title: Effect of power Doppler and digital subtraction techniques on the comparison of myocardial contrast echocardiography with SPECT.
abstract: OBJECTIVE
  To compare the accuracy and feasibility of harmonic power Doppler and digitally subtracted colour coded grey scale imaging for the assessment of perfusion defect severity by single photon emission computed tomography (SPECT) in an unselected group of patients.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Regional cardiothoracic unit.
  
  
  METHODS
  49 patients (mean (SD) age 61 (11) years; 27 women, 22 men) with known or suspected coronary artery disease were studied with simultaneous myocardial contrast echo (MCE) and SPECT after standard dipyridamole stress.
  
  
  METHODS
  Regional myocardial perfusion by SPECT, performed with (99m)Tc tetrafosmin, scored qualitatively and also quantitated as per cent maximum activity.
  
  
  RESULTS
  Normal perfusion was identified by SPECT in 225 of 270 segments (83%). Contrast echo images were interpretable in 92% of patients. The proportion of normal MCE by grey scale, subtracted, and power Doppler techniques were respectively 76%, 74%, and 88% (p < 0.05) at > 80% of maximum counts, compared with 65%, 69%, and 61% at < 60% of maximum counts. For each technique, specificity was lowest in the lateral wall, although power Doppler was the least affected. Grey scale and subtraction techniques were least accurate in the septal wall, but power Doppler showed particular problems in the apex. On a per patient analysis, the sensitivity was 67%, 75%, and 83% for detection of coronary artery disease using grey scale, colour coded, and power Doppler, respectively, with a significant difference between power Doppler and grey scale only (p < 0.05). Specificity was also the highest for power Doppler, at 55%, but not significantly different from subtracted colour coded images.
  
  
  CONCLUSIONS
  Myocardial contrast echo using harmonic power Doppler has greater accuracy than with grey scale imaging and digital subtraction. However, power Doppler appears to be less sensitive for mild perfusion defects.
authors: University of Queensland, Department of Medicine, Princess Alexandra Hospital, Ipswich Road, Brisbane, Qld 4102, Brisbane, Australia.
authors: B
authors: B
authors: Haluska
authors: C
authors: C
authors: Case
authors: L
authors: L
authors: Short
authors: J
authors: J
authors: Anderson
authors: T H
authors: TH
authors: Marwick
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003287:Contrast Media; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D015150:Echocardiography, Doppler / Q000379:methods*; D018618:Echocardiography, Doppler, Color; D005189:False Positive Reactions; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011134:Polysaccharides; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D003287:Contrast Media; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011134:Polysaccharides; D019275:Radiopharmaceuticals; C059891:SHU 508; C078700:technetium tc-99m tetrofosmin; D004176:Dipyridamole