Introduction: Proper vigilance for post-operative cervical spine fusion includes the patient-physician interaction and use of lateral cervical spine X-rays. When a measure of pre-operative symptoms persist or new complaints arise, CT scanning with supplemental contrast can lend a decisive hand in further treatment options. The sublimed admixture of Titanium and Tantalum metals, (Trabecular Metal, [TM],)creates a scaffolding for interbody grafting. The artifactual considerations for TM are obviated using a contrasted enhanced CT methodology for assessment.
Methods: The procedure starts with a maximum a posterior (MAP) reconstruction using an iterative reconstruction algorithm and a multimodal prior. This produces an artifact-free constrained image. This constrained image is the basis for an image-based projection completion procedure. The algorithm was validated on simulations, phantom and patient data, and compared with other metal artifact reduction algorithms.
Results: Metal implants such as hip prostheses and dental fillings produce streak and star artifacts in the reconstructed computed tomography (CT) images. Due to these artifacts, the CT image may not be diagnostically usable. A new reconstruction procedure is proposed that reduces the streak artifacts and that might improve the diagnostic value of the CT images.
Conclusions: Iterative deblurring methods using the expectation maximization (EM) formulation and the algebraic reconstruction technique (ART), respectively, are adapted for metal artifact reduction in medical computed tomography (CT). In experiments with synthetic noise-free and additive noisy projection data of dental phantoms.
Patient Care: Artifact reduction using metal implants
Learning Objectives: Bone Metal Interface
CT Scanning for Post-Operative Assessment
References: 1. Bobyn JD, Hacking SA, Chan SP, et. al. Characterization of a new porous tantalum biomaterial for reconstructive orthopaedics. Scientific Exhibit, Proc of AAOS, Anaheim CA, 1999.
2. Iterative deblurring for CT metal artifact reduction. Ge Wang Mallinckrodt Inst. of Radiol., Washington Univ., St. Louis, MO Snyder, D.L. ; O'Sullivan, J.A. ; Vannier, M.W. Volume: 15 , Issue: 5
Page(s): 657 - 664 Medical Imaging 1996