CT vendors fire new volleys in battle for high ground

Slice wars erupted again this year on the exhibit floor of the RSNA meeting, despite protests by vendors as recently as last summer that hostilities were nowhere in sight. The relative calm of the past two years, during which 16-slice scanners held the high ground, ended days before the meeting when Philips announced it would unveil a new family of CT scanners whose flagship would have more than 16 slices. When the exhibit floor opened, Philips was not alone. Its 40-slice Brilliance had been joined by megaslice versions of the Toshiba Aquilion and Siemens Sensation.

In the jockeying that followed, interpretations and definitions became the favored weapons of close combat. Resolution, clinical value, and coverage came into issue. As each of the superpremium scanners was still a work-in-progress, the only sure thing was the uncertainty that would prevail until these systems became widely available, a time that could stretch to the end of 2004.

GE Medical Systems

At this year's RSNA meeting, GE stayed out of the slice wars, focusing instead on extensions of existing products. These involved the 16-slice GE LightSpeed, standard-bearer for the company in CT, and a quadslice family member designed specifically for oncology.

• LightSpeed RT meets the special needs of radiation therapy planning. The quadslice scanner, unveiled a month earlier at the American Society of Therapeutic Radiology and Oncology, features an extrawide gantry aperture and wide field-of-view, as well as software specific to advanced oncology applications such as intensity-modulated radiation therapy. Oncology-specific software includes the Advantage 4D respiratory gating package, which suppresses motion artifact, allowing better localization of tumor margin.
• Xtream, a reconstruction and data storage platform, enhances visualization on the LightSpeed Pro16, allowing image reconstruction up to 15 frames per second. The platform was first shown nine months earlier at the European Congress of Radiology in Vienna with a maximum frame rate of six per second.

Philips Medical Systems

The acquisition in 2001 of Marconi Medical Systems transformed Philips into a global leader in multidetector CT. In 2003, the company took it up a notch, engineering a 40-slice scanner as the head of its new Brilliance family of scanners, with multiple price and performance points.

• Brilliance has offerings at six, 10, and 16 slices, each in production and ready for delivery. The 40-slice flagship will begin manufacture in the fourth quarter of 2004. The superpremium system is designed to rotate at 0.42 or 0.5 second. It will cover most if not all of an organ fast enough to freeze motion.
• RapidView reconstructs up to 40 images per second, raising the prospect of visualizing an entire data set before the patient leaves the exam room. Improved recon speed will be necessary, as the scanner will generate nearly 4000 slices in a 30-second run.
• Faster data acquisition with the 40-slice scanner improves the potential for CT to become the modality of choice for stroke assessment and coronary angiography and increases patient throughput.
• Guided Flow allows single-click operations, automatic processing, and integrated reporting packages that improve ease of use.
• Optical Slip Ring technology transfers data at 5 Gb/sec, increasing signal to noise and reducing radiation dose to the patient.
• Rate Responsive Technology automatically adjusts Brilliance systems to accommodate unpredictable patient heartbeats during cardiac exams.

Siemens Medical Systems

No other vendor has sought to populate the CT landscape with as many choices as Siemens. The company has two CT families, Emotion and Sensation, each oriented toward different market segments. Emotion appeals more to budget-conscious customers; Sensation more to customers with budgets in line with high-performance clinical demands. The work-in-progress Sensation flagship delivers 64 slices.

• Sensation 64 not only delivers 64 slices per rotation, but it does so in an unconventional way. Competing systems typically map out one slice per detector row, but Sensation 64 uses two focal spots, which doubles the number of slices. This as much as doubles resolution, according to the company, by doubling the sampling rate. It does not, however, translate into the amount of coverage that would typically be associated with 64 slices. FDA submission is pending.
• Speed4D technology, being built into premium performance Siemens CT scanners, features x-ray tube technology that allows 0.37-second gantry rotation and faster tube cooling, as well as optimized data reconstruction algorithms and automated x-ray dose calculations. Systems equipped with Speed4D will begin shipping in early 2004.

Toshiba America Medical Systems

Two families of CT scanners address the differing likes of Toshiba customers: the value-oriented Asteion and the premium Aquilion. The company this year highlighted a work-in-progress 32-slice Aquilion.

• Aquilion 32 features a 64-row detector design, isotropic scanning, and advanced image reconstruction technology. The Quantum Detector delivers 32 simultaneous isotropic slices with thickness of either 0.5 mm or 1 mm and a total z-axis coverage of 32 mm. The gantry has an aperture of 72 cm, tilts up to 30 degrees , and scans a maximum 1800 mm.
• Aquilion 16 CFX combines 400-msec gantry rotation with new cardiac function analysis software, called SureCardio, which produces multiplanar reformatted images, volume curves, and polar maps and performs wall motion analysis and functional parameter calculations. SureCardio automatically selects the optimum acquisition parameter based on the patient's heart rate.
• Sure software options available for the CFX and other Toshiba CT scanners automate complex CT imaging studies by incorporating imaging techniques that maximize clinical functionality and accuracy. Some are specific to the application, such as SureColon and SurePerfusion. Others are more general, such as SureWorkflow and SureScan.