title: Quantitative detection of myocardial ischaemia by stress echocardiography; a comparison with SPECT.
abstract: OBJECTIVE
  Real-time perfusion (RTP) adenosine stress echocardiography (ASE) can be used to visually evaluate myocardial ischaemia. The RTP power modulation technique angio-mode (AM), provides images for off-line perfusion quantification using Qontrast software, generating values of peak signal intensity (A), myocardial blood flow velocity (beta) and myocardial blood flow (Axbeta). By comparing rest and stress values, their respective reserve values (A-r, beta-r, Axbeta-r) are generated. We evaluated myocardial ischaemia by RTP-ASE Qontrast quantification, compared to visual perfusion evaluation with 99mTc-tetrofosmin single-photon emission computed tomography (SPECT).
  
  
  RESULTS
  Patients admitted to SPECT underwent RTP-ASE (SONOS 5500) using AM during Sonovue infusion, before and throughout adenosine stress, also used for SPECT. Visual myocardial perfusion and wall motion analysis, and Qontrast quantification, were blindly compared to one another and to SPECT, at different time points off-line.We analyzed 201 coronary territories (left anterior descendent [LAD], left circumflex [LCx] and right coronary [RCA] artery territories) in 67 patients. SPECT showed ischaemia in 18 patients and 19 territories. Receiver operator characteristics and kappa values showed significant agreement with SPECT only for beta-r and Axbeta-r in all segments: area under the curve 0.678 and 0.665; P < 0.001 and < 0.01, respectively. The closest agreements were seen in the LAD territory: kappa 0.442 for both beta-r and Axbeta-r; P < 0.01. Visual evaluation of ischaemia showed good agreement with SPECT: accuracy 93%; kappa 0.67; P < 0.001; without non-interpretable territories.
  
  
  CONCLUSIONS
  In this agreement study with SPECT, RTP-ASE Qontrast quantification of myocardial ischaemia was less accurate and less feasible than visual evaluation and needs further development to be clinically useful.
authors.affiliation: Department of Biomedical Laboratory Science, Malmö University, Malmö, Sweden. petri.gudmundsson@mah.se
authors.forename: Petri
authors.initials: P
authors.lastname: Gudmundsson
authors.forename: Kambiz
authors.initials: K
authors.lastname: Shahgaldi
authors.forename: Reidar
authors.initials: R
authors.lastname: Winter
authors.forename: Magnus
authors.initials: M
authors.lastname: Dencker
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kitlinski
authors.forename: Ola
authors.initials: O
authors.lastname: Thorsson
authors.forename: Ronnie B
authors.initials: RB
authors.lastname: Willenheimer
authors.forename: Lennart
authors.initials: L
authors.lastname: Ljunggren
mesh_terms: D000368:Aged; D004452:Echocardiography / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D010743:Phospholipids; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D010743:Phospholipids; D019275:Radiopharmaceuticals; C420843:contrast agent BR1; C078700:technetium tc-99m tetrofosmin; D013459:Sulfur Hexafluoride