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Updated: Dec 18, 2025
Author Spotlight: Advancements in Impedance Monitoring for Cochlear Implant Surgery
Published on: August 4, 2023
Predicting round window visibility by HRCT during cochlear implantation in children
Mohsen Rajati1, Mohamad Reza Afzalzadeh1, Navid Nourizadeh1
1Sinus and Surgical Endoscopic Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Iran.
Insights
Radiologic measurements, including the round window niche (RWN) angle and modified facial recess distance (MFRD), reliably predict round window visibility during cochlear implantation surgery.
Area of Science:
- Radiology
- Otolaryngology
- Neurosurgery
Background:
- Cochlear implantation requires precise visualization of the round window (RW).
- Predicting RW visibility preoperatively can optimize surgical planning and outcomes.
- High-resolution computed tomography (HRCT) of the temporal bone is a key diagnostic tool.
Purpose of the Study:
- To radiologically evaluate round window (RW) visibility during cochlear implantation using HRCT.
- To assess the predictive value of novel radiologic measurements for RW visibility.
Main Methods:
- A cross-sectional descriptive analytic study was conducted.
- Two new measurements were evaluated on presurgical HRCT: the RWN angle and modified facial recess distance (MFRD).
- These measurements were compared with intraoperative RW visibility reported by surgeons.
Main Results:
- Significant differences in both MFRD (P < 0.01) and RWN angle (P < 0.04) were observed between groups with visible and nearly invisible RWs.
- These findings suggest a strong correlation between the radiologic measurements and actual surgical visibility.
Conclusions:
- The RWN angle and MFRD are reliable predictors of round window visibility.
- These measurements can aid in preoperative planning for cochlear implantation.
Abstract:
Objective: The present study aimed to radiologically evaluate the visibility of round window during cochlear implantation by high-resolution computed tomography (HRCT) imaging of temporal bone. Study design: This was a cross-sectional descriptive analytic study. Methods: Two new radiologic measurements were evaluated on the presurgical HRCT of temporal bone, including (1) the angle between the line parallel to coronal axis that passes through the middle of the round window niche (RWN) and the line that connects the anterior portion of facial nerve (FN) to the middle of the RWN (RWN angle) and (2) the vertical distance between this coronal plane and the anterior portion of the FN, modified facial recess distance (MFRD). The measurements were then compared with the visibility of the round window (RW) during operation, as reported by the surgeon. Result: The present study compared the abovementioned CT scan findings of cochlear implanted children in visible (n = 21) and nearly invisible (n = 21) RW during surgery, as reported by the surgeon. The analysis revealed that both MFRD (P < 0.01) and RWN angle (P < 0.04) were significantly different between the two groups. Conclusion: the RWN angle and MFRD are fairly reliable predictors of round window visibility during cochlear implantation.
