CT brain interpretation: Difference between revisions
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==Mnemonic== | ==Mnemonic== | ||
Blood Can Be Very Bad | ''Blood Can Be Very Bad'' | ||
*Blood | |||
*Cisterns | |||
*Brain | |||
*Ventricles | |||
*Bone | |||
==Blood== | ==Blood== | ||
*Questions | |||
**Is blood present? | |||
**If so, where is it? | |||
**If so, what effect is it having? | |||
*Physiology | |||
**Acute blood is bright white (once it clots) | |||
**Blood becomes isodense at 1wk (exact time depends on size of clot) | |||
**Blood becomes hypodense at 2wks (exact time depends on size of clot) | |||
*Findings | |||
**[[Epidural hematoma]] (blood problem) | |||
***Lens shaped | |||
***Does not cross sutures | |||
***Classically described with injury to middle meningeal artery | |||
***Low mortality if treated prior to unconsciousness (<20% morbidity/mortality) | |||
**[[SDH|Subdural]] (brain problem) | |||
***Sickle shaped | |||
***Crosses sutures but not midline | |||
***Marker for severe head injury (mortality approaches 80%) | |||
****Small amount of bleed can be associated with major shift (secondary to brain injury/oozing) | |||
**[[SAH]] | |||
***Blood in the cisterns/cortical gyral surface/interhemispheric fissure | |||
****Suprasellar cistern is first place see SAH (location adjacent to circle of willis) | |||
***Aneurysm: 80% | |||
***[[AVM]]: 5% | |||
**Intraventricular/Intraparenchymal Hemorrhage | |||
***Typically obvious findings | |||
***Unimportant if intraventricular ruptured into parenchyma or vice-versa | |||
==Cisterns== | ==Cisterns== | ||
*4 key cisterns: | |||
**Circummesencephalic | |||
***First cistern to show increased ICP (squished shut) | |||
**Suprasellar | |||
**Quadrigeminal | |||
***"W" shaped | |||
***Second cistern to show increased ICP | |||
**Sylvian | |||
***May see isloated distal MCA bleed | |||
*2 questions: | |||
**Is there blood? | |||
**Are the cisterns open? | |||
==Brain== | ==Brain== | ||
*Compare side to side | |||
*Look for grey-white differentiation | |||
**Grey is denser so appears lighter on CT | |||
*Look at gyral pattern all the way around (gyri effacement indicator of increased ICP) | |||
*Findings | |||
**[[brain tumor|Tumor]] | |||
***May see increased hypodensity ([[cerebral edema in brain cancer|edema]]) | |||
***80% visible without contrast | |||
**Atrophy | |||
**[[brain abscess|Abscess]] | |||
**Hemorrhagic contusion | |||
**Mass effect | |||
**[[Stroke]] | |||
**Intracranial air ([[skull fracture]]) | |||
**Hyperdense middle cerebral artery or basilar artery sign | |||
***Suggests thrombosis of vessel | |||
**Suggestive of [[Cerebral venous thrombosis]] : | |||
***Empty delta sign: dense triangle in superior sagittal sinus | |||
***Cord sign: hyperattenuated, homogeneous linear or round foci in cerebral sinus <ref>Ram K. P. Vijay. "The Cord Sign."Radiology. 2006; 240:299-300.</ref> | |||
***Vein Sign: hypoattenuated foci in the deep vein <ref>Linn J, Pfefferkorn T. "Noncontrast CT in Deep Cerebral Venous Thrombosis and Sinus Thrombosis: Comparison of Its Diagnostic Value for Both Entities."AJNR Am J Neuroradiology. 2010; 30: 728-735. </ref> | |||
==Ventricles== | ==Ventricles== | ||
*Check all 4 for size and for hemorrhage | |||
**Temporal tips (comma-shaped) of lateral ventricle first place to show hydrocephalus | |||
**If enlarged must differentiate between [[hydrocephalus]] from increased pressure versus atrophy: | |||
***Are the gyri effaced? If yes suggestive of increased pressure | |||
==Bone== | ==Bone== | ||
*Inspect petrous ridges for [[basilar skull fracture|skull base fracture]] | |||
*Look at mastoid air cells full of fluid (blood) for indirect evidence of fracture | |||
==See Also== | ==See Also== | ||
*[[Head CT (Clinical Decision Rules)]] | *[[Head CT (Clinical Decision Rules)]] | ||
*[[CT Before Lumbar Puncture]] | |||
*[[Intracerebral Hemorrhage (ICH)]] | |||
*[[X-ray interpretation (main)]] | |||
== | ==References== | ||
*Blood Can Be Very Bad: CT Interpretation Course Guide | *Blood Can Be Very Bad: CT Interpretation Course Guide | ||
*www.uic.edu/com/ferne/pdf/acep2005_spring/perron_acep2005_spring_bcbvb_course.pdf | *www.uic.edu/com/ferne/pdf/acep2005_spring/perron_acep2005_spring_bcbvb_course.pdf | ||
<references/> | |||
[[Category: | [[Category:Neurology]] | ||
[[Category: | [[Category:Radiology]] |
Revision as of 22:47, 1 October 2019
Mnemonic
Blood Can Be Very Bad
- Blood
- Cisterns
- Brain
- Ventricles
- Bone
Blood
- Questions
- Is blood present?
- If so, where is it?
- If so, what effect is it having?
- Physiology
- Acute blood is bright white (once it clots)
- Blood becomes isodense at 1wk (exact time depends on size of clot)
- Blood becomes hypodense at 2wks (exact time depends on size of clot)
- Findings
- Epidural hematoma (blood problem)
- Lens shaped
- Does not cross sutures
- Classically described with injury to middle meningeal artery
- Low mortality if treated prior to unconsciousness (<20% morbidity/mortality)
- Subdural (brain problem)
- Sickle shaped
- Crosses sutures but not midline
- Marker for severe head injury (mortality approaches 80%)
- Small amount of bleed can be associated with major shift (secondary to brain injury/oozing)
- SAH
- Blood in the cisterns/cortical gyral surface/interhemispheric fissure
- Suprasellar cistern is first place see SAH (location adjacent to circle of willis)
- Aneurysm: 80%
- AVM: 5%
- Blood in the cisterns/cortical gyral surface/interhemispheric fissure
- Intraventricular/Intraparenchymal Hemorrhage
- Typically obvious findings
- Unimportant if intraventricular ruptured into parenchyma or vice-versa
- Epidural hematoma (blood problem)
Cisterns
- 4 key cisterns:
- Circummesencephalic
- First cistern to show increased ICP (squished shut)
- Suprasellar
- Quadrigeminal
- "W" shaped
- Second cistern to show increased ICP
- Sylvian
- May see isloated distal MCA bleed
- Circummesencephalic
- 2 questions:
- Is there blood?
- Are the cisterns open?
Brain
- Compare side to side
- Look for grey-white differentiation
- Grey is denser so appears lighter on CT
- Look at gyral pattern all the way around (gyri effacement indicator of increased ICP)
- Findings
- Tumor
- May see increased hypodensity (edema)
- 80% visible without contrast
- Atrophy
- Abscess
- Hemorrhagic contusion
- Mass effect
- Stroke
- Intracranial air (skull fracture)
- Hyperdense middle cerebral artery or basilar artery sign
- Suggests thrombosis of vessel
- Suggestive of Cerebral venous thrombosis :
- Tumor
Ventricles
- Check all 4 for size and for hemorrhage
- Temporal tips (comma-shaped) of lateral ventricle first place to show hydrocephalus
- If enlarged must differentiate between hydrocephalus from increased pressure versus atrophy:
- Are the gyri effaced? If yes suggestive of increased pressure
Bone
- Inspect petrous ridges for skull base fracture
- Look at mastoid air cells full of fluid (blood) for indirect evidence of fracture
See Also
- Head CT (Clinical Decision Rules)
- CT Before Lumbar Puncture
- Intracerebral Hemorrhage (ICH)
- X-ray interpretation (main)
References
- Blood Can Be Very Bad: CT Interpretation Course Guide
- www.uic.edu/com/ferne/pdf/acep2005_spring/perron_acep2005_spring_bcbvb_course.pdf