But is bigger really better? With each increase in field strength there are new engineering challenges to be addressed. The formation of the UCSF Program in Bioengineering and the provision of a home for it in QB3 have been critical to integrate advanced technical development with the solution of biologically relevant problems. Advances made in the last year have demonstrated these benefits, and recent tests of the 7 Tesla scanner's performance have shown the new machine really does do a better job.

In one study, researchers Duan Xu, a recent graduate of the Joint UCSF/UC Berkeley Graduate Group in Bioengineering, Dan Vigneron, professor in the Department of Radiology, and Douglas Kelley, senior scientist from GE Healthcare, have compared images of the brain from the 7 Tesla scanner with those from a 3 Tesla system with similar cutting edge hardware and software. These researchers used the MR systems in the Surbeck Laboratory for Advanced Imaging for Advanced Imaging at QB3 to scan the brains of healthy volunteers.

When these researchers compared the images from the two systems, they found that the higher strength magnet increased the sensitivity or "signal to noise ratio" of the images by 1.9 times. It also allowed the visualization of brain structures in more detail than has ever been seen before, which will have breakthrough benefits to patient care.

Better images of the brain's blood vessels will, for instance, "allow us to see small aneurysms and quantify the growth of abnormal blood vessels associated with tumors," says Dr. Sarah Nelson, director of the Program in Bioengineering at UCSF. "More detailed images of the architecture of the hippocampus will assist us in studying epilepsy and evaluating treatments for diseases such as Alzheimer's. We can also detect small changes in the gray and white matter that correspond to abnormalities in development or to early changes in brain structure associated with Multiple Sclerosis."

In addition to changes in tissue structure, the 7 Tesla system will allow researchers to more accurately detect biochemical changes that can be associated with psychiatric and neurological diseases, as well as brain and other cancers. But it is not just detection, emphasizes Nelson, who also directs the Surbeck Laboratory and is a professor of radiology at UCSF and a professor of bioengineering at UC Berkeley. "We can also track how tumors or other types of pathology respond to therapy and can assist in defining at an early stage whether new treatments are effective."

A Detailed Look at Bone Health

The 7 Tesla system holds promise for much more than just brain imaging. The stronger magnet lets researchers take a deeper, more detailed look at cartilage and bone structure, because it can highlight anatomy as small as 50-100 microns (a micron is one-millionth of a meter). This level of detail will help Sharmila Majumdar, a professor of radiology at UCSF and a professor of bioengineering at UC Berkeley, and her colleagues make earlier and more accurate assessments of osteo-arthritis and osteoporosis. Serial high resolution imaging will allow physicians to better evaluate the patient's response to therapy and to understand factors that are important in slowing down the rate of disease progression.

The 7 Tesla system was constructed by GE Healthcare Technologies, and was the first installed on the West Coast. A second, similar system will soon be operational at Stanford University. The system will be used for research and development rather than patient care, Dr. Nelson said, "although we will be studying patients in our translational research projects."

Two widely available commercial applications—a brain spectroscopic imaging tool and a prostate spectroscopic imaging tool—have arisen from the translational research programs of Dr. Nelson and her colleagues, Dan Vigneron and John Kurhanewicz. The installation of the 7 Tesla system is expected to lead to the translation of many other cutting edge technologies into the clinic.

Funding for the purchase, installation and research associated with the new magnet came from a combination of sources. These include the School of Medicine, the Department of Radiology, private donations, the State of California and an academic-industrial partnership between UCSF, UC Berkeley and GE Healthcare that is supported through the UC Discovery Program.

Source: Susan Davis