title: Visual identification of coronary calcifications on attenuation correction CT improves diagnostic accuracy of SPECT/CT myocardial perfusion imaging.
abstract: Coronary artery calcium (CAC) is a powerful CAD risk marker when assessed by dedicated calcium scoring CT scan. We assessed diagnostic implications of CAC visible on attenuation correction CT scans (CTAC) from SPECT/CT myocardial perfusion imaging (MPI).
  
  
  
  Visual presence or absence of CAC was assessed on CTAC in 1047 consecutive patients undergoing SPECT/CT MPI. Accuracy of MPI was assessed in patients undergoing invasive coronary angiography (ICA) within 1 year (n = 109). Outcomes were identified by retrospective chart review.
  
  
  
  Prevalence of true positive SPECT/CT MPI studies was greater among patients with CAC on CTAC (70% vs 16%; p < .001); prevalence of false positive studies was greater among those without (68% vs 15%; p < .001). PPV of MPI was 0.82 in patients with CAC, but only 0.19 in those without. Within median follow-up of 27.7 months, patients with CAC had higher all-cause mortality (6% vs 0.4%; p < .001), more late revascularizations (8% vs 0.4%; p < .001), and more MI (5% vs 0.2%; p < .001). Hazard ratio for all-cause mortality, MI, or late revascularization was 22.7 (p < .001) for patients with CAC vs those without.
  
  
  
  Visual assessment of CAC on CTAC should be performed during SPECT/CT MPI because it affects diagnostic certainty and may improve risk stratification.
authors: Department of Internal Medicine, Boston Medical Center and Boston University School of Medicine, Boston, MA, USA.
authors: Nicholas D
authors: ND
authors: Patchett
authors: Department of Internal Medicine, Boston Medical Center and Boston University School of Medicine, Boston, MA, USA.
authors: Sumeet
authors: S
authors: Pawar
authors: Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, New Haven, CT, 06520, USA. edward.miller@yale.edu.
authors: Edward J
authors: EJ
authors: Miller
mesh_terms: D016477:Artifacts; D000072226:Computed Tomography Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000072098:Single Photon Emission Computed Tomography Computed Tomography / Q000379:methods*; D014584:User-Computer Interface; D061205:Vascular Calcification / Q000000981:diagnostic imaging*
keywords: Myocardial perfusion imaging: SPECT; computed tomography (CT); coronary artery disease; diagnostic and prognostic application