Abstract 18308: Effective Atomic Number and Electron Density Number in the Infarcted Myocardium Were Significantly Lower Than Normal Group and Non-Infarcted Myocardium Using the Latest Spectral CT

Introduction: Spectral CT with a dual layer detector can be used to acquire new parameters, such as effective atomic (EAN) and electron density number (EDN). Hypothesis: The EAN and EDN obtained from the latest spectral CT with a dual-layer detector in infarcted myocardium were lower than the myocardial in the normal group and non-infarcted myocardia of patients with previous myocardial infarction (MI).

Methods: This retrospective study comprised two groups of patients: those with previous MI (MI group; n = 20; mean age, 73±7 years) and those with clinically suspected coronary artery diseases, no significant stenosis in the coronary arteries, and a normal ECG (normal group; n = 146; age 55±14 years). All patients underwent cardiac spectral CT (7500; Philips) with a dual-layer detector. The EAN and EDN were measured in the interventricular septum (IVS), left ventricle (LV) anterior wall of the (LVAW), and LV lateral wall (LVLW) within a 1.0 mm2 circle at the LV inflow level in axial images during the non-contrast phase and early phase (with a contrast agent).

Results: During the non-contrast phase, the EAN in the infarcted myocardium was significantly lower than those in the normal group (P < 0.01) and the non-infarcted myocardia in the MI group (P < 0.05). During the early phase, the EAN in the infarcted myocardium was also significantly lower than those in the normal group (P < 0.01) and the non-infarcted myocardia in the MI group (P < 0.05). During both phases, the EDN in the infarcted myocardium was significantly lower than those in the normal group (P < 0.01) and the non-infarcted myocardia in the MI group (P < 0.05).

Conclusion: During both phases, the EAN and EDN in the infarcted myocardium were significantly lower than those in the normal group and the non-infarcted myocardia in the MI group. Using this novel CT approach and the data from the non-contrast phase may aid in detecting abnormal characteristics (such as reduced blood flow, fibrotic changes, or inflammation) in the myocardium.