Qualitative and quantitative evaluation of microvascular obstruction with delayed enhancement cardiac computed tomography in patients with ST-segment elevation myocardial infarction.

We aimed to evaluate the capability of delayed enhancement cardiac computed tomography (DE-CT) for the qualitative and quantitative assessments of microvascular obstruction (MVO) in patients with ST-segment elevation myocardial infarction (STEMI) compared with late gadolinium enhancement magnetic resonance imaging (LGE-MRI). We compared DE-CT and LGE-MRI in patients with STEMI who underwent primary percutaneous coronary intervention (PCI) for a de novo lesion. Short-axis images from both modalities were used to measure hyper-enhanced areas (representing infarcted myocardium) and hypo-enhanced areas within the hyper-enhanced regions (representing MVO). These areas were summated for volumetric analyses. Twenty-two patients with STEMI underwent both DE-CT and LGE-MRI a median of eight days after successful primary PCI. MVO was identified in 16 (73%) patients on both DE-CT and LGE-MRI, with excellent agreement between modalities (κ = 0.88, P < 0.001). Quantitatively, the median infarct volumes were 6475 (1850-14260) mm³ on DE-CT and 5756 (1709-14860) mm³ on LGE-MRI. The median MVO volumes were 706 (437-2737) mm³ on DE-CT and 647 (390-2650) mm³ on LGE-MRI. The correlations between DE-CT and LGE-MRI for infarcted myocardium volume (ρ = 0.976, P < 0.0001) and MVO volume (ρ = 0.926, P < 0.0001) were very strong. DE-CT is a viable alternative to LGE-MRI for both qualitative and quantitative assessments of infarcted myocardium and MVO in patients with STEMI.