A comparison of three MDCT post-processing protocols: preoperative assessment of the ossicular chain in otitis media

The aim of this study was to examine and assess comparative values of HRCT-based multiplanar reformation (MPR), volume rendering (VR) and virtual endoscope built on three-dimensional (3D) shaded-surface display (SSD-based CTVE) for detections of ossicular chain's damage in patients with otitis media. 70 human ears from 70 patients suffering by chronic otitis media or cholesteatoma, who were examined with a preoperative multi-slice computer tomography (MSCT) examination and tympanoplasty in our hospital were collected. The patients ossicular chains were reconstructed with the aforementioned three protocols and assessed via a three-point scoring system by three radiologists. Then, all the patients ossicular chains were reviewed by a surgeon and a radiologist via the same three-point scoring system used during surgeries at same time. By calculation, the Youden's index and coincidence rate were acquired without a significant difference for display of malleus. With regard to the incus, the Youden's index and coincidence rate of VR and MPR did not show any difference, however, both were higher than CTVE. For representation of the stapes, the accuracy of these three modalities is very low; especially, for the CTVE. In conclusion, both MPR and VR are relative robust, and CTVE is not effective for evaluation of small ossicular structures, particularly the stapes. Furthermore, the VR images are real 3D ones. Therefore, it could be the more valuable protocols for detection of the damage of ossicular chain in the patients with otitis media, and should be further applied in the future work.