Evaluation of myocardial viability in myocardial infarction by low kilovoltage contrast-enhanced multi-slice CT

Objective: To prospectively evaluate the feasibility and reliablity of low kilovoltage contrast, enhanced multi-slice CT(MSCT) to detect the myocardial viability in chronic myocardial infarction, with comparison to magnetic resonance (MR) myocardial perfusion and viability imaging. Methods: Thirty-two patients with clinical diagnosed chronic myocardial infarction underwent the first pass and delay- enhanced myocardial imaging with 64-slice MSCT and MR. Left ventricle was divided into 16 segments. MSCT and MR images of all the patients were blindly analyzed. The size and extent of hypoenhanced regions in first pass phase and hyperenhanced regions in delayed phase were defined. The Kappa test was used to assess the ability of identifying the viable myocardium between the two methods. Results: In 32 patients with chronic myocardial infarction, MSCT showed hypoenhanced regions in 41 segments and normal in 471 segments during the first phase, while MRI revealed hypoenhanced regions in 47 segments and normal regions in 465 segments. The Kappa value was 0.650 and the concordance rate of the two techniques was 94.5% (484/512). MSCT showed 135 hyperenhanced regions which were non-transmural in 50 segments and transmural in 85 segments. And the other 377 normal segments showed no enhancement in the delayed phase. MRI revealed 120 hyperenhanced regions which were non-transmural in 56 segments and transmural in 64 segments. And the other 392 normal segments showed no enhancement in the delayed phase. The Kappa value of the two techniques was 0.609 and the concordance rate of the two techniques was 80.7% (413/512). Conclusion: The study showed that low kilovoltage CE MSCT has a good concordance with MRI and has high feasibility and reliability in evaluating the myocardial viability in chronic myocardial infarction. The radiation dose is still the important aspect of MSCT application. (authors)