This study is about using a special scan called 18F-DOPA PET/CT to help doctors understand certain diseases. This scan uses a tracer, similar to a chemical our body makes, to see how the body is working. It's mainly for children with conditions like congenital hyperinsulinism and neuroblastoma, and adults with issues like neuroendocrine tumors, Parkinson's disease, or brain tumors.

The study aims to see if a new camera and a medicine called furosemide make the scan clearer. Furosemide helps clear the bladder, which can improve the pictures the scan takes.

• The study will last around 5 years and include about 800 participants.
• Participants may need to lie still for up to an hour during the scan.
• This study is not random; all eligible patients will get the scan.

People can join if they have certain diseases and are referred by a doctor. However, they cannot join if they are pregnant, weigh over 225 kg, or cannot lie still for the scan. The study helps improve how doctors use this scan to help patients in Alberta, Canada.