Zhang is engaged in the research and development of radiopharmaceuticals. There are two main types of radiopharmaceuticals being researched at QST: those for diagnosis and those for therapy. One is a radiopharmaceutical for use in PET, an imaging technique that accurately determines the location of cancers and other diseases. Let's take for example the diagnosis of dementia. When a radionuclide-labeled compound is injected into a patient, the compound will bind and aggregate to the beta-amyloid that is believed to cause dementia, allowing the PET images to display where the disease is occurring.