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Case 28: Non-Infectious Mycotic Aneurysm on CT

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0:01

This was another patient with "worst headache of life."

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Thunderclap headache, WHOL—worst headache of life.

0:10

The CT scan initially was negative. However,

0:13

the patient was complaining so severely of the

0:15

headache that they did get a lumbar puncture.

0:19

The lumbar puncture revealed subarachnoid hemorrhage.

0:23

CT scan was negative.

0:24

They ordered a CTA to look for an intracranial aneurysm.

0:29

Now, there are other, um, etiologies for subarachnoid

0:34

hemorrhage besides aneurysms, and sometimes they

0:37

may be spinal etiologies where you have bleeds.

0:41

In this case, the CTA was done, and a priori,

0:44

we were a little bit skeptical that we would

0:46

find anything because the CT scan was negative.

0:51

And this was just based on the lumbar puncture.

0:54

So, on CT angiography for subarachnoid hemorrhage, I do

0:59

very much like I would do for atherosclerotic disease.

1:02

I will usually follow one vessel and identify all

1:06

of its branches to see where there are aneurysms.

1:09

Here’s our middle cerebral artery bifurcation.

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I’ll look at the posterior communicating artery origin.

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Clear that for aneurysm.

1:18

I’ll look at the anterior communicating

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artery here in the A1 segment.

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Make sure it does not show aneurysm.

1:27

I’ll go out to the periphery as well.

1:29

Go back to the vertebral arteries.

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Look for the takeoff of the

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posterior inferior cerebellar artery.

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This is the PICA takeoff.

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There’s no aneurysm there.

1:40

Meet at the vertebrobasilar junction.

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There's no aneurysm there.

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Come to the basilar tip.

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There's no aneurysm there.

1:50

Again, all this is going to be

1:51

confirmed also on the maximum intensity

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projection reconstruction in this case.

1:57

It was fortunate that I was a little bit observant,

2:00

in that the patient had a little blip right here.

2:05

Here it is out in the periphery,

2:06

very much like the preceding case.

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I don't know why it's favoring the posterior right

2:11

frontal-parietal region, but you can see that

2:14

there's a focal area where the vessel enlarges,

2:18

and this was another peripheral mycotic aneurysm.

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No risk factors on this patient, as opposed to

2:26

the previous patient, who had IV drug abuse and

2:29

subacute bacterial endocarditis.

2:31

This is a case that's going to be a little bit more

2:34

difficult to identify on our MIPs because it's so

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small, and the MIPs have some wider thickness than

2:43

if you were to do a conventional, uh, reconstruction.

2:48

But on this sagittal MIP, you can see the aneurysm,

2:53

as demonstrated here by my arrow in the right

2:58

parietal-frontal junction, and this was another

3:03

example of a mycotic aneurysm with no risk factors.

Report

Faculty

David M Yousem, MD, MBA

Professor of Radiology, Vice Chairman and Associate Dean

Johns Hopkins University

Tags

Vascular

Neuroradiology

Emergency

CTA

CT

Brain

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