[Measuring the cochlea using a tablet-based software package: influence of imaging modality and rater background].

Area of Science:

• Otolaryngology
• Medical Imaging
• Audiology

Background:

• Cochlear duct length (CDL) exhibits significant individual variability.
• Accurate CDL measurement is crucial for optimizing cochlear implant electrode array length, potentially improving speech recognition and sound quality.
• Tablet-based software enables CDL measurement at the organ of Corti (CDL_OC) for personalized cochlear anatomy-based selection of electrode arrays.

Purpose of the Study:

• To evaluate the influence of imaging modality (MRI vs. fpVCT) and rater background on cochlear duct length (CDL) estimates.
• To determine the clinical significance of differences in CDL measurements obtained through various methods.

Main Methods:

• Analysis of magnetic resonance imaging (MRI) and flat-panel volume CT (fpVCT) scans from 10 patients (20 cochleae) using OTOPLAN software.
• CDL_OC measurements were performed by an otorhinolaryngology specialist, an ORL resident, and an audiologist.
• Linear mixed models were employed to assess the impact of rater background and imaging modality on CDL measurements.

Main Results:

• Mean CDL_OC measurements were 36.69 ± 1.78 mm for fpVCT and 36.81 ± 1.87 mm for MRI.
• No statistically significant effect of rater background on CDL estimates was observed (p = 0.437).
• Imaging modality significantly affected CDL estimates (p < 0.001), with MRI yielding estimates 0.89 mm larger than fpVCT.

Conclusions:

• Rater background does not influence CDL estimates, indicating that non-specialist personnel can achieve comparable measurements.
• Although imaging modality impacts CDL results, the observed difference between MRI and fpVCT is minimal and likely of limited clinical relevance.