Early radiology relied on gray scale images, but the use of color in advanced medical imaging is becoming more commonplace. On its face, this may sound like terrific news, because subtle differences in color may be helpful to radiologists interpreting images. But consider the many places in the “image chain” where color information is captured and used.
You can take a color photograph of the same thing with two different cameras simultaneously and notice differences. Likewise, you can display the same color image on two different screens and find that they look different. Currently there’s no standard for how color is displayed in medical imaging. Nor is there consensus on display calibration, images, and displays to ensure consistent color.
Color Useful in Medical Imaging, With Some Caveats
While radiologists find color images useful, images are affected by many pieces of hardware and software between the object being viewed and the final display a radiologist sees. For consistency, each component in the image chain should have a clear description of its effect on color. Having a clearly defined color architecture throughout the process from image capture through display is important for accurate diagnosis. In medical imaging, grayscale images are calibrated and standardized, yet no agreed-upon standardization process has been adopted for color medical imaging.
Color Accuracy and Color Consistency
Color accuracy and color consistency are two qualities that must be understood for color medical imaging to achieve maximum usefulness. Color accuracy has to do with the ability of an imaging system to produce exact color matches from input through output. Color consistency is about the ability of the system to produce image data with an identical (or very similar) perception by human interpreters. At the same time, color images are sometimes processed to highlight features. Though there is nothing wrong with this, it’s essential that processing occurs on images that have been captured so as to maintain the best color accuracy and consistency to start with.
Color Variation in Microscopy
Color in microscopy introduces even more variables. Tissue handling protocols can vary, as can stain usage. With this type of medical imaging, test objects, assessment of color variation between instruments, and the use of test or calibration slides is critical. As yet there are no international standards for color reproduction in microscopy nor for tissue handling and staining protocols. But color variation between instruments and displays must be understood, particularly when one slide is viewed by multiple parties.
Surgery, Endoscopy, and Laparoscopy
A surgeon who does both open surgery and laparoscopic surgery may see color differences when viewing the same tissue, but experience allows him or her to mentally adjust for the difference between tissue seen with the unaided eye and tissue seen laparoscopically. With endoscopy, a physician may never see the tissue with the unaided eye, and must rely on a video screen. However, endoscopists rely on pathology exams of tissue for diagnosis, so non-ideal color reproduction may not be a significant factor. Even so, most clinicians agree that color standardization would be beneficial in display of endoscopic and laparoscopic images.
Medical photography is a type of medical imaging that is becoming more widespread due to the use of telemedicine. For example, a photo of a rash might be sent electronically to a dermatologist for diagnosis. Inconsistency or poor color accuracy could compromise diagnostic ability, and considerable variability can be introduced in telemedicine because of lighting, camera characteristics, and image display characteristics. Reliable processes and standardization (such as by the use of reference color charts included next to the object being photographed) are important best practices.
SteleRAD Experience in Medical Imaging
Microscopy, medical photography, and laparoscopy are three aspects of medical imaging that could benefit from improvements in color standardization and display calibration. Many factors affect an image from the time it is captured until it is viewed by a physician, and doctors must understand these factors in order to make the most accurate diagnoses.
The radiologist-owners of SteleRAD have decades of experience in medical imaging and understand the importance of accounting for image capture and image display characteristics to the highest quality radiology services.
Physician Spotlight – Dr. Lisa Abrams
Dr. Lisa Abrams is one of SteleRAD’s Board Certified breast imaging specialists. Named one of South Florida’s “Top Physicians” in 2006, Dr. Abrams has extensive experience with administering and interpreting MRI results for breast imaging. She also specializes in Vascular & Interventional Radiology. To learn more about Dr. Abrams and the rest of the breast imaging team, click here.
SteleRAD works with physicians’ groups, imaging centers, and hospitals throughout South Florida. If you would like to learn more about how SteleRAD can help your practice, please call 954-358-5250 or contact us online at any time.