[T1 mapping and late gadolinium enhancement for the diagnosis of dilated cardiomyopathy].

OBJECTIVE

To explore the role of T1 mapping and late gadolinium enhancement (LGE) for detection of dilated cardiomyopathy (DCM).

METHODS

Thirty-two DCM patients detected by ultrasonic testing with unknown origin heart failure from April 2018 to November 2019 were involved. In addition, they were compared with 18 physical examiner under cardiac magnetic resonance imaging (CMRI) in the same period. Phillip's Ingenia 3.0T MRI was used to examine heart function, plain scan included cine, T2 weighted imaging (T2WI) and pre-contrast native T1 mapping. The enhancement scan included perfusion weighted imaging, LGE imaging and post-contrast post T1 mapping. Using gadolinium injection, a bolus of 0.1 mL/kg of gadolinium-based contrast followed by a 20 mL saline flush was administered. After a 7-minute later start scanning, delay enhance sequence was started, including 4 layers, 2 cavities and 4 cavities. LGE and T1 mapping results were observed, including cardiac function indexes [left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), valvular regurgitation], cardiac morphological indexes [left ventricular mass (LVM)], histological characteristics (T2WI myocardial signal, presence of perfusion defect and its position and scope, presence of delayed enhancement and its position, shape and scope, pre- and post-contrast T1 values), extracellular volume (ECV) and the accompanying signs (pericardial effusion and pleural effusion). The receiver-operating characteristic curve (ROC) was drawn, the diagnostic value of T1 value of pre-contrast T1 mapping for DCM was evaluated, and the occurrence of clinical endpoint events was observed.

RESULTS

There were no statistically significant differences in DCM patients with gender, age, body mass index (BMI), blood pressure, heart rate (HR), hematocrit (HCT), creatinine (Cr), family history of hypertension or heart disease. In DCM group N-terminal brain natriuretic peptide precursor (NT-proBNP) level and proportion of patients with heart function level III, diabetes, smoking history, drinking history and medication history were significantly higher than those in control group. Compared with control group, LVEDV (mL/m: 234.9±35.9 vs. 121.8±27.6), LVESV (mL/m: 189.7±42.8 vs. 54.8±17.0), LVM (g: 197.6±56.3 vs. 110.5±22.9), pre-contrast T1 values (ms: 1 332.1±35.9 vs. 1 272.0±47.0), ECV [(45.7±4.9)% vs. (28.0±2.1)%] were significantly increased in the DCM group; LVEF (0.191±0.107 vs. 0.554±0.103), post-contrast T1 values (ms: 453.9±72.7 vs. 493.5±43.9) were significantly decreased (all P < 0.05). In DCM group, the proportions of valvular regurgitation, pericardial effusion and pleural effusion were 25.0%, 18.8% and 25.5%, respectively. ROC curve analysis showed that the cutoff value of pre-contrast T1 values was 1 220.22 ms, the area under ROC curve (AUC) was 0.84 (P = 0.015), the sensitivity and specificity were 77.8% and 88.9%, indicating that pre-contrast T1 values may be a certain prediction for diagnosis of DCM. In 32 patients with DCM, 22 cases (68.8%) had LGE in position wall, interventricular septum, inferior wall or under the epicardium, with local or multiple diffuse, 9 cases (28.1%) were both interventricular septum and inferior wall involved. During an average of 16 months follow-up, 3.1% patients appeared sudden cardiac death.

CONCLUSIONS

One-stop CMRI can improve the diagnostic efficacy of DCM, and T1 mapping with LGE imaging can improve the diagnostic accuracy, which is very meaningful for diagnosis and follow-up of patients.