title: Consistency of signal intensity and T2* in frozen ex vivo heart muscle, kidney, and liver tissue.
abstract: OBJECTIVE
  To investigate tissue dependence of the MRI-based thermometry in frozen tissue by quantification and comparison of signal intensity and T2* of ex vivo frozen tissue of three different types: heart muscle, kidney, and liver.
  
  
  METHODS
  Tissue samples were frozen and imaged on a 0.5 Tesla MRI scanner with ultrashort echo time (UTE) sequence. Signal intensity and T2* were determined as the temperature of the tissue samples was decreased from room temperature to approximately -40 degrees C. Statistical analysis was performed for (-20 degrees C, -5 degrees C) temperature interval.
  
  
  RESULTS
  The findings of this study demonstrate that signal intensity and T2* are consistent across three types of tissue for (-20 degrees C, -5 degrees C) temperature interval.
  
  
  CONCLUSIONS
  Both parameters can be used to calculate a single temperature calibration curve for all three types of tissue and potentially in the future serve as a foundation for tissue-independent MRI-based thermometry.
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California, USA. klena@stanford.edu
authors.forename: Elena A
authors.initials: EA
authors.lastname: Kaye
authors.forename: Sonal
authors.initials: S
authors.lastname: Josan
authors.forename: Aiming
authors.initials: A
authors.lastname: Lu
authors.forename: Jarrett
authors.initials: J
authors.lastname: Rosenberg
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Daniel
authors.forename: Kim Butts
authors.initials: KB
authors.lastname: Pauly
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology; D015925:Cryopreservation; D005615:Freezing; D006321:Heart / Q000502:physiology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D066298:In Vitro Techniques; D007668:Kidney / Q000502:physiology*; D008099:Liver / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D013696:Temperature; D013817:Thermography / Q000379:methods*