Clinical utility of non-gated 4-minute delayed dual-energy computed tomography for myocardial extracellular volume quantification.

Abstract

Objectives: To develop and validate the myocardial extracellular volume (ECV) obtained from non-electrocardiography (ECG)-gated delayed CT images acquired 4 minutes post-contrast infusion (4-min-nonECG-ECV) compared with the ECV obtained from ECG-gated delayed CT images acquired 10 min post-contrast infusion (Conv-ECV).

Methods: We retrospectively analysed 29 patients (males: 21) after a comprehensive CT protocol of both 4-min-nonECG-ECV and Conv-ECV on a dual-layer CT scanner. The mean volume of contrast medium administered: 90 ± 11.8 mL, the average heart rate during the CT examinations: 74.2 ± 18.2 bpm. Two independent observers calculated the respective 4-min-nonECG-ECV and Conv-ECV. We determined the correlation between the ECV obtained by the two methods and conducted a Bland-Altman analysis to identify systematic errors and determine the limits of agreement (LOA) between the 4-min-nonECG-ECV and Conv-ECV values.

Results: The respective median ECV values for observer 1 were 27.3 for 4-min-nonECG-ECV and 26.5 for Conv-ECV; for observer 2, they were 27.8 and 27.1. The correlation between the methods was 0.97 for both observers (p < 0.01). The Bland-Altman plots for observers 1 and 2 demonstrated a minor bias (-0.2% and -0.5%, respectively), with the 95% LOA ranges at - 4.4%-4.0% and -5.0%-4.0%, respectively.

Conclusion: The 4-min-nonECG-ECV provided ECV values comparable to those obtained by Conv-ECV.

Advances in knowledge: Myocardial ECV quantification is feasible using a non-gated, 4-minute delayed dual-energy CT scan with an already established CT acquisition method. This approach achieves ECV accuracy comparable to that of the conventional CT-ECV calculation method (gated 10-minute delayed imaging) while enhancing clinical efficacy and diagnostic throughput.