Re: Will Comedy Shows Ever Do A Skit On Michelle Obama?

The Daring Dufas wrote:
Rev Turd Fredericks wrote:
The Daring Dufas wrote:
Rev Turd Fredericks wrote:
The Daring Dufas wrote:
Rev Turd Fredericks wrote:
Onideus Mad Hatter wrote:
On Sat, 25 Oct 2008 21:26:31 -0700, Rev Turd Fredericks
<turdfred2@xxxxxxxxxxxx> wrote:


Both clockwise and counterclockwise. You posted that awhile back, do you remember where you found it?

I don't remember where I found it, but I archived the page text that
went along with it:
http://www.backwater-productions.net/_images/_Scraps/Right_Brain_vs_Left_Brain.html


Thanks. You got it from here http://www.news.com.au/heraldsun/story/0,21985,22556281-661,00.html

It's kind of an interesting graphic to show to somebody in an FMRI.

Do you have experience with PET or SPECT scans?
I know that the FMRI doesn't use isotopes and
is less invasive but will the FMRI show activity
in the brain like a PET scan?

TDD
Yeah, lots of experience with PET, none with SPECT. Basically, PET shows overall activity based on metabolism, FMRI uses the theory that blood flow increases as brain activity does. I have participated in a couple of FMRI studies but have not personally analyzed the data as I have with PET studies.

One of the studies I participated in with FMRI was very interesting. I had similar characteristics to a brain tumor patient (height, weight, handedness, age, race etc.) so they asked me to go in the scanner and they gave me a few tasks to perform. One was to repeatedly make a puff of air so they could locate the region which controlled my lips and tongue. They then analyzed the data to find the active brain area and it came up exactly as expected. They used the data from me to design the task(s) for the actual patient, so they could find the areas to avoid when going in to remove the tumor. Unfortunately, due to privacy regulations etc. I never did find out how the actual patient did.

The bottom line is that FMRI is much better for finding localized brain activity than PET (with a few caveats), and PET is better for assessing overall brain activity, and/or (depending on the properties of the isotope) finding such things as the overall amyloid load in the brain, neurotransmitter activity etc. The problem with PET is that you can't repeatedly test people in a short period of time and it has relatively low resolution, whereas with FMRI you can test people all day long every day and it is very high resolution. The disadvantage for FMRI is that the data analysis is not straightforward, and is statistically based to the point where slight deformations in the scan may show no activity where there is some, and/or activity where there actually is none. Each have their usefulness. I don't think FMRI is used as much for actual medical applications because of some of the data analysis issues. I work in research which is not a life or death thing, so we can take more of an experimental outlook with both methods.

Well, research is necessary to bring these things into
mainstream medicine. I remember MRI was NMR, the real
name scared the dumb masses because it had "Nuclear"
in it's name. Of course because of the atrocious state
of our educational system the dumb masses don't understand
science. How many people do you know that understand the
basic scientific principles by which the MRI scanner
works? Most folks think that "nuclear" only pertains to
ionizing radiation.


I for one don't really understand how the MRI works (at least not in a way I could explain to a class of physics students), but I have a basic understanding. I am merely a data analyst, I don't have to understand what the physicists and engineers do, that's why they are there; to supply me with data to process and analyze :-) I do get asked to volunteer as a "test pilot" quite often and have had a ton of MRI scans, from brain to full body.

My college major was physics. I've been licensed as
a broadcast engineer and two way radio tech for 30
years. I have had the opportunity to fool around a
little bit with things electrical/electronic, etc.

The MRI in the simplest terms uses a strong magnetic
field to line up the hydrogen atoms in the tissues
of the body. An RF pulse then knocks a number of
protons belonging to some of the hydrogen atoms out
alignment with the magnetic field. Sort of like when
you ring a bell. When the pulse goes off, the protons
realign with the magnetic field but emit radio waves
in the process. The radio waves emitted by the excited
hydrogen atoms are detected and used to produce an image.
That's the resonance part. The magnet and radio pulse
cause a resonance of the hydrogen nuclei. Thus the term
Nuclear Magnetic Resonance. This is a very simple
explanation of how it works and doesn't bring up things
like gradient magnets and the Fourier transform which
I could never explain. It's done in a magic box.

See I knew that, just couldn't explain it, again, I don't need to, and even if I did, I would likely be overruled by a physicist or an engineer. I just analyze the data and assume the other guys (including the scanning tech) did their jobs right. If I notice anything unusual about the data, I bring it to their attention.

BTW, you said you are involved in research. HOW BIG
ARE YOUR MAGNETS? *snicker*


The institute I work for has a 3T clinical scanner (the one I analyze the data for), a 4T experimental/clinical scanner, not generally used for clinical use but they do some kind of research with it, and a 7T totally experimental scanner used only on animals, the bore is only about the size of your fist on that one. The magnet on the 7T is strong enough to turn a metal screw into a bullet. Once I got into the 3-T and was wearing sweatpants. I accidentally had a bic lighter in my pocket and when I got close to the magnet, it pulled my pants off because the top of the lighter was magnetic, it was both embarrassing and funny at the same time.
.

Relevant Pages

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