Back in the golden age of rock-n-roll, Chubby Checker exhorted us to “Shake It Up, Baby!” Turns out he had a darn good idea, when applied to medical imaging techniques. In 1999, some clever researchers at the Mayo Clinic came up with an idea they called ultrasound-stimulated vibro-acoustic imaging (USVA). Since then, they’ve shortened the mouthful to “vibro-acoustic imaging” (VA), and found numerous uses for the technology, from using VA to detect subtle flaws in biomedical equipment to monitoring surgery in-progress.
VA is an extension of the widely-popular ultrasound technology used for so many life-saving diagnoses today. Like most really brilliant ideas, it sounds very simple and obvious once you hear it: introduce two known sources of vibration to cause resonance at a known frequency; listen to the reflections made; tumors or calcium deposits will reflect the vibrated ultrasound back differently than healthy tissue. There’s a really nice summary of VA research and innovation on the Mayo Clinic website as part of a retrospective of one of the co-inventors, a Dr. Greenleaf. Technical types will also want to read this detailed technical paper on VA imaging.
A paper being presented this week at a medical imaging conference describes using VA to distinguish benign fibroids from malignant tumors in the thyroid. This is especially good news for folks, like me, with thyroid problems. Most of us have thyroid nodules, and most thyroid nodules are benign. Of course, when they’re not, it’s often too late to do anything about them. Detection is mostly about watching for changes, which involves annual or quarterly expensive additional ultrasound or MRI that insurance companies are understandably reluctant to cover. The thyroid is sufficiently small that attempting to remove the items will usually result in removal of a substantial portion of the organ, and if they were benign, well, oops.
Another application is the extension of traditional mammography with VA techniques. Using VA, researchers were able to detect calcification in breast tissue samples. They have worked out a protocol to extend traditional mammograms with VA. There are also successful clinical trials are underway, using VA for early detection of breast cancer.
You’ll undoubtedly be hearing more about this non-destructive and incredibly useful imaging technique in medical news over the next few years. A 2005 paper describes a number of innovative future uses for vibro-acoustography, and I’m sure that more will follow. Many of the core technology elements are patented by the Mayo Foundation. I hope that they will be generous with licensing so that the technology can be deployed globally wherever there is need, especially in places where surgical biopsy is considered overly invasive for cultural reasons.
Thanks to the always-interesting Physics News Updates for the tip!