NEURORADIOLOGYNEURORADIOLOGYProf. Dr. Mahmoud El SheikhProf. Dr. Mahmoud El Sheikh

Professor of RadiologyProfessor of RadiologyFaculty of Medicine . University of AlexandriaFaculty of Medicine . University of Alexandria

Imaging ModalitiesImaging Modalities

• Conventional Radiography:Conventional Radiography: Plain, Contrast, Plain, Contrast, FluoroFluoro

• Computed Tomography:Computed Tomography: MDCT MDCT• Magnetic Resonance Imaging:Magnetic Resonance Imaging: fMR, MRS fMR, MRS• Ultrasonography:Ultrasonography: Color Doppler Color Doppler• Angiography:Angiography: DSA, MRA, CTA DSA, MRA, CTA• ScintigraphyScintigraphy, SPECT, SPECT• Positron Emission TomographyPositron Emission Tomography,, PET/CT PET/CT

Computed Tomography (CT)Computed Tomography (CT)

Digital ImageDigital Image

Air = -1000 HUAir = -1000 HUFat = -50 HUFat = -50 HU

Water = 0 HUWater = 0 HU

Soft Tissue = 25-35 HUSoft Tissue = 25-35 HUAcute Hemorrhage = 70-100 HUAcute Hemorrhage = 70-100 HUCalcification = 200-300 HUCalcification = 200-300 HUCortical Bone >= 1000 HUCortical Bone >= 1000 HU

Tissue Contrast depends on Attenuation Number (Hounsfield Unit)

CT Tissue CharacterizationCT Tissue Characterization

IV Contrast EnhancementIV Contrast Enhancement

► Improves the soft tissue contrast.Improves the soft tissue contrast.►Enhancement depends on:Enhancement depends on:

Extra-axial tissue:Extra-axial tissue: vascularityvascularity Intra-axial tissue:Intra-axial tissue: BBB BreakdownBBB Breakdown

Magnetic Resonance (MR)Magnetic Resonance (MR)

Closed Magnet Open Magnet

Advantages of MRAdvantages of MR

► No ionizing radiationNo ionizing radiation► High contrast resolutionHigh contrast resolution► Good spatial resolutionGood spatial resolution► Multiplanar capabilitiesMultiplanar capabilities► Multi weighted sequences: Multi weighted sequences:

Fluid attenuation (FLAIR)Fluid attenuation (FLAIR) Fat suppression (STIR)Fat suppression (STIR) Diffusion weighted (DWI)Diffusion weighted (DWI) Functional MR (fMR: BOLD)Functional MR (fMR: BOLD) Spectroscopy (MRS)Spectroscopy (MRS)

• Protons (nuclei of hydrogen atoms) Protons (nuclei of hydrogen atoms) placed in a strong magnetic field are placed in a strong magnetic field are excited by a radio-frequency pulse, then excited by a radio-frequency pulse, then allowed to loose energy.allowed to loose energy.

• The loss of gained energy occurs either The loss of gained energy occurs either to the surrounding matrix (T1) or through to the surrounding matrix (T1) or through interaction between each other (T2).interaction between each other (T2).

• The loss of energy is measured and used The loss of energy is measured and used to produce images. to produce images.

Normal MR BrainNormal MR Brain

T1 Weighted Image T2 Weighted Image

Other Pulse SequencesOther Pulse Sequences

Fluid Attenuation (FLAIR) Fat Suppression (STIR)

T1 or T2 Weighted ImagesT1 or T2 Weighted Images

► When reviewing an MR image, the easiest way When reviewing an MR image, the easiest way to determine the type of image, is to look at to determine the type of image, is to look at the the cerebrospinal fluid (CSF).cerebrospinal fluid (CSF).

► If the CSF is darkIf the CSF is dark it is a T1-weighted imaged. it is a T1-weighted imaged.

► If the CSF is brightIf the CSF is bright, it is a T2-weighted image. , it is a T2-weighted image.

Sagittal MR BrainSagittal MR Brain

T1 WI

MR Tissues Signal CharacteristicsMR Tissues Signal CharacteristicsT1T1 T2T2

Fluid DarkDark BrightBrightFat BrightBright DarkDarkSolid GreyGrey BrightBrightSubacute Blood BrightBright BrightBrightCalcificationsFlowing Blood DarkDark DarkDark

Acute, Ch Blood GreyGrey DarkDark

IV Contrast EnhancementIV Contrast Enhancement GadoliniumGadolinium

►Gadolinium increases signal intensity on Gadolinium increases signal intensity on T1-weighted images through shortening T1-weighted images through shortening the T1 relaxation time of the tissue.the T1 relaxation time of the tissue.

►Enhancement depends on:Enhancement depends on: Extra-axial tissue:Extra-axial tissue: vascularityvascularity Intra-axial tissue:Intra-axial tissue: BBB BreakdownBBB Breakdown

BRAINBRAIN

TRAUMATRAUMA

Plain X-RayPlain X-Ray

SKULL FRACTURESKULL FRACTURE

Fracture Line

Digital ImageDigital ImageSoft Tissue Window Bone Window

Traumatic Cranio-Cerebral LesionsTraumatic Cranio-Cerebral Lesions

Brain ContusionsBrain Contusions

Hemorrhagic Contusions

Brain LacerationsBrain Lacerations

Gunshot Injury

R

Extradural HematomaExtradural Hematoma

Subdural HematomaSubdural Hematoma

Subacute Subdural HematomaSubacute Subdural Hematoma

Subarachnoid HemorrhageSubarachnoid Hemorrhage

Diffuse Axonal Injury (DAI)Diffuse Axonal Injury (DAI)

Generalized Brain EdemaGeneralized Brain Edema

Mass Mass EffectEffect Brain HerniationBrain Herniation

MassMass

Brain Brain StemStem

Decompressive Craniectomy Decompressive Craniectomy

Non-Traumatic HemorrhageNon-Traumatic Hemorrhage

Non-Traumatic Intracranial HemorrhageNon-Traumatic Intracranial Hemorrhage►Very CommonVery Common

HypertensionHypertension AneurysmAneurysm Vascular Malformation AVMVascular Malformation AVM

► CommonCommon Embolic stroke with reperfusionEmbolic stroke with reperfusion Amyloid angiopathyAmyloid angiopathy Prematurity (Germinal Matrix Hemorrhage)Prematurity (Germinal Matrix Hemorrhage) CoagulopathiesCoagulopathies Drug abuseDrug abuse TumorTumor

► UncommonUncommon Venous infarctVenous infarct VasculitisVasculitis

Hypertensive HemorrhageHypertensive Hemorrhage

Massive Hypertensive HemorrhageMassive Hypertensive Hemorrhage

Hemorrhage in Arterio-Venous Hemorrhage in Arterio-Venous Malformation (AVM)Malformation (AVM)

Subarachnoid HemorrhageSubarachnoid Hemorrhage

Anterior Communicating AneurysmAnterior Communicating Aneurysm

Posterior Communicating AneurysmPosterior Communicating Aneurysm

Cerebral AngiographyCerebral Angiography

Cerebral AngiographyCerebral Angiography

► Direct AngiographyDirect Angiography► Catheter Angiography:Catheter Angiography:

ConventionalConventional Digital SubtractionDigital Subtraction

► Magnetic Resonance Angiography (MRA)Magnetic Resonance Angiography (MRA)► Computed Tomography Angiography (CTA)Computed Tomography Angiography (CTA)

MR Angiography

Anterior Communicating Artery Anterior Communicating Artery AneurysmAneurysm

Middle Cerebral Artery AneurysmMiddle Cerebral Artery Aneurysm

CT Angiography

InfarctInfarct

Cerebral Arteries TerritoriesCerebral Arteries Territories

AnteriorAnterior CACA Middle CAMiddle CA PosteriorPosterior CACA

Anterior Cerebral InfarctAnterior Cerebral Infarct

Acute Middle Cerebral InfarctAcute Middle Cerebral Infarct

Posterior Cerebral InfarctPosterior Cerebral Infarct

Focal Thalamic Infarct Focal Thalamic Infarct

Magnetic ResonanceMagnetic ResonanceT1 WI T2 WI

Brain Stem InfarctBrain Stem Infarct

T2 WI

Early InfarctEarly Infarct

CTCT

Early InfarctEarly Infarct

MR DiffusionCT Perfusion

Perfusion/Diffusion MismatchPerfusion/Diffusion Mismatch

Penumbra

Old InfarctOld Infarct

Neuro-InterventionNeuro-Intervention

BeforeBefore AfterAfter

Embolization of AVMEmbolization of AVM

Occluding Aneurysm with CoilsOccluding Aneurysm with Coils

Before After

Before After

Balloon AngioplastyBalloon Angioplasty

Brain LesionsBrain Lesions

AgeAge Clinical presentation Clinical presentation LocationLocation Characteristic imaging featuresCharacteristic imaging features

Similar lesions have Similar imaging featuresSimilar lesions have Similar imaging features

Parameters Used In Lesions Parameters Used In Lesions DiagnosisDiagnosis

Brain AgingBrain Aging

Involutional ChangesInvolutional Changes

HydrocephalusHydrocephalus

Aqueduct StenosisAqueduct Stenosis

Herpes Virus EncephalitisHerpes Virus Encephalitis

T1 WI T2 WI

Pyogenic Brain AbscessPyogenic Brain Abscess

Multiple SclerosisMultiple Sclerosis

Brain TumorsBrain Tumors

GliomaGlioma

T1 WI T2 WI T1 WI Post-Contrast

Glioblastoma MultiformeGlioblastoma Multiforme

OligodendrogliomaOligodendroglioma

Sellar & Suprasellar TumorsSellar & Suprasellar Tumors

Pituitary AdenomaPituitary Adenoma

Brain stem GliomaBrain stem Glioma

Cerebello-Pontine Angle TumorsCerebello-Pontine Angle Tumors

Acoustic NeurinomaAcoustic Neurinoma

Post Contrast CTPost Contrast CT Bone Window CTBone Window CT

Acoustic NeurinomaAcoustic Neurinoma

T1 WIT1 WI T1 WI Post ContrastT1 WI Post Contrast

MRMR

MeningiomaMeningioma

T1 WI Post ContrastT1 WI Post ContrastT1 WIT1 WI

MRMR

MetastasesMetastases

MetastasesMetastases

SPINESPINE

AnatomyAnatomy

Plain X-RayPlain X-Ray

A-P viewA-P view Lateral viewLateral view Oblique viewOblique view

MYELOGRAPHYMYELOGRAPHY

CTCT

MRMR

T1 WIT1 WI T2 WIT2 WI

T1 WIT1 WI T2 WIT2 WI

Sagittal ViewSagittal View

MR

Parasagittal ViewParasagittal View

T1 WI T2 WI

MR

Spinal TraumaSpinal Trauma

T1 WIT1 WI

CTCTPlain x-ray

Traumatic Cord ContusionTraumatic Cord Contusion

T2 WIT2 WI

DiscDiscNerve RootNerve Root

Thecal SacThecal Sac

Epidural FatEpidural Fat

Epidural FatEpidural Fat

Normal Intervertebral DiscNormal Intervertebral Disc

Disc HerniationDisc Herniation

Normal Disc

Rt Postero-lateral Herniation

Lt Foraminal Herniation

CT

T1 WIT1 WI T2 WIT2 WI

Disc HerniationDisc Herniation

MR

T1 WIT1 WI T2 WIT2 WI

Disc HerniationDisc Herniation

Caudal MigrationCaudal Migration

Sequestrated DiscSequestrated Disc

T1 WI PreContrastT1 WI PreContrast T1 WI PostContrastT1 WI PostContrast

Post-Operative SpinePost-Operative SpineRecurrent Disc/Scar tissueRecurrent Disc/Scar tissue

Enhancing Enhancing ScarScar

Nerve RootNerve Root

Degenerative ChangesDegenerative Changes

Disc bulge with vacuumDisc bulge with vacuum Apophyseal ArthrosisApophyseal Arthrosis

Lateral Recess

Spinal Canal StenosisSpinal Canal Stenosis

Developmental

Degenerative

Central Spinal Canal StenosisCentral Spinal Canal Stenosis

Calcified Ligamenta FlavaThickened Ligamenta Flava

MR CT

Foraminal StenosisForaminal Stenosis

Compression MyelomalaciaCompression Myelomalacia

SpondylolisthesisSpondylolisthesis

►Lytic►Degenerative

Spondylolisthesis is forward sliding of a vertebra over the vertebra below.Types:

Lytic SpondylolisthesisLytic Spondylolisthesis

Defect in Pars Inter-articularis

Pars InterarticularisPars Interarticularis

Degenerative SpondylolisthesisDegenerative Spondylolisthesis

Infective SpondylitisInfective Spondylitis

T1WIT1WI T1WI T1WI Post ContrastPost Contrast

Transverse MyelitisTransverse Myelitis

T2 WIT2 WI

SyringomyeliaSyringomyelia

T1 WIT1 WI

GliomaGlioma

T1 WI POST CONTRASTT1 WI POST CONTRAST

MeningiomaMeningioma

T1 WI POST CONTRASTT1 WI POST CONTRAST

MR T1 WIMR T1 WICTCT

Soft tissue Window

Bone Window

MetastasesMetastases

Normal

Isotope Bone ScanIsotope Bone Scan

Deposits

Prof Dr Mahmoud El Sheikh

THANK YOUTHANK YOU