Cochlear implant imaging with accelerated flat panel computed tomography: Image quality and dosimetry comparison to conventional high-resolution multislice computed tomography

Background and PurposeCone-beam CT (CBCT) and high-resolution multislice CT (HR-MSCT) are the mainstay postoperative imaging modalities following cochlear implant (CI) surgery, with CBCT often preferred due to lower susceptibility to metallic artifacts. However, CBCT is more prone to motion artifacts due to longer acquisition times. Recent advancements in accelerated flat panel CT (Acc-FPCT) available with latest generation angiography systems addressed traditional limitations of CBCT by significantly decreasing scan time. This study evaluates the diagnostic performance and radiation dose of Acc-FPCT compared to HR-MSCT in postoperative CI evaluation.MethodsFive cadaveric whole-head specimens (ten temporal bones) were operated on by an ENT surgeon. Ten CIs were inserted via cochleostomy. Post-operatively, specimens were scanned using six Acc-FPCT protocols and HR-MSCT. Three neuroradiologists assessed the image quality of FPCT protocols in comparison to HR-MSCT using a 5-point Likert scale. Seven electrode characteristics including scalar position and discernibility of individual contacts were evaluated. Radiation dose parameters (CTDIvol and DLP) were compared among protocols.ResultsTwo high-resolution Acc-FPCT (HR-FPCT) protocols were rated superior to HR-MSCT (<i>p</i> < .01). There were no significant differences between these two protocols (<i>p</i> = .25). The remaining Acc-FPCT protocols were rated inferior to HR-MSCT (<i>p</i> < .05). Inter-rater reliability was excellent (ICC (2,k) = 0.908; CI [0.85-0.94]). DLP was significantly lower in all Acc-FPCT protocols compared to HR-MSCT.ConclusionsThe results of this study underscore the utility of Acc-FPCT protocols as a feasible alternative to HR-MSCT in postoperative CI evaluation, allowing for better visualization of electrode array while significantly reducing scan duration and radiation exposure.