Toshiba sets 'dynamic volume' as new CT frontier

November 1, 2008
Doug Ryan

Volume 30, Issue 11

Early CT systems delivered insights about the body’s anatomy that were previously impossible.

Early CT systems delivered insights about the body’s anatomy that were previously impossible. The following generations of scanners provided new capabilities to cover more anatomical area and acquire volume data sets in a single short breath-hold, an evolution that leaped forward in the late 1990s with the introduction of the multirow detector. This gave clinicians the ability to acquire isotropic volumetric data using thin slices that could be viewed with equally high resolution in any plane.

Although this advanced form of CT has progressed rapidly since its introduction, even the newest such scanners are limited to 8 cm per gantry rotation and, therefore, still require helical scanning. Their limited coverage means the volumes acquired for whole-organ interpretation and perfusion studies are not temporally uniform, because each portion of the volume is acquired at different moments in time.

To overcome this clinical limitation, Toshiba designed a new generation of CT technology called dynamic volume CT. With our introduction of a wide area detector (320 rows x 0.5 mm covering 16 cm) onboard the Aquilion One, CT takes a significant leap beyond even the breakthroughs of the last 30 years, providing data sets of whole organs and orthopedic joints, and 4D data sets of complex motions that can be viewed over time. A simple example of this is the ability to acquire whole-brain perfusion studies that can be viewed over the precontrast, arterial, and venous phases. Beyond the enhanced clinical diagnosis that can be realized by a perfectly timed arteriogram and venogram, the data can also be displayed for the first time as a wholebrain CT digital subtraction angiography data set and a temporally uniform whole-brain perfusion study.

The capacity to display the data dynamically has created a significant advancement in the ability to diagnose patients in a noninterventional way. This technology makes a considerable impact on radiation dose as well by eliminating the need for helical scanning.

One of the greatest advantages of the Aquilion One dynamic volume CT is its potential to change clinical pathways and not only improve how patients are diagnosed, but also save the healthcare system money by eliminating duplicative tests. An example is the ability to get a complete neurological study in less than one minute with one contrast injection.

Using 320-detectorrow dynamic volume CT, the data necessary to evaluate a patient can be acquired with one study, using only 50 cc of contrast and 5 mSv of radiation dose. The use of dynamic volume CT for this patient is faster, safer, and more comprehensive and can be accomplished at a significantly lower cost to the healthcare system than any other imaging method. In covering 16 cm per gantry rotation, the Aquilion One can cover entire organs with a single low-dose acquisition. This opens up the possibility of visualizing dynamic motion and perfusion of anatomy in ways that has not previously been possible.