Finding the optimal electrode array before cochlear implantation based on CT or MRI

What is it about?

During the last years, individual cochlear implantat (CI) care has become an important topic. One aspect is the analysis of pre-operative imaging. Especially, the cochlear duct length (CDL) is of high interest for electrode length planning. Modern analysis tools offer automatic analysis of the whole inner ear where older tools relied on manual measurements of the key parameters (basal turn (A), height of the cochlea (H), and width of the basal turn (B)) for CDL estimation.

Featured Image

Photo by Alexander Grey on Unsplash

Photo by Alexander Grey on Unsplash

Why is it important?

We analyzed 159 inner ears using OTOPLAN4 on CT images in clinical routine on CI candidates. Partly automatic analyzation of the inner ear failed. In these cases, an experienced OTOPLAN user performed manual analyzation on CT or if not available on MRI images up to 1.0mm slice thickness. To ensure a reliable manual analyzation we used a large monitor of high resolution, brightness, and high-quality colors (HUAWEI MateView GT 34"). We intend to analyze postoperative outcome in comparison to anatomical data, electrode array length, and preoperative conditions like etiology or residual hearing. Results The key parameters could be measured in 153 ears with A=9.16±0.57 mm, H=4.17±0.42 mm, B=6.82±0.60 mm, and CDL=36.11±2.56 mm. 3 ears were implanted with a Flex34 electrode array. 39 ears with a CDL of 35.93±2.87 mm were implanted with a FlexSoft or Standard. 16 ears with a CDL of 35.95±2.60 mm were implanted with a Flex28. 6 ears with a CDL of 36.71±1.45 mm were implanted with Cochlear electrode arrays.

Perspectives