Multiparametric cardiovascular magnetic resonance imaging for the diagnosis of acute myocarditis: a single-center study

BackgroundThe Lake Louise Criteria (LLC) were updated in 2018 to improve accuracy in evaluating myocarditis. However, the diagnostic value of combining conventional magnetic resonance imaging (MRI) with contrast-enhanced whole-heart MRI (CE WH-MRI) in the diagnosis of acute myocarditis (AM) has not been determined.PurposeTo assess the diagnostic accuracy of the updated LLC and test the incremental value of CE WH-MRI in diagnosis of AM.Material and MethodsBetween March 2020 and November 2023, a total of 37 patients with clinically suspected AM were prospectively recruited for this study. The cardiac MR (CMR) protocol for myocarditis and controls included T2-STIR, breath-hold steady-state free precession, native T1, T2, CE WH-MRI, late gadolinium enhancement (LGE), and post-contrast T1 mapping.ResultsFor global native T1, the ideal cutoff value was 1308.5 ms (area under the curve [AUC]=0.879, sensitivity=82%, specificity=79%); for global T2, 43.2 ms (AUC=0.889, sensitivity=96%, specificity=75%), for ECV, 30.5% (AUC=0.946, sensitivity=97%, specificity=93%). The CE WH-MRI sequence detected 268 myocardial involvement (MI) segments, whereas 2D-LGE images identified 181 MI segments. Among 37 patients, 34 (91.9%) met the updated LLC definition for diagnosis, the AUC of updated LLC was 0.946.ConclusionThe updated LLC, as a recommended criterion for the diagnosis of AM, had better diagnostic accuracy compared with CMR mapping imaging. Moreover, this study highlighted the additional diagnostic value of CE WH-MRI in the identification of AM. Then, multiparametric CMR imaging can provide a satisfactory diagnostic value to enhance the accuracy of diagnosing AM.