Detection of temporal bone pathologies by high resolution computed tomography

Background: HRCT with its excellent imaging quality and the ability to eliminate bone and soft tissue, is the best method for evaluating the mastoid air cell system. It helps in accurate assessment of pathology prior to surgical exploration regarding location, extent and complication of the disease. HRCT is now established as the most useful and versatile procedure for showing bony detail in the petrous pyramid, soft tissue abnormalities in the middle ear and the extension of the disease into the cranial cavity. Objective: The objective of the study is primarily to understand the capability of HRCT in diagnosis and detection of pathologies of the temporal bone. Methods: The study was conducted in 60 patients with symptoms of mastoiditis, in the department of Radio-Diagnosis and Imaging in co-ordination with the department of Otolaryngology GMC Jammu. Contiguous 0.5-1mm thick slices were obtained using an ultra high algorithm in the axial axis. Coronal images were obtained perpendicular to the axial plane from the cochlea to the posterior semicircular canal. Intravenous contrast were administered wherever necessary to study for intracranial or extracranial extension of middle ear disease. Results: In our study population, age of patients ranged from 7 years to 64 years. There were 40 males ( 66.5%). There were 20 (33.5%) females. Male to female ratio of study population was 2:1. Patients with infections (n=36), cholesteatoma was seen in 20 cases and mastoiditis was seen in 9 cases. Combination of both cholesteatoma and mastoiditis was seen in 7 cases. Total 27 cases of cholesteatoma (20+7) and 16 cases of mastoiditis (9+7) were seen. HRCT diagnosed opacified mastoid air cells were seen in 16 cases however only 8 cases with associated cholesteatoma were operated and 8 cases of mastoiditis alone were treated conservatively. Conclusion: HRCT produced high quality images of soft tissue lesions in air spaces. HRCT has outdated the conventional modalities of investigations by providing better soft tissue contrast and is ideal for evaluation of Temporal Bone lesions.