Open source software aims to simplify monitor calibration
Gone are the days when viewing quality images in radiology required highly specialized monitors. High-end consumer-grade monitors now have the capability of displaying high-resolution images, and a small cadre of radiology professionals are working behind-the-scenes to offer ways to calibrate these new technologies.
Nicholas Bevins, PhD, senior staff imaging physicist at Henry Ford Health System in Detroit, says that swapping out high-dollar medical displays can be a huge investment, especially in larger hospitals. “It’s not always a huge deal if there’s a budget for it,” he says. “But for smaller clinics or even overseas, that might be out of the question.”
The solution, Bevins says, often lies in looking outside the medical display realm into the consumer market.
“You can’t get cheap medical displays, but you can buy a professional-level monitor that a photographer or graphic designer would use that’s relatively affordable and calibrate it to the DICOM standard.”
While professional medical displays come equipped with firmware to ensure the machine meets DICOM standards, consumer machines don’t come with the DICOM curves installed on the graphics cards.
To help assist radiologists in developing countries and here in the U.S., Bevins assisted Michael Flynn, MD, and Philip Tchou, PhD, in developing a software called pacsDisplay. Bevins presented the software at last year’s Radiological Society of North American annual meeting in Chicago.
“It’s a software that enables you to calibrate any monitor to follow the DICOM curve,” he says. “It can measure a display and enable it follow the full palate of grays available by loading a lookup table on the machine’s graphic card.”
This capability helps institutions with lots of different machines and monitors across various departments to ensure uniformity. “Here at Henry Ford, anytime someone pulls an image up, it looks the same on any monitor because they’re all calibrated the same,” says Bevins.
Instead of selling the calibration solution, Flynn, Tchou and Bevins developed it as open source software—making it free for anyone to download.
“With this particular software we just wanted to establish a user base and to give people the ability to calibrate monitors,” Bevins says. “And if people who are on the user base generate different look up tables for different machines, then it’s for the good of the scientific community.”
Strict adherence to DICOM standards isn’t mandatory across all display monitors and there aren’t many requirements that say what standards monitors must follow. However, some organizations are paying more attention these days when it comes to accreditation.
“Organizations like the ACR [American College of Radiology] are taking more time in their accreditation,” Bevins says. “They’re beginning to incorporate some display performance criteria as part of annual testing procedures. They’ll pull images up on a monitor and measure the luminance response.”
As monitor calibration becomes an increasingly important part of accreditation, the ability to uniformly calibrate display screens throughout an organization becomes a more challenging task.
But with tools like pacsDisplay, ensuring the uniformity of all machines in a department, whether high-grade medical displays or consumer brand computer monitors, is a much easier goal to achieve.
“With this type of technology, we’re calibrating secondary displays and increasing functionality,” Bevins says. “It’s relatively easy now to make sure every monitor’s display is identical and up to standard.”
To read more about pacsDisplay and to download the application or source code, head to pacsdisplay.org.