Joao Rodrigues Inacio MD, Presenter: Nothing to Disclose

Dwivedi Girish, Abstract Co-Author: Nothing to Disclose

Manuja Premaratne, Abstract Co-Author: Nothing to Disclose

Terry Ruddy, Abstract Co-Author: Research Grant, Nordion, Inc Research Grant, General Electric Company

Robert Beanlands, Abstract Co-Author: Nothing to Disclose

Benjamin Chow MD, Abstract Co-Author: Research Grant, General Electric Company Support, TeraRecon, Inc

Vasodilator contrast-enhanced MDCT Myocardial Perfusion Imaging (CT-MPI) has been used for the identification of perfusion abnormalities as a surrogate of myocardial ischemia. Rubidium 82 Positron Emission Tomography   Myocardial Perfusion Imaging (Rb PET MPI) is considered the gold standard for the assessment of myocardial ischemia in CAD. Our goal was to compare the diagnostic accuracy of Rest/ Vasodilator Stress CT-MPI with vasodilator Stress/ Rest Rb PET in identification myocardial ischemia in patients with diagnosed or suspected CAD.

CT-MPI in rest and during intravenous Dipyridamole infusion and rest/adenosine stress Rb PET MPI acquired within 30 days were performed in 45 patients. The extent and severity of perfusion defects on Rb PET-MPI were assessed: 1) qualitatively on a 5-point scale in a standard 17-segment model, and automated calculation of Summed Stress Score (SSS), Summed Rest Score (SRS), and Summed Difference Score (SDS). The extent and severity of perfusion defects on CT-MPI was visually assessed by 2 observers using the same grading scale and expressed as SRS, SSS and SDS. A SDS ≥1 in at least two contiguous myocardial segments was considered diagnostic for the presence of ischemia. CT-MPI was compared with Rb PET as the gold standard, with test comparisons performed on a per territory and per patient basis.

On a per-patient basis, there was moderate agreement between CT-MPI and Rb PET -MPI with a kappa of 0.44 for detection of stress perfusion abnormalities. Using Rb PET as a reference, CT MPI had 89% sensitivity (SS), 59% specificity (SP), 71% accuracy (AC), 89% negative predictive value (NPV) , and 59% positive predictive value (PPV) to diagnose perfusion deficits on a per patient basis. On a per territory analysis, CT MPI had 73% SS, 66 % SP, 67% AC, 91% NPV, and 34% PPV to diagnose perfusion deficits using Rb PET as a reference standard. CT MPI versus Rb PET MPI had an area under the ROC curve (AUC) of 0.74 and 0.70 for diagnosis of ischemia on a per patient basis and per territory respectively.

Stress reversible myocardial perfusion deficit assessed by CT-MPI shows good correlation with PET-MPI in identification of myocardial ischemia.

Stress vasodilator CT- MPI has the potential to identify and characterize coronary artery stenosis and myocardial ischemia in a single study.

Inacio, J, Girish, D, Premaratne, M, Ruddy, T, Beanlands, R, Chow, B, Comparison of Diagnostic Performance of CT Myocardial Perfusion with Rb-82 PET MPI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016204.html