GPs are being urged to refer patients with TIA and stroke quickly, but poor organisation in radiology units means over half wait longer than 24 hours for diagnostic scans.
Audit data shows that 55 per cent of patients admitted to hospital with suspected stroke wait more than 24 hours to undergo a diagnostic MRI.
A sub-analysis of the stroke audit of all hospitals in Eng- land, Wales and Northern Ireland in 2006 showed that although 93 per cent of patients were scanned after admission, just 9 per cent were scanned within three hours of suspected stroke and 45 per cent within 24 hours.
However, the delay was not due to a lack of MRI scanners, but bad organisation, say researchers from the Intercollegiate Stroke Group at the Royal College of Physicians who presented the data at the European Stroke Conference in Nice, France, last week.
Although 13,625 cases were included in the audit, just 6,559 had data about time between stroke and scan.
Looking at when scanning takes place, it is evident they are mostly carried out between 9am and 5pm - with a noticeable trough around 1pm, leading the researchers to conclude that there is 'spare capacity' during the lunch hour.
Dr Tony Rudd, chairman of the Intercollegiate Stroke Group, told GP: 'Scanners are idle at night, the issue is not that we've not got enough scanners it's about how effectively we've used the ones we've got.'
Updated audit data from 2007 is expected to be published in August, but Dr Rudd said that while the outcome is unknown, he would 'be surprised if it had changed very much'.
'Things are going to improve because we are going to centralise stroke centres,' he added. 'GPs are going to have a key role in making sure that no barriers are in place in getting patients to stroke unit.'
Health secretary Alan Johnson has called for all patients with suspected TIA to undergo MRI within 24 hours as part of the National Stroke Strategy.
Under revisions to the quality framework for 2008/9, GPs now have to ensure potential TIA or stroke patients are referred within one rather than the previous 12 months.
European Stroke Conference
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