Can you see the cranial nerves on an MRI?

[kippy6]

Can you see cranial nerves on an MRI? 

How can they tell that you have an acoustic neuroma (on the 8th cranial nerrve) from an MRI picture? I'm assuming it is b/c of it's location and shape. But can they actually see that it is attached to the 8th cranial nerve from the MRI films?
--My tumor was weird in that it did not originate in the Inner Auditory Canal. It originated in the Cerebellopontine Angle where nerves 6-11 pass. Do you think they could see my tumor attached to the 8th nerve on the MRI? How did they know it was an acoustic neuroma in this case?

Also, it is my impression that they can't tell if the AN tumor is attached to the facial nerve until surgery takes place. Is this true? Would a person be able to see from a MRI if the tumor is attached to a facial nerve?

Thanks

[tony]

Some deep stuff here for sure
It depends a bit on the type/form of MRI as to exactly what they can see
and the conclusions they will arrive at.
You have to balance two ideas here
One - an MRI with high contrast is probably the best non-invasive
way to diagnose the condition
Two - (Majid Sammi quote here) until you open up and go inside
you never really know what you are up against.
To some degree the MRI scan/interpretation of depends on the
experiance of the operator and investigation team.
By all means get a second opinion on the scans
if you are unconvinced - maybe get the neuro to take you through
them
Good Luck and Best Regards
Tony

[HeadCase2]

Kippy,
  Great guestions.  Having your AN extracanalicular, rather then intracanalicular, is probably not all that unusual.  Mine was [and I love saying was  ] in the same position.  I agree with Tony that they probably can only tell so much from the MRI, as far as cranial nerve involvment with the AN.  The facial [VII] nerve runs along with auditory and vestibular nerve through a portion of the auditory canal, so this may be why it can be affected more often than the other cranial nerves.  In my case, the neurosurgeon thought that removing my AN would go quickly, but once into it, he found that the AN was more involved with and stuck on the facial nerve than he had predicted.  After surgery I had some dry eye and slow blinking (both controled by the facial nerve) on the AN side for about 4 to 6 weeks.   I think they predict potential nerve involvement from their knowledge of cranial nerve anatomy and where your AN shows up on the MRI, and their learned experiences treating ANs-- another reason to use a highly experienced team to treat your AN.
  Doctors also use their experience and knowledge of tumors in general to help diagnose what type tumor they think you have.  In the literature I've read, tumors in this region are 92% of the time acoustic neuroma (vestibular schwannoma) and about 8% of the time they're meninginoma.  It's probably better to have an AN rather than meningioma.  Meningioma, from what I've read, is more likely to affect the surrounding area.
Regards,
 Rob

[Gennysmom]

It's my understanding that they never really know if it's an AN or meningioma till they get in there (that's what they told me) but that since an AN usually starts in the inner ear canal, inside of a bony area, that the shape (a small tail growing larger) is the giveaway as to what it is.  You never know though, Cinnamon just had one turn up to be a meningioma. 

[Kathleen_Mc]

I think they must be able to see the cranial nerves on MRI's 'cause the ones I've had done since my resection read "_______ cranial nerves notable absent on this scan". What I don't know is if they can tell if the tumor is just in front of/close by a nerve or if it's actually attached.
Kathleen

[tony]

The degree to which an AN is stuck to a nerve is one of the variables
that is different one patient to another - it is almost impossible
to predict the stickyness in advance of the OP itself.
One reason for having an experianced surgical team - they will
have met it before etc.
Best regards
Tony

[targa72e]

You can see the cranial nerves on the MRI. I asked the same question last time I was in for one year follow up. The facial nerve lies above the Cochlear and vestibular nerves. In my case the slices on the MRI lined up so the facial nerve showed up on one frame and the other two nerves showed up on the other. The frames that you can see the nerves on is not the ones with Contrast, if I remember you can see them on T2 images were the tumor shows up dark and the nerves show up white. You can also tell to some extent which nerve the tumor is most likely on with some testing VNG, VEMP and ABR. In my testing all the test were normal except the VNG indicating that the tumor is most likely on the superior vestibular nerve. It helps that my tumor is small as it only shows up in two frames of the MRI.

john