How long does an MRI scan take?

The short answer

The NHS says an MRI scan usually takes between 15 minutes and 1 hour, but it can take longer. One NHS trust gives a wider range of 15 to 90 minutes, depending on the size of the area being scanned and how many images are taken.

That is the time spent inside the scanner. The whole appointment takes longer, because you also need time to check in, answer safety questions and get changed. If you are thinking about a private MRI scan, it helps to know both numbers so you can plan your day.

How long does an MRI take for different body parts?

There is no single national timetable for MRI. Each hospital and clinic sets its own scanning protocols, so the figures below are a guide rather than a promise. They come from patient leaflets published by University Hospital Southampton NHS Foundation Trust (UHS), which gives a separate leaflet for each type of scan.

How long does a brain MRI take?

The UHS brain leaflet says a brain MRI takes approximately 20 minutes, and you go into the scanner head first, lying on your back. It also explains that if the pictures are not clear enough, the team may decide you need an injection of contrast dye, which adds some extra time. You can read more about this type of scan on our brain MRI page.

How long does a knee MRI take?

For the knee, foot or ankle, UHS says the scan takes approximately 40 minutes. You go into the scanner feet first, lying on your back on a motorised bed. Our knee MRI page explains more about what this scan looks at.

Spine and other areas

A spine MRI at UHS takes between 20 and 40 minutes, depending on how much of your spine is being imaged. Scanning the whole spine takes longer than scanning just the lower back.

Cambridge University Hospitals says it usually takes around 30 minutes to scan one part of the body, and that scanning more than one part takes longer. It adds that the timing also depends on the question your doctor is trying to answer.

Scans of more than one area

If your referrer has asked for two areas, such as both knees, or the neck and the lower back, expect each area to add time, because each one needs its own set of pictures. When you send an enquiry, tell the clinic exactly which areas you need. That way it can book an appointment slot that is long enough, and give you a more accurate idea of how long you will be there.

Why MRI scan times vary

An MRI scanner does not take a single snapshot. It builds up a series of images, each one showing a thin slice of the area being examined. Several things affect how long that takes.

The size and number of areas

A larger area, or more than one area, means more pictures. A knee on its own is usually quicker than a scan of the knee and hip, or of the whole spine.

The images your doctor needs

The radiographer takes several sets of pictures, and the number needed depends on what your referrer wants to look at. This is one reason why a scan to answer a complex question can take longer than a routine one, even for the same body part.

Contrast dye

Some people are given an injection of contrast medium (dye) to help show more detail in the pictures. When contrast is used, one NHS trust explains that several scans are taken before the injection and then repeated afterwards, so the scan takes longer. The NHS also says you may be asked to wait in the department for up to 30 minutes afterwards so staff can check you are well. Our guide to MRI with contrast explains more.

Keeping still

You need to lie still so the scanner can take clear pictures. Most people find this manageable, especially if they are comfortable before the scan starts. If you feel anxious about enclosed spaces, tell the clinic before your appointment. The NHS says some people are offered a relaxing medicine. If you have one, you should not drive for 24 hours and will need someone to collect you, so plan your journey with this in mind. Our guide to claustrophobia and MRI covers other options.

Time in the scanner versus total appointment time

The scan itself is only part of your visit. One NHS leaflet says taking the images usually takes about 20 to 30 minutes, but your total time in the department is likely to be about 60 minutes, and longer if there are delays, for example because of emergency patients. Another NHS trust simply asks patients to allow one hour for the scan.

A typical visit includes:

• checking in at reception
• completing a safety form about any metal in your body, such as surgical clips, a pacemaker or dental work
• removing metal items such as jewellery, hair clips and hearing aids, and changing into a gown if needed
• having a small needle (cannula) placed in your arm, if you need contrast dye
• the scan itself
• a short wait afterwards, if you had contrast

MRI scanners are noisy. The NHS says they make loud bangs and clicks as they take pictures, and you are given ear plugs or headphones. The noise is normal and does not mean anything is wrong.

For a step by step guide to the day, see what to expect at an MRI scan and how to prepare for your scan. If you have any metal implants, our guide to MRI safety and metal implants explains why the clinic will ask about them before the day.

How long do MRI results take?

You will not usually get your results while you are in the scanner room. A specialist doctor called a radiologist looks at the images and writes a report, which is sent to the person who referred you.

The NHS says it usually takes between 1 and 2 weeks to get MRI scan results. Some NHS trusts quote longer, and one leaflet says the reporting process normally takes up to 4 weeks. Private clinics set their own reporting times, so ask the clinic when you enquire. Our guide to how long scan results take explains what affects the wait and who will share the results with you.

A report describes what the scan shows about the area that was looked at. It is not a general health check, so talk through what it means with the clinician who referred you. If you would like a copy of the report or the images themselves, our guide to getting your scan images and report explains how to ask.

Is a private MRI any quicker?

The scan works in the same way whether it takes place in an NHS hospital or a private clinic. The time you spend in the scanner still depends on the body part, the number of areas, whether you need contrast and which images your referrer has asked for.

What can differ is how soon you are seen and how the clinic plans its day. Each clinic sets its own scanning protocols and appointment lengths, so ask how long to allow when the clinic contacts you. If waiting time is your main concern, our guide to NHS MRI waiting times versus private explains the difference.

Tips to help your scan run on time

• Arrive a little early. UHS asks patients to arrive 15 minutes before their appointment time.
• Tell the clinic in advance about any implants, devices or metal fragments in your body.
• Wear comfortable clothes without metal zips, poppers or underwire if you can.
• Let staff know if you are worried about lying still or feeling enclosed.
• If you are having a relaxing medicine, arrange for someone to take you home.

This article is general information, not medical advice. Please speak to your GP or the clinician who referred you about your symptoms or results, and if your symptoms are urgent, call NHS 111 or 999.

Finding a private scan

You can compare private MRI clinics on FindScan, see each clinic's own listed price and send an enquiry to the clinic you choose. The clinic will contact you to confirm the details, including how long your scan is likely to take and the final price. Some clinics accept self-referral for MRI, while others need a referral from a doctor, so check this with the clinic when you enquire.