MRI for spines – when to do them

a lady being prepared for an MRI by a radiographer

A lot of patients ask me if they should have an MRI to identify the cause of their back pain.

The usual answer is no.

For at least 95% of back pain, an MRI won’t show a definite cause.

Pain could be from tired muscles. Or from stiff joints in the low back. Or from a grumbling, early disc problem. Even over-straining ligaments can cause pain.

These are all common reasons for spinal discomfort, but an MRI won’t be able to see them.

So there have to be definite reasons why a doctor might, from time to time, think that an MRI is a good idea.

Consultants sometimes want to inject or operate on the spine. Here, the MRI helps the doctor see what they are getting into.

Or the doctor might suspect there is something unusual about the anatomy of the patient’s spine that’s causing the symptoms. For example, scoliosis can occasionally cause pain in children and young adults.

There may have been a recent trauma, like a skiing injury. Here, MRI can help identify a fracture, although in these cases, doctors also use X-rays and CT scans.

Rarely, a doctor asks for an MRI to see if there is a medical cause for a patient’s low back pain. Even more rarely, the spine causes medical symptoms and signs. There have to be definite clues in these situations that trigger the request for an MRI.

So for regular back pain, they don’t help much, and it isn’t easy to justify the cost and time involved.

There is one exception.

An MRI will, most of the time, accurately identify the origin of sciatica or arm pain caused by a trapped nerve in the low back or neck.

In these situations, an MRI can be worth doing, especially if the problem isn’t settling.

But for common-or-garden back pain, however painful?

No to the MRI, I’m afraid.