Arachnoid cyst size conversion question?
 

I was diagnosed with an arachnoid cyst via CT scan in 1999 but the report does not show the size of the cyst. In 2012 the cyst was measured at 3.1 x 1.6 cm on my right temporal lobe. I have been having issues and I requested a new MRI and the cyst was measured in millimeters instead of centimeters and the size was 22 x 20 x 30 mm. I am racking the internet trying find out how to compare the sizes between the two with no luck. I have tried the standard formula but that comes to 13,200 mm and I know that is not right. I am simply trying to figure out if the cyst has grown since 2012 as I wait on a reluctant GP to refer me to a neurosurgeon.

I was hit by a truck when I was 4 years old which left me in a coma with five skull fractures. I have always been socially different and very irritable although I long for social interaction. This could be my holy grail because no amount of medication has ever worked. If this thing is getting bigger then I know that it is the problem because you can't have the desire to be a good person that I have along with being physically normal yet being so socially abrasive that the world hates your guts without the cause being organic. Any help would be greatly appreciated.

Hi there,

There are 10mm in 1 cm, so your cyst now measures.

2.2 x 2.0 x 3.0 cm.

Do not be surprised if Drs insist it is asymptomatic, they often do contrary to all evidence.

Dave.

Thank you so much for your reply. The problem is that I don't understand what the difference between the cm value in the old MRI which was only two values when the new MRI, which is in mm has three values. Please forgive my stubborn ignorance! I can determine the speed of two vehicles prior to a collision using a graphing calculator but simple math is impossible to me. Did the cyst get bigger between 2012 and last week? I can get a picture of what 3.1 x 1.6 cm looks like as far as size but the three values is messing with my radar. Lol

:confused:

No experience with Arachnoid cysts, but I'm guessing that one is width, one is height and one is anteroposterior diameter.

I'm not sure what order it is though. Hopefully someone will know. :)

[anteroposterior diameter is a view taken from front to back through the cyst]

Possibly the tech reading the images was more detailed in the report , or the MRI system is been upgraded and better /cleared image.. so better measurements?

Is there an Impression section on the MRI report? What does it say..

I believe I have figured it out. But the missing third value in the old MRI is aggravating. The total volume from the first is 4.96 cm but the new volume is 13.2 cm. Did it grow or was the first MRI reader sleeping on the job? I am trying to gather as much evidence as I can to PROVE without a doubt that the cyst is not asymptomatic. I am corresponding with the NORD and I have yet to find the first case where cognitive defects were the only symptom without massive pain. I hope with all of my might that they will listen. I believe with all of my heart that if they can remove this insidious growth from my brain and publish it, maybe those out there who are suffering from a "benign" monster can get their lives back. In my case, I don't know what that life is.

The difference in length, 3.1 to 3.0cm is minimal and can be put down to the Dr/Radiographer determining the edge of the cyst.

The difference with the other measurements, I would say, is that your earlier measurement of 1.6cm was made on a cyst which was tubular. Now, it has expanded by 0.4 and 0.6cm to 2.0cm width and 2.2cm depth, so it is slightly flattened now.

That is just my take on it, but the measurements are definitely showing expansion.

Hope that is easier to understand.

Oh, there are 2.54cm in an inch.

Dave.

"IMPRESSION
1. Stable simple right middle cranial fossa arachnoid cyst.
2. No acute infarct, hemorrhage or increased mass effect."

I take #2 as it hasn't grown but I don't trust any doctors or specialists when the majority of the information that I have studied shows that they will dismiss anything that isn't bleeding or ruptured.

If it is getting bigger in three years, I hypothesize that I can get the doctors to believe that it needs to be removed. If it hasn't grown then I will have an uphill battle against the naysayers that believe that AC's are asymptomatic. It's hard trying to determine whether or not to tell the truth in order to secure freedom from ICP.

Mine is at the base of my brain, I have had years of unexplained weakness and numbness on my left side, over and above accident damage. Between '07 and '13 it grew 'significantly' according to my Neuro. I also have early-onset mental issues like Depressive Personality Disorder/Anxiety issues which some attribute to Arachnoid Cysts where present.

Of course, when you have a large lump pressing on parts of your brain, Neuros are loath to admit it may be doing anything at all.

Dave.