title: Functional impact of coronary stenosis observed on coronary computed tomography angiography: Comparison with ¹³N-ammonia PET.
abstract: OBJECTIVE
  We undertook this study to evaluate the functional impact of coronary abnormalities in patients with suspected coronary artery disease (CAD) by means of integrated positron emission tomography (PET) and coronary computed tomography angiography (CCTA) scan obtained on a hybrid state-of-the-art PET/CT scanner.
  
  
  METHODS
  We studied 29 consecutive, patients with a clinically suspected intermediate risk for CAD, using a hybrid PET/CT 64 slice scanner. During a single scanning session, CCTA was performed for coronary anatomy evaluation, and a rest/adenosine stress (13)N-ammonia PET was performed for myocardial perfusion assessment in 3D mode with CT attenuation correction.
  
  
  RESULTS
  Twenty four (82.7%) patients had atherosclerosis detected by CCTA; 15 patients had significant (≥50%) coronary stenoses and all 15 patients showed ischemia by PET; moreover, 10/15 patients had a Summed Stress Score >12.20/24 and 83.3% patients with atherosclerosis detected by CCTA showed ischemia by PET. Two of five patients with normal coronary arteries showed ischemia by PET. CCTA agreement in positive identification of PET ischemia was 91% and agreement in ruling out ischemia was 43%; PET agreement in detecting CCTA atherosclerosis was 83%, and agreement in ruling it out was 60%.
  
  
  CONCLUSIONS
  We found a strong relation between significant coronary stenosis identified by CCTA and ischemia by PET. However, in cases with low-grade stenosis, PET scan can assess the functional significance of atherosclerotic abnormalities.
authors.affiliation: Unidad PET/CT Ciclotrón, Universidad Nacional Autónoma de México, D.F., Mexico. alexanderick@yahoo.com
authors.forename: Erick Alexánderson
authors.initials: EA
authors.lastname: Rosas
authors.forename: Piotr J
authors.initials: PJ
authors.lastname: Slomka
authors.forename: Leonardo
authors.initials: L
authors.lastname: García-Rojas
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Calleja
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Jácome
authors.forename: Moisés
authors.initials: M
authors.lastname: Jiménez-Santos
authors.forename: Edgar
authors.initials: E
authors.lastname: Romero
authors.forename: Aloha
authors.initials: A
authors.lastname: Meave
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Berman
mesh_terms: D000641:Ammonia / Q000737:chemistry; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D049268:Positron-Emission Tomography / Q000379:methods*
chemical_list: D000641:Ammonia