Adapting Color Imaging Technique to Medical Imaging Applications

Scientists at the National Institute of Standards and Technology (NIST; Gaithersburg, MD) are devoting their efforts to ensuring that a powerful, color-based imaging technique can transition from a remote sensing method to use in the operating room. Known as hyperspectral imaging (HSI), the technique has been used in satellites because of its superior ability to identify objects by color. While many other visual surveying methods can scan only for a single color, HSI can distinguish the full color spectrum in each pixel, enabling it to perceive the unique color 'signatures' of individual objects.

"Because diseased tissues and cells also have distinct spectra, scientists have been trying to use HSI for medical applications as well," notes NIST physicist Jeeseong Hwang. "But any time you tell a machine to scan for something, you need to be sure it is actually looking for what you want, and you have to make sure that the image analysis algorithm extracts the correct color information out of a complex multicolor data set. We decided to create a way to calibrate an HSI device and to test its algorithm as well."

The team was assisted by Matthew Clarke, a former National Research Council-supported postdoctoral fellow in Hwang's group who is now working at the National Gallery of Art in Washington, DC. Clarke wrote new software for a device called a microarrayer, which can lay down hundreds of tiny sample droplets in specific places on a microscope slide's surface. This method can then be used to calibrate medical HSI devices and image analysis algorithms. When combined with HSI in a medical imaging application, this effort could allow a surgeon to look for cells with a specific chemical makeup, as determined by the cells' color.

"Scientists and engineers can create a custom slide with the exact colors representing the chemical makeup they want the HSI devices to detect," Hwang says. "It could be a good way to make sure the HSI devices for medical imaging perform correctly so that surgeons are able to see all of a tumor or diseased tissue when operating on a patient."