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Artificial Intelligence has been widely applied in cardiovascular diseases. Coronary artery disease, one of the most familiar cardiovascular disease, relies highly on visualized functional tests in its diagnosis and risk stratification, which caters to the advantage of artificial intelligence. Recently, several inspiring results of combining artificial intelligence and related functional tests in diagnosis and risk stratification of coronary artery disease were published worldwide. This review focuses on the application progress of artificial intelligence in diagnosis and risk stratification of coronary artery disease.
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Objective To evaluate the accuracy of automated quantification of myocardial perfusion imaging (MPI) using a method based on a Western normal database for the detection of coronary artery disease (CAD) in a group of Chinese patients. Methods Seventy-two Chinese patients who underwent coronary angiography (CAG) and MPI within 3 months were recruited into this study. Eighty selected from 140 Chinese patients with low probability of CAD ( ＜ 5% ) were enrolled into local normal database of 99Tcm-methoxyisobutylisonitrile (MIBI) MPI using Cedars quantitative perfusion SPECT (QPS) database. Two Western MPI normal databases (CSMC MibiMbiAuto and Mibimibi) were used for processing the Chinese CAD patients recruited in this study, and the results were compared with those using local normal database and visual interpretation. T-test and z-test were used for statistical analysis. Results The extent (EXT)measurement obtained from Mibimibi and local database was ( 10.73 ± 14.54)% and ( 14.22 ± 16.51 )%,respectively ( t = 7.87, P ＜ 0.001 ); the severity (SEV) was 1.07 ± 0.93 and 1.34 ± 1.20, respectively ( t =7.45, P＜0.001). The area under curve(AUC) by using EXT measurement for local database (0.85 ±0.05) was larger than that for CSMC MibiMbiAuto ( AUC = 0.72 ± 0.06, z = 2.50, P ＜ 0.01 ) and Mibimibi ( AUC = 0.77 ± 0.06, z = 2.47, P = 0.014). The AUC of local database showed no significant difference from that of visual interpretation (AUC=0.83 ±0.05, z=0.05, P＞0.05). Conclusion Quantification of MPI of our Chinese patients using Western normal database would decrease the accuracy for the detection of CAD.
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Objective To evaluate the effect of various iterative reconstruction methods on phase analysis of gated myocardial perfusion imaging (MPI). Methods Thirty consecutive patients scanned by the Philips CardioMD system were recruited into this study. The gated SPECT (GSPECT) data were reconstructed with filtered backprojection (FBP),maximum likelihood expectation maximization (MLEM),three-di-mensional (3D) resolution recovery MLEM (AST),attenuation corrected (AC) MLEM,AC and 3D Monte Carlo scatter corrected (ACSC) MLEM methods. Parameters of left ventricular ( LV ) dyssynchrony ( phase standard deviation and histogram bandwidth) were measured using the software SyncTool. Paired t-test was used to compare the differences of the LV dyssynchrony indices between FBP and MLEM,AC MLEM,ACSC MLEM,AST respectively. Results The phase standard deviations of stress GSPECT MPI for FBP,MLEM,AC MLEM,ACSC MLEM,and AST were 11.6°,10.9°,11.2°,11.6°,11.4° respectively;while the histogram bandwidths were 35.7°,34.3°,35.1°,36.9°,35. 1 ° respectively. The phase standard deviations of rest GSPECT MPI for FBP,MLEM,AC MLEM,ACSC MLEM and AST were 15.2°,14. 5°,15.4° ,15. 4°,14.8° respectively; while the histogram bandwidths were 47.3°,46.4°,46.4° ,47.9°,46.1 ° respectively. No statistical significance was observed between the FBP and various iterative reconstruction methods for both the stress and rest GSPECT MPI study (t:-1. 179 to 1.554,P＞0.05 forall). Conclusion The standard FBP reconstruction method is accurate enough for the measurement of LV dyssynchrony indices using the widely used clinical software SyncTool.
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<p><b>BACKGROUND</b>Stem cell transplantation has been shown to have beneficial effects on dilated cardiomyopathy. However, mechanism for stem cell homing to cardiac tissue in dilated cardiomyopathy has not yet been elucidated.</p><p><b>METHODS</b>Mesenchymal stem cells were obtained from rat bone marrow, expanded in vitro, and labeled with (99m)Tc. Cardiomyopathy model was induced by doxorubicin in rats. (99m)Tc labeled cells were infused into the left ventricles in cardiomyopathy and control rats. Sixteen hours after injection, animals were sacrificed and different tissues were harvested to measure specific radioactivity. By use of real-time polymerase chain reaction and immunohistochemistry, mRNA and protein expressions for stromal-cell-derived factor 1 in cardiac tissue were measured.</p><p><b>RESULTS</b>Labeling efficiency of mesenchymal stem cells was (70.0 ± 11.2)%. Sixteen hours after mesenchymal stem cell transplantation, the heart-to-muscle radioactivity ratio was increased significantly in cardiomyopathy hearts as compared to control hearts. Both mRNA and protein expressions of stromal-cell-derived factor 1 were up-regulated in cardiomyopathy hearts as compared with control hearts.</p><p><b>CONCLUSION</b>In dilated cardiomyopathy induced by doxorubicin up-regulated expression of stromal-cell-derived factor 1 in heart may induce mesenchymal stem cells home to the heart.</p>