Measures of Sarcopenia: The Utility of Ultrasound, Bioelectrical Impedance Analysis and Single-Slice Cross-Sectional Imaging

Weight and body mass index (BMI) are simple, commonly used tools to assess nutritional status, but since they do not provide information on body composition, they are significantly limited in their ability to identify patients as sarcopenic or non-sarcopenic. More sophisticated techniques, such as clinical image analysis (by computed tomography [CT] or magnetic resonance imaging), provide more detailed information about the quantity, quality and distribution of tissues such as skeletal muscle and adipose tissue. Here, we discuss the importance of accurately quantifying skeletal muscle mass in patients with liver cirrhosis and then outline a four-step systematic process for choosing the most appropriate body composition assessment tool in a clinical setting. We conclude by describing three important clinically friendly tools for body composition assessment in liver cirrhosis: bioelectrical impedance analysis (BIA), CT imaging and ultrasonography.