Role of dual energy CT with adjusted radiation dose in accurate assessment of electrode position in pediatric cochlear implant

Abstract

Background and purpose: Postoperative imaging of cochlear implant needs to provide detailed information on the position of individual electrodes; the aim of this study was to evaluate visualization of individual electrodes and measurement of the electrode–modiolus distance (EMD) using dual energy CT (DECT) – with low radiation dose using virtual monochromatic spectral (VMS) imaging comparing the images quality and radiation dose with those by using multidetector CT (MDCT). Materials and methods: 25 pediatric patients who underwent cochlear implantation were imaged using DECT (15 patients) and MDCT (10 patients), and the image quality and radiation dose of DECT were compared to those of MDCT. Measurement of EMD was done for 5 electrodes and the results were correlated with neural response telemetry (NRT) and behavioural mapping levels. Results: A statistically significant difference between the radiation dose of DECT and MDCT was confirmed (p = 0.002) without a statistically significant difference in images quality (weighted K = −0.129 and PABAK = 0.533). Statistically significant correlations were found between EMD and NRT threshold, T (threshold) and C (maximum comfortable) levels with p = <0.01. Conclusion: DECT accurately detects the electrode position with low radiation dose which helps in CI fitting.

Keywords

• Dual energy CT
• Pediatric cochlear implant
• Radiation dose reduction