CHICAGO, Jan. 23 (Xinhua) -- Northwestern University researchers have developed a new tool, called spectral contrast optical coherence tomography angiography (SC-OCTA), that can detect subtle changes in capillary organization for early diagnosis of disease.
SC-OCTA, a 3D-imaging technique, works by combining spectroscopy, which looks at the various visible light wavelengths or color spectra, with conventional optical coherence tomography (OCT), which is similar to ultrasound but uses light waves instead of sound waves. Like a radar, OCT pinpoints the tissue of interest, and then spectroscopy characterizes it.
SC-OCTA has many advantages over traditional imaging: it does not rely on injected dyes for contrast or harmful radiation. While many types of imaging only work if the area of interest is moving or completely still, SC-OCTA can take a clear picture of both. This enables it to image stagnant blood or moving organs, such as a beating heart.
"It can measure blood flowing regardless of how fast it goes, so motion is not a problem," said Vadim Backman, professor of biomedical engineering in Northwestern's McCormick School of Engineering who led the study.
"SC-OCTA's unique ability to image non-flowing blood could also become a valuable tool for the booming field of organoids, which studies how organs develop and respond to disease," said James Winkelmann, a graduate student in Backman's laboratory and the study's first author.
The new technology's only limitation is that it cannot image deeper than 1 millimeter.
Human body has more than 40 billion capillaries, which are tasked with carrying oxygen and nutrients to the far reaches of the human body. Unlike veins and arteries, capillaries are responsible for oxygen exchange, or delivering oxygen to organs and tissues throughout the body while shuttling carbon dioxide away. Low blood oxygen can cause mild problems such as headaches to severe issues such as heart failure.
The study has been published in the journal Light: Science and Applications.
