 Hello, this is Dr. Kashwini Swathi, second year post graduate. My paper topic is high resolution computer tomography evaluation of pathology of temporal bone. My co-author is Dr. Panil Kumar, MDRD professor, Dr. Pradeep Kumar, MDRD assistant professor, department of radio diagnosis, Shanthiram Medical College and General Hospital, Landyal. Introduction. It is a modification of routine CT, a revolutionary imaging model that helps in the evolution of bone and airspace anatomy and disorders of temporal bone. The purpose of this study is to evaluate the normal variation pathological process like infections, tubers and congenital anomalies and their extent involving the temporal bone. Temporal bone consists of five parts, squamous mastoid, pitrus, tympanic and styloid process. The air in the tympanic cavity surrounded by the dense temporal bone and the mastoid air cells provide an inherent natural contrast to the HRCT imaging of temporal bone and provides excellent delineation of bony landmarks within the temporal bone. HRCT provides higher spatial resolution and better soft tissue contrast. HRCT is for advantages in assessing the complications of infection. Aims and objectives of this study are to study the extent of medial infections and their complications to evaluate temporal bone neoplasms, to study the congenital anomalies of the ear, according to compartment involvement. Materials and methods or source of data patients attending are referred to the department of radiology, Shanthiram Medical College. Over a period of 14 months, 40 patients were clinically suspected of having symptoms related to the temporal bone, condom and HRCT. Sample size is 40. Inclusion criteria are patients presenting with earache, with discharge, hearing loss, vertebrae and tinnitus, patient presenting with fever, headache and vomiting. Exclusion criteria are patients with electric devices at the skull base such as cochlear implants and temporal bone trauma. CT machine used is a seamless sedatives-wise helical CT. Results and analysis. 40 patients were clinically suspected of having symptoms related to temporal bone, underwent HRCT. And the findings are tabulated as, this is the table 1 showing the distribution of the disease. Of all the patients, infections constitute 70%, tumors 25% and congenital anomalies 5%. This is the table showing distribution of infection. Cholestatoma is noted in 11 patients. Mastoiditis is 8 patients. CSOM in 8 patients. This is the table showing 8 and 6 distribution of the infection. The table showing comparison between the CT findings and operative findings in infections. The investigation of external ear cholestatoma and the internal intracranial extension is noted in HRCT and they are confirmed in operative. This is the table showing the distribution of neoplasms. Acoustic neuroma is noted in 6 patients. Bromus regulari in 2 patients. C.P. Angri meningoma in 1. Adrenal cystic carcinoma of the external ear in 1. This is the table showing age incidence of the tumor. Among the 40 cases which were studied, infection was found to be the most common temporal pathology with increasing preponderance in the younger age group. Neoplasm formed the second largest group of lesions with the acoustic neuroma being the most common. Continental anomalies are the least common pathology affecting the temporal bone in our study. This is the case of chronic otitis media with mastoiditis. HRCT adsorption shows the soft tissue density in the bilateral anticoantral and aditus antrum with erosion of the bilateral short process of the incus. You also see the sclerosis of the bilateral mastoid arches. This is the case of cholestatoma. In the middle ear, in these sections we see the soft tissue density in the middle ear involving the preserved space eroding the scutum and erosicals extending into superiorly into the attic and inferiorly into the mastoid antrum. Suggestive of cholestatoma. This is the case of right glomus jugulari. In this image we see the intensely enhancing mass in the right jugular foramen extending into the middle ear and expansion of the jugular foramen with eroding of the adjacent peterous bone. This is the case of bilateral acoustic neuroma. In this image we see the hypotenuse lesions in the bilateral CP hangers and contrast to CT shows the enhancing lesions with widening of the internal auditory canal extending medially causing the compression of the pons and medulla. And on the left side we see the lesion extending laterally into the mastoid arches and subcutaneous spleen displacing the pinna. This is the case of right sebillopantin angle meningioma. Here we see a well defined enhancing lesion in the CP angle. This is the case of right external auditory canal attrition. In this image we see a complete absence of the external auditory canal and the tympanic membrane. HRCT temporal bone plays a crucial role in addressing the challenge of delineating the details of temporal bone anatomy and pathology thus adding in more accurate diagnosis assessment of extent of disease. The air in the tympanic cavity surrounded by the dense temporal bone and the mastoid arches provide an inherent natural contrast to the HRCT imaging of temporal bone and towards excellent delineation of bone in landmarks within the temporal bone. Patients with infection from the largest proportion of the cases studied and the age range was from 15 months to 60 years. 28 cases were studied and out of which cholesterol over 11 cases mastoiditis were 8 cases CSOM, CSOM were 8 cases and one is a malignant otitis external. For the assessment of middle ear infection a close clinical relation is essential to evaluate the nature of the middle ear soft tissue masses as cholesterol is mimicked by many other middle ear pathologies. Feet scan plays an important role in assessment of residual or recurrent disease, status of inner ear, relationship of the facial node to any surgical change or cholesterol treatment. The status of the ear ossicles are the processes employed by the surgeon. Neoplasm constrict 20% of 25% of was studied and out of 10 neoplastic lesions that were scanned six were diagnosed as acoustic neuromers. When tumors present in the middle ear HRCT serves to differentiate tumor from vascular anomalies and to determine the extent of the deep involvement often avoiding the need for angiography. By precisely defining the anti-intro-tympanic mastoid, jugular wall, intra-labyrinthine and pretocepical involvement as well as posterior, middle and intratemporal forza extension, HRCT provides essential information for planning the surgical approach. So conclusion is HRCT outweighs the conventional modalities of investigations and traverse higher spatial resolution and better soft tissue contrast. Most common lesion in our study was infection with female preponderance. Most common tumor was acoustic neuroma. PKage was 4 to 60 decade. Excellent correlation between CT and operative findings in cholesterol metameter. HRCT is ideal for evaluation of temporal bone lesion. These are the references I used. John R. Haga, Daniel Pol, CT and MRI imaging of the whole body. Swart JD et al. high resolution CT of the middle ear and mastoid. Thank you.