PC monitors shine as inexpensive alternatives

A consumer-grade monitor made by Dell Computers may be good enough for interpreting radiographs, raising questions about the relative value of medical grade systems that can cost 10 times as much.

Radiography is one of the most demanding applications in radiology, according to a presentation at the RSNA meeting Nov. 30, yet the Dell 2405 color monitor handles this challenge well, delivering brightness equivalent to that of medical-grade monitors at one-10th the capital cost, said Dr. David Hirschorn, director of radiology informatics at Staten Island University Hospital.

Hirschorn said the Dell 2405 is gradually finding its way into radiology as an alternative to more expensive medical-grade monitors. He studied the relative value of Dell and medical-grade monitors at Massachusetts General Hospital, where he serves as a research fellow in radiology informatics.

Previous research by Hirschorn found that consumer-grade LCD monitors are sufficient for reviewing "small matrix" ultrasound, CT, and MR images. But the subtle findings on "large matrix" radiographs are more visually demanding and pose an additional challenge. Radiographs represent about 70% of imaging's workload.

The Dell monitor is set for a lower brightness out of the box, but it can be made brighter, an option provided so that consumers can watch DVDs from a greater distance than is commonly used in a desktop setting, Hirschorn said.

To test whether the Dell monitor would be suitable for radiography, the researchers selected 121 radiography exams. Thirty of the exams were previously interpreted as normal and 93 as abnormal. The abnormal images were chosen for subtle positive findings.

All of the studies were first reviewed by two board-certified radiologists using a pair of Dell 2405 displays. The findings were recorded based on conspicuity grades for each exam. One month later the same exams were reviewed in random order by the same radiologists on a pair of 3 megapixel gray-scale medical-grade monitors. Both displays were calibrated to the DICOM standard.

The researchers found that the medical-grade and the Dell consumer-grade monitors produced the same findings in 117 of 121 cases. Two fractures and one kidney stone were seen on the gray-scale monitors but not on the Dell 2405s. In 11 cases other findings seen on the Dell 2405s were not seen on the gray-scale devices. The differences were not of statistical or clinical significance.

"These results don't prove that you can use this display, but there is good chance to believe this is probably reasonable," Hirschorn said. "In practice a lot of radiologists use this setup and are comfortable using this system for primary interpretation of radiography."