Cardiac MRI patterns in cardiac amyloidosis vs. non-amyloid inflammatory and fibrotic cardiac involvement: A single-center pilot study

Objective: Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy that various non-amyloid inflammatory and fibrotic cardiac diseases with overlapping clinical features can mimic. This study aims to compare cardiac magnetic resonance imaging (CMR) patterns between these conditions to identify imaging features that facilitate accurate differential diagnosis. Methods: This single-center, retrospective, pilot comparative study included 27 patients who underwent CMR between December 2021 and November 2025. Fourteen patients had confirmed CA and 13 patients had non-amyloid inflammatory or fibrotic cardiac involvement, including cardiac sarcoidosis, connective tissue disease-related cardiac involvement, inflammatory myocarditis, systemic sclerosis, and endocardial fibroelastosis. All CMR examinations were performed on a 1.5-T magnetic resonance imaging system using a standardized protocol. Imaging parameters included left ventricular wall thickness, atrial size, presence of pericardial or pleural effusion, late gadolinium enhancement (LGE) patterns, and myocardial edema on T2-weighted imaging. Groups were compared using appropriate parametric or non-parametric statistical tests, as applicable. Results: Patients with CA were older than the non-amyloid group (51.7±13.8 vs. 36.6±13.4 years, p=0.008). Biatrial dilatation was more frequent in CA (71.4% vs. 15.4%, p=0.006), whereas pericardial and pleural effusions were more common in the non-amyloid group (61.5% vs. 14.3%, p=0.018; and 53.8% vs. 14.3%, p=0.046, respectively). Diffuse subendocardial LGE was strongly associated with CA (64.3% vs. 0%, p