2 The technologies
2.1 Aquilion ONE (Toshiba Medical Systems), Brilliance iCT (Philips Healthcare), Discovery CT750 HD (GE Healthcare) and Somatom Definition Flash (Siemens AG Healthcare) are new generation computed tomography (CT) scanners that have a variety of enhancements compared with earlier generation CT scanners. These enhancements, which vary among the four scanners, may include better temporal resolution, better spatial resolution and shorter acquisition times. It is claimed that the new generation CT scanners can better detect coronary artery stenosis in people with suspected or known coronary artery disease in whom imaging is difficult with earlier generation CT scanners. The scope of the evaluation was limited to these four new generation scanners that, although technically different, were viewed as being broadly comparable for cardiac imaging. The acquisition cost of these scanners varies depending on local discounts but estimates range from £900,000 to £1.1 million.