The NHS National Institute for Health and Clinical Excellence (NICE) has endorsed the use of next-generation CT scanners to help diagnose and manage patients with coronary artery disease (CAD) who are traditionally difficult to treat.
The guidance was prompted by Siemens submitting its SOMATOM Definition Flash dual source scanner for evaluation, drawing evidence from 24 published papers, of which 20 cited use of the technology.
Unique to the company’s equipment, dual source CT utilises two X-ray sources and two banks of detectors, enabling continuous improvement of spatial and temporal resolution to optimise visualisation within the coronary vessel, while also driving down radiation dose.
Peter Harrison, divisional director of imaging at Siemens Healthcare, said of the publication: “The guidance is a welcome approval of new generation CT scanners, and I am delighted that it draws evidence from so many experiences of Siemens dual source scanners. The guidance is not intended to be a comparison report, especially as dual source CT is still unrivalled and unique to the market.”
Siemens’ innovations within cardiac CT build on the high-end single-source Definition AS+, which was launched in 2008. This system, with a large bore of 78cm and increased tube rotation speed delivers a full rotation within 0.3 seconds. This provides temporal resolution down to 150ms, quick enough to freeze the cardiac motion on a wider range of patients – essential to complement the spatial resolution affording clarity of intra vascular detail, while delivering very low dose. These two parameters working in combination have led to the company installing more than 1,750 systems worldwide.
Harrison said: “The further development of dual source scanners such as the SOMATOM Definition Flash offer still greater flexibility of examination techniques to avoid patient exclusions, not only in cardiac imaging, but in all fields of CT imaging, such as paediatric and trauma imaging.
“Dual sources do not necessitate increased dose. In more than 64,000 cardiac ‘Flash’ exams we continue to experience an average radiation dose of 0.85mSv. Moreover, our latest iterative reconstruction (SAFIRE), which boasts FDA-approved dose potential of up to 60%, adds additional patient safety without compromising the high image quality of the 128 slice z-Sharp acquisition.”
The NICE guidance recommends the technology for first-line imaging of the coronary arteries in people with an estimated likelihood of CAD of 10–29%, in whom imaging with earlier generation CT scanners is difficult; and for first-line evaluation of disease progression, to establish the need for revascularisation, in people with known CAD in whom imaging with earlier generation CT scanners is difficult.
The document states: “In people with suspected CAD in whom imaging is difficult, the health economic analysis showed that, given a threshold of £20,000 per QALY gained, using new generation cardiac CT scanners instead of invasive coronary angiography is cost effective.”
Deepa Gopalan, a consultant cardiovascular radiologist at Cambridge University Hospitals NHS Foundation Trust, added: “While dose reduction continues to be important, cardiac CT today is also about ease of use of both the scanner and the evaluation of the images. The combination of the Siemens scanner and the new syngo.via platform moves cardiac imaging into a new dimension in terms of speed and confidence.”
Click here for the NICE guidance.