Ultra-high Resolution CT: the End of Stapes Prosthesis Measurement Misestimation

Modern temporal bone imaging systems, using 0.5 mm slice thickness, are reputed not yet able to depict the stapes piston position with a sufficient degree of accuracy, as high-resolution CT measurements consistently overestimated intravestibular piston dimensions (width by 44%, length by 6.25%) and vestibular intrusion (by 39%) because of metallic artifacts. . The exact limits of intravestibular depth are also unclear. The "safe" intravestibular prosthesis depth varies widely between studies and has been reported to range from 0.2 to 2.5 mm, so 39% may represent up to 0.9 mm of misestimation. Ultra-high resolution CT (UHR-CT) has improved spatial resolution to 0.12 mm by using ultra-small detector elements (0.25 x 0.25 mm), allowing better visualization of temporal bone structures compared to high-resolution temporal bone CT (HR-CT). However, this technique has not been described for stapes prosthesis measurement.