Low back pain — why imaging is commonly not recommended

Karen’s story

Karen felt a 'pop' in her back when she lifted a pot plant. ‘Oh no, not again!’ The next day, after a sleepless night, Karen was still getting sharp pain in her back every time she moved. So her husband took the morning off work, helped her off the lounge and into the car and drove her to the GP. She had some ‘in-date’ pain killers from the last time she’d had a bad back, but they were not controlling the pain. This was worse than previous episodes.

Does Karen need an X-ray?

Imaging is not recommended for acute (short-term) low back pain because:

  • Most people with low back pain feel better after about a month, whether they have an imaging scan or not.
  • X-rays may show spinal changes that are often completely unrelated to the pain and do not need any treatment. This can cause anxiety and stress, and potentially unnecessary follow-up tests and procedures (e.g. spinal injections, surgery).
  • X-rays expose you to radiation, so should only be used when there is a clear benefit (see Risks of an X-ray). Back X-rays deliver around 65 times more radiation than a chest X-ray.

Studies have compared a large number of people who had imaging scans for low back pain with people who didn’t. The results showed that having the imaging test generally made no difference to people’s wellbeing.

Karen’s story (continued)

After the GP had asked Karen about her injury and history of back troubles, and had performed a thorough examination of her back, he advised Karen on how to manage her condition. This included applying heat packs and liniment, strategies to avoid further injuring herself, and pain relief. He also suggested a local physiotherapist, and that she start moving around as soon as possible.

Karen was surprised he wasn’t going to order any X-rays or other imaging. ‘Shouldn’t I get a scan or something?’ she asked. ‘Wouldn’t it help work out what the problem is?’

‘I don’t think that we need to, Karen,’ the doctor replied. ‘An X-ray in this situation is unlikely to tell us anything useful, and a CT scan would only be recommended if we were worried about discs pressing on nerves down to your legs or other complications. From what you have told me, and what I found when I was examining you, I’m not worried about those sorts of things here.’

The doctor also explained that CT scans, in particular, involve a lot of radiation, and should only be performed if there was a clear reason to do so, which there wasn’t in this case. He also felt the cost and inconvenience of a MRI scan wasn’t justified, as it was unlikely to help her back situation.

‘You really only do those sorts of scans if you think there is something that might require surgery, or something serious like a tumour, which I am definitely not worried about here,’ the doctor said. ‘An X-ray might be useful to pick up something like arthritis, which I also think is unlikely. Are you okay with me not doing any further investigations at this stage?’

Karen was glad she didn’t need to get any X-rays or scans. ‘The less mucking around, the better’. The doctor told her to come back if things weren’t improving, or any new issues arose, and also listed some potential complications to watch out for. Her husband made an appointment with the physiotherapist.