title: Postfusion magnetic resonance imaging artifacts caused by a titanium, cobalt-chromium-molybdenum, and carbon intervertebral disc spacer.
abstract: Intervertebral spacers for anterior spine fusion are made of different materials, such as titanium and CoCrMo-alloys or carbon fiber reinforced polymers (CFRP). Implant-related susceptibility artifacts can decrease the quality of magnetic resonance imaging (MRI) scans. This cadaveric study aimed to demonstrate the extent that implant-related MRI artifacting affects the postfusion differentiation of the spinal canal (SC) and intervertebral disc space (IDS). In 6 cadaveric porcine spines, we evaluated the postimplantation MRI scans of a titanium, CoCrMo-spacer and CFRP-spacer that differed in shape and surface qualities. A spacer made of human cortical bone was used as a control. A defined evaluation unit was divided into regions of interest (ROI) to characterize the SC and IDS. Considering 15 different MRI sequences read independently by an interobserver-validated team of specialists artifact-affected image quality of the median MRI slice was rated on a score of 0-1-2-3. A maximum score of 15 points for the SC and 9 points for the IDS (100%) was possible. Turbo spin echo sequences produced the best scores for both spacers and the control. Only the control achieved a score of 100%. For the IDS the CoCrMo-spacer, titanium and CFRP-spacer maximally scored 0%, 0% and 74%, for the SC 60%, 80% and 99%, respectively. By using favored T1 TSE sequences the CFRP-spacer represented clear advantages in postfusion spinal imaging. Independent of artifact dimensions the used scoring system allowed us to create an implant-related ranking of MRI scan quality in reference to the bone control.
authors.affiliation: Departments of Orthopaedic Surgery, Georg-August-University of Goettingen, Goettingen, Germany. ternstberger@med.uni-goettingen.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Ernstberger
authors.forename: Gabert
authors.initials: G
authors.lastname: Heidrich
mesh_terms: D000818:Animals; D016477:Artifacts; D002244:Carbon; D007089:Image Enhancement / Q000379:methods; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019736:Prostheses and Implants; D013123:Spinal Fusion / Q000295:instrumentation*; D013552:Swine; D013904:Thoracic Vertebrae / Q000473:pathology* / Q000601:surgery*; D014025:Titanium; D014800:Vitallium
chemical_list: D014800:Vitallium; D002244:Carbon; D014025:Titanium