Intracranial hemorrhage CT: Difference between revisions

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{{Intracranial hemorrhage}}
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==Overview==
CAT scan ([[computed axial tomography]]) is the definitive tool for accurate diagnosis of an intracranial hemorrhage.
CAT scan ([[computed axial tomography]]) is the definitive tool for accurate diagnosis of an intracranial hemorrhage.
 
==CT==
===Cerebral Amyloid Angiopathy <small><ref>Christine P. Chao, Amy L. Kotsenas, and Daniel F. Broderick. [http://radiographics.rsnajnls.org/cgi/content/abstract/26/5/1517 Cerebral Amyloid Angiopathy: CT and MR Imaging Findings.] RadioGraphics 2006 26: 1517-1531.</ref></small>===
===Cerebral Amyloid Angiopathy <small><ref>Christine P. Chao, Amy L. Kotsenas, and Daniel F. Broderick. [http://radiographics.rsnajnls.org/cgi/content/abstract/26/5/1517 Cerebral Amyloid Angiopathy: CT and MR Imaging Findings.] RadioGraphics 2006 26: 1517-1531.</ref></small>===


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Image:Subarachnoid hemorrhage 004.jpg|CT: Diffuse subarachnoid hemorrhage
Image:Subarachnoid hemorrhage 004.jpg|CT: Diffuse subarachnoid hemorrhage
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====MRI====
*Fluid-attenuated inversion recovery (FLAIR) is the most sensitive MRI pulse sequence for the detection of SAH. '''SAH appears as high-intensity signal in normally low signal CSF spaces.'''
*T2- and T2*-weighted images can potentially demonstrate SAH as low signal intensity in normally high-signal subarachnoid spaces.
*On T1-weighted images, acute SAH may appear as intermediate- or high-intensity signal in the subarachnoid space.
*MR angiography may be useful in the evaluation of aneurysms and other vascular lesions that cause SAH.


===Subdural Hemorrhage===
===Subdural Hemorrhage===
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Image:Subdural-hematoma-003.jpg|CT: Subdural hemorrhage
Image:Subdural-hematoma-003.jpg|CT: Subdural hemorrhage
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====MRI====
*MRI is more sensitive than CT scanning in the detection of subdural hematomas because the multiplanar and superior tissue differentiation of MRI makes detection easier.
*The shape of the subdural hematoma on axial images is the same crescent-shaped pattern seen on CT scan images.
*The signal depends on the age of the hemorrhage and follows the signal pattern of intraparenchymal hematomas in acute and subacute cases.
*Chronic subdural hematomas, which appear as isoattenuation relative to CSF on CT scans, often demonstrate increased signal intensity on T1-weighted images because of the presence of free methemoglobin, though the intensity decreases over time.


===Perimesencephalic Hemorrhage <small><ref>Schievink, Wouter I., Wijdicks, Eelco F.M., Spetzler, Robert F. [http://www.ajnr.org/cgi/content/abstract/21/3/521 Diffuse Vasospasm after Pretruncal Nonaneurysmal Subarachnoid Hemorrhage.] AJNR Am J Neuroradiol 2000 21: 521-523</ref></small>===
===Perimesencephalic Hemorrhage <small><ref>Schievink, Wouter I., Wijdicks, Eelco F.M., Spetzler, Robert F. [http://www.ajnr.org/cgi/content/abstract/21/3/521 Diffuse Vasospasm after Pretruncal Nonaneurysmal Subarachnoid Hemorrhage.] AJNR Am J Neuroradiol 2000 21: 521-523</ref></small>===

Revision as of 18:31, 28 August 2012

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

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

CT

Cerebral Amyloid Angiopathy [1]

  • 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

  • CT: Epidural hematoma

    CT: Epidural hematoma

  • CT: Epidural hematoma

    CT: Epidural hematoma

  • CT: Epidural hematoma

    CT: Epidural hematoma

  • CT: Epidural hematoma

    CT: Epidural hematoma

Intracerebral Parenchymal Hemorrhage

Images courtesy of RadsWiki

  • CT: Intracerebral parenchymal hemorrhage

    CT: Intracerebral parenchymal hemorrhage

  • CT: Intracerebral parenchymal hemorrhage

    CT: Intracerebral parenchymal hemorrhage

  • CT: Intracerebral parenchymal hemorrhage

    CT: Intracerebral parenchymal hemorrhage

  • CT: Intracerebral parenchymal hemorrhage

    CT: Intracerebral parenchymal hemorrhage

Intraventricular Hemorrhage

Images courtesy of RadsWiki

  • CT: Intraventricular hemorrhage

    CT: Intraventricular hemorrhage

  • CT: Intraventricular hemorrhage

    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

  • CT: Diffuse subarachnoid hemorrhage

    CT: Diffuse subarachnoid hemorrhage

  • CT: Diffuse subarachnoid hemorrhage

    CT: Diffuse subarachnoid hemorrhage

  • CT: Diffuse subarachnoid hemorrhage

    CT: Diffuse subarachnoid hemorrhage

  • CT: Diffuse subarachnoid hemorrhage

    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

  • CT: Subdural hemorrhage

    CT: Subdural hemorrhage

  • CT: Subdural hemorrhage

    CT: Subdural hemorrhage


  • CT: Subdural hemorrhage

    CT: Subdural hemorrhage

  • CT: Subdural hemorrhage

    CT: Subdural hemorrhage

  • CT: Subdural hemorrhage

    CT: Subdural hemorrhage

Perimesencephalic Hemorrhage [2]

Images courtesy of RadsWiki

  • CT: Perimesencephalic hemorrhage

    CT: Perimesencephalic hemorrhage

  • CT: Perimesencephalic hemorrhage

    CT: Perimesencephalic hemorrhage

  • CT: Perimesencephalic hemorrhage

    CT: Perimesencephalic hemorrhage

  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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