Cochlear Duct Length Calculation: Comparison Between Using Otoplan and Curved Multiplanar Reconstruction in Nonmalformed Cochlea

Otol Neurotol. 2021 Aug 1;42(7):e875-e880. doi: 10.1097/MAO.0000000000003119.

Abstract

Objective: To describe a new method to measure the cochlear parameters using Otoplan software, and to compare it with the traditional method using curved multiplanar reconstruction (cMPR).

Study design: Retrospective analysis using internal consistency reliability and paired sample t test.

Setting: Tertiary referral center.

Patients: Thirty-four patients including 68 ears from a clinical trial were retrospectively reviewed.

Main outcome measures: The length, width, height (distances A, B, H), and cochlear duct length of each cochlea were measured independently using two modalities: Otoplan and cMPR. Internal consistency reliability of the two modalities was analyzed. The time spent on each measurement was also recorded.

Results: Otoplan software was compatible with all radiological data in this series. Distances A, B, and H showed no significant differences between Otoplan (9.33 ± 0.365, 6.61 ± 0.359, and 2.91 ± 0.312 mm) and cMPR (9.32 ± 0.314, 6.59 ± 0.342, and 2.93 ± 0.250 mm). The average cochlear duct length calculated by Otoplan was 34.37 ± 1.481 mm, which was not significantly different from that calculated by cMPR (34.55 ± 1.903mm, p = 0.215). The measurements with Otoplan had better internal consistency reliability compared with those by cMPR, and measurements with a higher peak kilovoltage (140 kVp) CT scan showed further higher internal consistency reliability. Time spent on each cochlea by Otoplan was 5.9 ± 0.69 min, significantly shorter than that by cMPR (9.3 ± 0.72 min).

Conclusion: Otoplan provides more rapid and reliable measurement of the cochlea than cMPR. Furthermore, it can be easily used in the laptop computer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cochlea / diagnostic imaging
  • Cochlea / surgery
  • Cochlear Duct
  • Cochlear Implantation*
  • Cochlear Implants*
  • Humans
  • Reproducibility of Results
  • Retrospective Studies