TwinBeam Dual Energy: New Benchmark in Single Source Dual Energy

Susanne Hoelzer and Johannes Georg Korporaal, PhD|2014-12-06

TwinBeam Dual Energy is an innovative technology unique to Siemens. It offers greater versatility than other computed tomography systems due to full Dual Energy capabilities with simultaneous acquisition of high and low energy datasets – delivering excellent images at the right dose.

Dual Source Dual Energy (DSDE) imaging introduced by Siemens in 2005 is the established benchmark in Dual Energy Computed Tomography. From the very beginning, the aim was to introduce clinically relevant Dual Energy CT applications rather than merely a research tool.

To bring the benefits of Dual Energy to more users, Siemens introduced single source Dual Energy with the Dual Spiral approach available on systems from 16 to 128 slices.

The Dual Energy Portfolio has now been extended even further with the introduction of TwinBeam Dual Energy1 technology on the SOMATOM Definition Edge scanners. This innovative Dual Energy approach allows simultaneous acquisition of high and low energy datasets using single source systems, enabling all applications utilizing iodine contrast.
Siemens Dual Energy CT is routinely applicable to virtually all patients without compromising on image quality or radiation dose.

TwinBeam Dual Energy: How it works
Fig.1: The schematic visualization of a TwinBeam scan shows the simultaneous acquisition of datasets.

TwinBeam Dual Energy is a new technology that provides a unique way to perform Dual Energy scans. To create two X-ray spectra simultaneously from a single tube, the beam is pre-filtered using two different materials: gold (Au) and tin (Sn). As a result, the 120 kV X-ray beam is split into a high- (Sn) and low-energy (Au) X-ray spectrum before it reaches the patient (Fig. 1). Due to the additional filtration, this acquisition technique requires sufficient tube power reserves, which are readily available on Siemens CT scanners with the STRATON® tube.

Image acquisition is possible for all rotation times (up to 0.28 seconds) and for the full field-of-view of 50 cm. Furthermore, different from other single source Dual Energy acquisition techniques, the full number of projections is available for both spectra resulting in uncompromised image quality. In terms of detection, the simultaneously acquired low- and high-energy data can be reconstructed separately to provide a high- and low-energy image series. These datasets can be examined independently. Alternatively, a composed reconstruction is available (disregarding spectral differences) to give a single energy image dataset with uncompromised image quality.

Clinical benefits of TwinBeam Dual Energy
Fig. 2: A whole body CT angiography acquired with TwinBeam Dual Energy shows an infra-renal abdominal aortic aneurysm (AAA). VRT images can be easily created after automatic bone removal (Fig. 2B).

TwinBeam Dual Energy enables simultaneous acquisition of high- and low-energy datasets. Therefore it is possible to use True Dual Energy applications on single source CT systems with no compromise on dose. The full range of dose reduction techniques such as ADMIRE2 and CARE Dose4D can be implemented consistently for compliance with the ALARA principle.

Among the major clinical benefits are, for example, evaluations of pulmonary embolism using syngo.CT DE Lung Analysis. This application provides immediate diagnostic information such as location of the affected vessel and details of the perfusion defect in the parenchyma, at a glance. TwinBeam Dual Energy together with syngo.CT DE Direct Angio delivers a bone-free view of the vascular system, making it easier to assess cardio-vascular diseases.

Initial clinical results have proven the concept of TwinBeam Dual Energy with positive outcomes. Iodine maps in the lungs, liver, and kidneys show the iodine distribution throughout the entire volume and produce artifact-free virtual non-contrast (VNC) images. Dual Energy bone removal also works very well, for both the thorax-abdomen scans as well as for the head. This indicates that the new TwinBeam Dual Energy acquisition technique can deliver high-quality images for confident diagnosis.

TwinBeam Dual Energy meets the technical requirements for the use in clinical routine entirely without any compromises. The Dual Energy CT application portfolio on syngo.via is now available for cases acquired using single source Dual Energy.

Susanne Hoelzer is Global Congress and Event Manager for Computed Tomography, Siemens Healthineers, Forchheim, Germany

Johannes Georg Korporaal, PhD, Computed Tomography, Siemens Healthcare, Forchheim, Germany