This study tests a special compound, **[18F]MHF**, to see if it can detect infections in knee implants. **[18F]MHF** contains a tiny amount of radiation and is injected into a vein. It naturally moves to areas with bacterial infections. After injection, a scan called a **PET scan** (Positron Emission Tomography) is performed, similar to an x-ray. This scan helps doctors see if there's an infection around the knee implant. The study compares infected and non-infected knee implants to find better ways of spotting infections. Only adults aged 18 or older can join. You must be able to lie still for the scan. The study is open to those who suspect an infection or have a healthy knee implant for six months or more. Some people, like those with certain health issues or recent treatments, cannot participate.

• **Length**: The PET scan lasts about 90 minutes.
• **Visits**: You might need to visit the hospital more than once.
• **Risks**: Minor radiation exposure; not suitable for some health conditions.