A new MRI scanning technique for analysing degenerated spinal discs opens up a promising pathway to better diagnoses of back pain.

The terrific technical breakthrough improves accuracy from 70 per cent using prevailing methods to 97 per cent.

It also opens up a discussion about how little doctors know about back pain, the imprecise imaging gained in MRIs – and the compromised effectiveness of existing treatments.

More bad backs land in hospital than appendicitis cases

More than 120,000 people with back pain (officially termed dorsalgia) presented at hospital emergency departments across Australia in 2017 to 2018, according to Australian Institute of Health and Welfare figures.

More than 37,000 of them were in such a bad way they couldn’t be sent home, and were admitted to hospital.

How these cases were resolved isn’t known – some may have eventually healed on their own but plenty of them were not so lucky.

“We don’t have effective treatments for people with back pain,” Dr Kyle Sheldrick, lead author of the study, and a PhD candidate with the UNSW spine lab, told The New Daily.

Walking, massage and psychology are treatment options

“The recommendations say that exercise is better than being sedentary. There is some evidence for massage and some evidence for psychological support, but they are all ineffective treatments.

“We’ve never cured a disease we don’t understand.”

While back pain affects about one in six Australians, in 95 per cent of cases, doctors can’t find any cause. “A huge proportion of my medical practise has been telling people with back pain we don’t know what’s causing it,” Dr Sheldrick said.

“This makes it very hard to treat individual patients, but also makes it very hard to find new cures.”

But now, the exact causes of an individual’s back pain may be better understood with the improved accuracy of MRI scans of spinal discs using a new technique they call “decay variance”.

In a paper published this week, the researchers show how they captured spinal disc degeneration in rabbits using the new decay variance technique, where they achieved an accuracy rate of 97 per cent.

Tests for disc degeneration not hitting the mark

This means they compared the image of the disc with the actual disc in a post-mortem examination, and the actual disc matched the image 97 per cent of the time.

Using traditional MRI methods, the images were found to match the actual discs only 70 per cent of the time.

“Experts think degeneration of the spinal discs is a cause of back pain but current tests for disc degeneration don’t work very well,” Dr Sheldrick said.

“Patients with discs that look healthy on MRI often have severe back pain, and patients with discs that look very degenerate on T2 MRI often have no back pain, so better technology is needed.”

Senior author Dr Ashish Diwan, who is an orthopaedic surgeon at Sydney’s St. George Hospital, said while MRIs have been especially helpful in creating pictures of soft tissues that don’t show up on x-ray examinations, the technology itself is not perfect.

“Most people wouldn’t realise that what the MRI produces in images is not necessarily an exact representation of what is actually going on in a patient,” Dr Diwan said in a statement.

“Now for the first time we’ve been able to demonstrate that MRI technology still has considerable room for improvement – and we’ve shown how it can be done.”

Comparing the new technique with what is currently used by radiologists in clinical practices, Dr Diwan says the difference represents a shift in the way the data is analysed.

“Current techniques see how quickly or slowly individual atoms line up with a magnetic field after a strong burst of radio waves – this is called signal decay,” he says.

“Instead of trying to figure out how fast or slow this signal decay is, our technique measures whether the atoms in a sample are lining up at the same speed as each other, or a range of different speeds – hence decay variance.”

The researchers are continuing to put their backs into it, with human trials only months away.