Does CT scan detect AN

[mom3 boys]

I am 37 years old, mom of three, very active. I started having a very loud ringing in my left ear first week of December, followed by a sinus infection which required steroids and antibiotic. The sinus pain and the ringing on the left side did not get better so I had a CAT scan in January of the sinuses and brain. It came back negative for abnormalities. I also saw ENT and audiologist and have no hearing loss in that ear. I have been unsteady on my feet for years and have severe vertigo a few times a year. I also have a feeling of fullness and pressure in that ear yet when they measured the pressure in that ear it was only 20, which they said was normal, although my right ear was a 0. I also have scalp sensitivity all around that ear and up to the crown of my head. I'm nervous that this very loud constant ringing, pressure, and dizziness is something like AN and they have missed it.  Does anyone know if my symptoms sound likely to be an AN or do you think the CAT scan and Dr. Evaluations seem accurate? I Have seen my primary, ER dr., ENT, and audiologist who have all said labrynthitis is the most likely cause or Meniere's disease. Should I follow up again, or would you trust the tests I have had done? Has anyone had ringing in an ear that has lasted months? I had an MRI 4 years ago when the dizziness was starting and it was negative. Also, I have Hashimoto's thyroiditis, but do not take meds to manage symptoms. Also, low red blood cells, low iron, and  low lymphocytes. Have no idea if any of this is all connected. Thanks so much!!!

[Jim Scott]

Hi, 'mom' ~

I'm not a physician but my advice to you is to try and convince your doctor to order an MRI scan (with contrast) to determine whether or not you have an acoustic neuroma.  They are expensive but the best way to find out if your symptoms are being generated by an AN.  The scan may discover something else is the cause of your symptoms but it will definitely rule an acoustic neuroma in or out, and that would be progress.   

Jim

[arizonajack]

I agree with Jim. An MRI with contrast is the way to go to determine if there is or isn't an AN. CT scans can often miss a small AN especially if done without contrast dye. An MRI with contrast is likely to ferret out an AN if there is one.

[PaulW]

My CT Scan came back as "suspect" with a 10mm AN, which prompted the MRI.
There are lots of things that can cause AN like symptoms, in fact they are often undiagnosed for years because the most likely cause is something other than an AN.

I guess AN's are typically slow growing.
The most common presenting symptom of an AN is hearing loss
Normally there is no sign of infection. So while an AN can't be ruled out, you are not really fitting into the classic profile of an AN either.

The only way to know for sure is to have an MRI with Contrast.


   

[cburley1]

I was diagnosed with AN in Nov 2010 w/MRI/contrast..it was 1.6 cm (16mm x 16mm).....they said I could have had it for years as normal growth is around 2mm per year approx.....well I had a CT scan with & without contrast in 2008 that showed nothing...I asked why that was as it indicated to me that it was growing faster than 1 or 2 mm per year....nobody has ever answered that question....makes me nervous as last two MRI's my radiologists are saying that since my Gamma Knife in 2011 it has grown another 2 1/2 mm....though my ENT didn't get the same measurements......so who knows...but from my own experience I trust an MRI more than a CT scan for diagnosis of AN...good luck

[arizonajack]

1mm to 2mm growth per year is an average.

Mine was diagnosed by MRI in Apr 2012 grew from 9mm to 11mm in 6 months.

[mikechinnock]

My AN was first diagnosed via a CT scan. That was back in 1978. I am sure CT scanners have gotten better with time, just as women, wine, and cheese do. Before MRI, CT scanners were the cutting edge. Bottom line is that I believe a CT scan can detect an AN. As noted above there are a number of conditions that can cause your symptoms and it is best to stick with your doctors advice and opinions. If the answers do not solve the problem, ask another question. Good luck and I hope your journey is successful, pleasant and has a positive outcome.

[PaulW]

Because CT scanners use X-rays they are best used for boney stuctures.
Detecting soft tissue changes is immensely more difficult.
The AN is typically pretty much invisible on the CT scans

When you have an AN its not unusual for it to put pressure on the internal auditor canal, which is a boney tube running between the inside of your skull and the inner ear. This pressure often deforms the bone, normally by making it thicker, the IAC is also made wider.

So looking for bone deformation around the IAC is how small AN's are detected.

When they get much bigger the tumour will start to displace the brain and brain stem.
Much larger tumours get picked up once the brain is visibly being pushed abnormally.

 

[Tumbleweed]

Dr. Chang (Stanford-based doctor) once explained to me that MRI is easier to interpret with the eye (therefore making it less likely that an AN would be overlooked by a reading radiologist), whereas a CT scan is more accurate for the purpose of treatment planning.

For this reason, MRI is the gold standard for determining if a tumor is present. So, if you are uncertain and uneasy with your doctors' reassurances, find a doctor who will order an MRI. But as others have stated, there are many reasons besides an AN -- some idiopathic, or for which no cause can be determined -- why someone can have the symptoms you are reporting.

Best wishes,
TW

[mom3 boys]

Thank you for all of your responses. I want to trust all of the Dr.s I have seen, but it's so hard when it's so debilitating and to think this is it, there is nothing that can be done. The ringing is just so intense as well as the vertigo. The ringing can be so high pitched then later in the day it's lower, sometimes the ear feels plugged and then " opens" later in the day. Can people have allergic reactions to the MRI with contrast? I have never had an MRI or CAT scan with contrast. Is that safe? Thanks again for the advice.

[Tumbleweed]

The contrast agent that's used with an MRI (gadolinium) is regarded as safe except for people who have kidney disease. As long as you drink plenty of water after the MRI is finished, you will very likely have no side effects.

Best wishes,
TW

[MDemisay]

Dear Mom of 3,

Firstly, let me welcome you to the ANA forum, it is an invaluable tool of support!

Secondly, let me tell you that I wish I could have gotten an MRI, unfortunately I cannot because due to a previous brain operation in the 70's I had a bunch of metal clips in my brain which remain there (which preclude me from having an MRI). A Magnetic Resonance Imaging scan with spinning magenets would serve to scramble my brain and would thus eliminate any need for further surgery as you can well imagine.

Thirdly, a CT scan with contrast will be good enough to identify an AN. Such testing is 2D imaging.

Fourthly, unless there is a medical reason why you can't, you should go through with it. An MRI with contrast will give you a 3D image allowing for more precise measurement on a height by width by depth basis.

Wish I could have had one! I thank my lucky stars for that previous surgery, and I know that were it not for that surgery(in 1974), I would be long dead. It kept me alive for my AN surgery in 2004 (30 years later) and my necessary radiation in 2012.

Mike

Good luck with your MRI with contrast.

As to the previous posters here I agree with all of them, I just thought you'd like a little information from a guy who was not allowed to have an MRI with or without contrast.

As always, Mom of 3, post often and use this vital resource well, you will find many answers here.

[nftwoed]

Hi, mom3 boys;

   In my thinking, the abnormal result of the tympanogram suggests a middle ear problem or eustachion tube problem and water backed into the area behind the ear drum. It may be cyclical, allergies, or ET dysfunction.
   Re, CT for AN; It's likely not so reliable as MRI. CT works much better imaging bone. An AN would widen the IAC, which is bony.
   But, of course this is a Dr's job to Dx. It may even be Meniere's Disease

[mom3 boys]

I really feel like what you are referring to, as far as water, fluid, etc. or Ménière's disease is a realistic diagnosis.   I just wish one of the doctors could give me an answer because I feel like I am worrying about it being something more serious, when it could be as simple as placing in a tube or something like that to help.  Any advice on next steps? I feel like my doctor will think I'm a hypochondriac if I go back again. Would you start by going back to the ENT? Thanks again for all of the advice.

[ewchisek]

Hi.
I would also try to get an MRI. I had two ct scans without contrast and neither of those scans picked up my AN, which was found less than a year later when my dr finally ordered an MRI. And my AN was over 2cm, do it was not small. Good luck