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Posterior Fossa Hematoma

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This was a patient who had a sports injury,

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a 14-year-old who had a sports injury.

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This is the initial scan,

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which was read as demonstrating scalp swelling

0:14

over the right frontal region.

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Once again,

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whenever I see the scalp swelling,

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I'm going to be looking contrecoup,

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and I notice that there is a little bit of

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swelling of the scalp up contralaterally,

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as if the patient may have had a two-part injury.

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But I'm not seeing anything with regard to

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midline shift nor parenchymal hemorrhage.

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I would then look at this with a subdural-based window and

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see whether I see any blood collections around the periphery.

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I would then look at my typical areas.

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I would look at the gyrus rectus region.

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Looks pretty good.

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I would look at the anterior temporal lobes where

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the greater wing of the sphenoid is.

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That looks pretty good.

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I would look at the brainstem to see whether the

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brainstem had banged up against the tentorium.

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That looks good.

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So, the initial scan was read as merely showing

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the scalp abnormality. Of course,

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you want to look on bone windows to see whether

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or not there's a fracture underlying the scalp.

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However, the patient wasn't doing very well.

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The patient had severe headaches and had some level

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of reduction in the level of consciousness.

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So, the patient was scanned 24 hours later as part of the

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follow-up while in the hospital under observation.

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This is the follow-up scan.

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And once again,

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we see the soft tissue swelling over the right frontal scalp.

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Nothing immediately evident contrecoup.

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However, when one examines the posterior fossa,

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we find this area of hemorrhage that,

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even in retrospect,

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was not present previously.

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Now, some might say, well,

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could there have been a little non-hemorrhagic contusion,

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a little bruise back here that evolved

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into the hemorrhage?

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That is possible.

2:00

In the posterior fossa,

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we usually have beam hardening artifact which sometimes

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will make this kind of an obscured area.

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But suffice it to say,

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the patient had a delayed intraparenchymal hematoma.

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Delayed intraparenchymal hematoma is correlated

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with a worse prognosis.

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Not only that,

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but this patient has a posterior fossa hematoma.

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And as I mentioned previously,

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the posterior fossa hematomas generally do worse than the

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same-sized supratentorial hematoma because the posterior

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fossa cannot handle the extra volume, if you will,

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of the hemorrhage.

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So, as with any hemorrhage,

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in order to determine surgical

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indication for intervention,

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we will measure this.

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Measuring 1.37 cm in AP dimension.

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We give it in the transverse dimension, 1.1 cm.

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Unfortunately,

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a coronal reconstruction had already been made for us

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and we can measure the superior inferior dimension as 1.8 cm.

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So, doing our mathematics,

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we would multiply 1.3 by 1.1 by 1.8,

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arrive at a product and divide that by two for the

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neurosurgeons to make a determination about whether or not

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they should intervene for the hematoma.

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In the posterior fossa,

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the other thing to make sure that you mention is the

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impact on the fourth ventricle

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as far as whether or not it's displaced.

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Doesn't appear to be in this situation,

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whether or not any of the basal cisterns are effaced,

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that is, we can no longer see the low-density

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subarachnoid space around the brainstem.

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And this looks perfectly fine.

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And then we would look inferiorly to make sure that the

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cerebellar tonsils are not herniating through

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the foramen magnum down this way.

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And just as the brain tissue can herniate downward,

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we can have superior herniation through the tentorium.

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This is the area of the tentorial edge.

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This is the superior vermis.

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And this looks normal.

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There's no effacement of the basal cistern or the

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perimesencephalic cistern seen on this CT scan.

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So a delayed hematoma in the posterior fossa,

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measuring 1.3 by 1.1 by 1.8 cm.

Report

Description

Faculty

David M Yousem, MD, MBA

Professor of Radiology, Vice Chairman and Associate Dean

Johns Hopkins University

Tags

Vascular

Trauma

Neuroradiology

Interventional

Emergency

CT

Brain

Bone & Soft Tissues

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