OBESUS (OBESity UltraSound): A Multiorgan Bedside Ultrasound Framework for Obesity Phenotyping

Obesity is a heterogeneous chronic disease in which cardiometabolic and functional risks are influenced not only by total body fat but also by its anatomical distribution, ectopic fat accumulation, and skeletal muscle quality. Traditional anthropometric measurements, such as body mass index and waist circumference, fail to capture these biological differences. Point-of-care ultrasound provides a portable, radiation-free, repeatable, and widely available bedside tool for assessing multiple adipose and muscular compartments, yet a broadly standardized framework integrating these measurements into a multiorgan obesity phenotype remains lacking. We propose OBESUS (OBESity UltraSound), a pragmatic multiorgan point-of-care ultrasound framework for structured obesity phenotyping. To facilitate competency-based and stepwise implementation, OBESUS comprises two complementary tiers: OBESUS-Core evaluates abdominal subcutaneous adiposity, preperitoneal fat thickness, hepatic steatosis, and rectus femoris muscle quality, whereas OBESUS-Plus incorporates epicardial and perirenal adipose tissue as additional cardiorenal ectopic fat depots. Rather than generating a numerical score, the framework integrates these findings into four non-mutually exclusive ultrasound-derived phenotypes: metabolic, myosteatotic, epicardial adiposity, and perirenal adiposity. This narrative review describes the conceptual basis, standardized acquisition methodology, pragmatic reference thresholds, and potential clinical applications of OBESUS. The framework is intended to provide a foundation for prospective evaluation of its reproducibility, clinical validity, prognostic significance and potential utility for longitudinal monitoring.