Fat Graft and MRI

[LizAN]

I'm having translab on July 3rd, at HEI.  I assume they will do a fat graft.  From the first case study on this page:

     http://www.acousticneuroma.org/casestudies

it looks like the fat will take up the gadolinium.  How can they tell if the tumor regrows, with all that fat in the way?

Liz

[james e]

I do not know why the tumor glows, but it will, and  the fat will not. In the photos, it looks like they put a lot of fat in your skull, but it is a very small amount. I'm sure someone here can explain it.

[nftwoed]

Hi;

  Hmn... I had Translab and an abdominal fat graft years ago. I have NF-2 so head MRIs yearly. The fat is not visible. Just an empty space fringed by scar tissue taking up the gadolinium. The edge is quite bright, but narrow.
  Interesting question though. Best wishes for your surgical success, Liz!

[leapyrtwins]

I had an adomenal fat graft with my surgery (retrosigmoid) and when my doc (neurotologist) orders my annual MRI he orders it with the "fat suppression technique".

He also orders it with and without gadolinium.

Jan

[LizAN]

I had an adomenal fat graph with my surgery (retrosigmoid) and when my doc (neurotologist) orders my annual MRI he orders it with the "fat suppression technique".

He also orders it with and without gadolinium.

Jan

Interesting.  I wonder what the fat suppression technique actually is.  I thought nerves, and the brain, were largely made of fat.   

I'm also wondering what happens to the fat cells in a graft, without a blood supply.  Such strange territory we're in.

Liz

[leapyrtwins]

It is my understanding that the fat suppression helps prevent the impression (on the MRI films) that the fat in my head is actually the tumor regrowing.

I don't know how the fat suppression technique works as far as the machine goes, but I do nothing beyond lying down, moving through the tube, and letting the tech take pictures.

Jan

[LizAN]

I still don't know what the fat suppression technique is, but here is an article about it, related to ANs.

http://journals.lww.com/otology-neurotology/Abstract/1995/09000/Evaluation_of_Residual_Acoustic_Schwannoma_Using.10.aspx

Liz

[sgerrard]

I once found an article on this, although the link is dead now. I quoted the best part in an old post, though:

"Bright fat in Turbo Spin Echo sequences"

"There are two reasons why fat appears bright in virtually all sequences that rapidly apply multiple RF pulses; Magnetization Transfer (MT) effects and J-Coupling. The multiple RF pulses act as off-resonance MT pulses, saturating the bound pool of protons. MT induced signal loss occurs in most stationary tissues but not much in fat, leaving it relatively brighter. The more significant effect is based on a phenomenon know as J-coupling or Scalar Coupling."

It went on for three pages like that to explain how they suppress the fat signal. It gives me a warm and fuzzy feeling about Fat Suppression MRI; how about you?

Steve

[LizAN]

It sounds like they know what they are talking about, and that's what matters.  I still don't have a much of a clue, but I don't need to understand the technical details.  I am still curious...

Liz

[leapyrtwins]

Gives me a warm & fuzzy 

Nice to see ya, Steve.

Jan