title: Single-scan rest∕stress imaging (18)F-labeled flow tracers.
abstract: OBJECTIVE
  The authors report a novel measurement strategy to obtain both rest and stress blood flow during a single, relatively short, scan session.
  
  
  METHODS
  Measurement of rest-stress myocardial blood flow with long-lived tracers usually requires separate scan sessions to remove the confounding effects of residual radioactivity concentration in the blood and tissue. The innovation of this method is to treat the rest-stress scan as a single entity in which the flow parameters change due to pharmacological challenge. With this approach the fate of a tracer molecule is naturally accounted for, no matter if it was introduced during the rest or stress phase of the study. Two new dual-injection kinetic models are considered that represent the response to pharmacological stress as a transitional or transient increase of myocardial blood flow. The authors present the theory of the method followed by the specific application of the theory to (18)F-Flurpiridaz, a new myocardial flow-imaging agent.
  
  
  RESULTS
  Myocardial blood flow was accurately and precisely estimated from a single-scan rest∕stress study for the long half-lived tracer (18)F-Flurpiridaz. By accounting for the time-dependence of the kinetic parameters, the proposed models achieved good accuracy and precision (5%) under different vasodilators and different ischemic states.
  
  
  CONCLUSIONS
  Detailed simulations predict that accurate and precise rest-stress blood flow measurements can be obtained in 20-30 min.
authors.affiliation: Department of Radiology, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: Nathaniel
authors.initials: N
authors.lastname: Alpert
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Dean Fang
authors.forename: Georges
authors.initials: G
authors.lastname: El Fakhri
mesh_terms: D003326:Coronary Circulation; D005240:Feasibility Studies; D006321:Heart / Q000000981:diagnostic imaging / Q000502:physiology; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D049268:Positron-Emission Tomography / Q000379:methods*; D011724:Pyridazines / Q000378:metabolism; D011849:Radioactive Tracers; D012146:Rest; D013312:Stress, Physiological
chemical_list: C525920:BMS 747158-02; D011724:Pyridazines; D011849:Radioactive Tracers