December 21, 2015 — Siemens Healthcare’s approach to delivering dose-neutral dual energy images obtained on Somatom computed tomography (CT) scanners using TwinBeam Dual Energy technology is now commercially available on the Somatom Definition Edge and Somatom Definition AS CT systems.
Dual energy imaging has gained momentum as a clinical imaging tool amid pressure to reduce the cost and frequency of medical imaging while increasing quality of care. With dual energy imaging, only one CT study is acquired, but the imaging data can be used in a variety of additional methods to improve clinical decision-making. Siemens says that its TwinBeam Dual Energy approach is unique in that it enables acquisition of this data without introducing additional radiation – a dose-neutral dual energy approach.
Dose-neutral dual energy imaging entails the examination of the same body region using two different energy levels. The resulting two datasets offer detailed information regarding tissue composition that extends beyond pure morphology. However, in cases where data have been acquired using fast kV-switching or dual layer detector technology, dual energy imaging has encountered significant drawbacks. In the past, single-source dual energy images acquired via these methods were excluded from routine clinical use because the X-ray tube did not emit the two energy spectra simultaneously, but rather in succession through rapid switching or spectral separation at the detector side. With kV-switching, image quality is impaired significantly due to the limited data per energy level. Also, increased X-ray doses are inevitable because the dose cannot be modulated to reduce radiation.
The design of Siemens’ TwinBeam Dual Energy technology enables a dose-neutral approach. Via a split filter within the X-ray tube, the X-ray beam is divided into two different energy spectra prior to reaching the patient. The result: simultaneous generation of dose-neutral dual energy images.
For example, Siemens’ approach to dose-neutral dual energy imaging in general offers tissue characterization that potentially may help physicians identify and classify challenging abdominal lesions. Additional information regarding contrast uptake in the tumor potentially may aid physicians in monitoring patient response to treatment.
With this approach to dose-neutral dual energy, CT systems with TwinBeam technology can simplify radiology workflow. Unlike other methods of single-source dual energy CT imaging, the Somatom Definition Edge’s acquired dual energy datasets are preprocessed intelligently directly after acquisition. The Somatom Definition Edge can also send datasets automatically to the picture archiving and communication system (PACS) with Siemens’ Fast DE Results technology.
For more information: www.siemens.com
October 20, 2025 
