title: Semi-quantitative myocardial perfusion measured by computed tomography in patients with refractory angina: a head-to-head comparison with quantitative rubidium-82 positron emission tomography as reference.
abstract: BACKGROUND
  Computed tomography (CT) is a novel method for assessment of myocardial perfusion and has not yet been compared to rubidium-82 positron emission tomography (PET). We aimed to compare CT measured semi-quantitative myocardial perfusion with absolute quantified myocardial perfusion using PET and to detect stenotic territories in patients with severe coronary artery disease.
  
  
  METHODS
  Eighteen patients with stenosis narrowing coronary arteries ≥70% demonstrated on invasive coronary angiography underwent rest and adenosine stress imaging obtained by 320-multidetector CT scanner and CT/PET 64-slice scanner. CT measured myocardial attenuation density (AD) and perfusion index (PI) were correlated to absolute PET myocardial perfusion values.
  
  
  RESULTS
  Rest AD, rest and stress PI did not correlate to PET findings (r = 0·412, P = 0·113; r = 0·300, P = 0·259; and r = 0·508, P = 0·064, respectively). However, there was a significant correlation between stress AD and stress PET values (r = 0·670, P = 0·009) and between stress and rest differences for AD and PI with PET differences (r = 0·620, P = 0·006; and r = 0·639, P = 0·004, respectively). Furthermore, significant differences were observed between remote and stenotic territories for rest and stress AD (48 ± 14HU and 37 ± 16HU, P = 0·002; 76 ± 19HU and 58 ± 13HU, P<0·001, respectively), PI (9·6 ± 2·9 and 7·5 ± 3·1, P = 0·002; 21·6 ± 4·1 and 16·9 ± 3·9, P<0·001, respectively) and PET (0·96 ± 0·37 ml g-1min-1and 0·86 ± 0·26 ml g-1min-1, P = 0·036; 2·07 ± 0·76 ml g-1min-1and 1·61 ± 0·76 ml g-1min-1, P = 0·006, respectively).
  
  
  CONCLUSIONS
  Semi-quantitative CT parameters may be useful in the detection of myocardium subtended by stenotic coronary arteries.
authors.affiliation: Department of Cardiology & Cardiac Catheterization Laboratory 2014, The Heart Centre, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Qayyum
authors.affiliation: Department of Cardiology & Cardiac Catheterization Laboratory 2014, The Heart Centre, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.
authors.forename: Jørgen Tobias
authors.initials: JT
authors.lastname: Kühl
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjaer
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.
authors.forename: Philip
authors.initials: P
authors.lastname: Hasbak
authors.affiliation: Department of Cardiology & Cardiac Catheterization Laboratory 2014, The Heart Centre, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.|Department of Radiology, Diagnostic Center, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.
authors.forename: Klaus Fuglsang
authors.initials: KF
authors.lastname: Kofoed
authors.affiliation: Department of Cardiology & Cardiac Catheterization Laboratory 2014, The Heart Centre, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, Copenhagen University, Copenhagen, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Kastrup
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging* / Q000503:physiopathology; D000072226:Computed Tomography Angiography; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D000072078:Positron Emission Tomography Computed Tomography; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012414:Rubidium Radioisotopes / Q000008:administration & dosage*; D012720:Severity of Illness Index; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D012414:Rubidium Radioisotopes; D014665:Vasodilator Agents; D000241:Adenosine
keywords: computed tomography; invasive coronary angiogram; myocardial perfusion imaging; positron emission tomography; rubidium-82