Assessment of Left Ventricular Shape Index and Eccentricity Index asPromising Parameters for Detection of Left Ventricular Remodeling inCardiovascular Events

Left ventricular remodeling (LVR) refers to the changes in the size, shape, and function of the left ventricle, influenced by mechanical, neurohormonal, and genetic factors. These changes are directly linked to an increased risk of major adverse cardiac events (MACEs). Various parameters are used to assess cardiac geometry across different imaging modalities, with echocardiography being the most commonly employed technique for measuring left ventricular (LV) geometry. However, many echocardiographic evaluations of geometric changes primarily rely on two-dimensional (2D) methods, which overlook the true three-dimensional (3D) characteristics of the LV. While cardiac magnetic resonance (CMR) imaging is considered the gold standard for assessing LV volume, it has limitations, including accessibility issues, challenges in patients with cardiac devices, and longer examination times compared to standard echocardiography. In nuclear medicine, LV geometry can be analyzed using the shape index (SI) and eccentricity index (EI), which measure the sphericity and elongation of the left ventricle. Myocardial perfusion imaging (MPI) using SPECT or PET is inherently a 3D technique, making it particularly effective for accurately and consistently assessing LV size and shape parameters. In this context, LV metrics such as EI and SI can significantly enhance the range of quantitative assessments available through nuclear cardiology techniques, with particular value in identifying early LV remodeling in specific patient groups. This article explores the diagnostic significance of left ventricular geometric indices through various diagnostic methods, highlighting the important role of nuclear cardiology.