Assessing the Accuracy of Cine Post‐Contrast Cardiac Magnetic Resonance Imaging: Application in Acute Viral Myocarditis

Background In myocarditis, cardiac magnetic resonance imaging (MRI) provides diagnostic and prognostic insights by assessing the presence of myocarditis lesions on late gadolinium enhancement (LGE) sequences and evaluating left ventricular ejection fraction (LVEF). The balanced steady‐state free precession (b‐SSFP) sequence is commonly used to assess LVEF. Recently, b‐SSFP after gadolinium‐based contrast injection (b‐SSFP‐Gd) has been integrated into cardiac MRI protocols. We hypothesized that b‐SSFP‐Gd enhances the MRI protocol for acute viral myocarditis diagnosis by improving lesion detection and reducing examination time. This study simultaneously evaluated the performance of b‐SSFP‐Gd for the detection of acute viral myocarditis lesions compared with the LGE sequence and for LVEF measurement compared with the b‐SSFP sequence. Methods This retrospective single‐center study included 38 patients with strong evidence of acute viral myocarditis. The 17‐Segment American Heart Association classification was used to compare the number of affected segments on LGE and b‐SSFP‐Gd. Diagnostic performance was assessed using sensitivity, specificity, and area under the curve analysis. LVEF was measured in 30 patients using b‐SSFP and b‐SSFP‐Gd. The results were statistically analyzed using Pearson's correlation, paired t‐tests, and intraclass correlation coefficients. Results The sensitivity and specificity of b‐SSFP‐Gd were 100.0% (95% confidence interval: 90.8%–100.0%) and 100.0% (95% confidence interval: 91.2%–100.0%), respectively, with an area under the curve of 1.000 for lesion detection. The number of segments measured on LGE sections correlated with the number of segments measured on b‐SSFP‐Gd in diastole ( r [36] = 0.83, p < 0.001) and systole ( r [36] = 0.78, p < 0.001). There was no statistically significant difference in LVEF between b‐SSFP and b‐SSFP‐Gd ( p = 0.34). Conclusions b‐SSFP‐Gd more accurately detected myocarditis lesions than the LGE sequence and was as effective as the b‐SSFP sequence for LVEF calculation. b‐SSFP‐Gd could be integrated into cardiac MRI protocols to aid in the diagnosis of acute myocarditis, along with the LGE sequence, while reducing the overall examination time by replacing b‐SSFP for LVEF measurement.