Myocardial scar imaging by standard single-energy and dual-energy late enhancement CT: Comparison with pathology and electroanatomic map in an experimental chronic infarct porcine model

• Single- and dual-energy CT delayed enhancement imaging overestimated scar compared to pathology.
• Dual-energy CT overestimated infarct size more than single-energy.
• Single-energy CT with 100kV outperformed 80kV imaging for scar quantification.
• Single-energy CT with 100 kV matched best to pathology and electroanatomical mapping.
• Larger human trials and technical-based studies optimizing varying different energies are needed.

BackgroundMyocardial scar is a substrate for ventricular tachycardia and sudden cardiac death. Late enhancement CT imaging can detect scar, but it remains unclear whether newer late enhancement dual-energy (LE-DECT) acquisition has benefit over standard single-energy late enhancement (LE-CT).ObjectiveWe aim to compare late enhancement CT using newer LE-DECT acquisition and single-energy LE-CT acquisitions with pathology and electroanatomic map (EAM) in an experimental chronic myocardial infarction (MI) porcine study.MethodsIn 8 pigs with chronic myocardial infarction (59 ± 5 kg), we performed dual-source CT, EAM, and pathology. For CT imaging, we performed 3 acquisitions at 10 minutes after contrast administration: LE-CT 80 kV, LE-CT 100 kV, and LE-DECT with 2 postprocessing software settings.ResultsOf the sequences, LE-CT 100 kV provided the best contrast-to-noise ratio (all P ≤ .03) and correlation to pathology for scar (ρ = 0.88). LE-DECT overestimated scar (both P = .02), whereas LE-CT images did not (both P = .08). On a segment basis (n = 136), all CT sequences had high specificity (87%–93%) and modest sensitivity (50%–67%), with LE-CT 100 kV having the highest specificity of 93% for scar detection compared to pathology and agreement with EAM (κ = 0.69).ConclusionsStandard single-energy LE-CT, particularly 100 kV, matched better to pathology and EAM than dual-energy LE-DECT for scar detection. Larger human trials as well as more technical studies that optimize varying different energies with newer hardware and software are warranted.