title: Blood oxygen level-dependent (BOLD) magnetic resonance imaging in patients with dypiridamole induced ischaemia; a PET comparative study.
abstract: BACKGROUND
  Blood oxygen level-dependent (BOLD) MRI relies on changes in deoxyhaemoglobin level in tissues under stress for signal variation and may be used for detection of ischaemic myocardium.
  
  
  METHODS
  15 patients with stress induced myocardial ischaemia on PET scanning underwent rest and dypiridamole stress MRI using a double breath-hold T2-weighted, ECG gated sequence to produce BOLD contrast images and cine-MRI for wall thickening assessment. Signal change on BOLD MRI and wall thickening were compared between rest and stress images in ischaemic and non-ischaemic myocardial segments.
  
  
  RESULTS
  Using PET, 156 segments were identified with reversible ischaemia and 324 as non-ischaemic. The ischaemic segments were found on BOLD MRI to have an average signal change between rest and stress of -16.7% compared to -14% in the non-ischaemic segments (p=0.04). The average wall thickening was 7.8 mm in the ischaemic segments compared with 9.5 mm in the non-ischaemic segments (p<0.0001).
  
  
  CONCLUSIONS
  BOLD MRI with wall thickening assessment may differentiate ischaemic from non-ischaemic myocardium in patients with stress induced myocardial ischaemia. Larger studies with improved spatial resolution would help define a threshold for detection of ischaemia as well as determine this technique's sensitivity and specificity.
authors.affiliation: Cardiology Department, Cardio-thoracic Centre, Thomas Drive, Liverpool L14 3PE, UK. m.egred@ctc.nhs.uk
authors.forename: M
authors.initials: M
authors.lastname: Egred
authors.forename: G D
authors.initials: GD
authors.lastname: Waiter
authors.forename: S I K
authors.initials: SI
authors.lastname: Semple
authors.forename: T W
authors.initials: TW
authors.lastname: Redpath
authors.forename: A
authors.initials: A
authors.lastname: Al-Mohammad
authors.forename: M Y
authors.initials: MY
authors.lastname: Norton
authors.forename: M J
authors.initials: MJ
authors.lastname: Metcalfe
authors.forename: S
authors.initials: S
authors.lastname: Walton
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000150:complications; D003326:Coronary Circulation; D004176:Dipyridamole / Q000494:pharmacology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology; D010100:Oxygen; D049268:Positron-Emission Tomography; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D014665:Vasodilator Agents; D004176:Dipyridamole; D010100:Oxygen