This document provides descriptions and images related to various neuroimaging signs seen in neuroradiology. It discusses signs seen in conditions such as multiple sclerosis, CADASIL, ischemic and hemorrhagic strokes, infections like abscesses, tumors, and other pathologies. Specific signs described include the boomerang sign, butterfly medulla sign, onion rings sign, trident sign, and others. Imaging features of various diseases and abnormalities are also outlined.
27. zARTERY OF PERCHERON INFARCT
Rare vascular variant, in which a single common trunk arises from one of the PCAs to
supply both thalami and the midbrain.
40. z
• Young age.
• Temporal lobe
affected.
CADASIL
Cerebral AD arteriopathy with
subcortical infarctions and
leukoencephalopathy.
• Old age
• Temporal lobe
NOT affected.
SAE
Subcortical arteriosclerotic
encephalopathy
41. z Tigroid pattern
• Spares subcortical U fibers.
• Low T2 thalamus.MLD
Metachromatic
leukodystrophy
• Early involvement of the subcortical
U fibers.
• Typically involve posterior limb of
internal capsule.
PMD
Pelizaeus merzbacher
disease .
55. z3- Multiple small white matter lesions
Ischemia
(sparing posterior fossa and
relatively temporal lobe).
CADASIL (involve temporal
lobes)
56. z
Viral encephalitis.
Both GM and WM affection.
Neurosarcoidosis.
Multiple enhancing lesions
Multiple small white matter lesions
57. zMultiple small white matter lesions
Vasculitis (SLE and PAN )
Normal MRAThe presence of microbleeds may help the diagnosis
(tiny hypointense dot / red arrow).
58. zEvans' index
Ratio of maximum width of the frontal horns
of the lateral ventricles and maximal
internal diameter of skull at the same level.
Ratio greater than or equal to 0.3 defines
ventriculomegaly.
Helpful in the diagnosis of normal
pressure hydrocephalus.
63. zPeripheral lesions at GM / WM
interface = Systemic origin lesions.
Gm/Wm junction -------- Regions of high blood flow
Septic emboli Metastasis
64. z
Causes:-
- Central venous
catheters.
- Thrombophlebitis.
- Endocarditis.
- IV drug users.
- Immunocompromised
patients. Petechial hemorrhages in SWI
Septic emboli
65. z
Septic emboli
Diffusion restriction and high FLAIR signal with relatively little vasogenic edema.
Neoplasms generally incite significant vasogenic edema and lack central restricted diffusion,
which suggests an infectious process in this case.
66. z
Phase-contrast cine image shows active CSF pulsation through the aqueduct (arrows).
Normal flow in CSF flowmetry
68. z Aqueductal stenosis post ETV (endoscopic third
ventriculostomy).
Phase contrast magnitude (b) and directional (c) Cine flow images showing fenestration in the anterior
third ventricle (Arrows).
75. z MSUD
Sites:-
o Peri-rolandic cerebral white matter
o Corticospinal tracts.
o Posterior limb of the internal
capsule, thalami, globe pallidi,
o Dorsal brainstem.
o Cerebral peduncles.
76. z MPS (Hurler’s disease)
o Macrocephaly.
o Foramen magnum stenosis.
o Dilated perivascular spaces.
(Swiss cheese sign / cribriform pattern)
77. z
Normal myelination at birth
Normally in newborn babies, there are
areas of high T1 and low T2 signal
located at :-
o The posterior half of the posterior
limb of the internal capsule
(pyramidal tract)
o The ventral posterolateral nucleus of
the thalamus.
78. z Hypoxic ischemic encephalopathy
Loss of the normal low T2 signal in PLIC
(Blue arrows)
Atrophy of the brain occurred after one
month.
79. z
Diffuse Excessive High Signal Intensity
(DEHSI)
Bilateral white matter
exaggerated T2 hyperintensities
due to mild hypoxic event.
’’ Red areas’’
80. z
BESS
o Normal in 2-7 months of age due
discrepancy in size between
skull and brain.
o Rapid head growth or frank
macrocrania.
o Neurologically normal.
Bridging veins ‘’ arrows’’
90. z
Embryonal Tumors of the CNS in pediatrics
Medulloblastoma
Most common CNS
embryonal
Tumor.
AT/RT (Atypical
teratoid rhabdoid tumor)
- Less common.
- Young (< 4y)
- Aggressive tumor ( Hge,
or cystic/necrotic
changes), Internal
calcifications.
CNS PNET /
embryonal tumor with
multilayered rosettes
(ETMR).
- Less common.
- Young (< 4y)
- Aggressive tumor
91. z
Embryonal Tumors of the CNS in pediatrics
Medulloblastoma
Most common CNS
embryonal
Tumor.
AT/RT (Atypical
teratoid rhabdoid tumor)
- Less common.
- Young (< 4y)
- Aggressive tumor ( Hge,
or cystic/necrotic
changes), Internal
calcifications.
CNS PNET /
embryonal tumor with
multilayered rosettes
(ETMR).
- Less common.
- Young (< 4y)
- Aggressive tumor