![]() ![]() A bony defect was defined as focal discontinuity of the anterior and/or inferior EAC wall. Comparison was also made with the contralateral side if imaged and if asymptomatic by history. Preoperative imaging was used for comparison if available. The images were reviewed for cortical change (including flattening of the floor of the EAC with apparent loss of the tympanic sulcus, thinning, and/or irregularity), bony defects, and soft tissue thickening along each EAC wall (anterior, posterior, superior, and inferior). with 7 years of experience with a Certificate of Added Qualification in neuroradiology). with 4 years of experience and board-certified in Thailand H.R.K. All CT images were independently reviewed by 2 neuroradiologists (V.M. The axial and coronal reformatted images from each temporal bone were reviewed on the PACS of our institution. The raw data voxel size was 0.5 × 0.08 × 0.08 mm, and the same standardized reformatted images were created in the axial and coronal planes, as described above. Scanning parameters were 90 kVp, 8 mA, 30.8-second rotation time, with a 60 × 60 mm FOV. The remaining 8 of 27 temporal bones were imaged on a digital volume tomography (conebeam) scanner (3D Accuitomo 170 J. The technologist then created standardized axial and coronal reformatted images along the plane of the lateral semicircular canal at the scanner console by using the sagittal images as a reference. Data from each ear were reconstructed into 0.6 (section thickness) × 0.2 mm (reconstruction interval) axial images in a bone algorithm at a display FOV of 100 mm and a matrix of 512 × 512. In pediatric patients, 120 mAs was used to decrease the radiation dose. Scanning parameters were 120 kV(peak), 320 mAs at 0.6-mm collimation, and a 0.55 pitch with helical acquisition extending from just superior to the petrous ridge through the inferior skull base. Of 27 temporal bones, 19 were imaged on a 40-section multidetector CT scanner (Somatom Sensation Siemens, Erlangen, Germany). The electronic medical record was reviewed for otologic history, clinical examination findings, and operative reports, in addition to demographic data.Īll 25 patients underwent dedicated temporal bone CT without intravenous contrast. Patients with a history of surgery for a primary EAC indication (such as exostosis removal or repair of EAC stenosis) rather than middle ear surgery were also excluded. Patients with a history of prior canal wall down mastoidectomy were excluded, given the distinctive appearance of the removal of the posterosuperior wall of the EAC. Confirmation of transcanal surgery with an operative report and/or clinical surgical note describing the alterations/drilling of the EAC was necessary for inclusion. Postoperative imaging was performed during a 7-year period from July 2007 to April 2014. ![]() Twenty-five patients with a history of transcanal middle ear surgery (including 2 patients with a history of bilateral surgery) and subsequent postoperative CT imaging were retrospectively identified from an imaging data base. This retrospective study was performed in accordance with the Health Insurance Portability and Accountability Act. ![]()
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