Patients facing longest wait for brain scans in Sutton and Epsom

The National Audit Office report reveals that Epsom General and St Helier Hospitals top the league for worst average waiting times for CT scans of between 25 to 48 hours.

Aside from being the slowest in London, the Epsom and St Helier's rating is also one of the slowest in the country.

However, at Kingston Hospital patients can expect to be seen within four hours and at Mayday Hospital, in Croydon, the wait is only five hours.

Epsom General and St Helier are also the worst in London for patients seeking MRI scans with waiting times of up to 48 hours, equalled only by Queen Mary’s Hospital in Sidcup.

According to NHS London, brain scans enable doctors to give an accurate diagnosis of the type of stroke they need to treat.

Stroke is the second highest cause of death and the most common cause of adult disability in London.

A spokesman for Epsom and St Helier University Hospitals NHS Trust said: "It is important to remember that the data for this report was taken from audits carried out in 2008 and 2009.

"Since then, we have worked hard to improve our stroke services at Epsom and St Helier hospitals.

"The majority of patients are now seen a lot quicker and every patient who needs an urgent CT scan is scanned within one hour of the request being made."

Health chiefs in the capital have drawn up a major overhaul of stroke services with care provided by a series of rapid-access units providing specialist care.

Stroke care in Britain costs the NHS £3billion a year with around 300,000 people in the UK living with severe to moderate disability after an attack.

Stroke patients should be immediately admitted to a specialist stroke unit but in 2008, according to the report, only 17 per cent reached a unit within four hours of arrival at hospital.

The Confederation of British Industry (CBI) believe treating more people at home or in high street walk-in centres could save the NHS £15billion.