Objective:To investigate the utility of cardiac magnetic resonance (CMR) multiparametric imaging in the etiological and differential diagnoses of troponin increase with non-obstructive coronary arteries (TINOCA).Methods:A retrospective analysis was conducted on patients diagnosed with TINOCA and confirmed by coronary angiography in Dongguan Kanghua Hospital from January 2018 to June 2023. CMR examinations were performed within 7 days of onset. The examination sequences included "black blood" single-shot balanced turbo field echo with breath-hold, balanced turbo field echo with breath-hold, T 2-weighted short tau inversion recovery black blood, modified gradient and spin echo black blood with SENSE, dynamic balanced turbo field echo, and phase-sensitive inversion recovery [late gadolinium enhancement (LGE)]. Based on the imaging findings, patients were categorized into 4 groups: myocardial infarction with non-obstructive coronary arteries (MINOCA) group, acute myocarditis group, Takotsubo syndrome group, and CMR negative group. The observed indices included left ventricular function, myocardial edema, first perfusion, and LGE of contrast enhancement. The differences in these parameters among the aforementioned disease groups were statistically compared. The categorical data were analyzed between groups using the chi-square test or Fisher′s exact probability method. The data in line with normal distribution were statistically described by xˉ±s. The independent-sample t test was used to compare the means of the 2 samples. The data with skewed distribution were described by M ( Q1, Q3). The Mann-Whitney U test was used for intergroup analysis. Results:A total of 33 patients were enrolled in this study, the 4 groups comprised 14(42.4%), 12(36.4%), 0, and 7(21.2%) patients, respectively. The positive rate of CMR diagnosis was 78.8%. The onset age in the MINOCA group significantly differed from that in the acute myocarditis group ( Z=3.32, P=0.001). No significant differences were observed in left ventricular function, number of myocardial edema segments, and T 2 value of the diseased myocardium between the 2 groups ( P>0.05), but the number of abnormal first perfusion was significantly distinct ( P<0.001). Significant differences were observed in the quality and volume of LGE between the 2 groups ( P<0.05 for all). Conclusion:CMR multiparameteric imaging technology plays a unique role in the etiological diagnosis of TINOCA, accurately distinguishing TINOCA caused by MINOCA, acute myocarditis, and other cardiac causes.