Ultrasound has been a welcome tool for many years to break up kidney stones, but finding the stones still requires radiograph or CT imaging. Researchers from the University of Washington and the National Space Biomedical Research Institute (NSBRI) believe they developed a method of detecting renal calculi using a modified diagnostic ultrasound equipment found in every modern hospital. Moreover, once detected, they are able to apply ultrasound in a controlled way so as to be able to push the stones in a desired direction. This may create a new treatment option, allowing physicians to guide stones toward the kidney exit that are refusing to pass naturally.
Detection of the stones is done thanks to the unexplained “twinkling artifact” phenomena that makes stones sparkle under Doppler ultrasound. Because X-rays are not used in detection, patients and clinicians would be less exposed to radiation, and diagnosis could be done faster and right at the point of care.
From a NSBRI press release:
“At the same time, we have gone beyond Twinkling Artifact and utilized what we know with some other knowledge about kidney stones to create specific modes for kidney stones,” [Dr. Michael] Bailey said. “We present the stone in a way that looks like it is twinkling in an image in which the anatomy is black and white, with one brightly colored stone or multiple colored stones.”
Once the stones are located, the ultrasound machine operator can select a stone to target, and then, with a simple push of a button, send a focused ultrasound wave, about half a millimeter in width, to move the stone toward the kidney’s exit. The stone moves about one centimeter per second. In addition to being an option to surgery, the technology can be used to “clean up” after surgery.
“There are always residual fragments left behind after surgery,” Bailey said. “Fifty percent of those patients will be back within five years for treatment. We can help those fragments pass.”
The ultrasound technology being developed for NSBRI by [Dr. Lawrence] Crum and Bailey is not limited to kidney stone detection and removal. The technology can also be used to stop internal bleeding and ablate (or destroy) tumors. Crum said the research group has innovative plans for the technology. “We envision a platform technology that has open architecture, is software-based and can use ultrasound for a variety of applications,” he said. “Not just for diagnosis, but also for therapy.”
Press release: Twinkle, twinkle kidney stone: With a push you could be gone