PET scans contain information about measured radiotracer activity. For example, the 18F-FDG radiotracer accumulates in areas with high metabolic activity, such as tumours. To compare activity measurements between patients, the measured activity values are normalised to standardised uptake values (SUV). SUV values are used both clinically and for research purposes. PET scans are stored in DICOM format. Information from DICOM files can be used to compute SUV values.. However, this processing this information is relatively complex, and can involve vendor-specific pathways. To ensure that any medical image processing software can reliably compute SUV values, the IBSI is preparing digital reference objects that cover both common and rare processing pathways.