Dual-Source CT

The Somatom Definition from Siemens Medical Solutions (Malvern, Pa) is the world's first dual-source CT system. In other words, it's the first CT to offer two x-ray sources and two detectors, rather than the single x-ray source and detector configuration of traditional CT. With dual-source technology, it is possible to examine every patient—regardless of his or her condition and heart rate. In addition, dual-source CT widens the spectrum to new clinical applications by offering dual energy acquisition—two x-ray sources working at different energy settings. The technology is capable of a range of clinical applications, including acute care, cardiology, neurology, and oncology.

The Definition uses two x-ray sources and twice the power, while offering the lowest possible radiation exposure in cardiac CT. To further minimize dose, the fastest possible scan speed is automatically selected depending on heart rate. The combination of these technologies doubles the acquisition speed while reducing radiation dose by as much as 50% for typical heart rates, compared to the most dose-efficient single-source CT scanners.

The Somatom Definition received 510(k) clearance from the US Food and Drug Administration in September 2005.

The Spec Sheet

1. 83-millisecond temporal resolution enables aquisition of cardiac studies in a few
2. seconds without the use of beta-blockers and multi-segment reconstruction.
3. 79-inch (200-cm) scan range enables whole-body interrogation of trauma patients and complete vessel status.
4. 31-inch (78-cm) bore opening enables scanning of obese patients.

The Visable Difference

Dual-source CT provides two different data sets, making it possible to isolate anatomy (eg, bones and vessels) from a single scan, and further characterize plaques in cardivascular CT and tumors in oncology.