Manufacturers address new QC standardFlat-panel displays hit the big time at the 2001 RSNA show, promising improvements in distortion and eye fatigue reduction, brightness, lifespan, and resolution."There was a tremendous interest
Manufacturers address new QC standard
Flat-panel displays hit the big time at the 2001 RSNA show, promising improvements in distortion and eye fatigue reduction, brightness, lifespan, and resolution.
"There was a tremendous interest in flat-panel displays this year," said Joe Marion, executive director at Superior Consultant. "Last year they were more of a novelty. This year they have definitely arrived-you had to look hard to find a conventional cathode ray tube."
Marion is advising clients to strongly consider using flat panels as part of their workstations due to advantageous life-cycle costs and performance enhancements compared with CRTs, particularly in heat generation and power consumption.
Dome and Barco are technology leaders in providing diagnostic flat panel displays to the vendors of imaging and PACS equipment. Karen Miller, Dome vice president of sales and marketing, noted the extended life of the company's flat panels. They last 30,000 hours, or between three and five years, Miller said. An automatic turn-off function could extend product life even more. Dome has leveraged its leadership in video display controller cards to build an extended client base in flat-panel displays. About 60 OEMS used Dome displays and controllers in their RSNA exhibits.
Dome's flagship is the C3 flat-panel monitor with three megapixels. The C3 accounts for most of the company's sales. Along with this model, Dome also showed the new C5, with five-megapixel display, at its RSNA booth. The C5 provides the highest resolution of any flat-panel monitor on the market.
Barco highlighted the Coronis 3MP three-megapixel flat-panel monitor. The unit features a protective front glass to protect the sensitive liquid crystal display, making special cleaning instructions unnecessary. The monitor, combined with a digital imaging board, provides 10 bits of gray scale, resulting in better image quality and improving visualization of structures, according to Barco. The company's monitors can be rotated into either portrait or landscape mode.
Other manufacturers of high-quality flat panels include Totoku and Advan. Totoku has manufactured CRT monitors for the television market for more than 60 years. The company currently supplies flat-panel monitors to Sony, Hitachi, and Toshiba. Totoku is also supplying monitors to GE specifically for medical imaging.
Totuku featured the ME202Lc flat panel, a 20.1-inch, two-megapixel color LCD monitor designed exclusively for PACS and radiology applications. The monitor has a 1600 x 1200-pixel display matrix and features 10-bit gray scale. The unit can switch between landscape and portrait orientations. Totoku's LCD products adjust luminescence brightness control automatically to compensate for any deterioration due to aging of the backlight.
Advan did not have its own booth but maintained a presence at the show in the Terra Recon booth. The company announced what it described as a new line of fourth-generation flat-panel displays. Using glass-panel technology developed in conjunction with Fujitsu (most other flat-panel manufacturers are utilizing IBM's glass technology), Advan's AGM 23TA 23-inch diagonal flat-panel display is the largest such monitor on the market for diagnostic-quality radiology viewing.
Nearly all manufacturers stressed monitor calibration. DICOM has defined a standard contrast curve, the Grayscale Standard Display Function (DICOM part 14), against which different types of display devices can be calibrated. With this, soft-copy displays can be calibrated against a standard that will ensure the images look the same viewed on different workstations at different times. With the new emphasis on soft-copy quality control, all major manufacturers addressed QC solutions.
Barco, a leader in this area, used the RSNA meeting to introduce new functionality to its networked QC system for flat-panel monitors. The system enables a PACS administrator to check and monitor calibration remotely. Barco has emphasized calibration with its I-Guard feature, which automatically monitors calibration, thereby eliminating the need to use a manual light meter to test the display for luminescence. I-Guard is integrated with the display system to provide constant monitoring of LCD and backlight stabilization.
Other flat-panel manufacturers showed systems for checking and calibrating their products, including Dome, which introduced the DMS system. With this system, a user can quickly and easily access information such as luminance levels, hours of backlight operation, and panel temperature. Although DMS monitors the flat panels internally, a manually applied external light meter is also required.
Data Ray and Barco underscored bit depth (the number of shades of gray that can be displayed) as an important criterion of monitor capability. Data Ray claimed the ability to display 10.5 bits, or 1531 shades of gray, the most of any flat-panel vendor, according to the company. Barco advertises 1024 shades of gray. It is not clear, however, what, if any, difference higher bit depths make to image quality or the ability to observe more detail in images.