The SOMATOM Definition acquires images of outstanding quality and detail even of hearts with a high heart rate or irregular heartbeat - at only half the dose of previous Siemens systems. The two X-ray tubes provide the system with features previously not existing in diagnostic imaging. This includes the possibility of, simultaneously, operating the X-ray tubes at different voltage levels (dual energy, or DE) in a single scan so that two data records with different patient information are generated, thereby displaying tissue and fluids and facilitating the distinction of vessels, bones, and soft tissue.
"The SOMATOM Definition moves CT to an entirely new dimension of diagnostic sensitivity where contrast in the image is not merely limited to X-ray attenuation differences, but may include elements of functional and tissue characterization. This additional information may be used to improve diagnostic outcomes and to simplify complex work flows", explained Peter Kingma, Vice President, CT, Siemens Medical Solutions USA Inc. "The Definition already offers enhanced resolution, speed, and power. Now, we are adding convenience of use to the mix."
One of the new dual energy applications for the SOMATOM Definition is syngo DE Heart PBV (Perfusion Blood Volume), which provides colour-marking of non-perfused parts of the myocardium during cardiology examinations. Moreover, syngo DE Heart PBV enables the isolated display of the heart, for example, without thorax structures. The heart perfusion is examined primarily after an infarction to determine damaged areas of the organ. For the first time, DECT can detect a stenosis and its degree, as well as the location and extent of the resulting reduced perfusion in the myocardium in a single scan.
Deposits of uric acid crystals in the joints of gout patients may damage the cartilaginous and osseous substance, particularly if the disease has been chronic for several years. With syngo DE Gout, CT can now also be used for gout detection. The new dual energy application assists the physician in clearly identifying uric acid crystals in the extremities and monitoring changes in the crystals in the course of treatment.
syngo DE Lung Vessels provides a whole series of applications to assist the physician in CT examinations of patients with suspected pulmonary embolism - a sudden occlusion of blood vessels in the lungs. The new applications enable the detection of non-perfused blood vessels and tissue of the lungs through colour-marking. The "lung isolation" application isolates the entire organ to allow the assessment of the perfusion situation without obstructing neighbouring organs.
syngo DE Brain Haemorrhage assists in the distinction between new and old haemorrhages in the event of cerebral bleeding. The two energy levels of the X-ray tubes are used to fade out the contrast medium (CM). In the past, this had required two scans. The contrast medium subtraction offers two advantages: a non-contrast medium enhanced examination is not necessary, and the patient is spared the dose of a second scan.
The four new dual energy applications presented by Siemens at the ECR 2008 supplement the six existing CT applications with dual energy features:
- syngo DE Direct Angio for the distinction of bone and vessel structures, particularly if the vessels are located directly next to the bone
- syngo DE Lung PBV for perfusion assessment of the lung tissue
- syngo DE Musculoskeletal for the display of ligaments and tendons
- syngo DE Calculi Characterization for the automatic distinction of the biochemical composition of renal calculi (e.g., uric acid or calcium oxalate)
- syngo DE Hardplaque for the display of calcification in the body and determination of the vessel status
- syngo DE Virtual Unenhanced for the subtraction of contrast medium in abdominal scans