The makers of CT and MR scanners opened the spigot of new introductions at RSNA 2008. They flooded the exhibit floor with products: some premium systems, others optimized to hit particular price points or address clinical niches.
Siemens Healthcare rolled out a new version of its dual-source CT, the Somatom Definition Flash, built on the company's unique dual-source xray technology. In its debut at RSNA 2008, the FDA-cleared system with the $2 million price tag promised to dramatically reduce dose and eliminate motion artifact in the chest while opening the door to routine scanning of the coronaries.
Despite using two x-ray tubes and matching detectors, the Definition Flash requires only a fraction of the radiation dose of other systems now on the market and exposes patients to just a third of the dose they naturally encounter in a year from background sources. A new filter purifies x-ray beams at high and low energies to emit only the planned spectra, enhancing tissue characterization.
Spiral heart scans can be done in a quarter of a second or about half a heartbeat. Rather than receive an increase in dose, as might be expected, patients undergoing a heart scan on the Definition Flash receive less than 1 mSv of dose.
Rotations every 0.28 sec provide the horsepower to cover 43 cm/sec and deliver a temporal resolution of 75 msec. Whole chests can be covered in just 0.6 sec, eliminating the need for breath-holds, according to the company. The scanner's extraordinary speed means staff will not have to sedate pediatric or trauma patients. This is possible because the second imaging chain, mounted in the gantry at a 90º angle to the first, provides the data that would otherwise be missed if a single-tube system were used.
