Value of cardiac magnetic resonance in the diagnosis of myocardial contusion / 中华创伤杂志

ABSTRACT

Objective:To evaluate the diagnostic value of cardiac magnetic resonance (CMR) in myocardial contusion.Methods:A case-control study was performed on 42 patients with blunt chest injury treated in Affiliated Hospital of Hangzhou Normal University from September 2018 to January 2021. There were 24 males and 18 females, with the age range of 23-66 years [(44.2±10.9)years]. The patients were divided into myocardial contusion group ( n=20) and non-myocardial contusion group ( n=22) according to the clinical diagnostic criteria of myocardial contusion (cardiac troponin I>0.06 ng/ml). All the patients underwent CMR examination within 7 days after hospitalization, and eletrocardiography (ECG) as well as transthoracic echocardiography (TTE) examinations with 24 hours. Abnormal findings on CMR, ECG and TTE were compared between the two groups. The receiver operating characteristic (ROC) curve was used for the comparison of the diagnostic efficacy of CMR, ECG and TTE for myocardial contusion. The area under the curve (AUC), sensitivity, specificity, positive predictive value and Youden index of CMR, ECG and TTE were calculated, respectively. Results:There were 15 patients (75%) presenting CMR abnormalities in myocardial contusion group compared to 2 patients (9%) in non-myocardial contusion group ( P<0.01). CMR abnormalities mainly included myocardial oedema, ischemia or hemorrhage, which were located in the left ventricle of 12 patients (71%), right ventricle of 3 (18%) and ventricular septal of 3 (12%). There were 12 patients (60%) showing ECG abnormalities in myocardial contusion group compared to 7 patients (32%) in non-myocardial contusion group ( P>0.05). Abnormal ECG changes included 8 patients (42%) with sinus tachycardia or bradycardia, 5 (26%) with ST-T changes, 3 (16%) with atrial premature beat, 2 (11%) with bundle branch block and 1 (5%) with frequent premature ventricular contractions. There were 10 patients (50%) showing TTE abnormalities in myocardial contusion group compared to 9 patients (41%) in non-myocardial contusion group ( P>0.05). TTE abnormalities manifested as left ventricular diastolic dysfunction in 12 patients (63%) and wall motion abnormalities in 7 (37%). The AUC of CMR, ECG and TTE for diagnosing myocardial contusion was 0.83 (95% CI 0.70-0.96), 0.64 (95% CI 0.47-0.81) and 0.55 (95% CI 0.70-0.72), respectively. For CMR, ECG and TTE, the diagnostic sensitivity was 75.0%, 60.0% and 50.0%, with the specificity of 91.0%, 68.2% and 59.1%, the positive predictive value was 88.2%, 63.2% and 52.6%, and the Youden index of 66.0, 28.2 and 9.1, respectively. Conclusion:CMR can accurately detect myocardial contusion, with better diagnostic performance than ECG and TTE as well as relatively higher sensitivity and specificity, indicating that CMR has great value for clinical diagnosis of myocardial contusion.