A Hospital based study of High Resolution Computed Tomography and Conventional Radiography for Evaluation of Pathologies of Temporal Bone

Background:Many imaging modalities have been in use for the evaluationof temporal bone lesions. Plain X-rays are cost-effectivehowever; they provide limited details and hence sometimesmay result in an inaccurate diagnosis. With the advent of HRCT,the method of imaging of temporal bone has evolved withspecial algorithms and multiplanar formats. In the presentstudy, we tried to evaluate the different pathologies of thetemporal bone with X-ray and HRCT.Methods: The study was conducted in the Departments ofOtorhinolaryngology and Radiology, Prathima Institute ofMedical Sciences, Naganoor, Karimnagar. A total of n=40patients were identified and selected based on their symptomsand clinical findings suggestive of a lesion involving thetemporal bone such as Otalgia, Otorrhoea, AndSensorineuronal deafness, pulsatile tinnitus, vertigo, andgiddiness. These patients were subjected to high resolutioncomputed tomography of the temporal bone on the 128 SliceCT Scanner (PHILIPS INGENUITY). The patients also underwentplain Radiography of temporal bone (CARESTREAM DRX-1System).Results: Of the total n=40 patients studied the most commontemporal bone disease was due to inflammation 85% andtumors were found in 15% of the patients. The common siteof involvement of middle ear and mastoid air cells in chronicotitis media was epitympanum in n=30(90%) of cases,Mesotympanum in n=20(60%) of cases. In diseased ears,radiographs of the mastoids revealed pneumatised mastoid in6(15%), diploic in 6(15%), and sclerosed mastoid in 28(70%)cases. HRCT temporal bone revealed pneumatised mastoid in9(22.5%), diploic in 5(12.5%) and sclerosed mastoid in 26(65%)cases.Conclusion: The role of plain radiography is found to be limitedto know the type of mastoid pneumatisation. It can also asOriginal Articledetect bony erosion in few cases. Because of the ability to seetemporal bone structures with great clarity, HRCT can berecommended not only in cases suspected with potentialcomplications but also in all cases of temporal bone pathologiesto know the extent of disease, inter-relationships of thetympanomastoid compartment with adjacent neurovascularstructures, varied pneumatisation and the presence ofanatomical variations, which should alert the clinician andguide in surgical approach and treatment plan.