MULTIPLE SCLEROSIS, ITS VARIANTS, DD OTHER DEMYELINATING DISEASES

1. Demyelinating and
Inflammatory
Diseases
By: Dr. Shivam Batra

2. INTRODUCTION
• Demyelinating diseases comprise of diseases of central and peripheral nervous system in
which disruption of myelin is a dominant feature.
• Demyelinating diseases include autoimmune, infectious, toxic, metabolic, and vascular
processes; dysmyelinating diseases in which a primary abnormality of the formation of
myelin exists include several hereditary disorders

3. Parts of
Neuron
• Cell Body
– Contains the nucleus
• Dendrites
– Receptive regions; transmit impulse to cell
body
– Short, often highly branched
– May be modified to form receptors
• Axons
– Transmit impulses away from cell body
– Axon hillock; trigger zone
• Where action potentials first develop
– Presynaptic terminals (terminal boutons)
• Contain neurotransmitter substance (NT)
• Release of NT stimulates impulse in next
neuron
– Bundles of axons form nerves

5. Myelin and
White matter
• The gray matter primarily contains
neurons and their processes, the
white matter is composed
predominantly of myelinated bundles
of axons
• The oligodendroglial cell membrane is
the source of the myelin sheath,
which is a tightly wrapped,
multilayered membrane composed of
a repeating structure characterized by
lipid- cytoplasm-lipid-water and which
ensheathes axons.

6. • Neuroglial cells, namely oligodendrocytes, astrocytes, and
microglia, are primarily responsible for the maintenance
or “well- being” of the white matter- by providing
structural and nutritional support of neurons, regulating
the extracellular environment, and acting as scavenger
cells

7. Normal
Progression Of
Myelination
• Proximal pathways before
distal (e.g., brainstem before
supratentorial brain)
• Sensory (visual and auditory)
before motor
• Central white matter before
peripheral
• Posterior before anterior

9. Myelinated Regions at Birth (or Shortly AfterBirth)
• Dorsal brainstem
• Inferior, superior cerebellar peduncles
• Perirolandic region
• Corticospinal tract
• Central portion of centrum semiovale
• Posterior limb of internal capsule to cerebral peduncle
• Ventrolateral thalamus
• Optic nerve, chiasm, tract

10. Myelination And MR Findings
• The most commonly used marker for evaluating normal brain
maturation on conventional MR is the progression of myelination.
• Myelination starts in the second trimester of gestation and continues
into adulthood, beginning with the peripheral nervous system and then
the spinal cord, the brainstem, and finally the supratentorial brain.
• Myelination of the brain evolves in a predictable sequential
fashion over the first 2 postnatal years.

11. • As white matter becomes myelinated, it appears hyperintense on
T1-weighted and hypointense on T2-weighted images relative to
gray matter
• During the first 6 months of life, T1-weighted images are most useful
for evaluating the progression of myelination.
• After 6 months of age, most cerebral white matter appears high
in signal intensity on the T1-weighted images, beyond this time
the T2-weighted images are generally relied on to further
evaluate myelin progression .

12. • By 24 months of age, the process of myelination is
essentially complete except for the terminal zones
of myelination found in the occipital-parietal
periventricular white matter.
• These regions appear as subtle, ill-defined
areas of hyperintensity

13. Axial T1-weighted imagesof a 2-
week-old infant born at 34 weeks of
gestation.
Hyperintensity is seen around the
fourth ventricle due to myelination
present in the surrounding
structures: medulla (m in a), vermis
(v in a), inferior cerebellar peduncle
(arrow in a), and dorsal aspect of the
pons (arrow in b). Increased signal
intensity is noted in the posterior
limb of the internal capsule as well
(arrow in c). The unmyelinated
supratentonial white matter is
hypointense with respect to the gray
matter, better seen in d.

14. • Matching T1-
weighted, T2-
weighted, images
from three
patients ages 5
weeks (A,B), 8
months (D,E), and
3 years (G,H).

15. Multiple
Sclerosis
MS is a progressive neurodegenerative disorder
characterized histopathologically by multiple
inflammatory demyelinating foci called "plaques.“
Demographics: Onset typically occurs in young to
middle aged adults from 20-40 years of age.
Etiology: Autoimmune-Mediated Demyelination,
environmental factors: Epstein-Barr virus (EBV)
exposure, chemicals, smoking, diet, and geographic
variability all contribute to MS risk and genetics
(human leukocyte antigen (HLA-A) gene)

16. Location
Supratentorial (90%), infratentorial (10%)
(higher in children)
 Deep cerebral/periventricular white
matter
• Predilection for callososeptal interface
• Perivenular extension (Dawson fingers)
Size and Number
• Multiple > solitary
• Mostly small (5-10 mm)
Giant "tumefactive" plaques can be several
centimeters
• 30% of "tumefactive" MS lesions solitary

17. Presentation
• Varies with heterogeneous neurologic
manifestations, evolution, and
disability.
• Intermittent neurologic disturbances
followed by progressive accumulation
of disabilities.
• The first attack of MS (most commonly
optic neuritis, transverse myelitis, or a
brainstem syndrome) is known as a
clinically isolated syndrome

18. Clinical MS Subtypes
• Radiologically isolated syndrome (RIS)
• Clinically isolated syndrome (CIS),
• Relapsing-remitting MS (RR-MS),
• Relapsing progressive MS (RP-MS),
• secondary-progressive MS (SP-MS),
• and primary-progressive MS (PP-MS).

19. Radiologically
isolated
syndrome
• RIS is a new subtype
• RIS refers to MR findings Of spatial
dissemination of T2/FLAIR lesions
suggestive of MS in persons with no
history of neurologic symptoms and
with a normal neurologic examination.

20. Clinically
Isolated
Syndrome.
• CIS refers to a first episode of
neurologic symptoms that (1) lasts at
least 24 hours and (2) is caused by
inflammation or demyelination in the
CNS.
• CIS can be monofocal or multifocal.
• In monofocal CIS, a single neurologic
sign or symptom (e.g., optic neuritis) is
caused by a single lesion.
• Multifocal CIS is characterized by more
than one sign or symptom (e.g., an
attack of optic neuritis accompanied by
extremity paresthesias) caused by
lesions in more than one location.

21. Relapsing-Progressive
MS
• Attacks ("relapses“ or
"exacerbations") are followed by
periods of partial or complete
recovery. New MR lesions often
occur as part of a relapse but
may also occur without
symptoms.
• RP-MS is also known as
secondary progressive MS. In
RP-MS, there is progressive
worsening of neurologic function
(accumulation of disability) over
time
Relapsing-Remitting
MS

22. Primary-
Progressive MS
• PP-MS is characterized by
worsening neurologic
function from the outset and
lacks periods of remission.
Approximately 5-10% of
patients have PP-MS.

23. Indications for MRI of the brain are:
• Clinically isolated syndrome suggestive of MS to prove
dissemination in time or space in order to fulfill the McDonald
criteria
• Patients with MS to determine the prognosis or response to therapy
• To specify an atypical lesion in the spinal cord
• To screen for opportunistic infections in patients receiving
immunosuppressive treatment (for example development of
Progressive Multifocal Leukoencephalopthy in patients using
natalizumab).

25. Imaging
• MS has a typical distribution of
WMLs.
This can be very helpful in
differentiating them from vascular
lesions

26. MR Findings
• According to the McDonald criteria for MS, the diagnosis
requires objective evidence of lesions disseminated in time and
space i.e. MRI shows multiple lesions (dissemination in space),
some of which can be clinically occult, and MRI can show new
lesions on follow up scans (dissemination in time).

27. T1WI
• Most MS plaques are hypo- or isointense.
• The hypointensity ("black holes") correlates
with axonal destruction.
• Faint, poorly delineated peripheral rim of mild
hyperintensity secondary to lipid peroxidation
and macrophage infiltration surrounds sharply
delineated hypointense "black holes." This
gives a characteristic "beveled" or "lesion-
within-a-lesion" appearance
• Chronic and severe cases typically show
moderate volume loss and generalized atrophy.
The corpus callosum becomes progressively
thinner

29. T2/ FLAIR
• Shows multiple hyperintense linear, round, or ovoid
lesions surrounding the medullary veins that radiate
centripetally away from the lateral ventricles i.e.
DAWSON FINGERS

31. • MS plaques often assume a distinct triangular shape with the base
adjacent to the ventricle on sagittal FLAIR or T2WI images. One of the
earliest findings is alternating areas of linear hyperintensity along the
ependyma on sagittal FLAIR, known as the "ependymal 'dot-dash'"
sign

33. • Larger lesions often demonstrate
a very hyperintense center
surrounded by a slightly less
hyperintense peripheral area and
variable amounts of perilesional
edema.
• Cortical demyelinating lesions are
common and present in early MS
and may even precede the
appearance of classic white
matter plaques in some patients!

34. In MS
• The image on the right is an
axial T2 weighted image of the
brainstem of an MS-patient,
showing typical peripherally
located white matter lesions,
often in or near the trigeminal
tract, or bordering the 4th
ventricle.

35. Confusion arises
• The image on the left is an axial
T2 weighted image illustrating
typical vascular brainstem
involvement, with a central
involvement of the transverse
pontine fibers

36. • The lesions in the deep white matter (yellow
arrow) are nonspecific and can be seen in
many diseases.
Typical for MS in this case is:
• Involvement of the temporal lobe (red arrow)
• Juxtacortical lesions (green arrow) - touching
the cortex
• Involvement of the corpus callosum (blue
arrow)
• Periventricular lesions - touching the ventricles

37. • In small vessel disease these
juxtacortical U-fibers are not involved
and on T2 and FLAIR there will be a
dark band between the WML and the
(also bright) cortex (yellow arrow).
• Juxta cortical lesions are specific
for MS.
These are adjacent to the cortex
and must touch the cortex.

38. T1C+
•MS plaques demonstrate
transient enhancement
during active
demyelination. Punctate,
nodular, linear, and rim
patterns are seen

42. • A prominent incomplete rim ("horseshoe") of enhancement with the
"open" nonenhancing segment facing the cortex can be present,
especially in large "tumefactive" lesions.
• Enhancement disappears within 6 months in more than 90% of
lesions. Steroid administration significantly reduces lesion
enhancement and conspicuity and may render some lesions virtually
invisible.

46. Enhancement is typical finding in MS.
• This enhancement will be present for about one month after the
occurrence of a lesion.
• The simultaneous demonstration of enhancing and non-enhancing
lesions in MS is the radiological counterpart of the clinical
dissemination in time and space.
• The edema will regress and finally only the center will remain as a
hyperintense lesion on T2WI.

47. Patient being re-examined 3
months after the first clinical
attack
• Multiple enhancing lesions
• Many of these lesions 'touch
the cortex' and must be
located in the U-fibers.
• These enhancing lesions all
are new lesions, since
Gadolinium enhancement is
only visible for about 1
month.
• So this finding is proof of
dissemination in time.

48. The patient on the left had a
follow-up examination 3 months
after the first clinical event.
• New lesions on T2W images
also indicate dissemination
in time.
• Notice how similar the
positioning is.
This allows good comparison
of the images.
Optimal positioning is
discussed in the MRI
protocol (see later).

49. MS in Spinal
Cord
• There are multiple lesions in the spinal
cord. This is another typical feature of
MS.
• Typical spinal cord lesions in MS are
relatively small and peripherally
located.
• They are most often found in the
cervical cord and are usually less than 2
vertebral segments in length.

51. Mc Donald’s
Criteria

52. An Attack is:
• Neurological disturbance of kind seen in MS
• Subjective report or objective observation
• At least 24 hours duration in absence of fever or infection
• Excludes pseudoattacks, single paroxysmal symptoms (multiple episodes of paroxysmal
symptoms occurring over 24 hours or more are acceptable as evidence)
• Some historical events with symptoms and pattern typical for MS can provide reasonable
evidence of previous demyelinating events, even in the absence of objective findings
Time Between Attacks:
• 30 days between onset of event 1 and onset of event 2
Positive CSF is:
• Oligoclonal IgG bands in CSF (and not serum) or elevated IgG index

54. The diagnosis is either:
MS : all
criteria
fulfilled
possible MS :
not all criteria
fulfilled
not MS : no
criteria
fulfilled

55. Differential Diagnosis
ADEM
• This is a monophasic, immune-mediated demyelinating disease which
often presents in children following an infection or vaccination.
• On MRI there are often diffuse and relatively symmetrical lesions in
the supra-and infratentorial white matter which may enhance
simultaneously.
• There almost always is preferential involvement of the cortical gray
matter and the deep gray matter of the basal ganglia and thalami.

56. Notice the extensive
involvement of the
cortical and gray
matter, including
thalamus.

57. Notice the involvement of the basal ganglia.

59. Others
• Vasculitis: often preferentially involves the basal ganglia
and spares the callososeptal interface.
• Lyme disease (LD): can appear identical to MS. Cranial
nerve enhancement is more common in LD than in MS.
• Susac syndrome: is often mistaken for MS on imaging
studies, as both have multifocal T2/FLAIR white matter
hyperintensities and both commonly affect young adult
women. Lesions in Susac syndrome preferentially involve
the middle of the corpus callosum, not the callososeptal
interface.
• "Tumefactive" MS: can mimic abscess or neoplasm
(glioblastoma multiforme or metastasis).
• Progressive multifocal leukoencephalopathy (PML) and
immune reconstitution inflammatory syndrome (PML-
IRIS) occur in a few MS patients treated with natalizumab.

60. Multiple Sclerosis Variants
Major MS variants are:
1. Marburg disease (acute, severe, fulminant MS)
(MD),
2. Schilder disease (SD),
3. Balo concentric sclerosis (BCS).

61. Marburg Disease
Clinical Issues:
• Rare acute fulminate MS variant
○ Rapid neurologic deterioration
○ Monophasic, relentless progression
○ Death usually within 1 year
• Usually young adults

62. Pathology
• Multifocal > solitary disease
○ Characterized by coalescent white matter plaques
○ Brain (including posterior fossa), spinal cord lesions
• Lesions characterized by massive inflammation, necrosis

63. Imaging
• Multifocal diffusely disseminated disease with focal and
confluent white matter hyperintensities on T2/FLAIR.
• Strong patchy enhancement on T1 C+ is typical, and large,
cavitating, incomplete, ring-enhancing, "tumefactive"
lesions are common

66. Schilder
disease
• Myelinoclastic diffuse sclerosis
○ Rare acute/subacute demyelinating disorder
○ Lesions may resolve; 15% progress to MS
• Young adults
○ Mean age at onset = 18 years
• Clinical features atypical for MS, ADEM
○ CSF normal
○ No history of fever, flu, vaccination
• Solitary > multifocal lesions
• Lesions look like "tumefactive" MS
• Differential diagnosis: neoplasm, abscess

67. Balo Concentric Sclerosis
• Occurs as a discrete, concentrically layered white matter lesion.
• It is often described as having an "onion ring" or "whorled"
appearance.
• i.e. there are alternative bands of demyelination and myelin
preservation, often in whorl-like configurations.

68. Imaging
• Acute lesions have significant surrounding edema.
• Two or more alternating bands of differing signal intensities are seen on T2WI
and resemble a "whirlpool" of concentric rings.
• The actively demyelinating layers enhance on T1 C+ sequences.
• Subacute or chronic BCS shows two or more alternating bands of iso- and
hypointensity on T1WI. The concentric layers appear iso- and hyperintense on
T2WI.

70. Postinfection and
Postimmunization Demyelination
• Acute disseminated encephalomyelitis (ADEM)
• Acute hemorrhagic leukoencephalopathy (AHLE)
• Acute necrotizing encephalopathy (ANE)- serious,
potentially life-threatening type of acute
encephalopathy in children

71. Acute Disseminated Encephalomyelitis (ADEM)
• ADEM is a postinfection, postimmunization disorder.
• It is an immunemediated CNS demyelinating disorder as, it is
precipitated by myelin antibodies.
• More common in childhood, with peak occurrence between 5
and 8 years of age

72. Pathology
Location:
• As the name implies, ADEM can involve both the brain and spinal cord.
• White matter lesions usually predominate, but basal ganglia involvement is seen in nearly half
of all cases.
Size and Number:
• Lesion size varies from a few millimeters to several centimeters ("tumefactive" ADEM), and
• Lesions have a punctate to flocculent configuration.
• Multiple lesions are more common than solitary lesions.

73. Imaging
• Multifocal T2/FLAIR hyperintensities
○ Bilateral but asymmetric white matter lesions
○ Most lesions small, round/ovoid
○ Hazy flocculent "cotton balls" (> 2 cm, usually in children) with “fuzzy” margins
○ ± Basal ganglia, posterior fossa, cranial nerves
• Enhancement varies from none to striking
○ Multifocal punctate, linear, partial ring
○ Can be perivenular
○ Large lesions ("tumefactive") less common

78. Acute Hemorrhagic Leukoencephalitis
• AHLE is also known as acute hemorrhagic leukoencephalopathy,
acute hemorrhagic encephalomyelitis (AHEM), and Weston Hurst
disease.
• It is a fulminant demyelinating disease of unknown etiology.
• May represent fulminant form of ADEM.

79. Pathology
Location:
• Predominantly affects the white matter (basal gamglia most commonly).
• Both the cerebral hemispheres and posterior fossa structures are affected.
• May affect the gray matter.
Size and Number: AHLE has two distinct manifestations:
• Focal macroscopic parenchymal hemorrhages
• Innumerable petechial microbleeds.

80. Imaging
General imaging:
• White matter edema
• Focal macroscopic hemorrhages or multifocal microbleeds
MRI:
• T1 scans are often normal.
• Multifocal scattered or confluent lesions on T2/FLAIR
• Corpus callosum, cerebral white matter, pons, cerebellum ± basal ganglia
• Cortical gray matter generally spared
• T2* (GRE, SWI) depicts microbleeds
• 50% show variable enhancement

83. Differential Diagnosis
• The major differential diagnosis is ADEM.
• Others include: fulminant MS, acute necrotizing encephalopathy
(ANE), and macrophage activation syndrome.
• ANE is most common in young children, is often associated with
influenza, and results from a para- or postinfectious "cytokine
storm."

84. Inflammatory- like
disorders

85. Neurosarcoidosis
• The CNS is involved in approximately 5% of cases.
• The hypothalamus and infundibulum are favored intracranial sites.
• It can involve cranial nerves, eye and periorbita, bone, the ventricles
and choroid plexus, and the brain parenchyma itself.
• Both supra- and infratentorial compartments are affected.
• The most common location is the leptomeninges, especially around
the base of the brain.

86. • Size and Number: NS lesions
vary in size from tiny
granulomas that infiltrate along
the pia and perivascular spaces
to large dura-based masses that
closely resemble meningiomas.
• Multiple lesions are more
common than solitary lesions.

87. Imaging
Most Common
• Linear/nodular leptomeningeal enhancement
○ Predilection for basilar cisterns
• Parenchymal enhancing lesions
○ Thick enhancing hypothalamus/pituitary stalk, gland
○ Perivascular infiltrating or mass-like lesions
• Cranial nerve enhancement (CN VII, CN II most common)

89. Less Common
• Solitary or multiple dura-
based masses
○ Diffuse/plaque-like or
focal mass
• Diffuse/focal non
enhancing T2/FLAIR
hyperintensities
Rare But Important
• "Tumefactive"
parenchymal masses
• Choroid plexus mass(es)

91. Differential Diagnosis
• The differential diagnosis of NS depends on lesion location.
• Meningitis (TB meningitis)—can look very similar to NS of the
basilar leptomeninges.
• For dura-based NS; DD includes meningioma, lymphoma, and
intracranial inflammatory pseudotumor (IIP)
• Hypothalamic/infundibular/pituitary NS may look like histiocytosis
or lymphocytic hypophysitis.

92. Neuromyelitis Optica Spectrum
Disorder
• Neuromyelitis optica spectrum disorder (NMO)—formerly known as Devic syndrome—is a
severe form of acute demyelinating disease that preferentially involves the spinal cord and
optic nerves with relative sparing of the cerebral white matter.

93. Pathology
Location:
• In classic NMOSD, one or both optic
nerves are involved together with the
spinal cord.
• The cervical cord is most commonly
affected, and lesions typically extend
over three or more consecutive
segments.
• Brain lesions cluster around the third
and fourth ventricles and the dorsal
midbrain/aqueduct of Sylvius.

95. Imaging
• The most common MR findings are:
(1) a hyperintense, enhancing cord lesion that extends over three or
more contiguous vertebral segments and swelling of the cord.
(2) optic nerve hyperintensity and/or enhancement

98. • Dorsal medulla and
periependymal posterior fossa
lesions are characteristic
findings in NMOSD with area
postrema syndrome and acute
brainstem syndrome,
respectively.

101. Differential diagnosis
• The major differential diagnosis of NMOSD is MS. The brain is
more involved in MS, whereas multisegmental contiguous spinal
cord disease is typical of NMOSD.
• Also,this is unlike MS, in which the lesions are usually smaller
and peripherally located

102. Intracranial Inflammatory Pseudotumors
• Aka idiopathic hypertrophic pachymeningopathy, plasma cell
granulomas, and inflammatory myofibroblastic tumors.
• It encompasses a spectrum of infectious, reactive, and reparative
processes.
• It can affect any part of the CNS but are typically meninges based
lesions that can be isolated or locally invasive.

103. • A common imaging finding is thickened dura along the
posterior falx and tentorium that is T2 hypointense and
exhibits strong enhancement around a central non
enhancing area
• This appearance is known as the "Eiffel by night" sign.

108. Imaging
• Focal mass-like dura-arachnoid thickening is the typical imaging.
• They are typically isointense on T1WI, hypointense on T2WI, and
enhance strongly and homogeneously on T1 C+ FS sequences
• Approximately 10% of intracranial IIPs invade the adjacent brain.

109. Chronic Inflammatory Demyelinating
Polyneuropathy
• A rare type of localized autoimmune demyelinating disease.
• Is characterized by repeated episodes of demyelination and
remyelination with "onion bulb“ hypertrophy of the affected
nerves.
• CIDP usually affects spinal and peripheral nerve roots but
occasionally involves cranial nerves.

110. Imaging
• Diffuse thickening with hyperintensity on T2/STIR and mild to
moderate enhancement of one or more cranial nerves are the
typical findings.

113. Aging of
Myelination

114. At Birth
T1WI T2WI

115. • Sagittal T1-weighted image
demonstrating high-signal
myelin within the dorsal
medulla, pons, and midbrain.
Compare with the
unmyelinated low-signal white
matter in the ventral pons and
hemispheric white matter

116. • Coronal T1-weighted three-
dimensional gradient echo
image demonstrates high signal
myelin in the posterior limbs of
the bilateral internal capsules
and the superior cerebellar
peduncles.

117. • Axial T2-weighted fast spin
echo inversion recovery image
demonstrating low signal
myelin in the bilateral ventral
lateral thalami.

118. • Axial T2-weighted fluid
attenuation inversion recovery
image demonstrates patchy
low signal in the deep frontal
and parietal white matter due
to high water content with
signal suppression.

119. At 2- 3 Months of age
T1WI T2WI

120. • Axial T1-weighted image
demonstrates prominent high-
signal myelination of the
posterior limbs of the internal
capsules and early myelination
within the anterior limbs.

121. • Axial T2-weighted fluid
attenuation inversion recovery
image shows uniform high
signal throughout the deep
hemispheric white matter. The
low-signal regions
characteristic of the newborn
have resolved by this age.

122. • Axial T2-weighted fast spin
echo inversion recovery (FSE-
IR) image demonstrating low-
signal myelin within the
posterior limbs of the internal
capsules, the anterior thalami,
and to a lesser extent, the
bilateral optic radiations.

123. At 4- 6 months of age
T1WI T2WI

124. • Sagittal T1-weighted fluid
attenuation inversion recovery
(FLAIR) image demonstrates
high-signal myelin throughout
the entire corpus callosum.

125. • Axial T2-weighted FLAIR image
showing low signal in the
posterior limbs of the internal
capsules and optic radiations
(arrows).

126. • Axial T2-weighted fast spin
echo (FSE) image confirms
complete myelination of the
ventral pons.

127. • Axial T2-weighted FSE image
demonstrating low-signal
myelin in the splenium of the
corpus callosum and the
posterior limbs of the internal
capsules.

128. The entire posterior fossa white matter is T2 hypointense by 18
months.
Within the posterior fossa, the ventral pons demonstrates T2
hypointense myelin by 6 months and the deep cerebellar white
matter becomes hypointense by 12 months.
Concurrent with these callosal signal changes, the anterior limb of
the internal capsule achieves T2 hypointensity by 8 months.
The genu of the corpus callosum will not demonstrate T2
hypointensity until 8 months.

129. By 8- 12 months of age
T1WI (8 months) T2WI (8 months)
T1WI (12 months) T2WI (12 months)

130. 12-month-old boy
• Coronal T1-weighted three-
dimensional gradient echo
image demonstrates an adult
pattern of myelination with
high-signal myelin extending
into the subcortical U-fibers of
the frontal and temporal lobes
as well as throughout the
cerebellum.

131. • Axial T2-weighted fluid
attenuation inversion recovery
image shows early low-signal
myelin in the deep white
matter of the anteromedial
occipital lobes best seen on the
right (arrow).

132. • Axial T2-weighted FSE-IR image
at a more superior level
demonstrating early
hypointense myelination of the
occipital subcortical U-fibers.
• There is low-signal myelin in the
deep temporal white matter;
however, the subcortical white
matter of the temporal lobes
demonstrates persistent high
signal.

133. At 18 months of age
T1 WI T2 WI T2 FLAIR

134. An 18-month-old girl
• Axial T2-weighted fluid
attenuation inversion recovery
(FLAIR) image shows early low-
signal myelin in the subcortical
white matter of the occipital
lobes (arrows).

135. • Axial T2-weighted fast spin
echo inversion recovery (FSE-
IR) image demonstrates
prominent subcortical white
matter myelination posteriorly
and significantly less
subcortical myelination in the
frontal lobes.

136. A 28-month-old boy
• Axial T2- (FLAIR) image
demonstrating near complete low
signal white matter myelination
with the exception of the anterior
temporal poles. Persistent high
signal in the occipital lobes
adjacent to the occipital horns of
the lateral ventricles represents a
normal FLAIR variant.

137. • Axial T2-weighted FLAIR image
confirms complete low-signal
myelination of the frontal and
parietal lobes with terminal
zones of high signal in the
periatrial regions as a normal
variant.

138. Axial fast spin echo T2-weighted images demonstrate complete low-signal
myelination throughout the brain

139. THANK YOU