Comparison of Original and 2018 Lake Louise Criteria for Diagnosis of Acute Myocarditis: Results of a Validation Cohort

Abstract

Purpose: To compare the diagnostic performance of the original Lake Louise criteria (LLC) and the 2018 LLC for the diagnosis of acute myocarditis and simultaneously validate previously reported cutoff values for parametric mapping techniques.

Materials and methods: A total of 40 patients with acute myocarditis and 26 control participants underwent cardiac MRI. Cardiac MRI protocol allowed for assessment of T2 signal intensity ratio, early gadolinium enhancement ratio, late gadolinium enhancement, T1 relaxation times, extracellular volume fraction, and T2 relaxation times. The original and the 2018 LLC were assessed, and differences between sensitivities and specificities were calculated with the McNemar test.

Results: The 2018 LLC yielded a sensitivity of 87.5% (95% confidence interval [CI]: 73.9%, 94.5%) and a specificity of 96.2% (95% CI: 81.1%, 99.3%). The original LLC had a sensitivity of 72.5% (95% CI: 57.2%, 83.9%) and a specificity of 96.2% (95% CI: 81.1%, 99.3%). Sensitivity of the 2018 LLC was significantly higher compared with the sensitivity of original LLC (P = .031). No differences in specificity were observed between both scores (P = .999).

Conclusion: Multiparametric cardiac MRI has a high diagnostic value for the diagnosis of patients clinically suspected of having acute myocarditis. The 2018 LLC further improve the diagnostic performance of cardiac MRI by increasing its sensitivity. An implementation of the new score into routine diagnostic protocols should be considered.© RSNA, 2019See also the commentary by Gutberlet and Lücke in this issue.Supplemental material is available for this article.

Figure 1:

Illustration shows original and 2018 Lake Louise criteria (LLC) in a 24-year-old man with acute myocarditis. Original LLC consisted of three main criteria: regional high T2 signal intensities on T2-weighted images (white arrows) or increased global T2 signal intensity ratio, increased early gadolinium enhancement ratio on T1-weighted images, and areas with high signal intensities in nonischemic distribution pattern on late gadolinium enhancement (LGE) images (white arrows). 2018 LLC consist of two main criteria (T1-based criterion and T2-based criterion). T1-based criterion is considered to be positive if increase of native T1 relaxation times, increase of extracellular volume (ECV), or positive LGE (white arrows) exist. T2-based criterion is positive in cases of increased T2 relaxation times or in cases with regional high T2 signal intensities on T2-weighted images (white arrows) or increased global T2 signal intensity ratio. Gd = gadolinium, SI = signal intensity, STIR = short tau inversion recovery.

Figure 2:

Graphs show receiver operating characteristic curves for, A, T2 signal intensity (SI) ratio (area under curve [AUC], 0.70), early gadolinium enhancement ratio (EGEr) (AUC, 0.67), late gadolinium enhancement (LGE) (AUC, 0.89), and Lake Louise criteria (LLC) (AUC, 0.84) and for, B, native T1 relaxation times (AUC, 0.92), extracellular volume (ECV) (AUC, 0.66), T2 relaxation times (AUC, 0.91), and 2018 LLC (AUC, 0.92).

Figure 3:

Column graph shows overall diagnostic accuracies for single parameters and for Lake Louise criteria (LLC). Error bars indicate 95% confidence intervals. ECV = extracellular volume fraction, EGEr = early gadolinium enhancement ratio, LGE = late gadolinium enhancement, SI = signal intensity.