ct brain by prof. wael samir
DESCRIPTION
TRANSCRIPT
Dr. Mohamed Wael Samir
Prof. of Neurosurgery
Ain Shams University
CT Brain
Intending Learning Objectives (ILOs)
Discuss the radiation hazards of CT Demonstrate the usage of different contrast agents safely Identify normal anatomical landmarks on CT brain Interpretation of CT perfusion in cerebral ischemia Interpretation of CT angiogram of cranial and cervical vasculature.
Facts
Radiation Dose Considerations
Single Radiographs Effective Dose, mrem (mSv)Skull (PA or AP)1 3 (0.03)Skull (lateral)1 1 (0.01)Chest (PA)1 2 (0.02)Chest (lateral)1 4 (0.04)Chest (PA and lateral)5 6 (0.06)Thoracic spine (AP)1 40 (0.4)Thoracic spine (lateral)1 30 (0.3)Lumbar spine (AP)1 70 (0.7)Lumbar spine (lateral)1 30 (0.3)
CT study Effective Dose, mrem (mSv)CT head1 200 (2.0)Lumbar spine series6 180 (1.8)Thoracic spine series6 140 (1.4)Cervical spine series6 27 (0.27)
Contrast Facts
Types: Ionic: Nonionic: Dimer or monomer
Dose: safety issues:
Idiosyncratic (nondose dependent), allergylike reactions: Acute Late:
Dose-dependent (nonidiosyncratic) Reactions: CVS: CIN: Thyroid function
Drug interactions:
Contrast Medium
Trade Name Molecular Weight (Dalton)
Iodine Conc
(mgI/mL)
Osmolality
(mOsm/kg water)
Viscosity at 20°C
(cP)
Viscosity at 37°C
(cP)
Ionic CM, monomer (High osmolar CM)
Iothalamate3 Conray 60% 809 282 1,400 6.02 4.0
Nonionic CM, monomer (Low osmolar CM)
Iohexol Omnipaque
821 300-&350 672844
11.820.4
6.310.4
Iopromide Ultravist 791 300& 370 607774
9.222.0
4.910.0
Serum Creatinine Levels (in mg/dL) Indicating an Estimated Glomerular Filtration Rate of less than 60 mL/min/1.73 m2
Age (years) 20 30 40 50 60 70 80
Men (not African American) 1.57 1.47 1.39 1.34 1.30 1.26 1.23
Women (not African American) 1.21 1.13 1.08 1.03 1.00 0.97 0.95
Men (African American) 1.86 1.73 1.65 1.58 1.53 1.49 1.46
Women (African American) 1.44 1.34 1.27 1.22 1.18 1.15 1.12
Preventive Measures for CMEN
Facts
Superior frontal sulcus
Precentral sulcus
Central sulcus
Precentral gyrus
Postcentral gyrus
Superior frontal gyrus
Lateral ventricle (anterior horn)
Third ventricle
Foramen of Monro
Lateral ventricle (trigone with
choroid plexus)
Pineal gland
Caudate nucleus (head)
Corpus callosum (genu)
Thalamus
Lentiform nucleus
Internal capsule
insular cistern
Quadrigeminal and ambient cisterns
Quadrigeminal plate (colliculus)
External capsule
Insula
Interhemispheric cistern
insular cistern
3rd ventricle
Hypothalamus
Midbrain
Aqueduct
Cerebral peduncle
Ambient cistern
Quadrigeminal cisternVermis of cerebellum
Sylvian fissure
Interpeduncular cistern
Optic chiasm
Lateral ventricle (temporal horn)
Sphenoid ridge
Petrous ridgeFourth ventricle
Pons
Dorsum sella
Prepontine cistern
Frontal air sinus
Orbital roof
Frontal lobe
Greater wing of sphenoid
Ant. clinoid
Pituitary fossa
Cavernous carotid
Basilar artery
Cerebello pontine cistern
Pons
4th ventricle
Cerebellar hemisphere
VII / VIII complex
Vermis
Straight gyrus and olfactory bulbEthmoid sinus
Sphenoid sinus
OrbitOptic nerve
SOF
Temporal lobe
Mastoid air cells
EAC
Medulla
Cerebello medullary fissure
Crista galle
SOFOptic foramen
Auditory canal
SOF
Optic foramen
Orbit
Paranasal sinuses
Petrous bone
Skull Base
CT Perfusion
Principles of CT perfusion (CTP)
CBF
50-80 ml/100 gm/min normal
15-20 ” Neurological
dysfunction
<10 ” infarction
CT Brain with Stroke window
Infarct signs on NCCT
B C
CTP
1) Mean Transition Time (MTT) or time to peak (TTP) 2) Cerebral Blood flow (CBF) , 3) Cerebral Blood Volume (CBV),
A B C
CT Angiogram
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
Cutoff morphology:
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
Tram track (nonocclusive or recanalized clot):
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
The tandem morphology:
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
Tapered morphology :
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
meniscus or flattened shape to clot (recent) versus reverse meniscus (older) :
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
Delayed (antegrade) flow :
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
Retrograde collateral flow :
Initial Angiographic Appearance of Intracranial Vascular Occlusions in Acute Stroke
Aneurysms:
CTA:sagittal MPRCTA:3D color VR
References
Sits
(Information adapted from www.radiologyinfo.org