title: Virtual monochromatic spectral imaging with fast kilovoltage switching: reduction of metal artifacts at CT.
abstract: With arthroplasty being increasingly used to relieve joint pain, imaging of patients with metal implants can represent a significant part of the clinical work load in the radiologist's daily practice. Computed tomography (CT) plays an important role in the postoperative evaluation of patients who are suspected of having metal prosthesis-related problems such as aseptic loosening, bone resorption or osteolysis, infection, dislocation, metal hardware failure, or periprosthetic bone fracture. Despite advances in detector technology and computer software, artifacts from metal implants can seriously degrade the quality of CT images, sometimes to the point of making them diagnostically unusable. Several factors may help reduce the number and severity of artifacts at multidetector CT, including decreasing the detector collimation and pitch, increasing the kilovolt peak and tube charge, and using appropriate reconstruction algorithms and section thickness. More recently, dual-energy CT has been proposed as a means of reducing beam-hardening artifacts. The use of dual-energy CT scanners allows the synthesis of virtual monochromatic spectral (VMS) images. Monochromatic images depict how the imaged object would look if the x-ray source produced x-ray photons at only a single energy level. For this reason, VMS imaging is expected to provide improved image quality by reducing beam-hardening artifacts.
authors.affiliation: Department of Radiology, Centre Cardiologique du Nord, Saint-Denis, 32-36 rue des Moulins Gémeaux, 93200 Saint-Denis, France. eric.pessis@gmail.com
authors.forename: Eric
authors.initials: E
authors.lastname: Pessis
authors.forename: Raphaël
authors.initials: R
authors.lastname: Campagna
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Sverzut
authors.forename: Fabienne
authors.initials: F
authors.lastname: Bach
authors.forename: Mathieu
authors.initials: M
authors.lastname: Rodallec
authors.forename: Henri
authors.initials: H
authors.lastname: Guerini
authors.forename: Antoine
authors.initials: A
authors.lastname: Feydy
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Drapé
mesh_terms: D016477:Artifacts; D008670:Metals; D019736:Prostheses and Implants; D011856:Radiographic Image Enhancement / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014584:User-Computer Interface
chemical_list: D008670:Metals