Cerebro-vascular disease Cerebro-vascular disease

Brain Brain ImagingImaging

Dr. ABD ALLAH Dr. ABD ALLAH NAZEER. MD.NAZEER. MD.

Vallecula

4th Ventricle

Medulla Oblongata

Cisterna Magna

4th Ventricle Cerebellar Hemispheres Vermis

Post. Fossa level

Pones

Middle Cerbellar Peduncle

Prepontine Cistern

Ambean Cistern

Basilar Art.

Cerebellar Folia Quadrigeminal

Cistern

Midbrain

Aqueduct of Sylvius

Posterior fossa level

Pons

Medulla

Ventricular anatomy

Quadrigeminal Cistern

Occipital horn, Calc. pineal body

Quadrigeminal Cistern

Head of caudate Lentiform nucleus Thalamus

Internal Capsule

External Capsule

3rd Ventricle

Insula

Basal Ganglia

Vellum interpositum

Retro-thalamic Cistern

Retro-thalamic Cistern

Sup.cerebellar Cistern

Quadrigeminal Cistern

Pineal body

Inter. Cerebr. veins

Pineal bodyInter. Cerebr. veinsVein of

Galen

Retro-thalamic Cistern

Septum Pleusedum

Body of caudate

F

O

F

P

F

T

O

F

P

O

P

P

T T

F

O

Supra-ventricular level

P PP

F

CT Vascular Anatomy

ICA

ACA (a1)

ACA (a2)

MCA A. Communicating A.

Basilar A.

PCA

P. Comm. A.

Strong magnetic field andStrong magnetic field and

Radiofrequency (RF) coilsRadiofrequency (RF) coils

Imaging are created by the motion of hydrogen protons in Imaging are created by the motion of hydrogen protons in response to the applied radiofrequencyresponse to the applied radiofrequency

Multiplanar imaging [ Multiplanar imaging [ axial, sagittal, coronal axial, sagittal, coronal ]] Any MR examination should include T1 and T2 Weighted Any MR examination should include T1 and T2 Weighted

images images

BRAIN MRI

Cerebral lobesCerebral lobes

Sulci and gyriSulci and gyri

Brodmann AreasBrodmann Areas

Axial, Axial, Sagittal Sagittal and Coronal and Coronal MRI MRI AnatomyAnatomy

MRI Vascular Anatomy

Normal venous sinus anatomy

CT & MRI Terminology

Hypodense= Less dense = Hypointense on MRI.

Hyperdense= more dense= Hyperintense on MRI.

Isodense= of equal density= Isointense on MRI.

Infarction Hemorrhage ?!

Hypo dense Hyper dense Isodense

Hypo intense Hyperintense Isointense

CT density [HU](AV).Brain Parenchyma 30 - 40 HU

Hypo dense Normal brain 30-40 HU

CSF 0 -15 HU Brain edema 20 HU

Infarction 25 HU Cyst ? Content

Fat > -10 to -150 HU Air - 2oo HU

Infarction

SOL

Cyst

Infarction

Is a hypo dense lesion Is not a SOL Hyperacute, Acute , Subacute

or chronic Has a vascular territory Has a cortical distribution Account for 80 % of stroke

cases.

Infarction phase?!

Acute

subacute Chronic

Infarction with edema

Infarction with volume loss

Infarction phase?!

Acute

subacute Chronic

Infarction with edema

Infarction with volume loss

Hyperacute finding:Visualization of the clot within the vessel.

Hyperacute and acute finding:

Acute infarction

Acute infarction

Acute One Day Old Infarction Involving the Right Middle Cerebral Artery (MCA) Territory

Acute infarction

Acute infarction with left MCA occlusion

CT study of Brain shows faint low attenuation involving right insular cortex and adjacent basal ganglia - insular ribbon sign. Faint T2 hyperintensity seen on FLAIR. DW images show an obvious infarct with restricted diffusion, seems to be an acute infarct as changes are not marked on FLAIR and CT study. Area of involvement is larger on DW compared to FLAIR, a FLAIR - Diffusion Mismatch.

T2WI

DWI

Subacute infarcts 3 weeks after stoke

Chronic infarction Hypodense lesion Loss of volume ( gliosis) negative mass effect on the ventricle and sulci [Evacuee dilatation]

Porencephaly

Hemorrhagic infarction

Venous thrombosis Arterial embolism

Infarction with hemorrhagic foci

Two main causes :

Hemorrhagic infarction

Chronic white matter leukoencephalopathy Chronic white matter leukoencephalopathy (low grade ischemia)(low grade ischemia) White matter ischemic changes diffuse hypo density Hypertensive, diabetic patients

White matter leukoencephalopathy

Lacunar infarctions , Lacunar infarctions , 2 CasesCases

Young age

Close to the ventricles

Perpendicular to the ventricle

High signal in PD or FLAIR

Enhancement of active lesions

Clinical picture

MS PLAQUES

MS PLAQUES with active stage

Calvarial bones

epidural

Subdural

Subarachnoid

Intra-cerebral

Intra-ventricular

Account of 20 % of strokes.

Acute hematoma ( Hyperdense)

Subacute hematoma ( Isodense)

Chronic hematoma ( Hypodense)

Intracranial Intracranial hemorrhagehemorrhage

Anatomic Anatomic localizationlocalization

Extra axial hematoma = blood extending along the inner skull table = hemorrhage outside the brain parenchyma

Extra axial hemorrhage ( epidural or subdural) Subarachnoid hemorrhage

Intra axial hematoma = hemorrhage inside the brain parenchyma

Subarachnoid Hemorrhage

Rupture of an anterior Communicating artery Rupture of an anterior Communicating artery aneurysmaneurysm

Subarachnoid Hemorrhage

Bilateral subarachnoid Hemorrhage

Subarachnoid Hemorrhage at MRI FLAIR images

Subarachnoid Hemorrhage at MRI images

Subdural hematoma Concave inner margin Do not cross midline

Can be acute, sub acute or chronic.Can cross the sutures.

Epidural hematoma

Convex inner marginCan cross midline

Almost always acute.Cannot cross sutures.

Epidural HematomaEpidural Hematoma

Convex inner margin Almost always acute

Post traumatic

Epidural Epidural HematomaHematoma

Epidural Epidural HematomaHematoma

Subacute epidural Subacute epidural HematomaHematoma

Subdural Subdural HematomaHematoma

Concave inner margin Can be acute , subacute or chronic Usually seen in elderly patient History of minor trauma Can occur in the interhemispheric fissure

AcuteAcuteChroniChronic c

SubacutSubacutee

Subacute hematoma Subacute hematoma with sedimentation, with sedimentation, upper hypodensity and upper hypodensity and lower hyperdensitylower hyperdensity

Subacute hematoma with Subacute hematoma with re-bleeding, with hypo and re-bleeding, with hypo and hyperdensity blood hyperdensity blood component component

Subacute subdural Subacute subdural HematomaHematoma

Subacute subdural Subacute subdural HematomaHematoma

Intracerebral hematomaIntracerebral hematoma

Post-traumatic

Hemorrhagic Contusion

Right intra-cerebral hematoma

Figure 1: MRI brain (a) and (b) Axial clear T1WI and T2WI showing a large right temporal hetero-intense lesion which is predominantly isointense on T1WI and T2WI and it has a peripheral zone that is hyperintense on T1WI and T2WI suggestive of acute clot. (c) MRI with GADO showing enhancement of the dural-based lesion along the temporal convexity

Intracerebral Intracerebral hematomahematoma

Intra-cerebral and intra-ventricular Intra-cerebral and intra-ventricular hematomahematoma

Acute Hematoma [Deoxy – Hb]Low signal T1 WI More low signal in T2 WIs

CT

Subacute Hematoma [Met – Hb]High signal T1 WIs High signal in T2 WIs

Intracerebral hematoma Intracerebral hematoma subacutesubacute

Hyper-acute Hematoma

Intra-cerebral and intra-ventricular Intra-cerebral and intra-ventricular hematomahematoma

Cerebral Cerebral contusioncontusion

Diffuse axonal Diffuse axonal injuryinjury

Dural sinus thrombosis

Dural sinus thrombosis

Dural sinus thrombosis

Q1, Case. M. EN. Q1, Case. M. EN. PP

Q2, Case. Q2, Case. EPHEPH

Q3, Case. SDH e cal.Q3, Case. SDH e cal.