title: Measurement of susceptibility artifacts with histogram-based reference value on magnetic resonance images according to standard ASTM F2119.
abstract: OBJECTIVE
  The standard ASTM F2119 describes a test method for measuring the size of a susceptibility artifact based on the example of a passive implant. A pixel in an image is considered to be a part of an image artifact if the intensity is changed by at least 30% in the presence of a test object, compared to a reference image in which the test object is absent (reference value). The aim of this paper is to simplify and accelerate the test method using a histogram-based reference value.
  
  
  METHODS
  Four test objects were scanned parallel and perpendicular to the main magnetic field, and the largest susceptibility artifacts were measured using two methods of reference value determination (reference image-based and histogram-based reference value). The results between both methods were compared using the Mann-Whitney U-test.
  
  
  RESULTS
  The difference between both reference values was 42.35 ± 23.66. The difference of artifact size was 0.64 ± 0.69 mm. The artifact sizes of both methods did not show significant differences; the p-value of the Mann-Whitney U-test was between 0.710 and 0.521.
  
  
  CONCLUSIONS
  A standard-conform method for a rapid, objective, and reproducible evaluation of susceptibility artifacts could be implemented. The result of the histogram-based method does not significantly differ from the ASTM-conform method.
authors.forename: Andreas
authors.initials: A
authors.lastname: Heinrich
authors.forename: Ulf K
authors.initials: UK
authors.lastname: Teichgräber
authors.forename: Felix V
authors.initials: FV
authors.lastname: Güttler
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003627:Data Interpretation, Statistical; D007090:Image Interpretation, Computer-Assisted / Q000379:methods* / Q000592:standards*; D060526:Magnetic Fields; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019736:Prostheses and Implants / Q000592:standards*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014481:United States