title: The prevalence and predictive accuracy of quantitatively defined transient ischemic dilation of the left ventricle on otherwise normal SPECT myocardial perfusion imaging studies.
abstract: OBJECTIVE
  TID in the setting of otherwise normal MPI has been suggested as a marker of high risk CAD. In this study we estimate the variance of TID in a normal population and the statistical frequency of false positive TID. This will provide an indirect measurement of predictive accuracy (PA) in a mixed referral population.
  
  
  OBJECTIVE
  To study the PA of TID in otherwise normal MPI.
  
  
  METHODS
  688 consecutive patients were studied. We defined TID according to the standard method at 2 cut-off values; 1SD and 2SD, and also by a BSA normalized volume difference with gender-specific 2SD limits (NrVD).
  
  
  RESULTS
  457 patients with otherwise normal MPI were analyzed. PA of TID at 1SD was 4% and 26% at 2SD. PA was slightly higher (42%) using the NrVD, however, still too low to be clinically useful as a high-risk marker. PA of TID in patients with perfusion abnormalities was 58% at 1SD, 80% at 2SD and slightly higher (93%) by NrVD.
  
  
  CONCLUSIONS
  In the setting of otherwise normal MPI, elevated TIDr has a low prevalence and poor predictive accuracy and should not be considered summarily as a marker of high risk CAD.
authors.affiliation: Cardiology Department, Al-Azhar School of Medicine, Cairo, Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Mandour Ali
authors.forename: Jamieson M
authors.initials: JM
authors.lastname: Bourque
authors.forename: Adel H
authors.initials: AH
authors.lastname: Allam
authors.forename: George A
authors.initials: GA
authors.lastname: Beller
authors.forename: Denny D
authors.initials: DD
authors.lastname: Watson
mesh_terms: D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D055414:Myocardial Perfusion Imaging / Q000706:statistics & numerical data*; D015995:Prevalence; D012016:Reference Values; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D014768:Virginia / Q000453:epidemiology