PET with magnetic resonance imaging examination (PET-MRI)

You will receive a pre-information form and detailed patient instructions from the referring unit, explaining how to prepare for the examination. Typically, you must fast before the examination and avoid physical exertion. Diabetic patients should ensure their blood glucose levels are as normal as possible before the examination. 

Remember to fill out the pre-information form carefully and bring it with you to the examination. Follow the instructions precisely to ensure the examination can be performed as scheduled. If you have metal or metal parts in your body, contact the imaging unit in advance. Due to the MRI examination, all jewelry must be removed. 

The diameter of the scanner tunnel is 70 cm, so for very large patients, it must be assessed whether they can fit into the MRI scanner. 

If you know or suspect that you are pregnant, inform your treating physician or contact the imaging unit well in advance. 

Children are not allowed to accompany adults to the examination, as the procedure involves the use of a radioactive tracer. 

• Patient instructions for examinations

A nurse will review the pre-information form with you and go over the examination. You will then change into hospital clothing and lie down to rest. Resting helps to balance muscle tension and metabolism, allowing the tracer to better target the areas being examined. 

During the examination, a small amount of radioactive tracer is administered via an intravenous line. The tracer does not cause any sensations or changes in your condition. The most commonly used tracer in PET-MRI is fluorodeoxyglucose (FDG). This tracer behaves like glucose in the body and is transported via metabolism to areas with increased metabolic activity, such as cancer cells. 

The MRI scanner produces loud noise, so you will be given hearing protection. If you wish, you can listen to the radio during the examination. You will also receive a call button to contact the nurse if needed. Successful imaging requires you to remain still. 

A contrast agent may be used during the imaging, administered intravenously. The contrast agent does not contain iodine. 

The entire examination visit lasts approximately 2–4 hours. The actual imaging takes about 30–70 minutes, depending on the area being imaged. 

A PET-MRI examination does not require follow-up. After the examination, it is advisable to drink more fluids than usual and urinate frequently, as the radioactive tracer is excreted through urine. On the day of the examination, avoid close contact with pregnant individuals and refrain from holding children in your lap or keeping them close. 

Breastfeeding mothers must take a break from breastfeeding after the examination. Milk expressed during this time should be discarded. The healthcare staff will provide detailed instructions to breastfeeding mothers after the examination. 

The physician who referred you for the examination will inform you of the results and how treatment will proceed. Contact your treating unit if you do not have a scheduled follow-up appointment or phone consultation. 

PET-MRI examination is painless. 

MRI is not suitable for everyone. Some implants and foreign objects in the body, such as pacemakers or metal fragments, may prevent imaging or require special arrangements.