Functional Magentic Resonance Imaging for Dummies

My first week of class has been really cool, I think I appreciate these unique opportunities more now that I'm an old fart than when I was a teenager.

Today's campus highlight for me was the 1st functional Magnetic Resonance Imaging (fMRI) course at the U of Iowa Carver College of Medicine.  Functional Magnetic Resonance Imaging is used in cognitive neuroscience research, meaning, research of your brains functioning when stimulated by different things (sight, smell, hearing, touch, etc).  Researchers will come up with studies like "what does your brain do when you listen to music?" and then a subject will lie on the table, listen to music, and an MRI will measure the the increased blood flow to different parts of the brain stimulated by the music. U of I researchers will then conduct their research studies using the images. It sounds just that simple, but I'm sure it is not.

A current research project that was recently publicized is one by a U of I researcher on alcoholism:
MRI Research on Alcoholism

Here is a photo of the Siemen's MRI at the Magnetic Resonance Imaging lab that we toured today:

I won't try to go review all of the physics equations on magnetism and aligning protons to measure RF energy to generate images  .... as I'm sure I did not grasp all of it either.  But, some of the light and fun things we learned today was that the big donut contains the magnet that is always 'on'.  The magnet is so powerful, it can suck something as big as a chair or a floor buffer inside of it (as shown below when a custodian left the floor buffer in a similar lab), so please use caution when in the lab was the message.  Here's a photo of such a phenomenon that Dr. Magnotta showed us today:

 

Here is a video on what happens if something like an oxygen bottle is brought into the MRI scanning area:

Oxygen Bottle in the MRI Video

We also covered how the MRI works on the inside, as shown in this diagram:

Essentially, the subject is positioned between the magnets, and because human's are predominately made up of water, the magnets cause the protons in your hydrogen molecules to align, the aligned molecules are generating RF (radio frequency) energy, and this RF energy is picked up by the RF detector of the MRI, and these signals are digitized into the MRI image file and stored on the computer.  

Frequency of various types of waves (from strongest to weakest, the ^ means 10 to the power of X...)

• X-rays ≈ 10^19,
• Ultra-violet ≈ 10^16
• Radio ≈ 10^7 (MRI)
• Visible Light ≈ 5x10^4

X-ray energy is a trillion times more energetic, and thus is more damaging to your body. Radio waves are not ionizing (cancer causing), the strength of signal in MR comes from the number of protons and not the high energy.

If you'd like to learn more about the MR Research Facility at the University of Iowa, you can go to this link:

University of Iowa MR Research Facility