Comparative study on native T₁ value of myocardium between using ConSept and SAX approaches in non-ischemic dilated...

T₁ mapping can noninvasively quantify the native longitudinal relaxation time (T₁ value) of myocardium and provide more information on myocardial fibrosis based on late gadolinium enhancement (LGE). However, the traditional approach of measuring T₁ value limits the popularization and application of this technology in clinic because the whole short axis (SAX) of myocardium is required in the regions of interest (ROI). This study aims to evaluate the diagnostic ability of native T₁ value obtained by comparison between the midventricular septum (ConSept) and SAX approaches in diffuse myocardial lesions.

Retrospective analysis was performed on 38 patients with non-ischemic dilated cardiomyopathy (NIDCM) and 27 healthy controls who underwent T₁ mapping and gadolinium delayed enhancement (LGE) scanning on a 3.0T cardiac magnetic resonance (CMR) in Xiangya Hospital of Central South University. Patients with NIDCM were divided into a LGE positive group and a LGE negative group according to the presence or absence of LGE. The native T₁ value was measured by the ROI placed in the ConSept and SAX, respectively. The ability to distinguish the impaired myocardium from the healthy myocardium and the native T₁ values of the myocardium measured by the 2 approaches were compared between the NIDCM group and the control group.

The native T₁ values of NIDCM group using ConSept or SAX approach were significantly higher than those in the control group (all P<0.001), and the native T₁ values in the LGE positive group were greater than those in the LGE negative group (all P<0.05). There was no significant difference in T₁ value of middle, basal, and apical layer between the ConSept approach and SAX approach (all P>0.05). ConSept and SAX approaches had a good consistency [concordance correlation coefficient (CCC)=0.954].

Comparing to the SAX approach, ConSept approach is a simple and equivalent method to measure the native T₁ value of myocardium and is suitable for clinical application.