In addition, the scanner features Siemens’ latest reconstruction algorithm called Advanced Modeled Iterative Reconstruction (ADMIRE), enabling better image quality at the same radiation dose. Furthermore, iterative Metal Artifact Reduction (iMAR) more effectively reduces artifacts from fillings and implants that often cause distortions that may result in less than diagnostic image quality, executives noted.
In dual energy imaging, the same region of the body is examined using two different energy levels. The resulting two datasets offer more detailed information about 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 had significant drawbacks, the company said. In the past, single-source dual energy images acquired with 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, the segmentation of the measuring points impairs image quality 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 tube design of Siemens’ new TwinBeam Dual Energy technology featured in the relaunched Somatom Definition Edge splits the X-ray beam into two different energy spectra prior to reaching the patient. The result: simultaneous generation of dual energy images. “With this technology, we are laying the groundwork for dual energy imaging in single-source computed tomography to be used in routine procedure,” said Walter Märzendorfer, CEO for Computed Tomography and Radiation Oncology at Siemens Healthcare.
Siemens’ approach to dual energy imaging technology in general offers tissue characterization that could be applicable in clinical situations like the evaluation of kidney stones to differentiate between uric acid and non-uric acid stones, which provides additional diagnostic information. Another example: When examining liver lesions, the material information contained in the dual energy imaging acquisition can indicate liver lesions, with information that is based on the determination of contrast uptake in the tumor (Iodine Maps).
The new version of the Somatom Definition Edge also can simplify the radiology workflow considerably, Siemens bigwigs said. Unlike other single-source dual energy CT imaging, the Edge’s acquired dual energy datasets are preprocessed intelligently directly after acquisition. The datasets also can be sent automatically by the Edge to the picture archiving and communication system (PACS) with the aid of Siemens’ new Fast DE Results technology.
To further improve not only the quality of dual energy examinations but also conventional CT scans using the Somatom Definition Edge, Siemens is introducing iMAR – a new iterative algorithm for metal artifact reduction. With iMAR, metal artifacts can be reduced. Installed Somatom Definition Edge and Somatom Definition AS+ CT scanners can be retrofitted with TwinBeam technology, iMAR and ADMIRE (in combination with the Stellar detector). iMAR is designed to yield images with a reduced level of metal artifacts compared to conventional reconstruction if the underlying CT data is distorted by metal being presented in the scanned object. The exact amount of metal artifact reduction and the corresponding improvement in image quality achievable depends on a number of factors, including composition and size of the metal part within the object, the patient size, anatomical location, and clinical practice.
Neither the iMAR algorithm nor the TwinBeam Dual Energy technology has been cleared for use in the United States by the U.S. Food and Drug Administration.
Based in Germany, Siemens AG develops medical imaging equipment such as CT and magnetic resonance imaging systems, laboratory diagnostics, clinical IT, wind turbine technology, power transmission solutions, automation/software solutions for industry. The company employs roughly 362,000 people worldwide.