A new high-definition body scanner is giving doctors the clearest ever view inside the human body - helping them spot problems that could cause heart attacks.

The HD body scanner, manufactured by GE Healthcare, generates pictures of diseased arteries in the heart that are twice as clear as older machines.

It means doctors at Plymouth's Derriford Hospital can identify problems at an early stage, long before patients suffer a heart attack or even develop any symptoms.

"When we started doing the heart research in 2002, we used to struggle to see the blood vessels, let alone see the narrowings within them," said Carl Roobottom, Professor of Radiology.

In just five seconds, the scanner takes 220 X-rays, each of them a cross-section of the heart.

Computers then turn the raw snapshots into a 3D image.

Doctors can add color to distinguish between different types of tissue, strip away layers that obscure problem areas, and rotate or flip the image to get the best possible view.

For John Hughes, such accuracy brings peace of mind.

He suffered chest pain while cycling uphill but the scanner showed it was not a heart attack.

"It's brilliant. It's a relief there is no structural problem for the chest pain, so I can get on with life now. Get back on the bike and have another go," Hughes said.

The scanner is also safer for patients.

The radiation dose is 20 to 30 times lower than that from machines being used just seven years ago.