Computed tomographic evaluation of non-metallic middle-ear prostheses.

Non-metallic middle-ear prostheses, including a plastipore total ossicular replacement prosthesis (TORP) and partial ossicular replacement prosthesis (PORP), a Teflon loop stapes piston, and a Ceravital PORP were used to reconstruct the ossicular chain in formalin fixed cadaver temporal bones. The temporal bones were examined using high resolution, thin-section computed tomographic techniques identical to those used for patient studies. The detail and resolution of the images were comparable with those obtained on standard patient exams. The temporal bones were evaluated to determine the appearance of the prostheses in normal and abnormal positions within the middle ear. The radiologist examined the images without fore-knowledge of the position of the prostheses and was able to accurately identify both normal and abnormal positions. With the proper technique an accurate evaluation of non-metallic middle-ear prostheses is possible by high-resolution computed tomography.