Friday 25 May 2012

Neck MR Angiography Pitfall

A young pt with recurrent episodes of TIA advised MR Angiography of neck along with Brain.
Non contrast 2D TOF MRA performed, a MIP image of neck demonstrating of left carotid bifurcation and a row axial image at the level of the ICA origin.
A focal notching in ICA at its origin appears to be:
1. Plaque.
2. External compression.
3. Artifactual.
Answer: it’s an artifact, due to turbulence of flow at the bifurcation as axial sections of contrast enhanced CT Angiography of same patient at the same level are normal. 


Carotid bulb is a normal focal expansion of cervical ICA at its origin is patent and relatively prominent in young patient. Again due to vigorous flow there is formation of an eddy circulation in bulb with reversal of flow. This reversed flow leads to diminished signal on 2D TOF MRA because of the linked saturation band that suppresses all caudal flow, regardless of its nature. 

This problem can be obviated by use of contrast during MR Angiography as in contrast enhanced MRA study, flow related signal by contrast is insensitive to direction of flow and demonstrates the normal contour of the carotid bulb.

Reference: Practical MR Physics and case file of MR artifacts and pitfalls, Alexander C. Mamourian, MD


Dr J Jagdish said...

Great job on the blog Dr Balaji..

Just a quick suggestion.. one may want to be careful when including patients' names on the images.

Keep up the great work.

Unknown said...

Hey please is there anyone? My problem is like that. Every month I experience this attack and i feel the tension in my neck and then my head turning around. But there is a problem that my doctor took a Mr view and said just you have a little hernia in your neck and this can not cause your dizziness. He said you should have to see a Neurology Doctor.

So I wonder what is my problem. I quickly wanted to search for it and I saw this post compared my Mr with this patient. This is almost same. Can I post my Mr to anyone who can help me in here? I am so frightened.

and I am sorry about my English. I am a foreigner. Sincerely.