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debirlfan
04-27-2011, 05:32 AM
Anybody know anything about brain scans?

Story is set circa 1995. My character has been "messed with" by aliens, and there is the possibility that they have changed the way he thinks/the way his brain works. I believe that what I'm looking for is called "functional imaging" - however, I have a couple questions.

From what I've read on wikipedia, it sounds as if they were just starting to use the MRI for this purpose at around that period. Unfortunately, my character has a whole bunch of metal (pins and such) in his body from a prior accident - I'm under the impression that makes him ineligible for an MRI?

The piece on wikipedia also mentions something about CT scans of the brain, but I'm unclear whether that would only serve to look for tumors/injuries and not do the sort of thing I'm talking about. (Also, would the metal affect a CT scan?)

Note, it's perfectly okay if they can't scan him - in fact, I'm rather hoping they can't. Thanks!

alleycat
04-27-2011, 05:43 AM
I had an MRI around that time, and some years earlier I had a CT scan and an EEG (back in the 1980s).

I'm not sure about the technology now, but back in the mid-1990s they were very strict about an MRI patient having any kind of metal objects on them.

An EEG might work for your story.

Medievalist
04-27-2011, 06:04 AM
I had my first fMRI in 1989. Go for it. There's even a lot of data about fMRI results online. Google away!

Metal is a problem, even rings or earrings.

chevbrock
04-27-2011, 09:32 AM
My hubby has a cochlear implant. They could only use one of the older models of the machines (2.5 tesla, if I remember correctly), and not the new ones, which I think are 5 tesla (but google it, don't take my fading memory as gospel). They had to firmly bandage his head beforehand. Most places we called were too scared to even attempt it.

I believe if you have any sort of shrapnel, pins, bullet bits or other metal paraphernalia inside you, they wouldn't even touch you.

shaldna
04-27-2011, 02:11 PM
I've had a couple of MRI's, and the first thing they ask you about is pregnancy, and then metal. This includes artifical joints, staples, surgical pins, earrings/piericings, metal plates, old shrapnel, metal teeth filings, braces, etc. They have a massive list that they go through with you before you are allowed a scan.

If the character has a lot of pins etc from a prEvious accident, then the chances are that he could not be scanned, as the MRI can cause metal to move.

For a CT scan, metal objects won't move, because it's a series of X rays rather than a magnetic imaging, so the metal won't move or prevent a CT, although any metal, especially plates, can block the scan, and means areas can't be seen. Also, most hospitals are less keen to use CT on your head, but will when a MRI is not an option,

alleycat
04-27-2011, 02:13 PM
I still like the EEG idea, because having one is just plain weird and I think it would fit in well with the rest of your plot.

DrZoidberg
04-27-2011, 02:20 PM
This was in 1999. It was an experiment to see how clever I was. I got to solve maths problems with my head in one of these:

http://en.wikipedia.org/wiki/Cyclotron

There was also a memory type game. They also showed me a bunch of pictures like smiling children and lush trees and rusted bicycles. I assume it was to calibrate it. Then I got a printout of my brain.

And what author wouldn't jump at the chance to use the word "cyclotron" in sentence?

sheadakota
04-27-2011, 03:13 PM
They won't even do an MRI if you have lots of tatoos- apparently the ink they use is metal based.:Shrug:

veinglory
04-27-2011, 06:12 PM
An EEG will not locate anything to a specific brain structure as it measures only electrical activity leaving the head.

Buffysquirrel
04-27-2011, 06:41 PM
Without a comparative scan made prior to the abduction, I'm not sure what use a scan would be anyway. Even if the character's brain is different from 'normal', it doesn't follow it's different from how it was before.

veinglory
04-27-2011, 06:48 PM
I suppose that if the change is startling enough it would be a reasonable hypothesis.

Buffysquirrel
04-27-2011, 06:50 PM
I suppose that if the change is startling enough it would be a reasonable hypothesis.

If you could establish that the person couldn't have been who they were or done what they did before with the brain they have now, yes. Natural variation would probably be the first thought, though.

alleycat
04-27-2011, 07:37 PM
An EEG will not locate anything to a specific brain structure as it measures only electrical activity leaving the head.
Well, if someone's brains have been "messed with" by aliens, an EEG might provide a clue. Maybe the person give off 220 volts . . . or sparkles! ;-)

The gave me one when they were looking for a possible brain tumor (along with a CT scan). The whole thing seemed silly to me. At that time they actually glued the wires to someone's head. As it turned out, they couldn't find a brain so there was no reason to worry about a tumor.

strictlytopsecret
04-27-2011, 08:07 PM
At that time they actually glued the wires to someone's head.

They still use the goop to stick the electrodes to your scalp. It's a pain in the tail to get it out of your hair.

~STS~

alleycat
04-27-2011, 08:29 PM
They still use the goop to stick the electrodes to your scalp. It's a pain in the tail to get it out of your hair.

~STS~
Really? I thought they had advanced to using little tape circles.

Actually, I half-way assumed maybe they had done away with EEGs entirely. Even at the time I had one, an EEG seemed like some kind of throwback to the 1930s.

strictlytopsecret
04-27-2011, 09:01 PM
Yes, there are the little circles. The goo goes onto the circles, then onto your scalp.

The ambulatory EEGs are quite the hassle. You get to leave the neuro's office looking like Frankenstein hauling a creepy little box.

~STS~

alleycat
04-27-2011, 09:04 PM
I remember looking in a mirror after my EEG. I looked like something from a low-budget horror flick.

Then they sent me to the CT scan . . . where I got hives from the stuff they injected into me (as well as almost throwing up). It wasn't a good day.

boron
04-27-2011, 11:07 PM
Having metals in your body doesn't prevent you to have an X-ray, CT or MRI. They ask you to remove any necklaces and such because they would appear on the image and hide the body structures, not because they would be dangerous. A metal would only hide nearby brain structures on the CT image, but since CT provides a series of images in the form of brain "slices", not pretty much of anything would be hidden.

Classical CT or MRI shows only images of the tissues.

Functional CT or functional MRI can detect variations in brain blood perfusion related to brain activity, or informations about tumor metabolic activity...I doubt these were available in 1995.

It is EEG, which gives most data about brain electrical activity (thinking process, for example). They use EEG in diagnosis of epilepsy, to study phases of sleep and such.

veinglory
04-27-2011, 11:31 PM
EEG gives very poorly localized information so it tend to cover gross levels and types of activity/consciousness not whether the activity indicates any specific emotion, thought or subject. Apples and oranges, really.

sheadakota
04-28-2011, 01:52 AM
Having metals in your body doesn't prevent you to have an X-ray, CT or MRI.

1/3 wrong- Having metal in your body contraindacates an MRI big time. Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body- These magnets are incredibly strong, if you have, say, a piece of metal in your eye, that magnet will pull that piece of metal out of and through your eye.
An MRI machine uses a powerful magnetic field to align the magnitization of some atoms in the body, and radiofrequency fields to systematically alter the alignment of this magnetization. This causes the nuclei to produce a rotating magnetic field detectable by the scanner—and this information is recorded to construct an image of the scanned area of the body. Strong magnetic field gradients cause nuclei at different locations to rotate at different speeds. 3-D spatial information can be obtained by providing gradients in each direction.


"MRI shows only images of the tissues"
Actually an MRI shows as stated above complex and detailed 3-D images of structure deep inside the body- it also shows ligaments tendons, and nerves as well as soft tissue and bone.

debirlfan
04-28-2011, 07:22 AM
Thanks, guys - got what I needed. Was hoping that an MRI was something that the doc might want to do, but not be able to do because of the character's medical history (pins and shrapnel.) I think it will work. Thanks again.

boron
04-28-2011, 10:19 AM
1/3 wrong- Having metal in your body contraindacates an MRI big time.

Yes, I should not include MRI.

cbenoi1
04-28-2011, 04:25 PM
PET scanners were deployed in many neurology departments across the US back in 1995. The resolution was much lower than that of MRI or CAT, but it provided more information about regions that were more active than others - the radioactive glucose got absorbed more densely there. So yeah, PET scaning would fit well in what you call "functional imaging".

EEG would be good for detecting sleep disorders, migraines, and seizures. But as far as detecting behaviour changes, then nothing beats a shrink for those cases.

Hope this helps

-cb (who has a master's degree in medical imaging, circa 92)