Siemens has presented its Somatom Definition Edge single source CT scanner at the 2011 Congress of the Radiological Society of North America (RSNA).
Siemens introduces a new reference in Single Source CT: the new Somatom Definition Edge with the entirely new developed Stellar Detector - the first fully integrated detector, designed to minimize electronic noise. It delivers an unprecedented spatial resolution in clinical routine and is a perfect match for low dose imaging especially in combination with iterative reconstruction solutions.
The Somatom Definition Edge is the fastest single source CT scanner in the company’s portfolio, which acquires 23 cm/s with a 0.28 s rotation speed. It sets new standards in low dose and image quality from a single source CT and can be operated in a Dual Energy mode. The scanner utilizes Stellar Detector’s TrueSignal Technology, which allows integration of the electronic detector components into the photodiode. It reduces electronic noise, and improves image signal-to-noise ratio. Even without an increase in radiation dose, it allows scanning of 0.5 mm ultra-thin slices at low strength leading to images with 0.3 mm spatial resolution.
Maintaining a good spatial resolution at high rotation speeds of the gantry has been a significant challenge. Short scanning time reduces motion artifacts on images taken of patients who are unable to stay immobile for long periods. Siemens has provided a new gantry that enables a high 142 ms spatial resolution, while requiring only 0.28 s/rotation. The CT can scan a 2 m tall patient in approximately 8.5 s. The scanner’s 1.7 pitch is equivalent to 23 cm/s acquisition speed.
The voltage has to be changed many times when Dual Energy examinations are performed with Single Source devices, which leads to lower image quality. The voltage and modulation current cannot be changed simultaneously. This leads to higher dose levels. The Siemens Somatom Definition Edge has a novel scanning technique, whereby two scans with different energy levels are performed successively. Each scan utilizes dosage approximately half the dose required in normal mode, leading to reduction in dose reduction. The completely automatic radiation exposure control system, Care Dose4D, can be employed. The Sinogram Affirmed Iterative Reconstruction (Safire) method for CT data iterative reconstruction can also be employed to reduce dose levels.
Siemens has developed the Somatom Definition Edge as part of its global Agenda 2013 initiative to boost its competitiveness and innovative power.