31. Emergency Cranial Radiological Assessment
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Bootcamp

32. Objectives Identify basic intracranial structures
Identify brain shift, intracranial hemorrhage, and skull fractures
Be able to communicate accurately to the chief resident or attending the important findings that may impact clinical decision making and emergent patient management.
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33. CT Scan
Bone Window
Soft Tissue Window

34. Foramen ovale Foramen spinosum Carotid canal Jugular fossa
# Left sphenoid bone – medial to foramen ovale, extends across carotid canal. Mastoids O.K.
Mastoid air cells
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35. Sphenoid sinus Carotid canal The Society of Neurological Surgeons
# Left sphenoid bone – medial to foramen ovale, extends across carotid canal. Mastoids O.K.
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36. Cisterns
Suprasellar
Interpeduncular
Ambient

37. Caudate
Internal capsule
Thalamus
Choroid Plexus

38. CT Scan
Computerized Axial Tomography or CT scan is the most often used emergency imaging study in neurosurgery. A CT scan is an excellent study for identifying intracranial hemorrhage and skull fractures.
Calcified structures such as bone or the pineal gland appear white or hyperdense.
Acute blood clot appears white or hyperdense. Chronic hematomas appear dark or hypodense.
Ischemic strokes are hard to identify on CT until they are about 6 – 12 hours old.

39. Hematomas Epidural Hematoma (EDH) Subdural Hematomas (SDH)
Subarachnoid Hemorrhage (SAH)
Intracerebral Hemorrhage (ICH)
Intraventricular Hemorrhage (IVH)

40. Epidural Hematoma Between the skull and the dura.
Biconvex or lens shaped.
More common in children and young adults. Uncommon in the elderly since the dura is very adherent to the skull.
Over 90% are associated with a skull fracture. Classically due to laceration of the middle meningeal artery.
Initial concussion - “lucid interval” - deterioration
Treatment is usually emergent surgery.

41. Case Example: 6 year old girl, MVA, GCS 7T, LOC at scene, lucid interval, now with lethargy and left side weakness
Taken to OR for emergent evacuation of EDH
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42. Acute SDH More likely to be “crescent shaped” than “lens shaped”.
Often holohemispheric.
Can extend along falx or tentorium.
Does not cross the midline.
Higher morbidity and mortality than EDH due to additional underlying brain injury.
50-90% mortality.

43. Subdural Hematoma: Clot age and CT Imaging Characteristics
Acute
Subacute
Chronic

44. Chronic SDH 50% without significant history of trauma
Hypodense/isodense crescent shaped collection
Evacuate if symptomatic
Looks like motor oil
Often occurs in the elderly on aspirin, plavix, or coumadin
Can be treated by twist drill craniostomy, burr hole or craniotomy

45. Subarachnoid Hemorrhage

46. Subarachnoid Hemorrhage: Pattern Recognition
ACoA Aneurysm
Perimesenchephalic syndrome
Diffuse SAH

47. Traumatic SAH 55 year old male, fell off ladder, no LOC, mild headache
Repeat head CT stable, discharged next day with routine follow up

48. Intracerebral Hemorrhage: Chronic Hypertension

49. Intracerebral Hemorrhage
Hypertensive IPH
50% in basal ganglia
15% thalamus
10-15% pons

50. IPH, IVH, Acute Hydrocephalus
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51. Lobar Intracerebral Hemorrhage:

52. Intraventricular Hemorrhage
Frontal Horn
Temporal Horn
Lateral Ventricle
FrontalThird
Fourth
Occipital Horns

53. Intraventricular Hemorrhage
Aneurysmal SAH w/ IVH
HTN w/ IVH

54. Traumatic Contusions Coup or contra-coup contusion
Hemorrhagic contusions can enlarge or “blossom” as well as develop extreme edema, so must follow examination closely and consider repeat CT scans
Surgical evacuation if there is excessive mass effect

55. 47 year old gentleman, was inebriated, fall, LOC,
GCS 7T (E2, M4, V1T), PERRL, In cervical collar
EVD placed, Medical management of ICP, gradually improved over several days, neck cleared after extubation and improvement in neuro status
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56. 18 year old male, shot in head while sitting in car, GCS 15 with no focal deficits, open scalp wound over skull fracture
Scalp debrided, bullet fragment extracted, wound closed

57. Acute Hydrocephalus
7 year old boy with posterior fossa tumor, drowsy, less responsive through the day
EVD
EVD placed, immediately better

58. Ischemic Stroke
Typically follow a vascular distribution such as the territory of the MCA, PCA or ACA.
A stroke may take several hours before it is apparent on a CT scan.
Typically is seen earlier on an MRI

59. MCA Infarcts

60. Infarct with a Midline Shift

61. Cerebral Edema Loss of Grey/White Differentiation Cisternal Effacement
Midline Shift

62. Cerebral Edema Vasogenic: from brain tumor Cytotoxic: from trauma
BBB disrupted
Responds to steroids
Cytotoxic: from trauma
BBB closed
NO steroids

63. Basal Cistern Effacement
Normal
Tight Swollen Brain

64. 49 y/o male, MVA
GCS 3T with fixed/dilated pupils
No improvement, pronounced brain dead 24 hours later

65. Fractures
Linear
Depressed
Open Depressed
Basal Skull Fracture

66. Depressed Skull Fracture

67. Open Depressed Skull Fracture

68. Open Depressed Skull Fracture s/p MVA

69. Reconstruction

70. Basilar Skull Fracture

71. Basilar Skull Fracture of the Temporal Bone Seen on Bone Windows

72. Basic Principles of MR Imaging
Images are created based on signals returning from spinning protons
Not based on density
Objects are described in terms of intensity (hypointense, isointense, hyperintense)
T1 and T2 Weighted Imaging
T1 Post Contrast Enhancement

73. T1 Weighted Image of the Normal Brain

74. T2 Weighted Image of the Normal Brain

75. MRI: Views in different planes
Axial
Sagittal
Coronal

76. T1 Post Gadolinium Image of a Brain Tumor

77. Diffuse Axonal Injury (DAI)

78. Magnetic Resonance Imaging: Stroke
Diffusion Weighted Imaging:
Ischemia
Cytotoxic edema
Increase in signal as soon as 5-10 minutes after stroke onset
Left: DWI
Right: ADC map