title: Estimation of absolute myocardial blood flow during first-pass MR perfusion imaging using a dual-bolus injection technique: comparison to single-bolus injection method.
abstract: OBJECTIVE
  To compare the dual-bolus to single-bolus quantitative first-pass magnetic resonance myocardial perfusion imaging for estimation of absolute myocardial blood flow (MBF).
  
  
  METHODS
  Dogs had local hyperemia of MBF in the left anterior descending (LAD) coronary artery (intracoronary adenosine). Animals (n = 6) had sequential single- and dual-bolus perfusion studies with microsphere determination of absolute MBF. Perfusion imaging was performed using a saturation-recovery gradient-echo sequence. Absolute MBF was by Fermi function deconvolution and compared to transmural, endocardial, and epicardial microsphere values in the same region of interest (ROI).
  
  
  RESULTS
  Signal and contrast were significantly higher for the dual-bolus perfusion images. The correlation with MBF by microspheres was r = 0.94 for the dual-bolus method and r = 0.91 for the single-bolus method. There was no significant difference between MRI and microsphere MBF values for control or hyperemic zones for transmural segments for either technique. When the ROI was reduced to define endocardial and epicardial zones, single-bolus MR first-pass imaging significantly overestimated MBF and had a significantly larger absolute error vs. microspheres when compared to dual-bolus perfusion.
  
  
  CONCLUSIONS
  Both single-bolus and dual-bolus perfusion methods correlate closely with MBF but the signal and contrast of the dual-bolus images are greater. With smaller nontransmural ROIs where signal is reduced, the dual-bolus method appeared to provide slightly more accurate results.
authors.affiliation: Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 05495, USA. Timothy.christain@uvm.edu
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Christian
authors.forename: Anthony H
authors.initials: AH
authors.lastname: Aletras
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Arai
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D003287:Contrast Media / Q000008:administration & dosage*; D003326:Coronary Circulation / Q000502:physiology*; D004285:Dogs; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D007089:Image Enhancement / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008863:Microspheres; D023421:Models, Animal; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA