A new type of scan offers a way to prevent heart attacks and strokes by spotting the early formation of deadly blood clots.
The imaging technique, called fluorescence molecular tomography, identifies a danger molecule in unstable fatty deposits on the walls of arteries.
When such "atherosclerotic plaques" rupture they can form clots that block the blood supply to the heart or brain.
Each year, heart attacks and strokes kill more than 100,000 people in the UK.
Spotting atherosclerotic plaques that might be about to rupture could give doctors time to treat them with targeted drugs before a life-threatening condition occurs.
Lead scientist Dr Ramzi Khamis, consultant cardiologist at the National Heart and Lung Institute in London, said: "With this research we're trying to pick out the plaques that are most likely to rupture before they cause a heart attack. Our next step will be to modify the technique that we've used here so that it can be used in patients to detect dangerous plaques."
The system, so far only tested in mice, uses an antibody tagged with a fluorescent marker that latches onto an oxidised form of the cholesterol chemical LDL (low density lipoprotein).
A description of the research appears in the journal Scientific Reports.
Professor Peter Weissberg, medical director of the British Heart Foundation, said: "If confirmed in humans with heart disease, this technique could lead to early intervention to prevent a heart attack."
Scientists also hope the homing antibody used in the scan could be used to deliver drugs directly to unstable plaques.