MRI-Related Artifacts After Implantation of Passive Titanium Devices and Their Impact on Cholesteatoma Assessment

Background: /Objectives: Surgical removal is the treatment of choice for cholesteatoma control. Depending on the size, the surgery involves partial resection of the ossicular chain and, if necessary, the bony skull base. Titanium foreign materials (prostheses, meshes) can be used to restore sound transmission and to cover larger defects of the skull base. After the operation, recurrence and residual control are necessary. This can be done by means of second-look surgery or an MRI examination with a non-EPI DWI sequence. Similar to other metal implants, artifacts may occur in the image due to the titanium used. This study aimed to estimate MRI generated artifacts due to the titanium foreign material (prosthesis, mesh) to get insights in a possible limiting role for recurrent cholesteatoma detection. Methods: 28 MRI examinations (T1-, T2-, non-EPI DWI sequences) in 14 males and 14 females (5,2-92,4 years) after cholesteatoma surgery and single-staged implantation of a PORP, TORP, or titanium mesh were considered. The size of the respective artifacts was measured, and the mean artifact sizes of the respective prosthesis types were compared. A second look surgery was performed in all cases due to the MRI result or clinical findings. Both were also compared. Results: Artifacts occurred in all titanium foreign bodies depending on the used MRI sequence (PORP, TORP, Mesh). We found a positive association between size of prosthesis and size of artifact. All subsequent second-look surgeries confirmed the MRI examinations according to a positive control for the presence of a cholesteatoma. The detection rate was 82.1%. Conclusions: Titanium material-related artifacts might influence the MRI detectability of recurrent cholesteatoma. Small cholesteatoma might be missed by an MRI based follow up. Single or two staged reconstructive concepts after cholesteatoma surgery need to be discussed.