Pediatric Subdural Hematoma

  • Etiology:
    — Venous hemorrhage due to tear of bridging veins and or intradural venous plexus
    — Anticoagulation
  • Imaging CT:
    — Semilunar or crescent shape
    — Crosses sutures
    — Does not cross falx or tentorium
    — Coronal and sagittal images very useful in identifying small subdural hematomas
  • Imaging CT Hyperacute:
    — Inner layer of high density clotted blood and outer layer of low density nonclotted blood
  • Imaging CT Acute:
    — High density clotted blood
  • Imaging CT Hygroma:
    — Post traumatic acute low density subdural collection
    — Not all acute subdural collections are dense on CT
    — A subdural collection can be hypodense similar to cerebrospinal fluid due to tear in arachnoid membrane
    — Subdural hematomas in anemic patients may also be low density
  • Imaging CT Chronic:
    — Common at convexity and posterior fossa
    — Contrast enhancing membrane forms at 1 week
    — Follow cerebrospinal fluid density
    — May come from acute subdural hematoma or subdural hygroma
  • Note: Can occur infratentorial as well as supratentorial, in anticoagulated patients hematomas do not become hyperdense on CT as quickly as in normal patients
  • Imaging evolution of subdural hematoma on CT:
    — Up to 3 hours – hypodense
    — 3 hours to 7-10 days – hyperdense
    — 1 week to 4 weeks – isodense
    — 1 month and up – hypodense
  • Note: Variation may be seen in acute subdural hygroma, subdural hematoma in anemic patient, cerebrospinal fluid leak into subdural collection through torn arachnoid membrane
  • DDX:
    — Epidural hematoma has biconvex or lentiform shape and is usually associated with a skull fracture
    — Benign enlargement of the subarachnoid space can mimic chronic bilateral subdural hematomas
  • Complications:
  • Treatment:
  • Clinical:
    — Small subdural hematomas commonly seen in neonates and are thought to be due to birth trauma – even in normal spontaneous vaginal deliveries
    — When seen in infants less than 2 years old without significant trauma history need to rule out child abuse as subdural hematoma is most common intracranial manifestation of child abuse

Imaging evolution of intracerebral hemorrhage evolution on MRI: (Note that this is most commonly used to date subdural hematomas)

AgeStateT1WIT2WI
< 1 dayOxyHbIsoBrightHyperacute
1-3 daysDeOxyHbIsoDarkAcute
3-7 daysIntracellularMetHbBrightDarkEarly Subacute
1-3 weeksExtracellularMetHbBrightBrightLate Subacute
> 3 weeksHemosiderinDarkDarkChronic

Radiology Cases of Subdural Hematoma

Radiology Cases of Acute Subdural Hematoma Due To Trauma

CT of subdural hematoma
Axial CT without contrast of the brain with normal (left) and sharpened (right) windows shows a left hemispheric high density cresenteric intracranial extra-axial fluid collection that extends anteriorly along the falx.
Radiograph of stellate skull fracture and CT of acute subdural hematoma due to accidental trauma
AP and lateral radiographs of the skull show numerous branching lucencies in the right parietal bone. Axial CT without contrast of the brain shows high density material in the right subgaleal tissues, a small high density cresenteric fluid collection in the right extra-axial space that extends posteriorly along the falx, and a mixed low-density and high density lesion in the right posterior parietal brain parenchyma.
CT of diffuse cerebral edema in child abuse
Axial CT without contrast of the brain shows normal density in the rounded top of the cerebellum (in the center of the left image) compared to the diffuse low-density throughout the cerebrum. There is obliteration of the basal cisterns and loss of the normal gray matter-white matter differentiation. There is also a small left sided high density extra-axial cresenteric fluid collection that tracks medially along the entire falx.
CT of hypoxic ischemic encephalopathy and interhemispheric subdural hematoma in child abuse
Axial CT without contrast of the brain shows decreased density of the cerebrum when compared to the density of the cerebellum. There is also loss of gray matter-white matter differentiation and effacement of the cerebral sulci and the basal cisterns. There is linear increased density present along the entire falx.
CT of acute subdural hematoma with interhemispheric extension
Axial CT without contrast of the brain shows a high density crescent-shape extra axial fluid collection best seen in the right frontal-parietal region that extends all the way posteriorly around the brain and that extends medially along the falx.

Radiology Cases of Acute Subdural Hematoma Due To Extracorporeal Membrane Oxygenation

US of subdural hematoma and intracerebral hemorrhage in patient on extracorporeal membrane oxygenation (ECMO)
Coronal US of the brain (below) shows echogenic material in right subdural space. Coronal and sagittal US of the brain (above) shows a right parietal round mixed echogenicity lesion.

Radiology Cases of Chronic Subdural Hematoma

Radiograph of parietal skull fracture and CT of chronic subdural hematomas in child abuse
AP radiograph of the skull shows a linear lucency in the left parietal bone that connects to the left lambdoid suture. Axial CT without contrast of the brain shows bilateral low density extra-axial fluid collections around the brain.

Radiology Cases of Acute and Chronic Subdural Hematoma

MRI of acute and chronic subdural hematomas in child abuse
Axial CT without contrast of the brain (upper left) shows bilateral large low density extra-axial fluid collections and a left frontal small high density extra-axial fluid collection. There is also prominence of the cortical sulci and the ventricular system. Axial T1 (upper right), T2 (lower left) and FLAIR (lower right) MRI without contrast of the brain better demonstrates the extra-axial fluid collections with the bilateral large collections being bright on T1 and T2 and the small left frontal collection being iso on T1 and dark on T2.
CT of acute and chronic subdural hematomas in child abuse
Axial (above) and coronal (below) CT without contrast of the brain shows a right moderate sized high density cresenteric extra-axial fluid collection that extends around the entire right cerebral hemisphere as well as interhemispherically. There is also a left moderate sized low-density cresenteric extra-axial fluid collection.
CT of tricompartmental chronic subdural hematomas in child abuse
Axial CT without contrast of the brain shows very large low density extra-axial fluid collections supratentorially around the left and right cerebral hemispheres and infratentorially around the cerebellum. There is also a round high density focus along the posterior right falx.