[Technique of radiologic measurements for the inner ear structures using computed tomography]

Area of Science:

• Radiology
• Anatomy
• Medical Imaging

Background:

• Accurate measurement of inner ear structures is crucial for diagnosis and surgical planning.
• Computed tomography (CT) is a common imaging modality, but precise measurements of complex inner ear anatomy can be challenging.

Purpose of the Study:

• To establish an accurate and feasible measurement technique for inner ear structures using CT.
• To assess the inter-observer agreement of this novel measurement technique.

Main Methods:

• Sixty patients with normal temporal bone anatomy underwent high-resolution CT.
• Multi-planar reformations (MPR) were used to visualize and measure the cochlea (height and width) and bony islands within the semicircular canals.
• Two independent readers performed measurements to evaluate inter-observer agreement.

Main Results:

• MPR provided satisfactory visualization of inner ear structures for radiologic measurements.
• Excellent inter-observer agreement was confirmed (P>0.05, r>0.9).
• Normative measurements included cochlear height (4.26±0.28 mm), cochlear width (7.03±0.39 mm), and bony island areas for anterior (25.49±3.84 mm²), posterior (20.07±2.93 mm²), and lateral (11.50±1.94 mm²) semicircular canals.

Conclusions:

• MPR is effective in displaying cochlear and semicircular canal structures along their central axes.
• This technique yields repeatable measurements and provides reliable morphologic parameters for inner ear structures.
• MPR represents a valuable tool for accurate radiologic assessment of the inner ear.