title: Diagnostic accuracy of myocardial perfusion imaging in a study population without post-test referral bias.
abstract: BACKGROUND
  Most previous studies on the accuracy of myocardial perfusion imaging (MPI) are hampered by post-test referral bias, in that referral for coronary angiography was influenced by the MPI result. In this way, patients with a normal MPI result less frequently underwent catheterization, a tendency supposed to cause an underestimation of test specificity and an overestimation of test sensitivity.
  
  
  RESULTS
  MPI by use of a gated dual-isotope protocol was undertaken before angiography in 357 patients referred for angiography for suspected stable angina pectoris. The MPI reports were kept secret to prevent post-test referral bias. The MPI study was normal in 215 patients (60%) and showed reversible perfusion abnormalities in 118 (33%) and fixed defects in 24 (7%). Angiography was normal in 231 patients (65%) and revealed 1 or more significant stenoses in 126 (35%). With angiography as the reference, the sensitivity and specificity of MPI for detecting significant coronary artery stenosis were 75% and 79%, respectively.
  
  
  CONCLUSIONS
  In this prospective study without post-test referral bias, we found a lower sensitivity and slightly higher specificity than in studies with post-test referral bias. The imperfect accuracy may reflect differences between anatomic and physiologic imaging.
authors.affiliation: Department of Nuclear Medicine, Odense University Hospital, Sdr Boulevard 29, DK-5000 Odense C, Denmark. allan.johansen@dadlnet.dk
authors.forename: Allan
authors.initials: A
authors.lastname: Johansen
authors.forename: Poul Flemming
authors.initials: PF
authors.lastname: Høilund-Carlsen
authors.forename: Henrik Wulff
authors.initials: HW
authors.lastname: Christensen
authors.forename: Werner
authors.initials: W
authors.lastname: Vach
authors.forename: Henrik Boel
authors.initials: HB
authors.lastname: Jørgensen
authors.forename: Annegrete
authors.initials: A
authors.lastname: Veje
authors.forename: Torben
authors.initials: T
authors.lastname: Haghfelt
mesh_terms: D015982:Bias; D015897:Comorbidity; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000453:epidemiology*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000453:epidemiology*; D011379:Prognosis; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*