Collagen Vascular Diseases Overview - Examples of FMD, Carotid Web
HIDEInteractive Transcript
0:01
So now, we'll talk a little bit about
0:02
collagen vascular diseases.
0:04
The most common is fibromuscular dysplasia.
0:06
It's seen in young Caucasian females.
0:09
Pathologically,
0:10
there are rings of fibrous tissue and smooth muscle.
0:13
And so, what you get is a string of beads.
0:16
And here's an example of a patient who has this
0:20
string of beads appearance throughout her right
0:22
cervical ICA to the left or extent
0:25
in the left cervical ICA.
0:28
And this is another patient who
0:29
has left cervical ICA beading.
0:32
So, that's what the classic spring
0:34
of beads appearance looks like.
0:36
25% to 30% of patients with FMD,
0:39
systemic FMD, like they have it in their kidneys,
0:42
also have intracranial FMD.
0:44
Of the patients who have intracranial FMD,
0:46
95% involve the ICA,
0:48
and 12% to 40% involve the vertebral artery.
0:51
It's very common to have it more in one vessel.
0:55
And FMD is responsible for 15% of spontaneous
0:58
cervical carotid dissections.
1:01
So, carotid web is thought to be a variant of FMD.
1:05
And on pathologies, there's thickened intimal
1:08
fibrous tissue that projects into the lumen.
1:11
This is seen in middle-aged patients who have
1:13
recurrent strokes.
1:14
And this is what you see,
1:17
you see a thin linear filling defect in the
1:21
posterior wall of the carotid bulb.
1:24
It looks exactly like that
1:25
on reconstructed images.
1:26
And you have to be really careful when you're
1:28
looking at axial images because you'll see,
1:30
you know, basically, the normal common,
1:32
and then you...
1:33
common carotid,
1:33
and then you just see this in the proximal internal.
1:35
You see on two images.
1:36
Remember, you're looking at 1000 images.
1:39
So, when you're looking at the bifurcating,
1:40
you have to go through it slowly.
1:41
This is a classic carotid web.
1:43
And the patient had an MCA embolus,
1:45
as you can see on this MIP reconstruction,
1:48
and had a small MCA stroke
1:50
involving the right lentiform nucleus.
1:52
So, remember to look closely at the carotid bulb
1:56
when you're looking at your images
1:57
because this can be easily missed.
Pamela W Schaefer, MD, FACR
Professor of Radiology, Vice Chair of Education
Massachusetts General Hospital
© 2024 MRI Online. All Rights Reserved.