Brief Answer:
Doesn't look like Chiari but having full exam would be useful.

Detailed Answer:
I read your question carefully and I understand your concern.

I am not sure that one single jpg image is enough to definitely exclude Chiari. An MRI exam is composed of many slices and if the slice you have chosen is not exactly in the midline it may alter evaluation of the landmarks used.
Furthermore Chiari malformation is diagnosed only when there is a descent of the cerebellar tonsils by 6 mm or more, simply being below the plane of the foramen magnum is not enough a slight descent is a normal variation which doesn't produce any symptom. So since we are speaking of fine margins measurement must be made which are not possible on a jpg image without a scale.

If I were to judge by that image alone I would say no, I do not think there is a Chiari malformation. However for a more confident reply it would be useful if you could upload the whole exam in the original DICOM format. An easy way to do that if you have the disc is to upload the folder containing the DICOM files, should be the first folder when you browse the CD. You can compress it in a single zip file for ease of use, upload that zip file into a file sharing service like Dropbox or Google drive and send the link.

I remain at your disposal for other questions.

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Brief Answer:
No Chiari

Detailed Answer:
Thank you for providing the images so quickly, that makes it much more easier.

After reviewing them I am even more confident in my previous opinion, there doesn't seem to be any descent of the cerebellar tonsils. Chiari malformation is not an issue fortunately.

Let me know if I can further assist you.

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Brief Answer:
Below

Detailed Answer:
https://drive.google.com/file/d/0Bw-Vbu3eScA1bUVKa1BXRTRKVFU/view?usp=sharing

I have selected and zoomed 4 images, one for each sagital plane sequence, these are the ones in the midline, where the line showing the plane of the foramen magnum is drawn.
As you can see in the images the cerebelar tonsils remain above the line (the foramen magnum plane). So there is no measuring in mm as there is nothing to measure. If they had descended below the line I would draw a perpendicular line to the one you can see from the lower tip of the tonsils and the software would measure it automatically for me, but in this case as tonsils remained over the line there wasn't any measuring necessary.

I hope to have been understandeable.

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Brief Answer:
Glad to have been of help.

Detailed Answer:
You're welcome! Glad to have been of help.

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