Radiographic imaging of mastoid in chronic otitis media: need or tradition?

Abstract

Background: Computed tomography is the imaging of choice in chronic otitis media (COM) but it is neither available at every centre nor is affordable to masses of economically weaker countries. In this situation where only X-ray facility is available should plain radiographs of mastoid be done ?. If yes then what is the analytical evidence? This study, was conducted to find the utility of plain radiographs of mastoid by comparing radiological findings vis-a-vis operative findings. Methods: Pre-operative radiographs of mastoids (Schuller’s view (s/v)) were taken and the radiological findings were statistically analysed with the operative findings. Results: Plain radiograph of mastoid (s/v) predicted some of the surgical landmarks of mastoid surgery viz tegmen and sinus plates with a fair degree of accuracy. The positive predictive value (PPV) for radiolucent shadow (assumed to indicate bone destruction and thus cholesteatoma) was also high but at the same time, a low negative predictive value and a Cohen’s kappa test showing only a fair agreement underscores the point that absence of a radiolucent shadow does not rule out the presence of cholesteatoma. Conclusions: Radiographs of mastoid are helpful in providing a prior knowledge of the surgical landmarks in mastoid surgery. Hence with this information, if a surgeon finds himself more at ease in operating a patient then this imaging should be done when CT scan facility is unavailable. However, citing the limited information on other aspects of the disease, its use as a ‘routine’ investigation in chronic otitis media is discouraged.