Accuracy of CT in the measurement of stapes prostheses using a temporal bone model

Objectives. Current 3D temporal bone models have either lacked the resolution (if volume‐rendered from imaging)¹ or lacked the interactivity (if surface‐rendered from sections)² necessary for surgical training. The objective was to produce a 3D volume‐rendered temporal bone model from serial sections. Method. High resolution images were acquired from serial histological sections of the temporal bone using a Canon SLR digital 8‐megapixel camera. Image registration was performed by aligning in Adobe Photoshop on a PC with a 256 Mb graphics card. Segmentation of surgically relevant anatomical structures was performed followed by 3D volumetric reconstruction. The model was finally checked for anatomical accuracy and interactivity by practicing otologists. Results. An anatomically accurate, high resolution 3D volume‐rendered model of the temporal bone was produced, containing many of the surgically relevant structures the otologist may come across during surgery. The course of the facial nerve, the labyrinth, internal carotid artery, jugular vein and all the ossicles where visualised (including the stapes footplate) along with the internal and external auditory meati and even the chorda tympani nerve in some projections. The model was interactive with the ability to rotate it in any plane, zoom into areas of interest and ‘cut’ volume to reveal underlying structures. Conclusions. To the best of our knowledge, this is the world's first 3D volume‐rendered model of the temporal bone from histological sections. At a time of difficulty in procuring cadaveric bones, this model could be a major aid to improving the future training of surgeons performing procedures on the temporal bone. References. 1 Wiet G.J., Schmalbrock P., Powell K. & Stredney D. (2005) Use of ultra‐high‐resolution data for temporal bone dissection simulation. Otolaryngol. Head Neck Surg. 133, 911–915 2 Mason T.P., Applebaum E.L., Rasmussen M., Millman A., Evenhouse R. & Panko W. (2000) Virtual temporal bone: creation and application of a new computer‐based teaching tool. Otolaryngol. Head Neck Surg. 122, 168–173