By Kurt Woock

When the Toshiba Aquilion ONE ViSION debuted late last year, it brought with it a bevy of new features. Marcus Chen, MD, director of cardiovascular CT at the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health, used the new Aquilion in a study leading up to the system’s FDA approval in November 2012. During the study, Chen and his colleagues looked at 107 consecutive patients who were undergoing a coronary CT exam and compared the radiation dose and image quality to the system they had been using before, a first-generation Aquilion ONE. Chen said the new Aquilion makes substantial gains, and he adds that the comprehensiveness of the upgrade is what makes the new scanner so effective. “It’s not just one feature that makes it stand out: it’s the combination of features.”

The Aquilion ONE ViSION used by Chen in the study featured Toshiba’s newest iterative dose reconstruction software, AIDR 3D. As a result of this technology and a faster rotation time, the average radiation dose across all patient exams was 0.93 mSv, compared to 2.67 mSv for the first-generation scanner. While AIDR 3D was not on the Aquilion ONE during this study, it now comes standard, significantly helping lower radiation dose on that system as well. Image quality also improved. Chen used four metrics to gauge image quality: blurriness, noise, contrast enhancement, and fine detail. Chen said that the new Aquilion was noticeably superior to the old system in three of the four metrics, and was comparable to the older system in the fourth (contrast enhancement).

The new scanner has 320 detector rows, as does its predecessor, which allows clinicians to scan a whole organ at once. The new scanner also rotates faster—one rotation takes 275 milliseconds, a 75-millisecond improvement, or approximately 20% faster than the original Aquilion. Chen said this improvement leads to less motion artifact. In addition, the new Aquilion’s 500-micron slices and third-generation iterative dose reconstruction software help render detailed images.

The x-ray generator is larger. Chen explains the benefit: “With a larger x-ray generator, you can use a lower tube potential and increase the contrast-to-noise ratio or make the images brighter.”

These enhanced capabilities deliver clearer information, but they also allow patients who otherwise might not be able to benefit from CT technology the opportunity to do so. Satrajit Misra, Toshiba’s senior director of CT, said that, from the beginning, the goal of the Aquilion’s development was to accommodate more patients. One way the manufacturer accomplished this was by increasing the bore size from 72 cm to 78 cm, an increase of nearly 10%. The higher gantry spin allows cardiac patients with higher heart rates to receive scans, whereas before the image would have been blurry. All things considered, Misra said the new Aquilion ONE ViSION will accommodate 15% to 20% more patients than its predecessor model.

The Aquilion currently is installed in three US locations, including the scanner at NHLBI with several more planned. Chen said the increased capabilities are “especially effective at cardiovascular imaging,” and he adds that it would be effective in “emergency rooms where you see a wide array of conditions.” The product also is targeted for use in large and mid-sized hospitals (200 plus beds).
Misra added, “Under the hood, there’s been a pretty dramatic change.” The increased rotational speed puts additional stress on the system, so engineers needed to redesign internal components. They also made the parts more accessible, which should lead to easier, more efficient servicing.