What to wear to a scan: MRI, CT, X-ray, ultrasound and PET

Wear something comfortable and loose, and choose items with as little metal as possible. Many people find that a plain T-shirt or jumper with an elastic-waist trouser or skirt, and a bra without wire or metal fastenings if one is needed, works for most examinations. The hospital may still ask you to change into a gown, particularly if the scan involves the body area where your clothes are, and some departments simply provide a gown for every patient.

This page is general. It draws on NHS guidance for each type of scan and on individual hospital leaflets. If your appointment letter says something different, follow the letter.

Metal matters for different reasons in different scans. In MRI, the scanner uses a strong magnet, and the NHS asks you to fill in a form about metal parts in your body, such as surgical clips, a pacemaker, and dental fillings or bridges. Metal on clothing and jewellery is removed for the same reason. For CT and X-ray, metal objects can block X-rays and appear on the pictures, which can hide the area the doctor wants to see.

Because of this, things that people do not think of as metal can still matter: zips, poppers, buttons, belt buckles, hooks on bras, underwiring, hair clips and some fabrics with metallic thread. The Cambridge University Hospitals MIBG leaflet gives a typical example, saying to avoid clothes with metal buttons and that you may be asked to remove buckles, coins, jewellery, buttons and zips while the pictures are taken.

For an MRI scan the NHS lists jewellery, a bra, hair clips and hearing aids as examples of items with metal, and also asks you to remove coins or keys from your pockets and not to wear make-up. If your clothes have any metal parts, such as zips, you may be asked to change into a hospital gown.

For a CT scan the NHS gives a similar list: jewellery, clothes with zips or poppers, bras and hair clips. It adds that you may be asked to follow a special diet, take certain medicines or not eat or drink for several hours beforehand. Neither page says what to do about glasses, dentures or hearing aids beyond the hearing aid mention in the MRI list, so ask the department about anything you need to keep on.

With ultrasound, the probe has to touch the skin over the area being examined, so access matters more than metal. The NHS says you may need to remove jewellery or piercings from that area, and that you might undress behind a screen or in a changing room and put on a gown, or sometimes just move your clothing out of the way. Clothing that is easy to move aside or take off from the relevant area makes this simpler. The NHS also notes that you can ask for a chaperone, who may be someone you know or a member of staff.

For X-ray, the same metal advice as for CT applies. The NHS adds that the gown depends on the part of the body being X-rayed. Dental X-rays are usually done in a dental surgery.

For PET the NHS says you will need to remove jewellery and any objects containing metal, and may be asked to change into a hospital gown. The Christie NHS Foundation Trust, writing about a gallium-68 PET-CT scan, advises leaving jewellery at home and wearing loose-fitting, comfortable clothes, which may mean you do not have to change into a gown.

For a MUGA scan, Chelsea and Westminster Hospital asks you to remove jewellery or metal objects from the chest area, since the camera sits close to your chest. These leaflets show the general principle: remove metal in the area being imaged and choose clothing that is easy to adjust.

A few practical steps make the day easier. None of them is a requirement, but they follow from the guidance above.

• Read the appointment letter and any safety questionnaire before the day. The NHS says the hospital will tell you what to do beforehand.

• Leave jewellery at home where you can, including body piercings that can be removed.

• Choose clothes without zips, poppers or metal buttons, and check for metal on underwear.

• Bring a list of your medicines and details of any implants or metal in your body, as the hospital will ask.

• Do not wear make-up for an MRI, as the NHS advises.

• If you are anxious or fear small spaces, tell the hospital before the day. The NHS says you may be able to have a medicine to help you relax and can ask to bring someone to support you.