A scanner that provides extraordinary high-definition images of the chest at the speed of half a heart beat, allowing doctors to pick up signs of cardiac disease undetectable by conventional tests, is to be introduced on the NHS.

Patients admitted to hospital with chest pains who might have been given the all-clear will be able to undergo the diagnostic scan to ensure they are not sent home only to suffer a heart attack later. At present patients are given an angiogram, for which dye is injected into the blood vessels, then X-rays to find signs of narrowing. The angiogram, however, can fail to pick up early signs of disease, and one in ten patients is discharged without an angiogram after performing well on initial tests, despite having blocked arteries.

The first of the new scanners, which cost almost £1 million, arrived last month at The London Chest Hospital, one of Britain’s leading cardiac centres. It has been used on 25 patients so far and doctors are preparing to introduce it for all chest-pain patients by the end of November.

A second machine has been ordered by Addenbrooke’s Hospital in Cambridge and is scheduled to begin operation on Monday. The machine, known as the Definition Flash and made by Siemens, uses computer tomography (CT) to generate high-definition three-dimensional images of the chest, and in particular the heart. Unlike angiograms, CT is non-invasive. Unlike other CT scans, however, the Definition Flash can carry out the detailed scan in a quarter of a second, thus exposing patients to the lowest possible dose of radiation.

Anthony Mathur, head of advanced cardiac imaging at Barts and the London NHS Trust, said that the new model involved a third of radiation exposure of angiograms or other CT scans, meaning that it could be used for patients previously not considered a high enough risk.

Professor Mathur described the scanner as “a major step forward that opened up a new area in diagnosis and treatment of heart disease”. It would enable experts at Barts and the London Cardiovascular Biomedical Research Unit, which is funded by the National Institute for Health Research, to explore how best to tackle the condition and other cardiac problems.

“What this scanner allows us to do is a non-invasive procedure at the lowest radiation, which means we can get an accurate and quick diagnosis of problems that may once have gone unnoticed. Twenty minutes after walking into a room you can be on your way home,” Professor Mathur told The Times.

“Before, it was a case of patients being admitted as a day case or on to a ward, and then undergoing an invasive procedure that involved putting bits of plastic into delicate parts of the body. The risks of complication are very small, but they are there nonetheless. But, more importantly, it could easily take six or seven hours.

“You would only want to do that on someone who has a high chance of a problem . . . For most people the risk-benefit balance just doesn’t add up. But now we can start helping a much larger number of patients.”

Professor Mathur said that about eight patients a day with chest pains were turned away because they did not fulfil the criteria for immediate admission to hospital. “These people come to casualty with a chest pain and we haven’t had an instant tool to assess what the problem is — whether the pain is coming from their heart or other areas, such as their lungs. They go home without a clear answer.”

The new technology removes the need for other more complicated diagnostic procedures, such as slowing down the patient’s heart with beta blockers.

The procedure is expected to cost between £350 and £500 per scan, which is similar to an angiogram, but it will save money by avoiding the hospital admission later of those missed by the system. Experts added that the technology could eventually remove the need for angiography, although angioplasties would still feature as a key procedure in cardiac care.

Ceri Davies, clinical director of the new Cardiac CT service at the London Chest Hospital, added: “A number of patients, who present with chest pain, may not be immediately diagnosed with a heart condition because they are at an early stage and their condition may not be picked up until much later. Thanks to this new machine, we will be able to diagnose these people much sooner and potentially prevent the serious consequences of their heart condition.”

Funding for the machine came from a £3.8 million award for biomedical research into cardio-vascular disease from the National Institute for Health Research, which has designated Barts and the London NHS Trust and Queen Mary, University of London, a Biomedical Research Unit in advanced cardiac imaging.

Dame Sally Davies, director-general of research and development at the Department of Health, said that such funding was essential. “Any new technology that allows us to detect heart problems at an earlier stage, while exposing patients to less radiation, is very good news. The sooner patients know there is a problem, the sooner they can begin to take action to prevent more serious problems later on.”

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