The leading manufacturers of ultrasound equipment have announced advances in ultrasound imaging called Harmonic Imaging and Contrast Ultrasound. This advanced ultrasound technique gives clinicians a new tool for evaluating cancer and determining the health of vital organs. This new contrast software enhances blood flow details in the body’s tiniest capillaries.

"Used with ultrasound contrast agents, Siemens patented Ensemble™ Contrast Imaging technology may open up new doors for diagnostic and therapeutic use of ultrasound in medicine," said Markus Kirchgeorg, M.D., vice president of worldwide marketing for Siemens Medical Systems, Inc., Ultrasound Group.

Ultrasound contrast agents are tiny, highly reflective, gas-filled microbubbles which, once injected into the blood stream, can travel into even the smallest capillaries. When exposed to an ultrasound beam, these agents return signals that are thousands of times more reflective than blood.

The innovation may offer clinicians a new, less-invasive method for evaluating tumor characteristics. VHL hemangioblastomas grow their own recognizable networks of blood vessels. In healthy tissue, blood vessel networks are tree-like networks, where large vessels branch into smaller ones at every bifurcation. VHL lesions and various malignant tumors develop more complex and less predictable vascular networks, featuring greater numbers of small capillaries. The ability to review these networks at the capillary level may help clinicians assess tumors and, ultimately, may offer clues to the tumor’s aggressiveness.

Ultrasound contrast can also be used to detect a lack of blood flow in organs, such as the kidneys and the heart, and in transplants, providing clinicians an early warning of poor organ health. It may also be used to evaluate the type of tumor in many other organs, evaluating the vascularization around the tumor.

Ultrasound contrast agents are administered through a simple intravenous line and the microbubbles dissolve harmlessly within the body, typically within a few minutes.

In response to our request for comment on its relevance to VHL, Dr. Peter Choyke, at the National Cancer Institute said, "This is a very interesting area of development for Ultrasound technology. A number of manufacturers of ultrasound equipment offer harmonic imaging which accentuates the effect of the ultrasound contrast agent. Unfortunately, the Food and Drug Administration (FDA) has not yet approved ultrasound contrast agents for general use in the United States so availability outside of research centers is limited. When it does become widely available it might permit some people with VHL to be screened by ultrasound alone. We are especially interested in it for intraoperative ultrasound where lesions can be difficult to see. I am following this area with great interest. However, one of the major limitations of ultrasound remains that it is highly dependent on who is doing it and the specific anatomy of an individual. For instance, it won’t be possible to examine most hemangioblastomas because the surrounding bone will block the sound waves. Nonetheless, I think it could be a huge development for the worldwide market where CTs and MRIs are less common."

Harmonic Ultrasound software is available from Siemens, Philips ATL Ultrasound, Hewlett-Packard Ultrasound, and others. http://www.aium.org/News%20Releases/3dharmonic.htm

As printed in the VHL Family Forum 7:3, September 1999. For permission to reprint, please contact VHL Family Alliance, editor@vhl.org. Further information is available from the VHL Family Alliance, info@vhl.org.