CT Scan vs MRI to Diagnose Brain Tumor

[tgan71]

Hi.

I am a 36 year old healthy male who was having some unexplained headaches and dizziness.  I still have them from time to time.  My doctor ordered a CT scan with contrast and it came back negative.  They have sent me for an MRI just to be sure.  My concern has been that I have some sort of brain cancer or tumor, but I am told by some that the CT with dye would have picked that up.  My mother died of cancer at 28 so I am concerned.  Is an MRI necessary for my care providers to diagnose or rule out brain cancer knowing they found nothing on the CT?  I don't want to be pumped full of radioactive dye if it isn't necessary.  Thank you so much for clarifying!

[MinerManiac]

That last line of my previous post should be, "Bottom line, do not trust the CT scan, and get an MRI with and without contrast.

[MinerManiac]

To get back to your original question, it is definitely possible to have a brain tumor that a CT scan fails to detect.  We took my mother to the ER after the right side of her face started to droop.  They did a CT scan, and some tests of her strength and dexterity, and determined that it must be Bells Palsy.  An MRI with contrast, done within the week at the request of her doctor, showed a lesion on her brain.  That lesion was misdiagnosed for six and a half weeks; finally a biopsy  determined it to be an anaplastic astrocytoma, a very aggressive brain tumor that would take her life 17 days after receiving the diagnosis.  In between the first CT scan and the biopsy she had another CT scan, which showed nothing.  Bottom line, don't trust the CT scan, and get an MRI with and without contrast.

[skinny_mulligan]

With Mercury/Silver fillings, 90% of the Mercury dissipates withing the first 5 years.  If most of them are old, then they probably aren't a health risk.  Also, removing them tends to release mercury during removal and will find it's way into your system.  Getting them removed all at once could give you poisoning symptoms.  Best to get them removed one or two at a time, removing the oldest first.

[massed]

How did they found out about the mercury poisoning as it seems that i have exactly the same problem as you did and i had quite a few mercury fillings before so just wondered if this is the cause for me too,cheers

[tgan71]

Great news.  My headaches and dizziness and every other symptom under the sun ended up being the result of recent mercury poisoning.  The levels are quite high.It appears I got this from when i was working with pressure treated wood in an enclosed space back in October.  My doctor confirms it has explained all my pins and needles sensations, metallic tasting tongue, burning and plugged ears, etc.  Following the diagnosis, I had my fillings removed and temporarily made the symptoms much worse; primarily with respect to glands being swollen in my neck, face, throat, etc.  I'm a vegetarian and have worked in an office all of my life so these two sources of exposure are the only likely culprits.

[Dennis MD]

Hi.
CT scan and MRI are the two imaging modalities used to demonstrate central nervous system lesions.  Gadolinium-enhanced MRI is the preferred modality because of its higher sensitivity to pathologic alterations.  Also, there are times when CT scan will not be able to detect a small lesion in the brain.  That is the time when MRI is requested.  
Maybe your doctor is thinking of other disease conditions that caused your headaches and dizziness, that is why he requested for an MRI.

[utahmomma]

MRIs are the standard for finding tumors.  The MRI doesn't use radiation and shows much more detail than CT scans can.  The MRI uses radio waves to align the hydrogen atoms (remember we are mostly water).  Usually no contrast agent is needed during MRIs but, if one is needed (as I have many times) then Gadolinium is typically used.

http://www.netdoctor.co.uk/health_advice/examinations/mriscan.htm

The biggest drawback of MRIs is for those who are claustrophobic or are very sensitive to noise.  Most MRI machines are long tubes and the can make claustrophobics very uneasy - some have to be sedated.  There is also a lot of noise to the MRI and patients have to wear hearing protection.  

Maybe you will be lucky and just fall asleep in them like I do.  :-)

Don't fear the MRI - with your mother's early, untimely death and your headaches it would be best to get some clear imaging.