It is becoming increasingly important to assess the amount of adipose tissue (fat) in animals in order to characterize its role in not only obesity, but also various metabolic disorders such as insulin resistance, type 2 diabetes, or cardiovascular diseases. In vivo microCT is a non-invasive technique that allows for repeated measurements in the same animal, making it possible to follow disease progression and treatment effect in a longitudinal manner. Adipose tissue is composed mostly of adipocytes and its role is to store energy in the form of lipids.
Because these lipids have a chain of carbon atoms, there will be a density difference with the surrounding soft tissue such as the abdominal muscle. This makes it possible to determine the amount of adipose tissue without the use of a contrast agent. Adipose tissue is generally distributed into two main compartments, immediately under the skin on top of the abdominal muscle (subcutaneous adipose tissue) and in the body cavity between the organs (visceral adipose tissue).