Quality-assured training in the evaluation of cochlear implant electrode position: a prospective experimental study

Abstract

Background The objective of this study was to demonstrate the utility of an approach in training predoctoral medical students, to enable them to measure electrode-to-modiolus distances (EMDs) and insertion-depth angles (aDOIs) in cochlear implant (CI) imaging at the performance level of a single senior rater. Methods This prospective experimental study was conducted on a clinical training dataset comprising patients undergoing cochlear implantation with a Nucleus® CI532 Slim Modiolar electrode (N = 20) or a CI512 Contour Advance electrode (N = 10). To assess the learning curves of a single medical student in measuring EMD and aDOI, interrater differences (senior–student) were compared with the intrarater differences of a single senior rater (test–retest). The interrater and intrarater range were both calculated as the distance between the 0.1th and 99.9th percentiles. A “deliberate practice” training approach was used to teach knowledge and skills, while correctives were applied to minimize faulty data-gathering and data synthesis. Results Intrarater differences of the senior rater ranged from − 0.5 to 0.5 mm for EMD and − 14° to 16° for aDOI (respective medians: 0 mm and 0°). Use of the training approach led to interrater differences that matched this after the 4th (EMD) and 3rd (aDOI) feedback/measurement series had been provided to the student. Conclusions The training approach enabled the student to evaluate the CI electrode position at the performance level of a senior rater. This finding may offer a basis for ongoing clinical quality assurance for the assessment of CI electrode position.

Word Recognition with a Cochlear Implant in Relation to Prediction and Electrode Position

“…When evaluating the scatter of d and insertion depth, the measurement error of the angle and length measurement based on the post-operative DVT must also be taken into account. In the literature, interrater differences of −0.5 to 0.5 mm for length measurements and 12° to 30° for angle measurements can be found [ 45 ].…”

Evaluation of CI electrode position from imaging: comparison of an automated technique with the established manual method

“…Conventional DICOM viewers (“RadiAnt DICOM viewer”, Medixant; “KaVO eXam Vision”, KaVo Dental GmbH) were used for the manual measurements and the verification of the scalar localization of the electrode array as well as for checking the image quality (visual assessment). Two experts with experience in evaluating the electrode placement measured each of the 50 image sets [ 7 , 16 , 23 ]. The manual CI localization was performed in accordance with a consensus panel on a cochlear coordinate system [ 28 ], in which the mid-modiolar axis is perpendicular to a plane through the basal turn of the cochlea, with the helicotrema as the origin of this axis (‘cochlear view’) [ 16 , 28 , 29 ].…”

“…In clinical practice this procedure is conducted by manual image-processing and may be affected by diagnostic errors (missing findings or misinterpretation of findings). Diagnostic errors in radiology commonly result from a combination of system-related factors and cognitive-perceptual biases that can be present in both experienced and inexperienced raters [ 18 – 23 ]. The use of accurate, automatic electrode localization techniques could be helpful in reducing such diagnostic errors.…”