontal and ethmoid sinuses varied widely between observers (range 1.9-54.0% and 0-58.9%, respectively), The sensitivity for the sphenoid sinus was very low (range 0-3.8%), even in radiographs which seemed to demonstrate it well. CONCLUSION: The Waters' view has its limits in the diagnosis of sinusitis of the maxillary sinuses and its contribution for diagnosing lesions in the remaining sinuses is very poor. Whenever access to CT is available, a low dose high-resolution CT study of the paranasal sinuses is highly recommended. (C) 2000 The Royal College of Radiologists.