Radio-imaging of the CNS Anca Ciurea, UMFIului Hatieganu Cluj-NapocaRadiology

Anatomy

Cranio-cerebral anatomy

Cranio-cerebral anatomy

Anatomy: the blood-brain barrier

Medullary membranes and spaces1 medulla2 subarachnoid space3 pia mater4 arachnoid5 extradural space6 transverse process7 dura mater

Spinal nerves1 dorsal root of spinal nerve + ganglion2 spinal nerve3 ventral root4 grey matter5 white matter6 dorsal branch7 ventral branch8 communicating branches9 sympathetic ganglionAxial section of the spinal cord

Techniques

Diagnostic imaging techniques in CNS pathologyComputer Tomography (CT)2 MRI (Magnetic Resonance Imaging)Cerebral and medullar angiographyMyelography and myelo-CTX-ray

4. Myelography/myelo-CT

5.Standard X-ray of the skull

5. Standard x-ray of the spine

1. Computer Tomography

CNS CT semeiologyThe densitometric scale - Hounfield Units (HU)Water = 0 HU CSF (fluid)= 0/15 HU = blackWhite matter (parenchyma) = 30 HU = dark greyGrey matter (parenchyma) = 35 HU = light greyVessels = dark grey, usually not evaluated without contrast

CNS CT semeiologyWHITE = HYPERDENSE (density > normal parenchyma)bone = + 1000 HU = very whitetentorium, venous sinuses = linear, very light greycalcification = (physiological - pineal gland, choroid plexus, falx cerebri)Blood in the first 7 days = spontaneous hyperdensity

WHITE = spontaneous HYPERDENSITY

RECENT HEMORRHAGE *cerebral hematoma becomes iso, then hypodense after 20 days *the hyperdensity of meningeal hemorrhage disappears in 5 days CALCIFICATION: *tumors: low-grade glioma, meningioma *cavernous angiomas *infectious sequelae: toxoplasmosis, cysticercosis *phakomatoses: Bourneville, Sturge-Weber

Cerebral CT/ spontaneous hyperdensityCapsulo-lenticular hematomaExtradural hematoma

Cerebral CT/ spontaneous hyperdensityThalamic ICB+ 4 weeksVentricular floodingMeningeal bleedingThalamic intra-cerebral Bleeding (ICB)

Cerebral CT/ spontaneous hyperdensityCalcified meningiomaCalcified tumorHemorrhagic tumor(glioblastoma)

Cerebral CT/ spontaneous hyperdensityCalcified cavernous angioma

Cerebral CT/ spontaneous hyperdensityCongenital toxoplasmosisTuberous sclerosis Bourneville disease

CNS CT semeiologyGREY (as white matter or grey matter) = ISODENSe (density = normal parenchyma)TumorsBlood between days 7 and 14Collection of pus (empyema)

Semiologie CT a SNCVERY DARK GREY=HYPODENSITY (density < normal parenchyma)

ischemia oedema cerebral tumor multiple sclerosis (MS) chronic subdural hematoma

Cerebral CT/hypodensitiesSylvian ischemiaTumor (low-grade glioma)Post-traumatic sequelae

CNS CT semeiologyIntense hypodensity/Black Stroke sequelae (ishemic lacunae),Lack of brain tissue= CSF densityArachnoid cyst (densities = +/- CSF)Lipid densities = -100 HU (epidermoid, dermoid, lipoma)air = -1000 HU

Cerebral CT/hypodensityArachnoid cystCystic tumorChronic subdural hematoma

Cerebral CT/lipid hypodensityLipoma of the corpus callosumSuprasellardermoid cyst

NORMAL CEREBRAL CT WITH INJECTION OF CONTRAST bone and physiological calcifications (pineal gland and choroid plexus) vessels grey matter white matter CSF fat airMaximal densityMinimal density

Normal cerebral CT with injection of contrast

Cerebral CT/hyperdensities after injection of contrast vascular anomalies: *venous angioma (1% of exams) = normal variants *arterio-venous malformation (AVM) *arterial aneurism *(cavernous angioma)VAAVMAA

Cerebral CT/hyperdensities after injection of contrast hypervascular lesions or lesions with vessles without BBB: *intra-axial malignant tumors (glioblastoma, metastases) *extra-axial benign tumors (meningioma, neurinoma, pituitary adenoma)GlioblastomaMetastases Meningioma Neurinoma VIII

Cerebral CT/hyperdensities after injection of contrast rupture of the blood-brain barrier (BBB): *recent ischemia (< 30 days) *inflammatory lesions: MS, encephalitis, abcessRight frontal abcessMSR sylvian ischemia

CT of the spine contour of the disk hydration of the disk contour of the dural sac contents of the dural sac nerve roots (-C/+C) bones para-vertebral regions+++++++-++++++++++

CT normal aspect

Spine CT

Burst fracture D12

Spine CT

Plasmacytoma D12

Spine CTDisk herniation L4/L5

2.MRI

MRI semeiology MRI (magnetic resonance imaging) = cantitative and qualitative mapping of water

2 main sequences: *T1: anatomic sequence sequence used to evaluate enhancement after iv injection of gadollinium *T2: sequence which is very senzitive to the variations of the quantity of water

MRI semeiology for aprox. 80% of lesions T1 and T2 are increased because of the growth in free water contents => hypo-intense T1 signal => hyper-intense T2 signal T1 enhancement after iv injection of gadollinium in alterations of the BBB or hypervascular lesionsMRI = good senzitivity, but low specificity

MRI semeiology T1 and T2 are low for aprox. 20% of lesions => hyper-intense signal in T1 = fat, subacute and chronic hematoma => hypo-intense signal in T2 = hemoglobin degradation products (hemosiderin) = the perifery of hematomas and cavernous angiomas = melanin = fat = calcification

T1 semeiology fat hyperintense signal because of enhancement white matter grey matter CSF compact bone air, vessels with fast flowhypersignallack of signal

T1 semeiologyfat hyperintense signal because of enhancement white matter grey matter CSF compact bone air, vessels with fast flow

T1 semeiology fat hyperintense signal because of enhancement white matter grey matter CSF compact bone air, vessels with fast flow

T2 semeiology

T2 semeiology CSF grey matter white matter fat compact bone air, vessels with fast flow

MRI semeiologyBrainstem ischemiaT1T2

MRI semeiologyT1T2L temporal arachnoid cyst

MRI semeiologyR frontal tumorT1T2

MRI semeiologyMultiple sclerosisT1T2

MRI semeiologyT1T2Cavernous angioma

MRI semeiologyHemorrhage in gliomaR temporal hematoma on AVMT1T2T1T2

MRI semeiology/spine contour of disk (sagittal) hydration of disk (T2) contour of the dural sac contents of the dural sac (spinal cord and cauda equina) nerve roots bone para-vertebral regions++++++++++++++

++++++++

MRI semeiology/spine

MRI semeiology/spine

MRI semeiology/spine

L herniated disk L4/L5

MRI semeiology/spine

MRI semeiology/spine

Disk degeneration L4/L5 and L5/S1

MRI semeiology/spineDeformation of the dural sacCLECCEMetastasis L3Luxation C6/C7

MRI semeiology/spineDeformation of the dural sac

MRI semeiology/spinePara-vertebral regionTB spondylodiscitis L3/L4 ; abcess of the right psoas muscle

MRI semeiology/spineBone anomaliesVertebral metastasesOsteoporotic vertebral collapse

ANGIOGRAPHY

Cerebral angiography(conventional, angio-MRI, angio-CT) vascular occlusion = embolism,thrombosis arterial stenosis= atheroma addition image = aneurysm arterio-venous fistula = AVM = angioma tumoral hypervascularity (blush) venous sinus: occlusion by tumoral invasion or thrombosis

Cerebral angiography

Cerebral angiography

Cerebral angiography

Cerebral angiography

Cerebral angiography(conventional, angio-MRI, angio-CT)

Cerebral angiography(conventional, angio-MRI, angio-CT)

ICA thrombosisL sylvian embolismR sylvian embolismAngio-MRI

Stroke

Arterial stroke

Techniques: A. Brain CT (parenchyma),

B. Brain MRI, in multiple planes (lesions of the parenchyma and vessles of the circle of Willis, DW)

C. Angio-MRI with gadolinium, both cerebral and carotid, orAngio-CT with Iopamiro (Ultravist, etc)

STROKEArterial or venousarterial : ischemic or hemorrhagicvenous : thrombosis and infarction

Arterial stroke Ischemic : - impairment of normal blood flow - lesions of the nervous structures: ischemia necrosis lack of nervous tissue; - cytotoxic oedema vasogenic oedema luxury perfusion; - the distribution is always that of a vasculary territory!!

Ischemic arterial strokeMechanisms: - low blood flow - thrombosis - embolism - occlusion

Ischemic arterial stroke1. CT : - Hypodensity of an arterial territory (vasogenic oedema) - Evolution towards resorbtion or the formation of a lacuna (CSF density)

Ischemic arterial stroke2 hours after onset24 hours after onset

Ischemic arterial stroke6 hours after onset24 hours after onset

Stroke sequelae

Ischemic arterial stroke2. MRI :

- hyposignal T1 / hypersignal T2, in an arterial territory (vasogenic oedema)

- evolution towards resorbtion or the formation of a lacuna (CSF density)

CTCTA2D-MIP3D-MIPMRI-FLAIRDWIMRI-ADC

DWIADCMR AngioPerfusion MR

Arterial strokePathology: Hemorrhagic - vascular rupture (HT, aneurysm) - parenchymal hemorrhagic effusions (hematoma); - absent or minimal perilesional vasogenic oedema - ventricular flooding (rupture of the BBB)- midline shift (with secondary herniation of brain structures)

Hemorrhagic stroke1. CT : - Hyperdensity which is not restricted to an arterial territory

- evolution: isodense - hypodense - resorbtion

Non-contrast CT

Hemorrhagic stroke2. MRI : - hyper- or hyposignal depending on the sequence and age of the hematoma

- not restricted to an arterial territory

- evolution: resorbtion or lacuna (CSF density)

T1 SEFLAIRAcute and subacute hemorrhage - deoxiHb+metHb

T2 EGT2 FSEFlairT1 SEHemorrhagic parieto-occipital stroke

QUIZ?

TUMORS

3. TumorsTechniques: A. Brain and spine MRI, in multiple planes (intra- and extraaxial parenchymal lesions, vertebral intra- or extracanalar position; vascularization);

B. Brain and spine CT (parenchyma and vascularization)

CEREBRAL CT/tumoral syndrome mass syndrome: *shift of the ventricles and vascular structures *erased cortical sulci density changes: *hypodensity: parenchymal and cystic component *spontaneous hyperdensity: hemorrhagic or calcified component *post-injection hyperdensity: contrast enhancement (absence of BBB and hypervacularity) intra-axial malignant T (glioblastoma, metastases) extra-axial benign T (meningioma, neurinoma, adenoma)

CEREBRAL MRI/ tumor syndrome intra- or extraaxial origin mass syndrome signal changes *hyposignal: parenchymal and cystic component in T1 *hypersignal in T2 *calcified component: hyposignal in T1 and T2 * or hemorrhagic : depends on the age of the lesion * hypersignal in T1 after injection: enhancement (absence of BBB and tumoral hypervascularity) * the more inhomogeneous the lesions are and the more they enhance, the more malignant they are.

Cerebral CT/ tumor syndrome/ MRIGlioblastoma

TraumaAnca Butnaru, UMF Cluj-Napoca

The most common CNS lesions:1. Trauma2. Stroke3. Tumors

1. Trauma

Pathology:

lesions of the bony sheath and its contents,

or only one of the two components

1. Trauma

Pathology: - loss of bone continuity - lesions of the parenchyma (contusion, laceration, ischemia) - blood effusions in the: epicranian, epidural, subdural, subarachnoid spaces; - vascular rupture (intraparenchymal hematoma, secondary ischemia), avulsion of nerves - abnormal communications (fistula, ventricular flooding)

1. Trauma

Techniques: A. X-ray of the skull and spine in 2 perpendicular views (bone lesions) B. Non-contrast CT of the head and spine (bone and parenchyma, especially for fresh blood = hyperdense)

C. MRI of the brain and spine, in multiple planes (brain parenchyma, spinal cord and disks, meninges not bones!!!!)

X-ray of the skull and spine

first exam for : - trauma (including post-stroke head trauma) - suspicion of bone tumor (osteolysis or osteosclerosis)

A.Standard X-ray- two perpendicular views:A fracture on one view = suspicionA fracture on both views = certainty

Pathology on x-raySkull fracturesSkull-base fracturesFacial fracturesFractures of nose bonesmechanism: strong impact-acceleration, deceleration/rotation

1. Trauma

Skull x-ray semeiology: - fracture line (lucency) - opacities in the paranasal sinuses (indirect sign of fracture of the sinus wall) - soft tissue changes

Head trauma x-ray

1. Le Fort I2. Le Fort II3. Le Fort III

Spine x-ray semeiology: - changes in the shape and contour of the vertebral bodies, pedicles, apophyses - displacement of vertebral bodies - fracture lines (lucency), with interruption of the cortical bone

LL X-rayFractureC4

Computer Tomography- trauma -

Head Ct: - fracture lines (hypodense, interruption of bone) - extracranial hematoma - fresh blood (subdural h., extradural h., intraparenchymal h., subarachnoid hemorrhage = emergency !!!!) - cerebral contusion (hypodense +/- hyperdense) - mass effect - brain herniation (emergency!!!!!).

CT bone windowReconstructions: 3D and MIP

Comminuted fractureDepressed fracture

Head trauma/ CT123456

Spine CT: - fracture lines (hypodense, interruption of bone) - fresh blood - compression of the dural sac - compression of the spinal cord and nerve roots

C2 (axis) fracture

1. Trauma

Brain MRI: - hematomas presence, position

- bloood signal is different depending on the age of the lesion - mass effect and secondary herniation of brain structures - confirms post-traumatic ischemia (the state of the arterial system)

Fronto-basal contusion CT MRI -T2

MRI- trauma -

Normal MRI

1. Trauma

Spine MRI: - changes in structure and shape of bone - compression of the dural sac - spinal cord compression (MRI emergency!!!!!) - spinal cord section - extradural hematoma - spinal cord contusion

MRIT1 sagittalT2 sagittalFractureD8

Extradural hematomaMRI T1

Spinal cord section

fractures C4,C7 and D2C4