title: Myocardial oxygenation in coronary artery disease: insights from blood oxygen level-dependent magnetic resonance imaging at 3 tesla.
abstract: OBJECTIVE
  The purpose of this study was to assess the diagnostic accuracy of blood oxygen-level dependent (BOLD) MRI in suspected coronary artery disease (CAD).
  
  
  BACKGROUND
  By exploiting the paramagnetic properties of deoxyhemoglobin, BOLD magnetic resonance imaging can detect myocardial ischemia. We applied BOLD imaging and first-pass perfusion techniques to: 1) examine the pathophysiological relationship between coronary stenosis, perfusion, ventricular scar, and myocardial oxygenation; and 2) evaluate the diagnostic performance of BOLD imaging in the clinical setting.
  
  
  METHODS
  BOLD and first-pass perfusion images were acquired at rest and stress (4 to 5 min intravenous adenosine, 140 μg/kg/min) and assessed quantitatively (using a BOLD signal intensity index [stress/resting signal intensity], and absolute quantification of perfusion by model-independent deconvolution). A BOLD signal intensity index threshold to identify ischemic myocardium was first determined in a derivation arm (25 CAD patients and 20 healthy volunteers). To determine diagnostic performance, this was then applied in a separate group comprising 60 patients with suspected CAD referred for diagnostic angiography.
  
  
  RESULTS
  Prospective evaluation of BOLD imaging yielded an accuracy of 84%, a sensitivity of 92%, and a specificity of 72% for detecting myocardial ischemia and 86%, 92%, and 72%, respectively, for identifying significant coronary stenosis. Segment-based analysis revealed evidence of dissociation between oxygenation and perfusion (r = -0.26), with a weaker correlation of quantitative coronary angiography with myocardial oxygenation (r = -0.20) than with perfusion (r = -0.40; p = 0.005 for difference). Hypertension increased the odds of an abnormal BOLD response, but diabetes mellitus, hypercholesterolemia, and the presence of ventricular scar were not associated with significant deoxygenation.
  
  
  CONCLUSIONS
  BOLD imaging provides valuable insights into the pathophysiology of CAD; myocardial hypoperfusion is not necessarily commensurate with deoxygenation. In the clinical setting, BOLD imaging achieves favorable accuracy for identifying the anatomic and functional significance of CAD.
authors.affiliation: University of Oxford Centre for Clinical Magnetic Resonance Research, John Radcliffe Hospital, Oxford, United Kingdom.
authors.forename: Jayanth R
authors.initials: JR
authors.lastname: Arnold
authors.forename: Theodoros D
authors.initials: TD
authors.lastname: Karamitsos
authors.forename: Paul
authors.initials: P
authors.lastname: Bhamra-Ariza
authors.forename: Jane M
authors.initials: JM
authors.lastname: Francis
authors.forename: Nick
authors.initials: N
authors.lastname: Searle
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Robson
authors.forename: Ruairidh K
authors.initials: RK
authors.lastname: Howells
authors.forename: Robin P
authors.initials: RP
authors.lastname: Choudhury
authors.forename: Ornella E
authors.initials: OE
authors.lastname: Rimoldi
authors.forename: Paolo G
authors.initials: PG
authors.lastname: Camici
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Banning
authors.forename: Stefan
authors.initials: S
authors.lastname: Neubauer
authors.forename: Michael
authors.initials: M
authors.lastname: Jerosch-Herold
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Selvanayagam
mesh_terms: D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D003326:Coronary Circulation / Q000502:physiology*; D004562:Electrocardiography; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D011379:Prognosis; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D010100:Oxygen