ANA Discussion Forum
General Category => AN Issues => Topic started by: MDemisay on February 23, 2012, 01:26:13 pm
-
Most of us humans perceive and live in three dimensions, yet why do we have to live or perceive reality in 2 dimensions such as some of us are forced to do when it comes to mapping our AN's? I am talking of course about differences in CT scans as opposed to MRI's.
I can't have an MRI which is measured thus: A x B x C as opposed to CT scan which is only measured in one plane Height x Width or A x B. This seems patently unfair!
What I want to know is there any other way to map an AN scientifically? Inquiring minds have a right to know!
Last night, I got a flavor of how much "Irv" had grown when I requested 5 additional CT scan copies which they gave me. It says that since May 2009 and October 2011 there has been a .4 x .4 increase.
My question is: Is that a lot? Measured in cm?
Doesn't point mean that anything on the other side of the dot mean that it is millimeters?
Mike
-
Hi Mike, obviously I am NOT a doctor, just passing on what my neurosurgeon told me. She said that if my AN did not change => 2 mm by the next MRI in April, 6 months since discovery, that she would leave me on W&W. Of course, my AN is snugly lodged in the IAC so I suspect that not only size but location matters. (like real estate - location, location, location...) :D
Karen
-
I'm not sure what you mean by mapping an AN scientifically, but as far as the math.
.4 cm = 4 mm.
-
Thanks Rupert! :D
Mike
-
Rupert,
I meant by scientifically, any other way of getting the 3rd dimension which is the depth.
Mike
-
I was curious why some are given three measurements. Most of the time I'm only given the largest measurement of my MRI and have to ask about the second measurement.
Lisa
-
Simplistically speaking, MRIs can provide three measurements, because they can provide images both "horizontally", which provide the transverse (i.e. side to side) and AP (front to back) dimension, as well as "vertically", which provides the coronal dimension. Anyone who has checked out their MRI scans, will have seen that there are series of images, in each of these directions. This is how the tumors can be mapped in 3-D. It is up to the radiologist if he/she will report all three measurements, they are often content with providing the TRxAP, since they are more relevant in terms of the impact to brain structures.
On the other hand CT technology is not able to do this, that's why you are only left with the 2D information. These two instruments work completely differently, MRIs use a magnetic field, whereas CT uses X-rays. I suppose there may be an indirect way to tell what the 3rd dimension is, by taking multiple slices, and knowing what the distance between each slice is. In any case, like I mentioned previously the two dimensions TRxAP are the most relevant, so CT should be able to provide this information.
Marianna
-
Thank you for the explanation.
Lisa
-
Thanks ever so much, Mariana! Now I can arrange a multiple slice CT! I wonder how difficult that will be?
Mike
-
When you aggregate multiple slices (slides) from an MRI sequence like sheets in a book, you get the 3rd dimension along a series of pictures (series within the SAME sequence/study). The MRI pictures typically say: this is a 1mm slice, or a 2mm slice, or a 4mm slice, or a 5 mm slice. This builds out a volumetric object in the 3 dimensions (2 on the slide and the other by overlaying multiple slides in the sequence). When you amass a few of these you can get a sense (actually a precise measurement when computer software is used) of what the volume is. Recent medical papers have made the point that VOLUME is a much better measure that the axb 2 dimenision sizing people often quote ...
Annamaria
-
After my first MRI, I was given only 2 numbers for each of my tumors. The MRI done at MGH just over a month ago was more detailed and they calculated the volume of the tumors. I liked that much better and hope that they'll give me those measurements after any future MRIs.