High diagnostic performance of dynamic flat-panel computed tomography (Cone-Beam-CT) in detecting anatomical structures of temporal bones of healthy probands and patients with ear diseases

Background This retrospective study aimed to investigate the diagnostic performance of flat-panel computed tomography (Cone-Beam-CT) in detecting normal anatomy and pathologies of the temporal bone. Methods Cone-Beam-CT scans of 216 persons (291 temporal bones; median age 58 years; 50.9% women) performed at a tertiary university center in Germany from 2015 to 2018 were analyzed. Patients were divided into three cohorts: healthy temporal bones ( n = 58), those with temporal bones pathologies ( n = 108), and those with cochlear implantation (CI, n = 50). Depiction quality of 24 middle and inner ear structures was graded on a three-point scale by one observer. Angular insertion depth (AID) and scalar location of CIs were evaluated. Results The median slice thickness across the cohorts was 0.5 mm. The median slice distance of Cone-Beam-CT was 0.5 mm, in case of healthy temporal bones was 1 mm. Several middle and inner ear structures were depicted with significantly higher in the pathology cohort than in healthy temporal bones ( p < 0.01). Thinner slices and smaller spacing yielding significantly better depiction ( p < 0.01). Cone-Beam-CT enabled reliable assessment of AID (mean 392°) and scalar location of CIs in implanted patients. Conclusions Cone-Beam-CT demonstrates high diagnostic performance in detecting anatomical structures within temporal bones, with better visualization in diseased temporal bones compared to healthy ones, thereby establishing its suitability as a diagnostic method. Cone-Beam-CT is also a reliable, low-dose tool for postoperative CI electrode position control.