Looking inside the heart

A vast amount of knowledge about the structure and function of the heart has been gained since 1961, thanks to rapid technological advances in heart and blood vessel imaging. BHF-funded research has been at the forefront of how best to use these technologies to benefit patients.

Using CT scans to improve prevention

X-rays in the 1960s were good for taking images of parts of the body that are not moving (like bones) but were less good at producing detailed images of internal organs. In the 1970s, X-ray technology took on a whole new dimension when British inventor Sir Godfrey Hounsfield came up with the idea of CT scanning, in which the X-ray beam moves in a circle to take many different images, which are then combined to form one 3D image.

A CT coronary angiogram (CTCA) shows the structure of the arteries that supply blood to your heart, including any narrow areas that may mean you have coronary heart disease. Increased interest in its potential as a non-invasive way to detect coronary heart disease led to rapid advances in both equipment and software. Until recently, CTCA was mainly used as a test to rule out coronary heart disease in people at low risk of having the condition, but was less useful for providing a diagnosis. BHF-funded work helped to change this.

In 2015, BHF Professor David Newby at the University of Edinburgh published the results of a clinical trial that propelled CTCA into broader use for the diagnosis of coronary heart disease. The SCOT-HEART study involved over 4,000 people with suspected angina (chest pain linked to coronary heart disease). Participants were randomly assigned to receive either standard tests or standard tests plus CTCA to identify the underlying cause. The study showed that using CTCA as an additional test in people with suspected angina increased the certainty of diagnosing coronary heart disease. Participants in the CTCA group diagnosed with coronary heart disease were then started on preventive treatments like statins, and the rate of future heart attacks was almost halved compared to standard care.

SCOT-HEART has changed clinical practice in the UK. Since 2016, UK guidelines have recommended CTCA as one of the first tests for someone experiencing new chest pain that may be caused by coronary artery disease. A 10-year follow-up of the trial, published in 2025, found that around 6,000 heart attacks in the UK have been avoided in the last decade as a result of introducing the scan. Professor Newby is now leading a new trial, called SCOT-HEART 2, to test whether CTCA could be used to better identify people who are at risk of developing coronary artery disease in the future. The trial will involve 6,000 people aged 40 to 70 in Scotland, who do not currently have heart problems but have a risk factor such as high blood pressure or diabetes. The aim is to see whether using CTCA in this way can better identify people who would benefit from preventative measures.

Using echocardiograms to improve diagnosis

One of the most common types of heart scan is an echocardiogram, which uses ultrasound – the same technology that is used for routine pregnancy scans.

The BHF was involved from the early days of echocardiography, funding a programme in the 1980s which provided ultrasound scanners for several hospitals in the UK for clinical and research use. The BHF also helped to make echocardiograms more widely available, by giving grants for portable echo machines that could be used outside of hospitals, and by enabling the training of specialist technicians.

More recently, we have funded Professor Darrel Francis at Imperial College London who is using an advanced echocardiographic technique called strain imaging. This ultrasound method measures changes in the heart’s shape and size (referred to as strain) as it beats. This can provide a more accurate assessment of heart function than other commonly used methods and is useful for detecting early signs of heart disease.

However, doctors don’t routinely use strain imaging because scanning machines from different manufacturers give different results. To fix this, Professor Francis and his team have developed a new way to calculate strain – called Tensor Mapping - which could solve this problem.

The team are taking these discoveries forward in a new BHF-funded project which aims to harness the potential of artificial intelligence (AI) to speed up echocardiography. This could make it easier for heart patients to be examined earlier and for their results to be processed more quickly, so they can receive diagnosis and treatment as soon as possible.

Leading the way in the use of cardiac MRI

Another type of heart scan that is now commonly used is magnetic resonance imaging (MRI). The basic concept of MRI was discovered in the 1970s. But it wasn’t until the late 1980s that MRI was developed for heart patients, thanks to pioneering work by BHF Professor George Radda at the University of Oxford, Professor Donald Longmore at the Royal Brompton Hospital in London and their teams, with support from the BHF.

Since the 1980s, BHF funding has supported developments in cardiac MRI, helping establish it as a reliable clinical tool. Cardiac MRI has also changed our understanding of the structure and function of the heart. The research has spanned a broad spectrum of heart and circulatory diseases and has changed clinical practice and guidelines, making direct impact on patients’ treatment and lives. BHF support over the last 40 years also helped create a unique and world-leading capacity in cardiac MRI within the NHS by supporting more than 100 BHF-funded clinical research fellows who have been trained to become experts in cardiac MRI before returning to clinical work.

Today, we continue to support research to develop new cardiac MRI diagnostic tests. In 2012, Professor John Greenwood and BHF Professor Sven Plein at the University of Leeds showed that MRI can detect which narrowed coronary arteries need a stent or surgical treatment, matching as accurately and reliably as the most common test (a SPECT scan –which involves a radioactive dye first being injected). This avoids the need to use radiation, which although low risk for most people, is a risk that is avoidable by using MRI.

In recent years, advancements in AI have accelerated MRI scan times. With BHF-funding, a team at University College London led by Dr Rhodri Davies developed a new AI tool that can analyse cardiac MRI scans in just 20 seconds, compared to the 13 minutes it typically takes a human. This tool, which has begun rolling out across the NHS, not only speeds up the diagnostic process but also enhances accuracy, allowing for quicker and more precise treatment decisions. The researchers estimate that the tool could save around 3,000 clinical days every year.

In 2024, a study we part-funded at the University of Oxford found that thousands of patients admitted to hospital every year with suspected heart attack could avoid an unnecessary invasive procedure if they had a routine MRI scan first. If similar results are found in a larger trial it could help doctors identify patients who won’t benefit from the invasive procedure, allowing them to avoid the small but important risk of complications.

Find out more about our impact on cardiac MRI research in our research impact report.

When images can save lives

Today, we know more about the structure and function of the heart in people living with heart and circulatory diseases than was once dreamed possible. This knowledge is being translated into better diagnosis, more effective and personalised treatment, and more lives saved. Getting a window on the heart has been the cornerstone that much of modern cardiac medicine is built on.

First published 1st June 2021

Last updated February 2025