This document provides an overview of head and brain CT imaging. It discusses the basics of CT imaging, indications for head CT, and an approach to interpreting brain CT scans. The approach involves examining images for blood, cisterns, brain tissue, ventricles, bone, and other areas. Key anatomy is identified on various axial image slices. Several case examples are also presented and discussed.

1. Head and Brain CT
Presented by Dr. shaikhah A.O.Bawazir
Pediatric resident R3
Saudi pediatric program – MCH – Buridah

2. Objective
 Understand the basics of head CT imaging
 Identify and describe basic cerebral anatomy
 Develop an approach to brain CT interpretation
 Identify pathologic lesions found on head CT
 Cases

3. Introduction

4. Introduction
• CT Fast tool
• high radiation risk.
• Best for bone and calcification.
• radiation exposure during childhood causes larger additional
cancer risk 10 % than a corresponding exposure in adulthood.

5. Indications
• Acute head trauma
• Acute neurologic deficits
• Increased intracranial pressure;
• Suspected acute intracranial hemorrhage;
• Suspected intra cranial lesion ( mass , tumor or
abscess)
• Suspected shunt malfunctions, or shunt revisions
• Suspected acute hydrocephalus, Brain herniation

6. • Non-febrile seizures
• Skull bone lesions (Langerhans cell histiocytosis,
neuroblastoma, etc)
• Craniosynostosis/ plagiocephaly
• Detection of calcification
• Immediate postoperative evaluation following brain
surgery (evacuation of hematoma, abscess drainage,
etc)
• When magnetic resonance imaging (MRI) imaging is
unavailable,

7. Basics of CT Imaging

8. Section and density
• Sagittal
• Coronal
• Cross section
• Transverse
• axial
• Bright (hyper density)
• Isodense ( gray)
• Dark (hypo density)
Bone
Contrast
Acute blood
Soft tissue
Water
Fat
Air

9. Hyperdense things on CT
acute blood
ocular lens
calcifications
contrast (dye)bone
metal (bullets w/
streak artifact)

10. Isodense things on CT
• Note that white matter is less dense than gray
matter and therefore:
(white matter is darker than gray matter)
Gray matter (cerebral
cortex)
Gray matter (basal
ganglia)
White matter

11. Hypodense things on CT
fat
air
CSF (water)
Area of infarction

12. Three window

13. Approach

14. General Approach to the Evaluation of an Axial
Imaging of the Head
• Use the mnemonic ”Blood Can Be Very Bad”
B Blood Blood
C Can Cisterns
B Be Brain
V Very Ventricles
B Bad Bone

15. B = blood
• Look for any evidence of
bleeding in:
 epidural, subdural,
 intraparenchymal,
intraventricular,
 subarachnoid
 Hyperdense (bright): Acute
blood
 Isodense: Subacute (1
week)
 Hypodense: Subacute to
chronic (2 weeks)

16. C = Cisterns
• Look for blood in the cisterns and to see if they are open:
• Suprasellar : contains the optic chiasm and pituitary stalk
• Quadrigeminal : extends laterally around the midbrain, from the great cerebral vein to the
third ventricle
• Sylvian : contains several arteries, including the middle cerebral artery.
• cisterna magna (cerebellomedullary cistern): is the largest of the subarachnoid cisterns
• Cerebellopontine angle cistern : Schwannomas (nearly 80% of all CP angle tumors) ,
Medulloblastoma, arachnoid cysts

18. B = Brain
Look COMPARTIVLY at both hemispheres of the brain:
• the grey-white mater differentiation-- > signs of atrophy ,ischemia
and earl stroke.
• the symmetry of the brain
• midline shift -- > indicates an intracerebral mass, edema, or a herniation.
• the parenchyma
-- > anatomical distortion or altered attenuation -- >
indicative of a mass, bleed, or vascular malformation

19. Axial suction at orbital level
• A = orbit
• B = sphenoid sinus
• C = temporal lobe
• D = external auditory canal
• E = mastoid air cell
• F = cerebellar hemispheres
• J = medulla oblongata J

20. Axial suction at level of Pons
• A = frontal lobe
• B = superior surface of
orbital part
• C = dorsum sellae
• D = basilar artery
• E = temporal lobe
• F = mastoid air cells
• G = Cerebellar hemisphere FM
Pons
cisterna magna

21. Axial suction at level of the 4th ventricle
• A . Frontal lobe
• B. sylvian Fissure
• C . Temporal lobe
• D . Suprasellar cistern
• E . Midbrain
• F . 4th ventricle
• G . Cerebellar hemisphere

22. Axial suction at level of the Basal ganglia
• A . Genu of corpus call.
• B. Ant.horn of Lat.Vent.
• C . Internal capsule
• D . Thalamus
• E . Pineal gland
• F . Choroid plexus
• G . Straight siuns
3rd vent

23. Axial suction at level of the lateral ventricle
• A = Falx cerebri
• C . Lateral vent. body
• D . splenium
• G . Superior sagittal sinus
• B = frontal lobe.
• E . Parietal lobe
• F . Occipital lobe
3rd vent

24. Axial suction at level of the Parietal lobe
• A = Falx cerebri
• B = sulcus
• C = gyrus
• D = superior sagittal sinus

25. V = Ventricles
• Dilation
• Compression
• Shift
• bleeding
• Compare the ventricle size to the patient’s age

26. B = Bone
• Examine by bone window :
• fractures
• evaluate the sinuses for fluid or soft tissues accumulation
• Mastoid air cell
• Fluid in the sinus may be a clue to a facial injury !!

27. Additional Areas to Examine
• Major venous sinuses to detect hypo density which is indicative of
thrombosis
• Venous thrombosis is a difficult diagnosis to make
• Soft tissues and skin through the parenchymal window looking for
lesions or hematomas
• Soft tissue injuries noted on the scan should initiate a detailed evaluation of
the subjacent structures.
• Check the orbits
• Look at every image
• Review sagittal and coronal if available

28. C A S

29. Case :8 years old boy involved in RTA

30. case: 1 Y/o girl with history of full done from 4 day ,
present to ER with hematoma.

31. Case :31 months old boy came to ER with
decreased level of consciousness

32. Case :A Flat neonate delivered by emergency C/S
after abruption placenta , CPR done in OR room
Bilateral diffuse cerebral hypo-densities.
Mild dilatation of the ventricular system.

33. Case
• 12 years old girl presented
with left periorbital cellulitis
for CT Brain including orbitals
• Accidently CT brain show this

34. Physiologic calcifications
• Choroidal plexus-rare before 10yrs
• Basal ganglia-rare before 40ys
• Pineal gland-common after 30 yr rare before 10yr
• Falx

35. Case :30 d/o boy FT , NSVD with history of Abnormal
movement for one day (tonic colonic focal seizure)

36. Your differential diagnosis:

37. In the END Systemic Approach to Head CT
 Symmetry : Compare left and right side of the cranium
 Midline: Look for midline shift
 Cross-sectional anatomy (Review anatomical landmark for each section)
 Brain tissue : the gray matter, white matter and intracerebral lesions
 CSF space (ventricle (dilated or not) )
 Skull and soft tissue : scalp swelling, fractures, sinuses, orbit
 Subdural windows : Look for blood collection adjacent to the skull
 Bone windows : Skull, orbit and sinuses, intracranial air
Our use ”Blood Can Be Very Bad”

38. ANY QUESTION !