Head for technical exhibition to learn about latest advances in CT

Speed and efficiency are two of the buzzwords used most commonly in the highly competitive field of CT imaging. When the wraps were lifted from the ECR 2009 technical exhibition, the dazzling improvements in data acquisition speed achieved by the new generation of CT scanners emerged. Vendors claim that huge improvements can be expected, in both radiology department workflow and patient safety.

Siemens is showcasing its Somatom Definition Flash, which the company insists will set new standards for speed and radiation dose reduction in CT. The scanner is a dual-source machine in which the gantry can rotate around its own axis in 0.28 seconds. This enables a scan speed of up to 43 cm per second with a temporal resolution of 75 msec. The patient is moved through the CT tube more than twice as fast as with any conventional system, according to Siemens.

Radiation dose is much lower than with previous generations of CT scanners, which operate with an average effective dose for a heart CT examination that ranges from 8 mSv to 40 mSv. The new Siemens machine exposes the patient to 1 mSv. Because the radiation dose for the new scanner is less than that from an intracardiac catheter examination, it is possible for CT to be used as the modality of choice for routine cardiac examinations. A scan of the entire heart can be performed in 250 msec, less than half the time required for a normal heart beat.

The machine also features a new application, X-CARE, intended to selectively reduce the radiation exposure of particularly dose-sensitive regions of the body, such as the female breast. This is achieved by switching off the x-ray tube assemblies during the rotation phase in which the anatomical regions concerned are most directly exposed to radiation. In this way, it is possible to reduce the radiation exposure of individual anatomical regions by up to 40%.

"The Somatom Definition Flash is not only the world's fastest CT scanner, but also the one with the lowest radiation exposure," said Bernd Montag, CEO of Siemens' imaging and IT division. "We have always given top priority to radiation dose reduction, and we are proud that our company has once again set a new standard in this regard."

GE Healthcare is equally confident about the clinical advantages of its latest product, the LightSpeed CT750HD. This was introduced at the end of last year after an eight-year development project that reexamined the whole of the data acquisition chain. The outcome was the introduction of the vendor's first new scintillator material for 20 years, called Gemstone. This new detector allows the scanner to deliver images 100 times faster than traditional equipment, with up to 33% greater detail throughout the body and up to 47% improvement in the detail achieved in cardiac examinations, according to GE. At the same time, it is reportedly capable of reducing radiation dose by up to 50% across the whole body and by as much as 83% for cardiac scans.

An important feature of the new technology is its Gemstone Spectral Imaging function, which allows the creation of images separating key bodily components such calcium, iodine, and water.

"This allows better characterization of tissues, which is something that CT has not been very good at until now," said François Roche, CT premium product manager at GE Healthcare. "It can see anatomical structures, it can define them, but previously it wasn't able to characterize them. This clearly is very important in oncology and also in cardiac imaging, where the new technology will be able to distinguish between soft plaques and calcium deposits in the heart vessels."

The system can also improve diagnostic confidence by producing clearer images, he said. It can produce a monochromatic image with substantially reduced beam-hardening artifacts normally attributed to bone, metal, and iodine, and can provide the tissue contrast optimization necessary for better lesion detection.

One of the centerpieces of the Philips booth will be its 256-slice Brilliance iCT scanner launched in late 2007, which continues to capture a significant share of the CT market, according to the company. Again, speed is a key feature of the product, and it can acquire the data to image the entire heart in just two beats, while potentially reducing the radiation dose for patients by up to 80%. The overall scan time is also much quicker than with earlier systems, as the gantry rotates four times in a single second or 22% faster than previous systems.

The Brilliance iCT scanner incorporates Essence technology, which comprises a set of innovations throughout each step of the CT scan, including new x-ray tubes, detectors, and reconstruction design elements. This technology can provide detailed and clear 3D images of an entire organ, including the heart and brain, and radiologists can expect key clinical insights for a wide range of applications in radiology and cardiology, according to Philips.

Toshiba Medical Systems will also be presenting a premium CT scanner that aims to improve clinical practice. Its Aquilion ONE is the first CT unit capable of acquiring isotropic volumes of an organ with a single rotation of the gantry, according to the manufacturer. This feature creates a number of new potential solutions, including the neuro ONE protocol that allows the acquisition of multiple low-dose volume scans of the entire brain during contrast infusion to provide whole-brain perfusion and dynamic vascular analysis in a single examination. Dynamic volumetric acquisition protocols can also be used to review moving joint structures in 3D, providing new clinical applications for orthopedic imaging.

With its 16-cm-wide detector unit, Aquilion ONE provides sufficient coverage to allow the scanning of most organs within one rotation, with clear advantages for patient safety. By eliminating the need for helical scanning, this dramatically reduces the resulting radiation dose, and the ultrafast scan times will also decrease the amount of contrast media used.

The Technical Exhibition will be open on Friday from 14:00 to 18:00. You can also visit the exhibits from 10:00 to 18:00 on Saturday, Sunday, and Monday.