Recent Modalities in the Diagnosis of Obesity

Obesity has been an emerging health problem worldwide which has a major impact on public health. It is associated with medical, psychosocial and economic implications with increasing prevalence among both adult and paediatric population. Obesity led to an increased risk of medical conditions like diabetes mellitus, hypertension, coronary artery disease, insulin resistance and sleep apnoea. Obesity has a major impact on cardiovascular system causing structural and functional changes leading to cardiac dysfunction. Hence it is important to diagnose obesity at the earliest for timely prevention of associated complications. Apart from routine diagnostic methods for obesity like body mass index, anthropometry (waist circumference, hip circumference, neck circumference), several recent modalities were described for the diagnosis of obesity like radioimaging, nuclear medicine imaging which will be described in detail in this review article. MRI (Magnetic resonance imaging) aids in the detection of adipose tissue at various sites and organs, whereas MRS (Magnetic resonance spectroscopy) helps in mapping of small quantity of lipids. MRI helps in delineating ectopic adipose tissue accumulation establishing that obesity alone is not a major cause for derangement in metabolic profile. An additional advantage is MRI brain is an excellent imaging guide for studying the role of central appetite regulatory systems in the occurrence of obesity. Sonography is not accurate in the estimation of hepatic steatosis. But advancements in sonographic modalities gives an extra edge in evaluation of hepatic steatosis by availing special physical characteristics such as stiffness of adipose tissue and its sound absorption. Positron Emission Tomography (PET) (Nuclear medicine imaging) helps in studying central pathophysiology, activity of brown adipose tissue and disruption of gut-brain homeostasis.