title: Susceptibility artifacts detected on 3T MRI of the knee: frequency, change over time and associations with radiographic findings: data from the joints on glucosamine study.
abstract: OBJECTIVE
  To determine the prevalence of intraarticular susceptibility artifacts and to detect longitudinal changes in the artifacts, on 3T magnetic resonance imaging (MRI) of the knee in a cohort of patients with knee pain, and to assess the association of susceptibility artifacts with radiographic intraarticular calcifications.
  
  
  METHODS
  Three hundred and forty-six knees of 177 subjects aged 35-65 were included. 3T MRI was performed at baseline and at 6 months. Baseline radiographs were assessed for presence/absence of linear/punctate calcifications within the tibiofemoral joint (TFJ) space. Corresponding MRIs were assessed for susceptibility artifacts (i.e., linear/punctate hypointensities) in the TFJ space on coronal dual-echo steady-state (DESS) sequences. Kappa statistics were applied to determine agreement between findings on baseline DESS and radiography. Changes in artifacts over time were recorded.
  
  
  RESULTS
  In the medial compartment, 13 (4%) of the knees showed susceptibility artifacts at baseline. Six knees had persistent artifacts and six knees had incident artifacts at follow-up. Agreement between DESS and radiography was κ = 0.18 (-0.15, 0.51) in the medial compartment. Frequency of artifacts in the lateral compartment was low (2%).
  
  
  CONCLUSIONS
  Susceptibility artifacts detected on knee MRI are not frequent, and likely correspond to vacuum phenomena as they commonly change over time and are not associated with intraarticular calcifications. Radiologists should be aware of these artifacts as they can interfere with cartilage segmentation.
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, FGH Building 3rd Floor, 820 Harrison Avenue, Boston, MA 02118, USA.
authors.forename: M
authors.initials: M
authors.lastname: Jarraya
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, FGH Building 3rd Floor, 820 Harrison Avenue, Boston, MA 02118, USA; Department of Radiology, Bridgeport Hospital, Yale University School of Medicine, 267 Grant Street, Bridgeport, CT 06610, USA.
authors.forename: D
authors.initials: D
authors.lastname: Hayashi
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, FGH Building 3rd Floor, 820 Harrison Avenue, Boston, MA 02118, USA. Electronic address: Ali.Guermazi@bmc.org.
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
authors.affiliation: Division of Rheumatology and Clinical Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Pittsburgh VA Healthcare System, Pittsburgh, PA 15240, USA.
authors.forename: C K
authors.initials: CK
authors.lastname: Kwoh
authors.affiliation: Division of Rheumatology and Clinical Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Hannon
authors.affiliation: Department of Nutrition and Food Science, Texas Woman's University, Houston, TX 77030, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Moore
authors.affiliation: Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Jakicic
authors.affiliation: Division of Rheumatology and Clinical Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Green
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, FGH Building 3rd Floor, 820 Harrison Avenue, Boston, MA 02118, USA; Department of Radiology, University of Erlangen, Erlangen, Germany.
authors.forename: F W
authors.initials: FW
authors.lastname: Roemer
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D002114:Calcinosis / Q000000981:diagnostic imaging / Q000473:pathology*; D002357:Cartilage Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology*; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography
keywords: Knee; MRI; Osteoarthritis; Susceptibility artifact; Vacuum phenomenon