Medical Diagnostic Imaging Monitors: The Basics of What & Why
What is important in Medical Diagnostic Displays?
Medical Diagnostic displays are just monitors right? Wrong!! These displays are some of the most important and powerful tools used in medicine today. In order to speak intelligently on the topic one must know a bit about how they are used and why they are different than their consumer grade cousins. In this article I will outline the 4 ways these displays are different and how they are used.
Is that Black or is that Gray: Quality Assurance and Calibration Makes That Clear
The single most important thing that medical diagnostic facilities have to ensure when working with medical diagnostic displays is performing regularly scheduled calibration. The reason why this is so extremely important for medical imaging displays is to guarantee the best image quality and to ensure that light levels are the same throughout the screen not only now but also over time as the monitor ages.
LCD displays can last more than a decade under typical use, but the light source for backlit screens does not last nearly as long. As the bulbs age, they become dimmer and their ability to show shades of gray or color becomes unbalanced. That translates into a loss of quality images for the physicians and medical professionals and can mean a missed or incorrect interpretation for the patient. In our very litigious world this is what the malpractice attorney’s lust after, the proverbial smoking gun. Attorneys will frequently subpoena the maintenance records of the displays used for interpretation if there is a missed diagnosis or medical malpractice case. Asking to see the calibration records and maintenance reports on the diagnostic monitors used on their client is potentially enough to start to build a potential case.
Medical monitors are generally only covered under warranty for five years. Why five years? The five year mark is when the projection lamps start to age and deteriorate after typical use. Typically, these displays usually include a built-in monitoring system to ensure their diagnostic quality. These sensors limit the down time for these monitors and no longer requires a tech to physically come and test each monitor (an example of True IoT Technology). Medical diagnostic imaging is not only supremely important in the identification, diagnosis, treatment and prevention of disease it is a very high money maker for these facilities. Having these machines down or under testing slows down the facility and as we have heard many times before Time is Money.
What standard are these monitors held to and how is it completed? DICOM is the testing standard for diagnostic monitors. In order for a display to be DICOM-calibrated, a photometer (a device for measuring the intensity of infrared, ultraviolet, or visible light) is held to the screen manually or the display may have a built-in front sensor attached to the bezel. While color monitors might be preferred because of their versatility, QA to maintain calibration of monochrome displays is much easier. Uniformity of colors can be an issue over time and requires closer attention and maintenance.
Imaging without Boundaries: Eliminating the Bezel
The typical setup for a radiology review station is two monitors side-by-side so that the physician can review before and after images. Vendors are now offering larger, single displays that eliminate the need for two monitors as well as the bezel separating the two screens. This allows for better viewing without the distraction of the bezel when going between the images. Curved displays are also popular in this setup to wrap the physician in the image horizontally. Ensuring the monitors are calibrated is extremely important.
Color vs. Monochrome:
Until the recent past all diagnostic imaging was done in black and white with grayscale showing different densities within the study. Color typically lacked the brightness needed to give a proper radiographic interpretation. Color typically needed more energy to produce brighter outputs, this would have a negative effect on the lamps and the system as a whole. Now using OLED Technology (An organic light-emitting diode (OLED) is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light in response to an electric current. This layer of organic semiconductor is situated between two electrodes; typically, at least one of these electrodes is transparent) the displays are not backlit at all thus allowing for color to be used more widely. With OLED, Black is true black and not a backlit black. This shows a greater contrast when using these displays for diagnosis. OLED Technology displays are typically lighter and thinner than traditional displays.
The use of color, specifically red and blue can now show the flow of venous and arterial blood within an image to aid in the diagnosis of vascular conditions like stenosis or calcification of arteries. Today the technology is so advanced that these displays can show flowing blood and track the velocities of the blood as it moves through the arteries and veins of the body. A narrowing of the artery called a stenosis can affect the speed (clinically known as velocity) of the blood flow in the body and can even block blood flow all together (an occlusion). Medical professionals can visualize this in real time. These monitors can also show blood flow to tumors in concert with visualizing the size (growing or shrinking) of these tumors without subjecting a patient to exploratory surgery.
Consumer Grade vs. Medical Grade
Consumer-grade monitors typically lacked ample luminance, so they were not bright enough to adequately display enough shades of gray for diagnostic interpretation. As the technology advances commercial grade monitors are getting close to being acceptable. One would be hard pressed to find consumer grade monitors in a true medical diagnostic lab. Consumer grade displays are used however throughout hospitals and physicians offices but not for diagnostic purposes. There is typically a designated diagnostic computer setup as outlined above where the physicians interpret the medical images. Again a malpractice attorney would be licking their lips to know that a consumer grade monitor was used instead of a medical grade DICOM monitor to make an interpretation and or diagnostic.
The Wrap Up
In summary a medical grade diagnostic medical imaging monitor is an extremely important medical device and shouldn't be treated as "just another monitor" DICOM certification keeps the monitors working in a uniformly manner. Having a designated "Command Center" for medical imaging review within a Diagnostic center is a must and having the proper equipment is of utmost importance. OLED Technology is bringing and has brought color to medical imaging and can aid in the interpretation and diagnosis of specific medical conditions. Medical imaging is not only essential to care but it is a large moneymaker for medical centers, down time on these command stations literally can cost the facility thousands of dollars.
