Not too long ago, hospitals began to recognize the importance of digitizing their workflow. They found it could save money, increase profits, and quicken diagnosis time by investing in hospital information systems, picture archiving and communications systems and electronic medical record systems. Color monitors and displays were mainly purchased for hospitals viewing stations. They were found to be esthetically pleasing when viewing EMR, HIS, and patient data; and monochrome displays could be found in diagnostic imaging to be used in conjunction with PACS. However, now color displays are now coming out of the back office and becoming highly useful tools in viewing diagnostic and even therapeutic images.
The use of color in medical imaging has proven to be highly effective and more widespread in the United States today. Companies such as Barco, Planar Systems, Siemens Display Technologies, NEC Display Solutions of America and Eizo Nanao Technologies have introduced color LCD monitors and projectors that are utilized across a variety of clinical specialties. These companies, along with others, recognized that the need for a variety of color displays was necessary to advance healthcare technology.
Defining color displays
There are two main types of color displays used today in the healthcare arena: medical grade and consumer grade. Medical grade color displays are most often purchased by hospitals for modalities such a nuclear medicine, computed tomography, positron emission tomography, ultrasound and magnetic resonance imaging as well as viewing images in cardiology. These medical grade color displays have a higher megapixel count, as opposed to their consumer grade counterparts. "Our facilities typically use three megapixel displays for diagnostic imaging and two megapixel displays for tech images," says Margery Sandner, PACS administrator for Sutter Health of Central Valley, Calif. Margery says that they have been implementing NEC monitors for applications such as nuclear medicine, ultrasound and cardiology in their organizations since 2004 and have found their use irreplaceable.
Hospitals also purchase consumer grade color monitors with a smaller megapixel count for back office environments for web browsing, patient data look ups, or reviewing EMRs. Color displays have proven to be versatile and can be used with a wide array of other technologies, including PACS, patient monitoring, EMR, HIS and RIS.
Monochrome vs. color
Most hospitals in the United States continue to use grayscale displays for the majority of image viewing. Grayscale displays have been the mainstay due to their higher pixel counts. Color displays range between one and three megapixels while their grayscale cousins can go up to five. As a result, the contrast is sharper and the brightness is greater.
Few color medical displays have DICOM compatibility with the ability to display eight bits of grayscale per color (16 million colors). These displays usually come with a brightness of 400 cd/m2 and a typical contrast ratio of 400:1. Grayscale is currently leading the race in gradation smoothness and sharpness.
Because of this smoother gradation and better visibility, it is currently standard that mammography exams and most radiology exams, if digitized, must utilize grayscale display for diagnosis. However, color displays are being implemented for a wide array of uses today not only for viewing of patient and EMR data, but also for diagnostic procedures.
"The radiologists think that digital imaging used in conjunction with color displays is the way to go," says Sandner. "The color displays have made it easier to diagnose problems in areas such as ultrasound and nuclear medicine. For the procedures that involve cardiac patients, the diagnoses are easier to determine due to the ease of viewing with the color displays."
Grayscale monitors are predominantly used with modalities such as x-ray and mammography. Cancerous cells are easier to detect and more clearly seen using grayscale monitors. However, color displays are highly effective for CT, nuclear medicine, and other modalities that find 3D images with color increase the ease of diagnosing pathological issues that would be much harder to detect if using grayscale or manual film imaging.
Eizo's RadiForce Products are examples of color monitors that enable both accurate color and grayscale gradations that can be used by modalities such as MRI and PET and also utilize 3D image rendering.
Though most hospitals