Ben Huang MD MPHUniversity of North Carolina School of Medicine

Department of Radiology

Beyond Blood Can Be Very Bad: Brain Imaging 2018

➢ Current neuroimaging modalities

➢ Brain anatomy

➢ How to approach a head CT

➢ Wrap up

➢ Computed tomography (CT)

➢ Magnetic resonance (MR)DWI ‒ SWIDSC PWI ‒ DTI1H MRS ‒ DCEfMRI

➢ Ultrasound

➢ Angiography to include noninvasive

Pros

▪ Fast

▪ Excellent screening tool

▪ Clinician comfort Cons

▪ Poorer soft tissue contrast

▪ Ionizing radiation

▪ Acute contrast nephropathy

Pros

▪ Better soft tissue contrast

▪ Multiplanar acquisition

▪ Gives more information

▪ No ionizing radiation

Cons

▪ Takes a long time

▪ ↑ susceptibility to motion

▪ More difficult to interpret

▪ Certain implants/FB contraindicated

▪ NSF

T1-weighted

T1-weighted + Gd

T2-weighted

FLAIR

Diffusion Weighted

Diffusion Weighted (ADC)

MRI Sequences

➢ Current neuroimaging modalities

➢ Brain anatomy

➢ How to approach a head CT

➢ Wrap up

SMG AngGPreCS

PostCSCS

SF

Superior frontal gyrus

Middle frontal gyrus

Precentral gyrus(Frontal lobe)

Central sulcus

Postcentral gyrus(Parietal lobe)

Precentral sulcus

Superior frontal sulcus

Postcentral sulcus

Pars marginalis Falx cerebri

Vertex to Tonsils:CT Anatomy

Central sulcus

Centrum semiovale

Precentral sulcus

Postcentral sulcus

Precentral gyrus(Frontal lobe)

Intraparietal sulcus

Superior frontal gyrus

Middle frontal gyrus

Parieto-occipital fissure

Postcentral gyrus(Parietal lobe)

Lateral (Sylvian) fissure, posterior segment

Caudate body

Central sulcus

Corona radiata

Lateral ventricle

Superior temporal gyrus

Parieto-occipital fissure

Intra-occipital sulcus

Superior temporal sulcus

Superior sagittal sinus

Lateral (Sylvian) fissure

Thalamus

Internal capsule, posterior limb

3rd ventricle

Basal ganglia, lentiform nuclei (GP & putamen)

Caudate, head

Lateral ventricle, occipital horn

Lateral ventricle, frontal horn

Internal capsule, anterior limb

Insula

Parieto-occipital fissure

Calcarine sulcus

Superior temporal sulcus

Lateral (Sylvian) fissure

Quadrigeminalcistern

MidbrainCerebral aqueduct (of Sylvius)

Superior temporal gyrus

Olfactory sulcus

Gyrus rectus

Suprasellar cistern

Amygdala

Hippocampus

Cerebellum

Interpeduncular cistern

Ambient cistern

Cerebral peduncle

Sella turcica

Prepontine cistern

Temporal lobe

Pons

4th ventricle

Vermis

Middle cerebellar peduncle (Brachium pontis)

Cerebellar hemisphere

Cerebellopontine angle cistern

Sigmoid sinus

Mandibular condyle

Medulla

Cerebellar tonsil

Mastoids

Nasopharynx

Foramen magnum

ThalamusInternal capsule, posterior limb

Basal ganglia, lentiform nuclei (GP & putamen)

Caudate, head

Internal capsule, anterior limb

Deeper Dive intoCT & MR Anatomy

PGP

C

Th

Ascending/Descending▪ Coronal radiata

▪ Internal capsule

Association - link different cortical areas in different lobes of same hemisphere▪ SLF − Fronto-occipital fasciculus

▪ Arcuate fasciculus − Uncinate fasciculus

▪ Extreme capsule − Cingulum

Commissural - crossing fibers linking areas in different hemispheres▪ Corpus callosum − Hippocampal commissure

▪ Anterior commissure − Habenular commissure

▪ Posterior commissure

Centrum semiovale Corona radiata Internal capsule

ACPC

PinealOC

Pit MB

Associated with memory and emotional, fight/flight & sexual responses

Consists of:▪ Amygdala

▪ Hippocampus

▪ Parahippocampalgyrus

▪ Cingulate gyrus

▪ Subcallosal Gyri

Uncus

Associated with memory and emotional, fight/flight & sexual responses

Consists of:▪ Amygdala

▪ Hippocampus

▪ Parahippocampalgyrus

▪ Cingulate gyrus

▪ Subcallosal Gyri

Uncus

1 = Optic chiasm2 = Pituitary infundibulum (stalk)3 = Tuber cinereum4= Mammillary body

Network of ependymal lined CSF filled spaces

▪ Derivative of neural tube cavity

4 ventricles:

▪ Paired lateral ventricles

▪ 3rd ventricle

▪ 4th ventricle

Body, lateral ventricle

Frontal horn, lateral ventricle

Occipital horn, lateral ventricle

3rd ventricle

Foramen of Monro

3rd ventricle

4th ventricle

Cerebral aqueduct(of Sylvius)

Sylvian Fissure

Ambient Cistern

Quadrigeminal Plate Cistern

Interpeduncular Cistern

SuprasellarCistern

CP AngleCistern

Prepontine Cistern

Cerebellum

▪ Paired hemispheres joined by midline vermis

▪ Coordination & muscle tone

Brainstem

▪ Midbrain, pons, medulla

Cerebellum

▪ Paired hemispheres joined by midline vermis

▪ Coordination & muscle tone

Brainstem

▪ Midbrain, pons, medulla

MCP

BrainstemMidbrain Pons Medulla

Cerebral Peduncle

Substantia Nigra

Cerebral Aqueduct

Red Nucleus

MCPICP

4th VentricleICP

Olive

Pyramid

C1 – Cervical C5 – ClinoidC2 – Petrous C6 – OpthalmicC3 – Lacerum C7 – Communicating (Terminal)C4 - Cavernous

C1 – Cervical C5 – ClinoidC2 – Petrous C6 – OpthalmicC3 – Lacerum C7 – Communicating (Terminal)C4 - Cavernous

➢ Current neuroimaging modalities

➢ Brain anatomy

➢ How to approach a head CT

➢ Wrap up

➢ Blood (intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!*

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

*Dr Andy Perron

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Hypertensive intraaxialhemorrhage

Posttraumatic extraaxialhemorrhage - epidural

Epidural Hemorrhage Epidural hemorrhage forms between inner table of calvarium and outer layer of the dura, results from middle meningeal arterial tear.

>90% are assoc with skull fx usutemporoparietal bones, also frontal and parieto-occipital regions.

On CT: hyperdense biconvex lens shape, mass effect. Early identification critical to guide evacuation vs early reevaluation

Epidural Hemorrhage Epidural hemorrhage forms between inner table of calvarium and outer layer of the dura, results from middle meningeal arterial tear.

>90% are assoc with skull fx usutemporoparietal bones, also frontal and parieto-occipital regions.

On CT: hyperdense biconvex lens shape, mass effect. Early identification critical to guide evacuation vs early reevaluation

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Stroke CT windowing W 30 L 30 –note left parietal lobe loss of gray-

white matter differentiation compared to right

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Stroke CT windowing W 30 L 30 –note left parietal lobe loss of gray-

white matter differentiation compared to right

Complete loss of gray-white matter differentiation bilateral

hemispheres

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Stroke CT windowing W 30 L 30 –note left parietal lobe loss of gray-

white matter differentiation compared to right

➢ Is there midline shift?➢ Is brain symmetry preserved?➢ Are the cisterns patent

(smile and pentagon)?➢ Is the 4th ventricle patent

and symmetric?➢ Are the ventricles enlarged

with sulcal effacement?

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

+midline shift+hemispheric asymmetry

+cistern effacement+lateral ventriculomegaly and

sulcal effacement

Subdural Hemorrhage Subdural hemorrhage (SDH) collects in the potential space between the inner dura and the arachnoid layer

Result from bridging vein tear in a MVA or fall

On CT: hyperdense crescentic shape when acute, then isodense to hypodense when subacute and chronic. Mass effect -> altered mental status

+SDHCT Checklist:

+ Midline shift

+ Loss of symmetry

+ Cisternal effacementSubfalcine and uncalherniation

Needs NSU !

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Stroke CT windowing W 30 L 30 –note left parietal lobe loss of gray-

white matter differentiation compared to right

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Note bilateral lateral ventriculomegaly. Distinguish

hydrocephalus from atrophy via diffuse sulci prominence

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

BonesDepressed skull fx left parietooccipital bone from

penetrating trauma

➢ Blood (Intra- vs extraaxial)➢ Gray/white differentiation➢ Edema➢ Masses/Mass effect (midline shift, cistern

effacement, herniation ➢ Ventricles (hydrocephalus)➢ Bones (fx, lysis, sclerosis)➢ Paranasal sinuses and mastoids➢ Extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

Expansile soft tissue massleft frontal sinus

➢ Blood - intra- and extraaxial➢ Cisterns and extraaxial CSF - effacement or

asymmetry➢ Brain parenchyma - gray/white differentiation

symmetry, shift, hyper- hypodensity➢ Ventricles - too large or too small➢ Bones - skull fx, paranasal sinuses, mastoids

and extracranial soft tissues

Blood Can Be

Very Bad!

~~~~~~~~~~~~

Blood

Cisterns

Brain

Ventricles

Bones

➢ CT vs MRICT is a great screening tool

MR is good for problem solving & assessing established pathology

➢ Brain anatomy

➢ How to approach a head CTBlood Can Be Very Bad

➢ Emergency checklist Shift, cisternal effacement, or hydrocephalus

Thank you for participating!

http://guides.lib.unc.edu/radiology/booksNeuroradiology references

benjamin_huang@med.unc.edu