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]

Overview

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

CT

CT scan showing hemorrhage in the posterior fossa

Spontaneous ICH with hydrocephalus on CT scan

Cerebral Amyloid Angiopathy

• 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 extraaxial 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

• 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

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  CT: Epidural hematoma

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  CT: Epidural hematoma

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  CT: Epidural hematoma

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  CT: Epidural hematoma

Intracerebral Parenchymal Hemorrhage

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  CT: Intracerebral parenchymal hemorrhage

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  CT: Intracerebral parenchymal hemorrhage

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  CT: Intracerebral parenchymal hemorrhage

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  CT: Intracerebral parenchymal hemorrhage

Intraventricular Hemorrhage

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  CT: Intraventricular hemorrhage

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  CT: Intraventricular hemorrhage

Subarachnoid Hemorrhage

Computed Tomography

• 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

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  CT: Diffuse subarachnoid hemorrhage

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  CT: Diffuse subarachnoid hemorrhage

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  CT: Diffuse subarachnoid hemorrhage

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  CT: Diffuse subarachnoid hemorrhage

Subdural Hemorrhage

Computed Tomography

• 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

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  CT: Subdural hemorrhage

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  CT: Subdural hemorrhage

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  CT: Subdural hemorrhage

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  CT: Subdural hemorrhage

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  CT: Subdural hemorrhage

Perimesencephalic Hemorrhage

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  CT: Perimesencephalic hemorrhage

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  CT: Perimesencephalic hemorrhage

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  CT: Perimesencephalic hemorrhage

References

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