title: Analysis of subtraction methods in three-dimensional contrast-enhanced peripheral MR angiography.
abstract: OBJECTIVE
  To compare the effectiveness of three image subtraction algorithms designed to improve arterial conspicuity in first-pass contrast-enhanced magnetic resonance (MR) angiography.
  
  
  METHODS
  Three subtraction methods were analyzed through computer simulations, phantom studies, and clinical studies. These algorithms were: complex subtraction, magnitude subtraction, and maximum intensity projection subtraction.
  
  
  RESULTS
  In high resolution three-dimensional imaging, maximum intensity projection subtraction generally yields the best background suppression. Complex subtraction is effective in reducing partial volume effects in low resolution imaging. Magnitude subtraction works better in high resolution, low contrast concentration protocols.
  
  
  CONCLUSIONS
  Choosing the appropriate subtraction method according to the protocol is helpful in optimizing image quality.
authors: Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada. huangyx@sten.sunnybrook.utoronto.ca
authors: Yuexi
authors: Y
authors: Huang
authors: Christie A
authors: CA
authors: Webster
authors: Graham A
authors: GA
authors: Wright
mesh_terms: D000465:Algorithms; D015901:Angiography, Digital Subtraction / Q000379:methods*; D003198:Computer Simulation; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D016491:Peripheral Vascular Diseases / Q000175:diagnosis*; D019047:Phantoms, Imaging
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA