title: Measurement of absolute epicardial coronary artery flow and flow reserve with breath-hold cine phase-contrast magnetic resonance imaging.
abstract: BACKGROUND
  Noninvasive measurement of absolute coronary arterial flow and coronary flow reserve would be of considerable use in the diagnosis and management of patients with coronary artery disease. Phase-contrast magnetic resonance imaging (MRI) has been used to measure flow in a variety of vessels. The goal of the present study was to determine if MRI measurements of coronary artery flow in a single breath-hold can be used to determine flow reserve and the severity of pericardial stenosis.
  
  
  RESULTS
  In eight mongrel dogs, a closed chest model of partial left anterior descending coronary artery (LAD) occlusion was created. Coronary flows in the left circumflex artery (LCx) and LAD were measured at rest and during adenosine infusion using velocity-encoded, breath-hold MRI and perivascular ultrasound (US) flowmeters. MRI measurements of absolute coronary flow and coronary flow reserve were highly correlated with US (r = .96 and .94, respectively). Flow reserve measured in the constricted LAD was significantly lower than that in the unconstricted LCx by both US (P = .002) and MRI (P = .011).
  
  
  CONCLUSIONS
  MRI measurements of coronary flow and flow reserve were in good agreement with US measurements. In addition, MRI measurements of coronary flow reserve successfully discriminated stenotic from normal vessels. These results indicate that MRI is a useful method for the noninvasive assessment of coronary flow and stenosis.
authors.affiliation: Department of Radiology, University of Texas Southwestern Medical Center at Dallas 75235-9071, USA.
authors.forename: G D
authors.initials: GD
authors.lastname: Clarke
authors.forename: R
authors.initials: R
authors.lastname: Eckels
authors.forename: C
authors.initials: C
authors.lastname: Chaney
authors.forename: D
authors.initials: D
authors.lastname: Smith
authors.forename: J
authors.initials: J
authors.lastname: Dittrich
authors.forename: W G
authors.initials: WG
authors.lastname: Hundley
authors.forename: M
authors.initials: M
authors.lastname: NessAiver
authors.forename: H F
authors.initials: HF
authors.lastname: Li
authors.forename: R W
authors.initials: RW
authors.lastname: Parkey
authors.forename: R M
authors.initials: RM
authors.lastname: Peshock
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000000981:diagnostic imaging / Q000502:physiology; D003326:Coronary Circulation / Q000187:drug effects; D004285:Dogs; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010496:Pericardium / Q000000981:diagnostic imaging / Q000502:physiology*; D012016:Reference Values; D012119:Respiration; D012212:Rheology; D014463:Ultrasonography
chemical_list: D000241:Adenosine