Assessment of left ventricular thrombi using cardiac CT: A comparative evaluation of non-contrast, CT-angiography, delayed-enhanced images, and extracellular volume maps.

BACKGROUND: To evaluate and compare the diagnostic performance of non-contrast, early-phase, delayed-phase images, and CT-derived extracellular volume (ECV) maps in detecting left ventricular (LV) thrombus (LVT) using cardiac computed tomography (CT).

METHODS: We retrospectively analyzed 30 patients (mean age 64.3 ​± ​13.6 years) with clinically diagnosed LVT who underwent multiphase cardiac CT. Imaging protocols included non-contrast CT, coronary CT angiography (early-phase), delayed-phase CT acquired 7 ​min post-contrast, and CT-derived ECV mapping. Quantitative analysis involved measuring CT attenuation values of LVT, myocardium, and LV cavity. Two cardiovascular radiologists independently performed qualitative visual conspicuity scoring. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS: Early-phase, delayed-phase, and ECV maps demonstrated significant differentiation among LVT, myocardium, and LV cavity, with ECV maps showing the highest classification accuracy. Visual conspicuity scores were also highest for ECV maps. ROC curve analysis revealed superior diagnostic performance for delayed-phase images (AUC 0.95) and ECV maps (AUC 0.98), compared with early-phase (AUC 0.78) and non-contrast images (AUC 0.55).

CONCLUSION: Delayed-phase imaging and CT-derived ECV mapping significantly improve the detection and characterization of LVT compared with non-contrast and early-phase CT. Incorporating these imaging techniques into cardiac CT protocols may improve diagnostic confidence and facilitate timely clinical decision-making in patients at risk of thromboembolic events.