DWI , SWI , and others explained

1. Some problem solving in Neuro-
Imaging: a practical approach
• Dr. Vincent Batista Lemaire
• Locum Consultant Radiologist
• St. Richards Hospital ,West Sussex Hospitals Trust, NHS .
• Chichester , England , UK .

2. Some problem solving in Neuro-
Imaging
A practical Approach

3. Some problem solving in Neuro-
Imaging : A practical Approach
• Learning Objectives :through some interesting cases :
• 1. Recognise perivascular spaces
• 2. Cut off for fluid in the optic nerve-sheath complex.
• 3. How to measure an acoustic neuroma
• 4. Spontaneous intracranial hypotension
• 5. Recognise some vascular anatomical variants and disease.
• 6. Intracranial cyst differential diagnosis .
• 7. Pathologic conditions with restricted diffusion .
• 8. Pathologic conditions with blooming or signal loss.
• 9. Hint for reporting Multiple Sclerosis .
• 10, Hint for reporting Dementia .

4. The barbershop

5. The barbershop
“combing” appearances of the Virchow-Robin spaces; “aspect peigne”

6. A very common perivascular space:
“leave me alone “

7. A very common perivascular space:
“leave me alone “

8. Choroid plexus xantogranuloma
“leave me alone

9. The optic nerve-sheath and CSF
• The orbital subarachnoid space surrounding the optic nerve is
continuous with the circulation system for cerebrospinal fluid (CSF).
• Patient with increased intracranial pressure (ICP) often develop
papilledema (swelling of the optic disc which is a ophthalmologic
diagnosis )is a vision -threatening condition . Apparently , the
increase in the CSF volume in the peri-optic space results in
unfolding of the optic nerve sheath , and it is believe that this, in
turn , compresses the nerve, causing stasis of the axonal transport
and producing swelling of the optic nerve axons . So thee is
widening of the optic nerve sheath and flattening of the posterior
sclera.
• Low CSF –pressure may be involved in the pathogenesis of the
glaucoma : the subarachnoid space is narrowed .

10. The optic nerve-sheath and CSF
Best sequences : Axial and Coronal t1 /t2 and t2fat sat

11. The optic nerve-sheath and CSF
• The optic nerve: homogeneous , dark , does not enhances:
enhances or become bright in neuritis , or larger in
tumours. Diameter 3 mm .
• The sheath has normal CSF , or narrow like in glaucoma or
increase , like in ecstatic or more conspicuous as in
Idiopathic intracranial hypertension or non idiopathic
intracranial hypertension .The sheath is 1 mm wide in each
side + 3 mm optic nerve =5 mm . When there is ICH =6 mm
, 1.5 mm in each side .
• The fat stranding or enhancement mean pathologic
conditions .
• Tram –track enhancement : optic nerve-sheath complex
peri-optic meningioma narrows the nerve.

12. Optic neuritis: STIR
• 59y/o M; decreased left vision, probable optic neuritis. Vision 6 x 36 in the
left eye and 6 x 6 in the right eye. Left afferent pupillary defect. Pain on
eye
movement. Previous leg numbness.
•

13. Optic neuritis : STIR
• 46y/o F ; reduced vision right eye

14. Optic gliomas and unidentified bright
object in NF1
• 13 y/o M ; headaches wakes from sleep.
• When confined to the optic nerves (Dodge stage 1 – see below), they can
safely be referred to as optic nerve gliomas. Often, however, they are
either centred on or extend to involve the chiasm and optic radiations. In
such cases, they are difficult to distinguish from hypothalamic
gliomas and such a distinction is in most instances artificial.
• Unidentified bright objects tends to receded after 10 years all and affect
mainly the Globus pallidus and the brainstem .

16. At 10 mm the optic nerve-sheath complex =5 mm ,
if the optic nerve 3 mm and sheath > 2 mm ,we
need to think in abnormal enlargement of the
subarachnoid space

17. normal

18. The optic nerve-sheath and CSF
:papilledema
• 19 y/o F ,5 weeks headache and bilateral papilledema .
• Flattening of the posterior eyeball at the optic disc and fluid surrounding
the optic nerve in patient with pineal glioma .Left , 4 months later after
endoscopic ventriculostomy .
Endoscopic ventriculostomy

19. The optic nerve-sheath and CSF
:papilledema
• Post endoscopic 3rd ventriculostomy

20. The optic nerve-sheath and CSF
• Clinical History : 74 y/o , f , progressive field loss right eye, normal intra-
ocular pressure ; ? compressive optic nerve.

21. Dural ectasia: no intracranial abnormality

22. The optic nerve-sheath and CSF
• Clinical History : 63 y/o , M, background ophthalmoplegia migraine. 6/12
sudden onset worsening left gaze. O/E complete VI nerve palsy. ?structural
cause.

23. The optic nerve-sheath and CSF
• 1.There is CSF surrounding the optic nerve.
• 2. The cut off for abnormal CSF is 2 mm behind the globe .
• 3. Rule out brain tumor , dural sinus thrombosis or hydrocephalus.
• 4. Is there papilledema? Overweight patient?, Visual loss?, field defect ?
• 5. look for empty sella turcica , enlarged Meckel cave and prominent
arachnoid pits.
• think about: IDIOPATHIC INTRACRANIAL HYPERTENSION

24. The optic nerve-sheath and CSF
• Clinical History : 63 y/o M; pale optic disc left eye ; field of vision worse ;
r/o meningioma

25. 1.Prominent subarachnoid space around the left optic nerve.
2. Tortuosity of the left optic nerve.
3. Pale optic disc ; field of vision worsening
Asymmetrical idiopathic intracranial hypertension

26. How to measure an acoustic neuroma?
• 1. Perpendicular to the posterior petrous ridge
Ice cream cone
Thanks to Dr. Steve Connor

27. How to measure an acoustic neuroma
• 2. Parallel to the posterior petrous ridge

28. How to measures an acoustic neuroma
3. Greatest craniocaudal dimension

29. How to measure an acoustic neuroma
The acoustic neuroma measures 16.4 x 18 .6 mm perpendicular and parallel to the
petrous ridge x 14.5 mm in its greatest craniocaudal dimension .

30. How to measure an acoustic neuroma
Increased despite gamma knife

31. How to measures an acoustic neuroma
• More difficult task: intra-labyrinthine extending to the superior and lateral
semi-circular canal. Take the greatest diameter and describe the lesion .
normal

32. The low laying cerebellar tonsil
• The differential diagnosis :
• MR demonstration of less than 2 mm of tonsillar ectopia is probably
of no clinical significance in the absence of syringomyelia.
• The Chiari I malformation is defined as displacement of the
cerebellar tonsils into the cervical spinal canal . Unlike many
malformations of the central nervous system (CNS), this entity
manifests itself in early adulthood and middle age, often with a
confusing clinical picture . Additionally, a low degree of cerebellar
ectopia is often of no clinical significance .
• Arnold Chiari II to IV : tonsillar and cerebellar herniated.
• High intracranial pressure: expansive process .
• Low intracranial pressure : CSF leak

33. The low laying cerebellar tonsil
• Clinical History : 37 y/o , M, headache on sitting and standing, nausea,
neck pain, balance disturbance, negative CT .

34. The low laying cerebellar tonsil

35. The low laying cerebellar tonsil
• SPONTANEOUS INTRACRANIAL HYPOTENSION : CSF pressure <7cms
H2O: postural headache, nausea, vomiting , neck pain , visual and
hearing disturbances, and vertigo from CSF leaks.
• 1. pachymeningeal enhancement ( most common finding )
• 2.prominent veins and dural venous sinuses
• 3.enlargement of the pituitary gland
• 4.subdural effusion
• 5.reduced CSF volume : sagging (sink, bulge downward) brainstem
and cerebellar tonsillar herniation . Drooping penis sign ( drop of
the splenium ).
• Treatment : localise the leak and non-targeted epidural blood patch

37. The low laying cerebellar tonsil
• SPONTANEOUS INTRACRANIAL HYPOTENSION
At arrival 18 months later

38. Vascular normal /abnormal pipelines

39. The veins
• Normal veins
• Development venous anomaly
• AVM
• Dural sinuses: pacchionian granulation
;prominent confluences ;dural venous
malformation ; sinus hypoplasia, sinus
thrombosis.

40. Normal veins
• 62 y/o F ; LOC ; PMH breast ca on Herceptin
• Vein of Labbe , inferior anastomotic system

41. Normal veins
• 74 y/o F, fall, on warfarin. 3 aneurysm and Vein of Trolard : superior
anastomotic system

42. Trolard vein thrombosis

43. DEVELOMENT VENOUS ANOMALY
• 27Y/O,m, MIGRAINE

44. AVM
12 y/o ,M , headaches, numbness and paraesthesia left arm/leg

45. Dural sinuses
• Hypoplastic left transverse dural sinus and jugular bulb

46. Pacchionian granulation and pineal
cyst

47. Prominent sinus confluence

48. Dural venous malformation
• 82 y/o M ; ataxia.

49. Dural venous thrombosis
• 34y/o F; headache, vomiting , photophobia

50. Chronic SSS thrombosis with partial
recanalization
• 46 y/o M; headache , confusion , collapsed, neck stiffness , <power
On admission Month later

51. Month later

52. 6 Years later

53. 6 Years later
1. Not return to normal calibre
2.Discontinuous signal in SSS
3. Thickened nodular dura

54. The arteries
• Normal variant
• Aneurysm
• Arteritis
• Thrombosis
• Tiny arteries we must know: the inferior
anterior cerebellar artery :tinnitus and SNHL;
and the superior cerebellar artery :trigeminal
neuralgia .

55. Trigeminal artery
• The persistent trigeminal artery usually arises from the presellar ICA as it
exits the carotid canal and enters the cavernous sinus and it extends
posteriorly to join the distal third of the basilar artery usually between the
origins of the superior and anterior inferior cerebellar arteries.

56. Trigeminal artery
• 59 y/o F with R III nerve ( oculomotor) palsy; ? Compression

57. Double MCA

58. Double MCA

59. Fenestrated basilar artery

60. Left vertebral artery ending in PICA

61. Aneurysm
• 66 y/o M; ataxia ; R leg weakness.
• Dilatation of the petrous segment of the right ICA .

62. Aneurysm
• 60 y/o F , one month R eye loss of vision , full scotoma .
• 21 mm R internal carotid artery supra-clinoid aneurysm.

63. aneurysm
• 60 y/o F ; headaches, double vision and pressure R eye .
• Aneurysm right cavernous segment right ICA

65. aneurysm
• 61 y/o M; collapsed, slurred speech.
• Small right M2 aneurysm spotted on MRI

66. Vasculitis
• 43 y/o M ; multiple infarcts on Methotrexate
• Stenosis , and beaded appearances.

67. MOYA MOYA 38A

68. Thrombosis
• 79 y/o M, slurred speech , left weakness.
• Right MCA hyperdense sign .

69. Thrombosis
• 56 y/o M; slurred speech ; left side weakness
• Right MCA hyperdense sign

70. Occlusion of the artery of Percheron
• Common trunk from posterior cerebral artery
with symmetrical infarcts in the paramedian
cerebral peduncle and thalami.

71. Dissection
73y/o F ; left weakness , HTN .
R ICA dissection

72. Dissection
• 48 y/o M , left Horner syndrome
• Left carotid dissection , t1 FS ;TOF 3D

73. Dissection
• 62 y/o M ; ataxia , right weakness.
• Right vertebral artery dissection
DWI
ADC
TOF 3D multi-slab
T1 FS

74. Dissection
• 76 y/o M , repeated right leg weakness.
• Left internal carotid and right vertebral artery dissections.

75. Dissection
• 44 y/o F; non traumatic headaches x 10 days ; episodes of expressive
dysphasia , CT NAD.
• B/L internal carotid artery dissection .

76. 2 months later on warfarin

77. right left

78. Vascular loop over the V cranial nerve
• 40 y/o M R trigeminal neuralgia.
• Superior cerebellar artery loop ; ? causing compression

79. Vascular loop over the V cranial nerve
• 68 y/o F ; recurrent R trigeminal neuralgia, shooting pain V2,V3.
• R trigeminal atrophy and 2 segments ( porus trigeminus and cisternal
segment)contacted by the superior cerebellar artery .

81. Vascular loop over the V cranial nerve
• 59 y/o F , facial pain left side .
• Trigeminal nerve atrophy and vascular loop

82. Vascular loop over the trigeminal
nerve
• 68 y/o M; pain behind left eye
• Vertebrobasilar dolichoectasia abutting the left V cranial nerve.

83. Vascular loop over the VI cranial nerve
• 54 y/o F, internal strabism ,VI N palsy (abducens to rectus lateral muscle )
• The left vertebral artery joins the right to form the basilar artery to the
right of the midline at the level of the acoustic canal and then curves to
left left apparently abutting the R VI.

84. Vascular loop over the VII-VIII cranial
nerves
• 57y/o M , left side high frequency SNHL .
• Left AICA (anteroinferior cerebellar artery)abutting the left VII-VIII.

85. Vascular loop over the R VII-VIII cranial
nerves
• 68 y/o F ; asymmetrical SNHL + tinnitus .
• Right AICA abutting the statoacoustic nerve

86. Swirl sign
85 y/o woman :Lobar haemorrhage . Almost no surrounding
edema.The basal ganglia are spared. Low density in the core
In keeping with active bleeding . Severe edema effacing
the sulci and sylvian fissure.

87. Diffuse cerebral oedema
• 72 y/o woman ; intubated , hypertonicity

88. Brain death
• 24 y/o woman ; cardiac arrest after allergic
reaction .
24 y/o woman cardiac arrest
Normal 12 y/o girl

89. Intracranial cysts : classification
according to Origin or Pathogenesis
• Normal and or variant: extra-axial :pineal ;
intra-axial :choroid plexus, ependymal , PVS
,neuroglial .
• Congenital :extra-axial: arachnoid, epidermoid
,dermoid , neurenteric , Rathke cleft; intra-
axial : colloid
• Note: intraventricular lesions are intra-axial

90. Intracranial cysts : classification
according to Origin or Pathogenesis
• Traumatic : post vascular event or surgery
intra-axial :porencephalic .
• Infectious : extra/intra-axial
:neurocysticercosis , hydatid , others.
• Tumor-associated : extra-axial: vestibular
schwannoma (true arachnoid cyst),
craniopharyngioma and pituitary macro-
adenoma ( enlarge the PVS), meningioma
( trapped CSF).

91. Classification of intracranial cysts according to
most common location : Osborn and Preece.
• Cyst Location
• Arachnoid middle cranial fossa
• Choroid plexus atria lateral ventricle
• Colloid pillar of fornix straddle the cyst ( Monro foramen).
• Craniopharyngioma (PVS) suprasellar
• Dermoid sellar , parasellar, midline
• Enlarged PVS basal ganglia/ midbrain
• Epidermoid cerebellopontine angle cistern
• Ependymal lateral ventricle
• Hydatid parietal lobe
• Meningioma with trapped CSF convexity or planum sphenoidale
• Neurenteric prepontine
• Nuerorocysticercosis convexity or basal subarachnoid spaces
• Neuroglial frontal lobe
• Pineal pineal gland
• Pituitary adenoma (PVS) parasellar
• Porencephalic cerebral hemispheres
• Rathke cleft sellar or suprasellar
• Schwannoma with arachnoid cyst cerebellopontine angle cistern

92. Dermoid cyst
• Origin : ectodermal, midline cyst
• Made of epithelium , collagen , dermis with hair follicles, sebaceous
glands , apocrine glands and liquid cholesterol . May contain teeth.
• Active production of hair and oils by the dermal appendages : early
rupture, which could cause chemical meningitis that may lead to
vasospasm , infarction , and even death .
• Capsule is thicker than that of epidermoid often contains plaques of
calcification .
• Well –defined; lobulated ; hyperintense on T1 , heterogeneous on t2,
suppress signal on STIR .

93. Dermoid cyst
• 59 y/o F; headaches , intermittent R hand weakness
• Epidermoid cyst resemble CSF ; craniopharyngioma high on t2 and
enhances .

94. Dermoid cyst
• 52 y/o F left migraine and hearing loss
Fatlike droplets is subarachnoid cistern : rupture

95. Dermoid cyst

96. Neuroglial cyst
• Benign epithelial-lined lesions , rounded , smooth , uniloculated , non-
enhancing with minimal to no surrounding signal intensity abnormality ,
mainly in the frontal lobe.
• 44 y/o M , fall , ? Seizures. Incidental finding .

97. Neuroglial cyst
• Right 44 y/o F , headaches ; Left 65y/o M , active tremor

98. Neuroglial cyst ???
• 18 y/o M , Post viral ataxia; f/u t2; bottom 1 year later. ?low grade glioma ;
parasitic?

99. Arachnoid cyst
• Space occupying lesion that follows CSF in all sequences.
• Sharply demarcated , displace or deform the adjacent brain ; scalloping of
the calvarium .
• Occasionally : haemorrhage or proteinaceous content.

100. Arachnoid cyst
• 46 F ; right sided numbness + odd feeling
• Spinal arachnoid cyst

101. Arachnoid cyst
• 44 y/o F ; chronic headaches
• R ambient /perimesencephalic cistern

102. Arachnoid cyst
• 86 y/o F ; widened Silla turcica on CT .
• Intrasellar arachnoid cyst .

103. Arachnoid cyst
• 29 y/o M; infantile hemiparesis and seizures.
• Multilocular temporoparietal arachnoid cyst.

104. Arachnoid cyst
• 40 y/o M ; right leg dragging , head pain .
• Posterior fossa arachnoid cyst with Ommaya reservoir .

105. DWI: restricted water motion produces high signal
intensity on diffusion MR and hypointensity on
apparent diffusion coefficient (ADC)
Free water diffusion restricted diffusion
Facilitated diffusion

106. Restricted diffusion : mechanism
• 1. The brain shows restricted diffusion because is made of highly packed
cells with ADC values at 750. CSF values 3000-3050
• 2. cellular swelling in cytotoxic oedema : DWI: the extracellular space is
only 20% of the brain but dominant contributor to the ADC values. The
ADC reflect the state of the EXTRACELLULAR SPACE . In Ct the hypodensity
is due to water coming from the capillary to the extracellular space long
after the cytotoxic edema converts into ionic oedema with hypertonicity
in the extracellular space.
• 3. high cellularity in tumor ( lymphoma , medullablastoma );pus within
abscess; viscous fluid; blood products : the random ,fast-moving -moving
water protons to slow Brownian motion . The necrotic centre of a GBM
show high ADC .

107. Restricted diffusion : mechanism

108. Restricted diffusion
• acute stroke 500 x 10-6 mm2/
• White matter 750 x 10-6 mm2/s
• Oedema 1500 x 10 -6/s
• CSF 3200 x 10 -6/s
• S DWI = S b=0 x e (-bx D)

109. Restricted diffusion
• Disease Cause
• Hyper acute stroke (0-6hrs) cytotoxic oedema
• Acute stroke (6hrs -3days ) cytotoxic oedema
(sensibility > 90% in first 24hrs )
• Haemorrhage oxyhemoglobine intracellular
• Abscess increase viscosity and cellularity
• Tumour increase in cellularity
• Epidermoid tumour viscosity (debris , keratin , cholesterol )
• Encephalitis cytotoxic oedema
• Creutzfeldt -Jacob unknown
• Multiple sclerosis
( a few acute lesions) unknown

110. Restricted diffusion: acute ischaemia
• 76 y/o F ; sudden onset left side headache and vertigo; difficulty reading
and memory problems.

111. Restricted diffusion: acute ischaemia
• 73 y/o M; temp 41.c ; reduced GCS , intubated.
• External border zones of ACA, MCA and PCA + PICA: watershed ischaemia

112. Restricted diffusion: haemorrhage
• 66 y/o F ; disorientation .

113. Restricted diffusion: embolism

114. Restricted diffusion: abscess
• Differential diagnosis of rim-enhancing lesions:
• - glioma
• - abscess
• - demyelinating disease
• - metastasis
• - radiation
• - infarct
• -evolving haematoma
• Demonstration of restricted diffusion within the central portion strongly
suggest abscess rather than a necrotic primary tumour or metastasis .It
will show high signal on DWI . T2 hypointense ring .

115. Restricted diffusion: abscess
• 1. point to ventricles.
• 2. daughter ring
• 3.homogeneous wall thickness but thicker
towards the cortex .
• 4. Fussy margins, no perfect sharp line .
• 5.T2/STIR superimposed dark line; low ADC .
• 6. If the lesion is not bright on DWI it is not
and abscess.

116. Restricted diffusion: abscess
• 84 y/o M; acute onset loss vision R eye; nystagmus.

117. Restricted diffusion: abscess
• 79 y/o M; sepsis , low GCS. Multiple Klebsiella abscess

118. Restricted diffusion: tumour
• 73 y/o F ; solitary breast metastasis and 3 months f/u after cyber knife
therapy .
• Rim of restricted diffusion
f/u 3 months

119. Restricted diffusion: GBM
• If to much people in this party think about
GBM : traverse the grey-white matter junction ;single or multifocal ;
heterogeneous with irregular contour; annular contrast enhancement ,
central necrosis , haemorrhage; extends beyond enhancing rim ; over
corpus callosum butterfly wings ; dural extension ; mass over effect over
ventricles. (Dr.Mufudzi Maviki ; Jean-Louis Dietemann)

120. Restricted diffusion: GBM
• GBM:
• 1. rarely ring enhancement .
• 2. solitary , corpus callosum , deep white matter ,
irregular, random , ugly geographic necrosis ,
irregular peripheral enhancement recruiting new
vessels VS metastasis :no affecting the corpus
callosum , at the grey white matter junction ,
more spherical ,attention with haemorrhagic
mets which could be similar to and abscess.

121. Restricted diffusion: GBM
• 67y F ; found on floor ; left weakness and neglect
• Cystic GBM

122. Restricted diffusion: GBM
• 56 y/o M ; fall , right weakness an sensory changes .
• High grade multifocal GBM treated with dexamethasone; f/u 5 months

123. Restricted diffusion: GBM
• 69y/o M ; 2 weeks left side weakness.
• Cystic GBM

124. Restricted diffusion: lymphoma
• Deep settle: contact to the ventricles (juxta ventricular )and corpus
callosum , butterfly ; basal ganglia ,subependymal and gyral. Shows 1 mm
blurred along the margin, vividly homogeneous enhancement, no flow
void. Higly cellular , low ADC .
• 68 y/o F ; changes in personality , headaches .

125. Restricted diffusion: lymphoma
• 59 y/o F odd behaviour, seizure.
• Primary multifocal lymphoma
Multifocal :embedded or connected by Multicentric :not connected

126. Restricted diffusion: lymphoma

127. Restricted diffusion: lymphoma

128. Restricted diffusion: lymphoma
Blurred margin

129. Restricted diffusion: epidermoid tumor
• Fibrous capsule, containing keratohyalin and cholesterol crystal .
Lobulated, irregular , “cauliflower-like” mass with “fronds” .Surrounds,
engulfs vessels and nerves .
• Low heterogeneous signal on t1; t2/flair hyperintense ; high signal on DWI
and low on ADC .( same ADC as the brain tissue 735).High lactate on
spectroscopy .
• 49 y/o ; F ; asymmetrical sensorineural hearing loss

130. Restricted diffusion: epidermoid
tumour
The ADC is the same of the white matter : 750

131. Restricted diffusion: encephalitis
• 37 y/o M; headaches, ataxia

132. Restricted diffusion: encephalitis
• 45 years old female, focal seizures .

133. Restricted diffusion: encephalitis
• 45 years old , female , focal seizures , left arm rigid

134. Restricted diffusion: encephalitis
• 49 y/o M. transient left side weakness , headache , photophobia

135. HSV Encephalitis ,the anti N-acetil
aspartate receptor encephalitis

136. HSV Encephalitis ,the anti N-acetil
aspartate receptor encephalitis
2 months
10 months

137. HSV Encephalitis ,the anti N-acetil
aspartate receptor encephalitis
• 42 years old male patient , with fever and seizures.

138. RESTRICTED DIFFUSION : Creutzfeldt -
Jacob
• 63 y/o F ; memory loss, progressive ataxia; ? Encephalitis

139. Restricted diffusion: multiple sclerosis
• 58 y/o F ; RRMS; new left weakness

140. Susceptibility weighted imaging
• Previous know as BOLD venographic imaging . Differs significantly from a T2*-
weighted GE sequence, as SWI is based on a long echo-time(TE), with high
resolution, flow compensation , and filtered phase information in each voxel.
• Magnetic susceptibility is the relative ability of a substance to become
magnetized when exposed to a magnetic field: positive , ferromagnetic (Iron:
Fe2+,Fe3+) or paramagnetic (hemosiderin and deoxyhemoglobin + basal
ganglia calcification ; Gadolinium); negative, diamagnetic (free water and most
human tissue including cortical bone + calcification outside the basal ganglia).
• In a left handed system the iron deposition and haemorrhage
(paramagnetic) look bright on the phase and dark on SWI image relative to
the surrounding brain tissue and the calcium (diamagnetic) looks dark on
both phase and SWI image relative to brain tissue .
• Deoxyhemoglobin is paramagnetic. So the veins in the sulci and along the
lateral ventricle appear bright (positive phase) and are a marker of a left
handed system. Oxyhemoglobin is diamagnetic in nature, so arteries appear
dark (negative phase).

141. Data sets generated during the scan. 1. Magnitude. 2.
Filtered Phase image. 3. SWI. 4. SWI mIP. References:
Columbia Asia Hospital, Bengaluru.
Susceptibility weighted
imaging
1.Original Magnitude Image – shows
reduced anatomic differentiation.
2.Phase Mask Image - shows inverse
contrast behavior.
3.SWI data- is a combination of
magnitude and phase information.
4.Minimum intensity projections of
SWI(mIP SWI) with thickness of 3-
5mm.
In phase the blood is white and the calcium shows signal void

142. Susceptibility weighted imaging: SWI
and T2*gradient-echo hypointensities
:blooming
SWI mip Phase mask

143. Susceptibility weighted imaging: SWI and
T2*gradient-echo hypointensities :blooming
• 1. Amyloid angiopathy : cortical subcortical microbleeds and spontaneous lobar
cerebral haemorrhage.
• 2. Hypertensive angiopathy : basal ganglia, thalamus , pons.
• 3. Diffuse axonal injury: grey /white matter junction in the frontal and temporal lobes ;
corpus callosum and posterolateral brainstem.
• 4. Multiple cavernomas :subcortical and cerebellar .
• 5. Venous angiomas
• 6. CADASIL : subcortical lacunar infarcts ,white matter lesions + foci in centrum
semiovale, thalamus , basal ganglia and pons. SWI subcortical . External capsule and
anterior temporal pole in patient with migraine, dementia and family history.
• 7. Tumor : haemorrhage and calcifications ; SWI used both , before and after the
administration of contrast could differentiated the vessels than change their signal
intensity from the regions of inactive haemorrhage which do not change.
• 8. Metastasis : melanoma , choriocarcinoma , lung ,breast and renal cell ca.
• 9. Multiples sclerosis : due to iron deposition ; central vein detection ;could detect near
50%more lesions .
• 10. Cerebral vasculitis , meningitis .
• 11. Dermoid : intracranial fat

144. SWI: amyloid angiopathy
• 67 y/o F ; sudden onset difficulty walking , R hemiparkinsonism .

145. SWI: amyloid angiopathy
• 76 y/o M; memory problems ; MRI suspicious of multifocal glioma
3 months later

146. SWI: amyloid angiopathy
• 3 years later

147. SWI: amyloid angiopathy
• 13 months later: the lesions have resolved
Cerebral amyloid angiopathy related inflammation

148. SWI: amyloid angiopathy
• 65 F , transient global amnesia

149. SWI: hypertensive angiopathy
• 64 y/o M , reduced power right upper limb ,dysarthria. Pontine stroke .

150. SWI: trauma , contusion , diffuse axonal
injury, subarachnoid haemorrhage
• 73 y/o M, trauma , diplopia , nystagmus.

151. SWI : subarachnoid haemorrhage
• 81 y/o F ; right facial drop

152. SWI : multiple cavernous angiomas
• 12 y/o F; developmental delay, hypotonia , motor impairment, learning
disability .

153. SWI : multiple cavernous angiomas
• 69 y/o F ; right vocal cord palsy ; incidental finding of lesion at the base of the skull
.Multiple meningiomas and cavernous angiomas in neurofibromatosis type II

154. SWI : multiple cavernous angiomas
T2, t2+PD do not exhibit the classical “pop corn “ appearance. The cavernomas in
this case are well seen on SWI

155. Venous malformation
• 38 y/o M ; migraines .

156. SWI: CADASIL (Cerebral Autosomal –Dominant
Arteriopathy with Subcortical infarcts and
Leucoencephalopathy )
• 59 y/o M; progressive gait + cognitive disturbance.

157. SWI :tumour
• 85 y/o F ; road traffic accident ; confused, poor speech ; r/o subdural
• Too much people in this party : GBM

158. SWI :metastases
• Haemorrhagic intracranial metastases are considered to
represent between 3-14% of all cerebral metastases (c.f. 1-
3% of gliomas are haemorrhagic).
• Melanoma
• Choriocarcinoma
• Thyroid carcinoma: papillary carcinoma of the thyroid has
that highest rate .
• Renal cell carcinoma
• Lung carcinoma
• Breast carcinoma
• Hepatocellular carcinoma
• Mnemonic: MR CT BB
Dr. Maxime St-Amant and Prof. Frank Gaillard ; Radiopedia .

159. SWI :metastases
• 63 y/o previous resection met from RCC R frontal lobe; now seizure,
suspicious of recurrence.

160. Dermoid cyst
• 52 y/o F ; left migraine with aura ; clumsy , hearing loss.
• Ruptured dermoid cyst

161. Reporting Multiple Sclerosis

162. Reporting Multiple Sclerosis
• I recommend The Radiologist Assistant :
multiple sclerosis by Frederik Barkhof, Robin
Smithuis and Marieke Hazewinkel.
• Highly recommended : post contrast scan at 5
or 15 minutes post injection .

163. Reporting Multiple Sclerosis
• For dissemination in space (DIS) lesions in two out of four typical areas of the
CNS are required: periventricular; juxtacortical ; infratentorial ; spinal cord.
• For dissemination in time (DIT) there are two possibilities: A new T2 and
/or gadolinium-enhancing lesion (s0 on follow-up MRI , with reference to a
baseline scan , irrespective of the timing or simultaneous presence of
asymptomatic gadolinium enhancing and non enhancing lesions at any
time .

164. Reporting Multiple Sclerosis

165. Reporting Multiple Sclerosis
• Where are the lesions :
• 1.Juxtacortical : U fibers that touch the cortex
• 2.calloso-septal interphase : inferior surface of the
corpus callosum :cret –du-coq ; Dawson fingers : plaques
with perpendicular orientation at callososeptal
interphase along penetrating venules .
• 3. temporal lobe: juxtacortical or at the stem
• 4. brainstem , cerebellar peduncles and optic nerves .

166. Reporting Multiple Sclerosis
• Shape of the lesions:
• 1. ovoid
• 2. round
• 3. whorl , loop , coil : Balo’s concentric sclerosis
• 4. mass : tumefactive MS : open ring sign ; less oedema than
expected for the mass that we see.

167. Reporting Multiple Sclerosis
• Meaning :
• 1. low signal on T1W , low signal on FLAIR with
hyperintense halo , no enhancement : wet black holes,
permanent chronic demyelination ; axonal loss, matrix
destruction .
• 2. High signal on FLAIR: load lesion with demyelination .
• 3. Ring enhancement : old lesion or reactivation
• 4. Nodular enhancement : acute, recent lesion .

168. Reporting Multiple Sclerosis
Black holes

169. Reporting Multiple Sclerosis
TUMEFACTIVE DEMYELINATION
54 y/o male admitted with cognitive decline and left hemiparesis

170. Reporting Multiple Sclerosis
• 6 weeks post treatment with steroids and
plasma exchange

171. Reporting Multiple Sclerosis
• Interval scan :
• 1. new lesions : new focus , could be load lesion or acute
lesions .
• 2. enhancing to non enhancing lesions .
• 3. less conspicuous lesions / cleared lesions
• 4. acute lesion : contrast uptake
• 5. subacute lesions : early period , within 10 weeks and
reduce oedema ; late period: gliosis/re-myelination .
• 6. load lesion to wet lesions .
• 7. brain volume change 1% a year , in 10 year :
pseudoatrophy.

172. Hint reporting dementia
• Dementia: role of MRI updated version, The Radiologist Assistant by
Frederik Barkhof, Marieke Hazewinkel, Maja Binnewijzend and Robin
Smithuis Alzheimer Centre and Image Analysis Centre, Vrije Universiteit
Medical Center, Amsterdam and the Rijnland Hospital, Leiderdorp, The
Netherlands
• The Addenbrooke's Cognitive Examination-III (ACE-III) is a brief cognitive
test that assesses five cognitive domains: attention, memory, verbal
fluency, language and visuospatial abilities. ... The total score is 100 with
higher scores indicating better cognitive functioning.
• During the MMSE,Mini-Mental State examination , a health professional
asks a patient a series of questions designed to test a range of everyday
mental skills. The maximum MMSE score is 30 points. A score of 20 to 24
suggests mild dementia, 13 to 20 suggests moderate dementia, and less
than 12 indicates severe dementia.

173. Hint reporting dementia :type and
location .
• Alzheimer :hippocampus
• Fronto-temporal: (former Picks )more than parietal + genus of
corpus callosum .
• Lewy bodies: non-specific ; more white matter lesions than in
Alzheimer .
• Aphasia Progressive :severe anterior temporal atrophy .
• Posterior cortical atrophy (Benson’s syndrome): atrophy
parieto-occipital and posterior temporal B/L .
• Corticobasal degeneration : parasagittal frontoparietal, basal
ganglia , sustantia nigra and tegmentum .
• Vascular Cortical: ischaemic lesions corticosubcortical.

174. Hint reporting dementia :type and
location
• Vascular Subcortical :
- Binswanger, lacunar infarcts in the basal ganglia secondary to severe
hypertension ;
- leucoaraiose; white matter degeneration with progressive demyelination
secondary to small vessels disease.
- CADASIL ( Cerebral Autosomal Dominant Arteriopathy with Subcortical
Infarcts and Leucoencephalopathy ): lacunar infarcts in the basal ganglia and
brainstem + diffuse leucoaraiose predominant at the external capsule, anterior
insula and anterior temporal lobe; absent in the parietal and occipital lobes.
. Amyloid Angiopathy
. Infective encephalitis : Leucoencephalopathy Multifocal Progressive (LEMP),
virus JC; Creutzfeldt-Kakob .
. Toxic : Wernicke, lack of B1: periaqueductal high signal ; 3rd ventricle and
mammillary bodies.
.Korsakoff syndrome : ETOH; hippocampus-mammillary bodies-thalami with
severe atrophy of the mammillary bodies.

175. Hint reporting dementia :type and
location: Benson’s syndrome
• Posterior cortical atrophy

176. References .
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C. Lagana, L. Fernandez . Hypointensities in the brain on T2* weighted gradient echo MR Imaging : what radiologist
should know. Educational Exhibit. ECR 2014
Bruno Di Muzio and Prof Frank Gaillard et al. Primary CNS lymphoma .Radiopedia.Org.
Bernard Croisile. Benson’s syndrome or Posterior Cortical Atrophy .Orphanet Encyclopaedia. Sept.2004
Marion A. Hughes et al. MRI of the Trigeminal Nerve in Patients With Trigeminal Neuralgia Secondary to Vascular
Compression. AJR 2016: 206: 595-600
Mufudzi Mavike : neuro MRI: space occupying lesions . 7th MRI Study Day. Rapidology , Royal Free Hospital, London
October 11th 2014.
Jean-Louis Dietemann : ; Neuro-Imagerie diagnostique: Imagerie Medical Precis.Elsevier Masson 2007.
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