QUESTION: Hello Dr. K...
I have had three brain MRIs
1. 2010 seizure
2. May 2015 Severe headache/ER
3. July 2015 Follow up to better determine possible Chiari and pituitary adenoma due to multiple symptoms (which was not found)
My question is related to the pituitary.
I have copies of all three disks and have compared the images of my pituitary and have spent time learning the basics on MRI imaging of the pituitary. After comparing my most recent MRI to the one in 2010 and articles/images online I found a few images in question. I cant save the images from 2010 to my computer so I cant upload an image to compare to a recent image.
The two images attached are from the July MRI (I adjusted the exposure and contrast to enhance the images)
1.T1w_tse cor pre-contrast
In the series the image before is of the posterior pituitary and knowing what the shape of pituitary gland looks like I don't understand how the dark cystic (looking) filled area is the anterior pituitary. It looks more like an adenoma on a post-contrast image from what I've seen online. Can you please explain what part of the pituitary that is.
2.T1w_tse sag pre-contrast
The pre-contrast posterior bright spot on 2010 MRI T1w_tse image is larger and very clearly defined and "normal looking". In the attached image the bright spot is significantly less and much darker where it was white in 2010. Is there a reason why?
I know its hard to tell much from two pre-contrast images but any insight/explanation would be greatly appreciated.
ANSWER: Hello Elizabeth,
Sounds like you certainly did a lot of research on the subject :)
And you are right that it is very difficult to say much from the two images.
Regarding question 1: i can see what you are concerned about...and I would need to look at post contrast images to have a better understanding and a probably T2 type sequence. There may not be a lesion after all...the roundish area may be secondary what is called volume averaging. The slice thickness is 3-4 mm on the sella MRI (usually) so everything that is within these 3 mm has the same grey signal. It may be just the case here. because the slice also through the sphenoid bone/clivus which is closer to the back of the pituitary gland. At the back of the pituitary gland there are several thing structures that I think volume averaged in the slice. But again...need more images.
I think the same may apply to your second question. However, there are other things that can be at play that have to do with different MRI machines, different slice thickness, whether or not fat suppression was used etc... All of these things may contribute to how the posterior bright spot would look.
Hope this clarifies some things.
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QUESTION: Thank you so much for taking the time to respond to my question. This is the most information I've received since I had the MRI. The doctor who ordered the my last MRI was actually ordered by his physician assistant and she had a hard time answering my questions. I unfortunately never saw the neurologist the two times I visited their office. After a few months of going over all my disks and learning about imaging of the pituitary I saw another neurologist for a second opinion and I left feeling even more frustrated with my questions unanswered. So thank you for your clear explanations!!
I know you are a busy man but if you wouldn't mind if I ask a few more questions it would much appreciated. :)
1. Coronal Image: I wasn't sure by roundish area if you meant the small round spots inside the big round area or if you meant the whole round area. My question was regarding the whole round area and the small bubble looking spots inside of it. Is the whole round area a normal looking pituitary? Or is that what you meant by roundish area?
After reading about volume averaging is it safe to say that is the same thing as an artifact? If so, the small roundish bubble looking spots are in all of the different scans pre and post contrast. My second MRI in May wasn't very clear but there is definitely a faint round spot in the coronal image. After adjusting the exposure and contrast of the image it is very clear. Can an artifact show up in two different MRI's?
2. Sagittal Image: One thing I forgot to ask was regarding the pituitary stalk. I noticed in all the sagittal and some coronal images there is a section of the stalk that looks like is interrupted. In the image I sent you the stalk has an hour glass shape (like it has kink in the middle) In other images (and some from May MRI) it is very clear that the stalk stops and continues on. It doesn't have the defined funnel shape. (it did in my 2010 scan) Is there a reason why it would look like this now?
Regarding the posterior bright spot...in the post contrast images fat suppression was used. I read an article that the posterior bright spot still "shines on" even when fat suppression is used. Is this correct? If so, my bright spot does not shine on in the post fat sat images.
Again, I know its difficult to come to conclusions with the two images I sent. I am reluctant to have a third opinion after my previous experiences, but with all my continuing symptoms and questions about the images, I think a third opinion might be beneficial. Your thoughts?
Thank you for your time...Elizabeth
Yes definitely would be easier to sit in one room look at the images and answer your questions.
Yes volume averaging I guess can be referred to as an artifact. On coronal image, I was referring to the whole dark spot inside the pituitary gland. On the sagittal image, the appearance of the stalk may vary as it is a small thin structure and i can be imaged on two different adjacent images. also there is usually less than a millimeter skip between two adjacent slices so some of the tissue is "lost". on sella MRI it is usually 0.3mm skip but sometimes the skip is 0...just depends on the protocol. Same volume averaging can certainly be seen on two MRIs.
I have to say that if there is adenoma, it is usually a functional adenoma, meaning it will secrete hormones, usually prolactin. so I would talk to your doctor and perhaps draw some labs.
posterior bright spot would certainly still be bright on fat suppression and may be better seen but it is a small structure and sometimes is not well seen depending on the slice thickness. I know i keep explaining everything with small size and volume averaging...unfortunately, sella MRI is just kind of a study. :) and without looking at the whole scan, I am afraid my answers are limited.
Hopefully that is still helpful.
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QUESTION: Hello Dr.K...Yes! Your explanation was very helpful!
I don't mean to wear out my questions, but I have two more quick question... if that's ok?
The attached image is T1tse post fat sat. Again, I enhanced the image to better see definition of areas.
Are pituitary glands supposed to look this messy/bumpy/cystic looking?
Also, do prolactin secreting adenomas always raise prolactin levels?
For over a year I have had issues with galactorrhea in one breast but my prolactin levels have been normal. (That's why I've had a hard time getting doctors/endocrinologists to further explore symptoms/issues...because, besides having Hashimoto's my blood tests/ hormone levels have been normal)
(I had a normal mammogram/breast ultrasound/had full hysterectomy six years ago)
I promise these are my last questions! :)
Please ask away, that's what I am here for.
Do they look messy? well, not necessarily. I think as you make the images more contrasty then all the little dots stand out a little more. Also, the way pituitary gland enhances varies tremendously due to at least two factors. One is the timing of imaging after the contrast has been injected. the earlier you image, the more heterogeneous (messy) it looks. Another factor is a venous supply to the pituitary gland which varies from person to person so it may be delayed or more prominent in some and not in others. In general, delayed imaging will show uniform enhancement of the gland. In your case, I can see if someone could question a small adenoma because of the messy enhancement. However, if your hormone levels are normal then I do not think you have one. Especially if you have galactorrhea and no prolactin elevation then it is not due to an adenoma. Was it really a milk like discharge or perhaps a different fluid? As you said you had a normal breast work up but lesions like papillomas may result in a nipple discharge.
Hope this is helpful.