Abstract 15476: Advanced Assessment of Regional Differences in Myocardial Perfusion by Spectral CT in Patients With Acute Myocarditis

Abstract

Introduction: Spectral CT (SCT) is a valuable tool for assessing coronary anatomy and myocardial damage. Iodine distribution maps (IDM) obtained by SCT serve as surrogates for first-pass myocardial perfusion, exhibiting reduced iodine uptake in ischemic areas and increased uptake in hyperemic areas due to inflammatory injury. Hypothesis: We aimed to determine if SCT data analysis can detect regional differences in first-pass myocardial perfusion reflecting inflammatory injury in acute myocarditis (AM) patients. Methods: We retrospectively searched for acute myocarditis patients admitted to our center who also underwent SCT angiography to rule out CAD. Spectral images (40 keV monoenergetic images and IDM) from a dual-layer CT scanner (Philips Spectral CT 7500) were analyzed using a perfusion tool developed by Philips Research. LV myocardium was segmented following the AHA-17 model, and CT number (HU) and iodine density values (mg/ml) were quantified. Data were normalized using blood pool values. Healthy controls were included for comparison and differences were assessed with a one-way ANOVA. Results: Six patients with myocarditis (median age: 57 [IQR 30-65]; table 1) and 3 controls (median age: 50 [IQR: 47.5-59.5]) were analyzed. Myocarditis patients (figure 1) showed higher normalized median iodine density values (ratio 0.13 vs. 0.11, p<0.001) and similar differences in 40 keV monoenergetic images (ratio 0.16 vs. 0.13, p=0.005). Conclusions: Spectral CT data analysis can detect first-pass myocardial perfusion differences in acute myocarditis patients, likely reflecting hyperemia. Further research is needed to evaluate the clinical benefits of SCT in this context.