title: Fat-referenced MR thermometry in the breast and prostate using IDEAL.
abstract: OBJECTIVE
  To demonstrate a three-echo fat-referenced MR thermometry technique that estimates and corrects for time-varying phase disturbances in heterogeneous tissues.
  
  
  METHODS
  Fat protons do not exhibit a temperature-dependent frequency shift. Fat-referenced thermometry methods exploit this insensitivity and use the signal from fat to measure and correct for magnetic field disturbances. In this study, we present a fat-referenced method that uses interpolation of the fat signal to correct for phase disturbances in fat free regions. Phantom and ex vivo tissue cool-down experiments were performed to evaluate the accuracy of this method in the absence of motion. Non-heated in vivo imaging of the breast and prostate was performed to demonstrate measurement robustness in the presence of systemic and motion-induced field disturbances. Measurement accuracy of the method was compared to conventional proton resonance frequency shift MR thermometry.
  
  
  RESULTS
  In the ex vivo porcine tissue experiment, maximum measurement error of the fat-referenced method was reduced 42% from 3.3 to 1.9°C when compared to conventional MR thermometry. In the breasts, measurement errors were reduced by up to 70% from 6.4 to 1.9°C.
  
  
  CONCLUSIONS
  Ex vivo and in vivo results show that the proposed method reduces measurement errors in the heterogeneous tissue experiments when compared to conventional MR thermometry.
authors.affiliation: GE Global Research, 1 Research Circle, Niskayuna, NY 12309, USA. hofstett@ge.com
authors.forename: Lorne W
authors.initials: LW
authors.lastname: Hofstetter
authors.forename: Desmond T B
authors.initials: DT
authors.lastname: Yeo
authors.forename: W Thomas
authors.initials: WT
authors.lastname: Dixon
authors.forename: James G
authors.initials: JG
authors.lastname: Kempf
authors.forename: Cynthia E
authors.initials: CE
authors.lastname: Davis
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Foo
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000502:physiology; D000818:Animals; D001831:Body Temperature / Q000502:physiology; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011467:Prostate / Q000033:anatomy & histology* / Q000502:physiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D013817:Thermography / Q000379:methods*