Brain Imaging Facility to Open at McLean

Client:

McLean Hospital

Audience:

Hospital employees

Goal:

Introduce the hospital's new Magnetic Resonance Imaging Facility

Role:

Writing (also managed and produced the newsletter of which this article was a part)

...MRI uses the interactions of radio waves, a strong external magnetic field, and the body's own magnetic properties to create images. Here's how it works.

The nuclei of many atoms found in human tissue have "spin" which creates a magnetic field. "These nulei usually spin every which way," explains Dr. Woods. "But when you put them in a strong external magnetic field, they'll line up with it - they're like weather vanes lining up with the wind."

The aligned nuclei rotate at known frequencies, which are different for each element. When nuclei are exposed to radio waves of their preferred frequency, they "resonate" and flip over. As the nuclei relax by returning to their original positions, they emit electrical signals that vary in both strength and duration depending upon the chemical characteristics of different body tissues. The scanner picks up these varying signals and translates them into the gradiations of grey, black, and white that make up an MRI image. One of the reasons that MRI images of the brain are so detailed is that about two-thirds of the atoms in the brain are hydrogen, one of the elements that resonates and can be imaged.