Heart watch

A system that converts x-rays of the heart into high-quality digital pictures marks a breakthrough in cardiac imaging technology, German engineers have claimed.

Siemens Medical said its new biplane x-ray system will give doctors highly detailed views of even the heart’s smallest vascular structures, aiding diagnosis of disease.

According to Siemens, the system – called Axiom Artis dBC – is the first in the world to successfully use a pair of digital flat panel detectors (FPDs) in unison to generate an image from x-rays of the heart.

The use of twin FPDs, both working at up to 30 frames per second, allows the system to keep pace with the constant and complex movements of the heart – the most difficult of the body’s organs from which to generate an image.

Erik Busch, Siemens Medical project manager, said it had previously only been possible to use one FPD because the x-rays captured on each plane would interfere with each other, distorting the image.

However, he said the Siemens team had now overcome this obstacle, opening the way for two FPDs to work together and dramatically improve the quality of the available image.

As a bonus, the amount of contrast agent needing to be placed in the patient’s body is reduced.

Digital FPDs are increasingly viewed by the medical technology community as a superior replacement to conventional systems based on image intensifiers.

These systems, first developed in the 1960s, require a lengthy chain of components to translate X-rays into visual images suitable for viewing. After being amplified by an intensifier, the image must pass though a series of lenses, be electronically scanned for conversion into a analogue video signal and finally digitised for viewing. Each step in the chain risks degrading the image.

According to Busch, the advent of flat panel detectors in medical imaging several years ago ‘was the equivalent of the move from film-based to digital photography’.

The panels act as a substitute for every other step in the conventional systems, converting x-ray signals into digital images as soon as they leave the body, significantly reducing the opportunity for them to degrade.