Role of high resolution computed tomography in evaluation of temporal bone diseases

Background: The imaging modalities for evaluation of temporal bone are plain radiographs, multidirectional tomography, angiography, CT and MRI. Plain X-ray is an inexpensive method to study temporal bone, but results in an inaccurate diagnosis. Multidirectional tomography provides excellent bony details; however, soft tissues can't be delineated. Also, there is increased radiation to the eye lens. Angiography is the gold standard for evaluation of vascular lesions but is invasive with the risk of complications. The aim of the present study was to evaluate Role of High Resolution Computed Tomography in Temporal Bone Diseases and correlate HRCT image based findings with the operative and pathological findings to determine the accuracy of HRCT findings wherever possible. Materials and methods: This prospective study was done in Department of Radiodiagnosis & Imaging of Govt. Medical College Srinagar, J&K in collaboration with the Department of Otorhinolaryngology, in patients suspected of having temporal bone disease. All the patients who were, suspected of unsafe chronic serous otitis media (CSOM), evaluation of congenitally deaf child, having known or suspected deformities of inner, middle or external ear, tinnitus or vertigo, tumors of temporal bone and temporal bone fracture were included in the study. While exclusion criteria included, Patients of age <1 or >70 years. Results: Various findings associated with temporal bone trauma on HRCT showed 10 cases of Hemotympanum, 6 with facial nerve involvement, 2 with Labyrinthine involvement and Intracranial involvement was seen in 6 cases. In the current study 9 patients had symptomatic congenital anomalies involving various structures of the ear and temporal bone. Conclusion: With the advent of modern high-resolution CT scanners, detailed demonstration of temporal bone anatomy has become a practical reality. The improved contrast and soft tissue definition possible with HRCT has resulted in production of excellent images of soft tissue lesions in air spaces. However HRCT has its own limitations like in evaluation of labyrinthine soft tissue structures, evaluation of enhancement pattern and associated radiation hazards to the eye lens. Despite its limitations, HRCT of the temporal bone is a highly efficacious modality for accurate delineation of the anatomy and various pathologies of the temporal bone and it has revolutionalized the role of radiology in diagnosis and management of temporal bone diseases.