Evaluation of combined coronary CT angiography and dual-energy myocardial perfusion imaging for detection of acute myocardial infarction via second-generation dual-source CT: an experimental study in a porcine phantom model

Objective: To evaluate the diagnostic accuracy of dual-energy 'one-step' combined CT coronary angiography (CCTA) and myocardial perfusion imaging (MPI) for the detection of acute myocardial infarction via second-generation dual-source CT compared with histopathological and conventional coronary angiography (CAG) findings in a porcine phantom. Methods: Seven minipigs underwent transcatheter embolization of the coronary arteries by using gelatin sponge to produce acute myocardial infarction. CAG, dual-energy CCTA, and MPI were performed 20 min before, immediately after, and 24 h following the modeling procedure, respectively. A color-coded iodine map was used to evaluate the myocardial perfusion defects on the 17-segment model. In consensus, two radiologists interpreted all iodine map imaging results from MPI and CCTA. Considering CAG and pathological staining as gold standards, the sensibility and specificity of the CCTA and iodine maps from MPI were evaluated using dual-energy CT. Results: Models of acute myocardial infarction were successfully made in five minipigs. Following coronary embolization, dual-energy CT iodine maps showed 45 infarcted segments and 40 non-infarcted segments. Persegment analysis indicated the sensitivity, specificity, positive predictive value and negative predictive value as 93%, 95%, 95% and 93%, respectively. The corresponding values obtained by per-territory analysis were 100%, 86%, 89% and 100%, with CAG and histopathological findings as reference standards. The effective radiation dose of each dual-energy scan was 3.07 ± 0.85 mSv (2.21-4.49 mSv). Conclusions: Dual-energy 'one-step' combined CCTA and MPI iodine maps for the detection of acute myocardial infarction via second-generation dual-source CT showed enhanced diagnostic accuracy with CAG and histopathology as gold standards. (authors)