New Medical Imaging Technique First to Use Low-Dose X-Rays to Reveal Soft Tissue
X-rays from the National Synchrotron Light Source at
Brookhaven Lab are being employed for the first time in diffraction
enhanced imaging, a new, low-dose experimental technique to visualize not
only bone, but also soft tissue. This new imaging technique may eventually
greatly enhance the detection of cancer and other soft-tissue pathologies.
by Laura Mgrdichian and Karen McNulty Walsh
To look below the surface of the human body in search of deep-seated injury or disease, today’s radiologists use an alphabet-soup of imaging techniques: computerized tomography, or CT; magnetic resonance imaging, or MRI; positron emission tomography, or PET; single photon emission computed tomography, or SPECT; whole body scanners; and ultrasound.
Despite the advancements in non-invasive medical imaging since 1895 — the year in which Wilhelm Röntgen discovered a new, higher energy, shorter wavelength form of light able to penetrate solid objects which he called the x-ray — 80 percent of radiology still involves the plain, old x-ray.
But x-ray imaging technology has not changed very much over the past 100-plus years, since the day that Röntgen made the world’s first x-ray of his wife’s hand, complete with wedding ring. For the most part, x-rays still produce an image that shows bone very clearly, but, if a contrast agent is not used, distinguishes poorly among non-calcified soft tissue, such as ligaments, cartilage, or blood vessels.
Now, thanks to researchers working at Brookhaven Lab, x-rays from the National Synchrotron Light Source (NSLS) are being employed for the first time in a new, low-dose experimental technique to visualize not only bone, but also soft tissue in a way that not is possible using conventional x-rays. Called diffraction enhanced imaging (DEI), the technique provides all the information provided by conventional x-rays, plus additional data on soft tissues that were previously accessible only using alternative methods such as MRI or ultrasound. Even compared to those images, DEI delivers a much sharper and more detailed view of soft tissue.
Once DEI is scaled down for clinical use, this new imaging technique may eventually greatly enhance mammography and be used in the search for breast cancer, as well as be employed for the detection of other soft-tissue pathologies such as osteoarthritis and lung cancer.
“We’ve previously shown that this technique can visualize tumors in breast tissue and cartilage in human knee and ankle joints, but this is the first time that we have shown it to be effective in visualizing a variety of soft tissue, such as skin, ligaments, tendons, adipose pads, and even collagen and large blood vessels,” explains NSLS physicist Zhong Zhong (pictured, above), who heads this research project. “The ability to use just one technique to visualize such a range of soft tissue as well as bone has many potential diagnostic applications.” Performed with Rush Medical College, the research is funded by the National Institutes of Health, GlaxoSmithKline, Inc., and the U.S. Department of Energy.