Simultaneous Assessment of Left Atrial Fibrosis and Epicardial Adipose Tissue Using 3D Late Gadolinium Enhanced Dixon MRI

Abstract

Background Epicardial adipose tissue (EAT) may induce left atrium (LA) wall inflammation and promote LA fibrosis. Therefore, simultaneous assessment of these two important atrial fibrillation (AF) risk factors would be desirable. Purpose To perform a comprehensive evaluation of 3D Dixon water–fat separated late gadolinium enhancement (LGE‐Dixon) MRI by analysis of repeatability and systematic comparison with reference methods for assessment of fibrosis and fat. Study Type Prospective. Population Twenty‐eight, 10, and 7 patients, respectively, with clinical indications for cardiac MRI. Field Strength/Sequence A 1.5‐T scanner, inversion recovery multiecho spoiled gradient echo. Assessment Twenty‐eight patients (age 58 ± 19 years, 15 males) were scanned using LGE‐Dixon. A 5‐point Likert‐type scale was used to grade the image quality. Another 10 patients (age 46 ± 19 years, 9 males) were scanned using LGE‐Dixon and 3D proton density Dixon (PD‐Dixon). Finally, seven patients (age 62 ± 14 years, 4 males) were scanned using LGE‐Dixon and conventional LGE. The scan time, intraobserver and interobserver variability, and levels of agreement were assessed. Statistical Tests Student's t‐test, one‐way ANOVA, and Mann–Whitney U‐test were used; P < 0.05 was considered significant, intraclass correlation coefficient (ICC). Results The scan time (minutes:seconds) for LGE‐Dixon (n = 28) was 5:01 ± 1:40. ICC values for intraobserver and interobserver measurements of LA wall fibrosis percentage were 0.98 (95% CI, 0.97–0.99) and 0.97 (95% CI, 0.94–0.99) while of EAT were 0.92 (95% CI, 0.82–0.97) and 0.90 (95% CI, 0.80–0.95). The agreement for LA fibrosis percentage between the LGE‐Dixon and the conventional LGE was 0.92 (95% CI, 0.66–0.99) and for EAT volume between the LGE‐Dixon and the PD‐Dixon was 0.93 (95% CI, 0.72–0.98). Conclusion LA fibrosis and EAT can be assessed simultaneously using LGE‐Dixon. This method allows a high level of intraobserver and interobserver repeatability as well as agreement with reference methods and can be performed in a clinically feasible scan time. Evidence Level 2 Technical Efficacy Stage 3

FK-means: automatic atrial fibrosis segmentation using fractal-guided K-means clustering with Voronoi-clipping feature extraction of anatomical structures

“…with 5 years of experience in cardiovascular imaging) independently confirmed the ground truth and manually labelled the anatomical parts using the same methodology as described by Skoda et al . [21]. This approach allowed us to compare the performance of the current automated segmentation methods against an established reference method.…”

“…and I.S.) provided two sets of manual segmentations for both MV and PVs [21], which were then clipped manually to obtain two Clipped_LA from each set of segmentations. The repeatability analysis was performed using SPSS.…”

“…To assess the accuracy of the current automated segmentation methods for identifying LA fibrosis, the valve reference method used by Skoda et al . [21] was employed as ground truth for validation. This method relies on a valve intensity to identify fibrosis as a valve reference model.…”

“…In a recent study, 3D late gadolinium enhanced Dixon MRI was found to be a feasible method for simultaneous assessment of LA fibrosis and epicardial adipose tissue (EAT) [21]. In the current study, the data and labels obtained from this former study are considered for LA fibrosis segmentation based on the valve reference method [22] to generate a ground truth for the current work.…”

The role of epicardial adipose tissue dysfunction in cardiovascular diseases: an overview of pathophysiology, evaluation, and management

“…Moreover, CMR measures EAV, left ventricular compliance, pulse wave velocity, and other indicators simultaneously, which can evaluate aortic stiffness, myocardial strain, and fibrosis ( 50 , 51 ). A combined measurement by CMR may support the evaluation of risk and prognosis of CVDs.…”