Inflammation plays an important role in a myriad of human diseases. Interstitial Lung Diseases (ILDs) are characterised by widespread inflammation and represent a major burden to the health sector. Imaging offers a method of assessing lung inflammation which is non-invasive and may help facilitate the development of new therapeutic drugs. Positron Emission Tomography (PET) is a sensitive imaging modality that uses radioactive material to highlight areas of disease. 18F-FDG is the most common radioactive tracer; it accumulates in cells with an increased metabolic rate. Previous studies have shown that inflammatory cells have an increased metabolic rate, thus PET imaging could highlight inflammation. 18F-FDG PET has been used in many studies exploring lung diseases; the concentration of tracer is thought to relate to the severity of inflammation.