Intracranial hemorrhage CT

Intracranial hemorrhage Microchapters

Patient Information

Overview

Classification

Subdural hematoma
Epidural hematoma
Subarachnoid hemorrhage
Intraventricular hemorrhage
Intraparenchymal hemorrhage

Causes

Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

## CT

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CT scan (computed axial tomography) is the definitive tool for accurate diagnosis of an intracranial hemorrhage.

CT scan showing hemorrhage in the posterior fossa | Spontaneous ICH with hydrocephalus on CT scan

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### Cerebral Amyloid Angiopathy [1]

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* Cerebral amyloid angiopathy manifests radiologically as part or all of a constellation of findings including:
* Acute or chronic ICHs in a distinctive cortical-subcortical distribution
* Leukoencephalopathy
* Atrophy

* CT allows rapid establishment of the presence or absence of an ICH and exclusion of an  acute cerebral infarction.
* Non-enhanced head CT is the preferred imaging modality for initial work-up as it provides crucial information regarding the characteristics of the ICH, including size, location, shape, and extension to the extra-axial spaces.
* If an ICH is present in a cortical-subcortical location suspicious for cerebral amyloid angiopathy, the patient should undergo additional evaluation with MR imaging.
* GRE is currently the most sensitive MR imaging sequence for detection of the chronic cortical-subcortical microhemorrhage.

### Epidural Hematoma

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* Typical appearance is a biconvex, elliptical, extra-axial fluid collections.
* Acute EDH may contain both a hyperattenuating clot and a swirling lucency (believed to represent a mixture of active bleeding and the serum remaining after previous clot formation).
* Subacute EDH becomes homogeneously hyperattenuating.
* Chronic EDH is at least partly hypoattenuating as the clot undergoes breakdown and resorption.

Images courtesy of RadsWiki

* CT: Epidural hematoma

* CT: Epidural hematoma

* CT: Epidural hematoma

* CT: Epidural hematoma

### Intracerebral Parenchymal Hemorrhage

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Images courtesy of RadsWiki

* CT: Intracerebral parenchymal hemorrhage

* CT: Intracerebral parenchymal hemorrhage

* CT: Intracerebral parenchymal hemorrhage

* CT: Intracerebral parenchymal hemorrhage

### Intraventricular Hemorrhage

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Images courtesy of RadsWiki

* CT: Intraventricular hemorrhage

* CT: Intraventricular hemorrhage

### Subarachnoid Hemorrhage

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#### Computed Tomography

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* Subarachnoid hemorrhage appears as a high-attenuating, amorphous substance that fills the normally dark CSF-filled subarachnoid spaces.
* These findings are most evident in the largest subarachnoid spaces, such as the suprasellar cistern and Sylvian fissures.
* Acute subarachnoid hemorrhage is typically 50-60 HU.
* When CT scanning is performed several days to weeks after the initial bleed, the findings are more subtle.
* The initial high-attenuation of blood and clot tend to decrease, and these appear as intermediate gray.
* These findings can be isointense relative to normal brain parenchyma.
* In addition to detecting subarachnoid hemorrhage, CT is useful in localizing the source of bleeding.

Images courtesy of RadsWiki

* CT: Diffuse subarachnoid hemorrhage

* CT: Diffuse subarachnoid hemorrhage

* CT: Diffuse subarachnoid hemorrhage

* CT: Diffuse subarachnoid hemorrhage

### Subdural Hemorrhage

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#### Computed Tomography

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* Unlike epidural hematomas, subdural hematomas are not restricted by dural tethering at the cranial sutures.
* They can cross suture lines and continue along the falx and tentorium.
* They do not cross the midline because of the meningeal reflections.

* In the acute phase, subdural hematomas appear as a crescent-shaped extra-axial collection with increased attenuation that, when large enough, causes effacement of the adjacent sulci and midline shift.
* The attenuation changes as the hematoma ages.

* Subacute subdural hematomas may be difficult to detect because they may have isoattenuation compared with adjacent gray matter

* Chronic subdural hematomas have isoattenuation relative to the cerebrospinal fluid.

* Rebleeding into subdural hematomas also may occur and is depicted as a layer of high-attenuation hemorrhage within a lower attenuation hematoma.

Images courtesy of RadsWiki

* CT: Subdural hemorrhage

* CT: Subdural hemorrhage

* CT: Subdural hemorrhage

* CT: Subdural hemorrhage

* CT: Subdural hemorrhage

### Perimesencephalic Hemorrhage [2]

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Images courtesy of RadsWiki

* CT: Perimesencephalic hemorrhage

* CT: Perimesencephalic hemorrhage

* CT: Perimesencephalic hemorrhage

## References

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1. ↑ Christine P. Chao, Amy L. Kotsenas, and Daniel F. Broderick. Cerebral Amyloid Angiopathy: CT and MR Imaging Findings. RadioGraphics 2006 26: 1517-1531.
2. ↑ Schievink, Wouter I., Wijdicks, Eelco F.M., Spetzler, Robert F. Diffuse Vasospasm after Pretruncal Nonaneurysmal Subarachnoid Hemorrhage. AJNR Am J Neuroradiol 2000 21: 521-523

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