title: Myocardial blood flow at rest and stress measured with dynamic contrast-enhanced MRI: comparison of a distributed parameter model with a Fermi function model.
abstract: OBJECTIVE
  To assess the feasibility of simultaneously measuring blood flow (Fb ), Gd-DTPA extraction fraction (E), and distribution volume (vd ) in healthy myocardium at rest and under adenosine stress using dynamic contrast-enhanced MRI.
  
  
  METHODS
  Sixteen volunteers were examined at 1.5 T and 11 returned for a repeat study. The data were analyzed using a distributed parameter (DP) 2-region model to arrive at estimates of Fb , E, blood volume, and interstitial volume. For comparison, estimates of Fb were also obtained using a Fermi function model.
  
  
  RESULTS
  DP model fits were successful in 49 of the 54 data sets. Estimates obtained using DP and Fermi models did not differ for either rest Fb or myocardial perfusion reserve though DP estimates of stress Fb were lower than Fermi estimates. The repeatability of the DP parameters Fb , E, and vd was better than or equal to the repeatability of Fermi-Fb . E at rest and under stress was estimated to be 66% and 57%, respectively.
  
  
  CONCLUSIONS
  The results suggest that characteristics of the microvasculature of healthy myocardium can be reliably determined using dynamic contrast-enhanced MRI at rest and under stress and that delivery of Gd-DTPA to the myocardium is not flow-limited.
authors: Division of Medical Physics, Leeds Institute of Genetics Health and Therapeutics, Faculty of Medicine and Health, University of Leeds, Leeds, UK; Department of Medical Physics and Engineering, Leeds Teaching Hospitals NHS Trust, Leeds, UK; Multidisciplinary Cardiovascular Research Centre, University of Leeds, Leeds, UK.
authors: David A
authors: DA
authors: Broadbent
authors: John D
authors: JD
authors: Biglands
authors: Abdulghani
authors: A
authors: Larghat
authors: Steven P
authors: SP
authors: Sourbron
authors: Aleksandra
authors: A
authors: Radjenovic
authors: John P
authors: JP
authors: Greenwood
authors: Sven
authors: S
authors: Plein
authors: David L
authors: DL
authors: Buckley
mesh_terms: D000241:Adenosine; D000328:Adult; D000465:Algorithms; D001783:Blood Flow Velocity / Q000502:physiology; D003198:Computer Simulation; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008955:Models, Cardiovascular; D015233:Models, Statistical; D012016:Reference Values; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity; D014665:Vasodilator Agents
chemical_list: D003287:Contrast Media; D014665:Vasodilator Agents; D019786:Gadolinium DTPA; D000241:Adenosine
keywords: extraction fraction; myocardial blood flow; myocardial perfusion reserve; reproducibility; tracer kinetic modeling