title: MR temperature imaging using PRF phase difference and a geometric model-based fat suppression method.
abstract: BACKGROUND
  Because protons in fat do not exhibit a temperature-dependent frequency shift, proton resonance frequency shift (PRFS)-based MR thermometry always suffers from disturbances due to the presence of fats or lipids.
  
  
  OBJECTIVE
  A new fat suppression method for PRFS-based MR thermometry is proposed to obtain accurate variation of phase angle.
  
  
  METHODS
  Similar to the approach of separating fat and water with the two-point Dixon technique, we first scan a complex MR image for reference and then scan another complex image varying with temperature at the same TE point. Based on the conventional PRFS method, we use geometric relationships to remove the effect of fat on the variation of the phase angle.
  
  
  RESULTS
  Two phantoms with different water-to-fat ratios are involved in the temperature mapping test. Experimental results show that the temperature images of two phantoms are approximated under the same conditions.
  
  
  CONCLUSIONS
  The proposed fat suppression method is simple and effective for PRFS-based MR thermometry.
authors.forename: Shoubin
authors.initials: S
authors.lastname: Liu
authors.forename: Yanming
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D019047:Phantoms, Imaging; D011522:Protons; D013696:Temperature; D062125:Thermometry / Q000379:methods*
chemical_list: D011522:Protons
keywords: MR thermometry; PRFS; fat suppression; geometric model