MRI scanners can help diagnose a range of illnesses

Urgent referrals to the Royal Victoria Hospital may not be dealt with for up to four months, but a similar case at the Ulster could take a few days.

It is a similar story in the waiting times for non-urgent scans.

MRI scans help diagnose a range of conditions including cancer, multiple sclerosis and orthopaedic problems.

Karl Mullowney was referred by his consultant for an urgent scan after complaining of numbness in his body.

At times he cannot move his right arm and some of the muscles in his right leg have wasted away.

Karl, who had his scan last week after four months on the waiting list at the Royal, said he could not follow the logic of the waiting lists.

"I don't understand why it has to be that way," he said.

"There are people waiting and they could be seen a lot earlier if there was one queue serving all the scanners, instead of each scanner having its own queue."

The Royal Victoria Hospital said very urgent patients would be seen within a fortnight.

Meanwhile, for non-urgent scans, hospitals vary between a six-week queue at Antrim Area Hospital and a 17-month wait at the Royal.