MRI effective method for revealing anatomical details of soft tissues

January 13, 2016

Contrast agents can help to make these images even clearer and allow physiological processes to be followed in real time. Conventional gadolinium complexes currently used as MRI contrast agent cannot reveal anatomic structures. As reported in the journal Angewandte Chemie, Korean researchers led by Jung Hee Lee at Samsung Medical Center and Taeghwan Hyeon at Seoul National University have now developed a new MRI contrast agent using manganese oxide nanoparticles that produces images of the anatomic structures of mouse brain which are as clear as those obtained by histological examination.

Magnetic resonance images after injection of the manganese oxide nanoparticles gave a view into different areas of the mouse brains, in excellent resolution. "We have developed the first truly biocompatible MRI contrast agent for anatomical brain imaging," Lee and Hyeon point out. "With this agent, we are able to get high-contrast views of the anatomical details of live mouse brain." The researchers hope that their new contrast agent will allow better research and diagnosis of brain diseases involving the CNS (central nervous system), such as Alzheimer's disease, Parkinson's disease, strokes, and tumors.

Furthermore, the Korean team was able to attach antibodies to the manganese oxide nanoparticles. These antibodies recognize and specifically bind to receptors on the surface of breast cancer cells. In mouse brains with breast cancer metastases, the tumors were clearly highlighted by the antibody-coupled contrast agent. The same principle should allow other disease-related changes or physiological systems to be visualized by using the appropriate antibodies.

interscience.wiley

In this study, researchers combined four large prospective cohort studies, The Women's Health Initiative, and three from the Harvard School of Public Health: the Nurses, Health Study, the Health Professionals Follow-up Study, and the Physician's Health Study. From this large database, they performed a prospective nested case-control study to examine plasma concentrations of the nutrients from participants who had donated blood and answered questionnaires about their food intake and vitamin use before any cancer developed. Their analysis included 208 pancreatic cancer cases and 623 cancer-free control cases.

No one knows why vitamin pills may not help ward off cancer, or why, in this study, it might have a deleterious effect, Dr. Schernhammer said, but some research in animals suggests that ,if there is a dormant tumor, folate and other similar vitamins may stimulate growth." That might be especially true if a person did not take in enough of these nutrients consistently through diet, and then suddenly started taking multivitamins in an effort to become healthy, she said.

"People think that dietary intake of these nutrients reflects a lifelong healthy eating habit, and in those cases, these nutrients may be protective, but they could have an opposite effect if they are used in a person with an occult cancer," Dr. Schernhammer said. "It might all depend on whether a person is cancer-free at the time they start using these nutrients."

The same kind of association has been found with use of soy, which is an estrogen-rich food, she said. "Women who have eaten soy all their lives, such as people in Asia, have a reduced risk of developing breast cancer, but some studies have found that increased soy intake in women who have not eaten it before appears to be harmful."

The researchers say their study cannot definitively say that one carbon nutrients either pose a benefit or a hazard to most people, but they note that it is the best analysis that can be performed outside of a randomized clinical trial

aacr