Endogenous assessment of late gadolinium enhancement grey area in patients with chronic myocardial infarction using T1rho mapping.

BACKGROUND

The grey area in myocardial infarction (MI) patients is crucial for prognosis. T1rho mapping is a promising magnetic resonance imaging (MRI) technique for ischemic cardiomyopathy. This study aims to investigate the feasibility of T1rho in evaluating the tissue characteristics of the grey area adjacent to the infarcted myocardium.

METHODS

A total of 40 chronic MI patients with positive late gadolinium enhancement (LGE) and 23 healthy controls were enrolled in the study. For the MI patients, the myocardium was divided into the LGE core [5 standard deviation (SD) above remote myocardium], grey area (2-5 SD above remote myocardium), and remote myocardium based on LGE signal intensity. We compared the native T1, T1rho, and extracellular volume (ECV) values among different myocardial regions in MI patients and healthy controls and assessed their diagnostic performance in identifying grey areas.

RESULTS

The native T1, T1rho, and ECV values were significantly different across the four myocardium categories (LGE core, grey area, remote area, and healthy controls, P<0.001). Pairwise analysis showed significant differences in these parameters between the grey and remote areas (native T1: 1,341.34±57.27 . 1,264.79±46.42 ms; T1rho: 53.47±4.83 . 44.26±2.68 ms; ECV: 36.95%±5.66% . 28.03%±1.87%, all P<0.05). Receiver operating characteristic (ROC) analysis indicated that T1rho was a more effective discriminator between the LGE grey area and the remote area of patients [area under the curve (AUC): 0.985 . 0.863 and 0.982] compared to native T1 and ECV, with its Youden index reaching 0.921.

CONCLUSIONS

T1rho mapping presents a viable tool for detecting fibrosis of a grey area in chronic MI patients.