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CT grading of otosclerosis
1Division of Neuroradiology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
AJNR. American Journal of Neuroradiology
|March 27, 2009
Summary
The Symons/Fanning CT grading system for otosclerosis demonstrates excellent reliability. This system for assessing otosclerosis severity on CT scans shows high agreement between radiologists and within a single radiologist over time.
Area of Science:
- Radiology
- Otolaryngology
- Medical Imaging
Background:
- Otosclerosis is a common cause of conductive hearing loss.
- Accurate CT grading of otosclerosis is crucial for diagnosis and management.
- The Symons and Fanning CT grading system was proposed in 2005.
Purpose of the Study:
- To evaluate the interobserver and intraobserver agreement of the Symons/Fanning CT grading system for otosclerosis.
- To determine the reliability of this CT-based grading system in assessing disease severity.
Main Methods:
- 997 petrous bone CT scans were reviewed.
- Two blinded neuroradiologists independently graded 162 petrous bones using the Symons/Fanning system.
- One reviewer repeated grading after 7 months to assess intraobserver agreement.
Main Results:
- Excellent interobserver agreement was found (mean kappa = 0.92).
- Excellent intraobserver agreement was demonstrated (kappa = 0.94).
- 95% agreement between initial readings and 93% agreement between delayed readings were observed.
Conclusions:
- The Symons/Fanning CT grading system for otosclerosis exhibits excellent reliability.
- This grading system, based on the location of otosclerosis involvement, is highly reproducible.
- The findings support the use of this CT grading system in clinical practice.
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