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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6009_Библиотеки_им_академика_М_И_Перельмана.pdf
Astrocytoma
KEY FACTS
TERMINOLOGY
• Primary neoplasm of astrocytic origin within spinal cord
IMAGING
• Fusiform expansion of cord with enhancing component of
variable morphology
○ Almost always enhances
• Cervical > thoracic
• Usually ≤ 4 segments
○ Occasionally multisegmental, even holocord (more
common with pilocytic astrocytoma)
• ± cyst/syrinx (fluid slightly T1 hyperintense to CSF)
• Hyperintense on proton density and T2WI MR
Neoplasms, Cysts, and Other Masses
TOP DIFFERENTIAL DIAGNOSES
• Ependymoma
• Hemangioblastoma
• Metastasis
• Syringohydromyelia
(Left) Sagittal graphic of
cervical spine astrocytoma
shows a fusiform solid mass
ſt with a rostral cystic cord
component . (Right)
Sagittal T1WI C+ MR reveals a
heterogeneously enhancing
cervical cord mass ſt. The
tumor subtype and
histological grade are the
most important prognostic
factors. Malignant
transformation, while
common in recurrent adult
low-grade gliomas, is unusual
in pediatric low-grade
intramedullary spinal cord
tumors.
• Autoimmune or inflammatory myelitis
PATHOLOGY
• 80-90% low grade
• 10-15% high grade
CLINICAL ISSUES
• Slow onset of myelopathy
• May cause painful scoliosis
• Most are slow growing
○ Malignant tumors may cause rapid neurologic
deterioration
• Most common intramedullary tumor in children and young
adults
• Overall, ependymomas > astrocytomas (2:1)
DIAGNOSTIC CHECKLIST
• Myelopathy should be evaluated with MR
290
(Left) Sagittal T2WI MR (left)
illustrates an anaplastic
astrocytoma of the thoracic
cord with a long segment of
cord expansion and
hyperintensity ſt. Sagittal
T1WI C+ FS MR (right) reveals
minimal enhancement of
the lesion. (Right) Sagittal
T1WI C+ MR depicts a large
enhancing mass in the thoracic
cord with long segment
fusiform expansion ſt.
Differential diagnoses include
astrocytoma vs. ependymoma.
Pathology revealed
glioblastoma multiforme.
High-grade astrocytomas
account for ~ 10% of cases.
Astrocytoma
IMAGING
General Features
• Best diagnostic clue
○ Enhancing infiltrating mass expanding spinal cord (SC)
• Location
○ Cervical > thoracic
• Size
○ Usually ≤ 4 segments
○ May be extensive, especially with pilocytic histology
• Morphology
○ Fusiform spinal expansion with enhancing component of
variable morphology
○ Occasionally asymmetric, even exophytic
– Eccentric > central growth pattern
Radiographic Findings
• Radiography
○ ± scoliosis
○ ± expansion of osseous canal
CT Findings
• NECT
○ Enlarged SC
○ ± expansion, remodeling of osseous canal
• CECT
○ Mild/moderate enhancement
MR Findings
• T1WI
○ Cord expansion
– Usually < 4 segments; occasionally multisegmental,
even holocord (more common with pilocytic
astrocytoma)
○ ± cyst/syrinx (fluid slightly hyperintense to CSF)
○ Solid portion hypo-/isointense [minority of cases may
have areas of hyperintensity (methemoglobin)]
• T2WI
○ Hyperintense
• T2* GRE
○ Hyperintense; minority of cases may have hypointense
areas if hemorrhagic products
• DWI
○ ↓ fractional anisotropy, ↑ ADC
• T1WI C+
○ Usually enhance (partial > total)
○ Mild/moderate > intense enhancement
○ Heterogeneous/infiltrating > homogeneous/sharply
delineated
Imaging Recommendations
• Best imaging tool
○ Contrast-enhanced multiplanar MR
• Protocol advice
○ Sagittal and axial T2WI and T1WI C+ MR
DIFFERENTIAL DIAGNOSIS
Ependymoma
• Intense, sharply delineated enhancement
• Central > eccentric growth pattern
• More often seen in low thoracic cord
Neoplasms, Cysts, and Other Masses
Other Neoplasms
• Ganglioglioma
○ Mixed T1 signal intensity due to solid, cystic components
○ Homogeneous > heterogeneous T2 hyperintensity
• Lymphoma
○ Intramedullary form presents as poorly defined,
enhancing lesion
• Metastasis
○ Intramedullary nidus of enhancement much more focal
with extensive edema
○ Pial metastasis can simulate hemangioblastoma
• Hemangioblastoma
○ Focal, enhancing pial/subpial nodule
○ Associated syrinx simulates astrocytoma
Syringohydromyelia
• Cyst fluid similar to CSF; no enhancement
Autoimmune or Inflammatory Myelitis
• Demyelinating disease (± patchy, ill-defined enhancement if
acute)
○ Multiple sclerosis
○ Transverse myelitis
○ Infectious myelitis
– Viral myelitis, granulomatous osteomyelitis, bacterial
meningitis
• Spinal cord infarction
○ Abrupt onset
○ Risk factors: Atherosclerosis, hypertension, diabetes
○ Clinical setting: Aortic dissection, abdominal aortic
aneurysm, or surgery
• Dural vascular malformation
○ Typically, cord shows mild edema and enlargement
○ Prominent pial vessels
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Slow onset of myelopathy
• Other signs/symptoms
○ Painful scoliosis; radiculopathy; sensory or motor deficits;
incontinence
Treatment
• Serial monitoring for asymptomatic individuals; resection
reserved for progressive neurologic decline
• Microsurgical resection (low-grade tumors)
• Adjuvant therapy
○ Option for WHO grades III-IV astrocytomas; no evidence
that radiation therapy and chemotherapy improve longterm outcome
DIAGNOSTIC CHECKLIST
Consider
• Myelopathy should be evaluated with MR
Image Interpretation Pearls
• Axial and sagittal T1WI enhanced fat-saturated MR to
exclude dural or pial lesion inciting syringomyelia
291
Cellular Ependymoma
KEY FACTS
TERMINOLOGY
• Neoplasm arising from ependyma lining spinal cord central
canal
IMAGING
• Circumscribed, enhancing hemorrhagic cord mass with
surrounding edema
• Associated cysts common
• Cervical > thoracic > conus
• T1WI: Isointense or slightly hypointense to spinal cord
• T2WI: Hyperintense relative to spinal cord
• Cap sign: Hemosiderin at cranial or caudal margin
• Most tumors enhance
Neoplasms, Cysts, and Other Masses
• Peripheral enhancement of tumoral cysts
TOP DIFFERENTIAL DIAGNOSES
• Astrocytoma
• Hemangioblastoma
• Demyelinating disease
(Left) Coronal graphic depicts
an intramedullary
ependymoma mildly
expanding the cervical cord.
Cranial and rostral cysts, as
well as hemorrhagic products,
are associated with this mass.
(Right) Sagittal T1WI C+ MR
demonstrates a cervical
intramedullary mass with solid
and cystic components causing
fusiform cord expansion. There
are 2 areas of enhancing solid
components ſt and a rostral
cyst extending cephalad
into the brainstem. The
adjacent solid portion shows
little enhancement .
• Idiopathic transverse myelitis
PATHOLOGY
• Arises from ependymal cells of central cord canal
○ Most intramedullary
○ Rarely can be intradural extramedullary
• Most WHO grade II
• Rarely WHO grade III
○ Anaplastic ependymoma
• Association with neurofibromatosis type 2
CLINICAL ISSUES
• Most common presentation
○ Neck or back pain
• Other presentations
○ Progressive paraparesis, paresthesias
DIAGNOSTIC CHECKLIST
• Spinal cord neoplasm with associated peripheral
hemorrhage suggestive of cellular ependymoma
292
(Left) Axial T1WI C+ MR
reveals an expansile
intramedullary ependymoma
ſt with robust enhancement
pattern. (Right) Sagittal T2WI
MR illustrates the mixed cystic
and solid appearance of
cervical ependymomas ſt in a
patient with
neurofibromatosis type 2. In
addition, there is a duralbased intradural
extramedullary meningioma
st.
Cellular Ependymoma
TERMINOLOGY
Synonyms
• Spinal ependymoma
Definitions
• Neoplasm arising from ependyma lining spinal cord central
canal
IMAGING
General Features
• Best diagnostic clue
○ Circumscribed, enhancing hemorrhagic cord mass
• Location
○ Cervical > thoracic > conus
• Size
○ Multisegmental: Typically 3-4 segments
• Morphology
○ Symmetric cord expansion
○ Well circumscribed
○ ± exophytic component
MR Findings
• T1WI
○ Isointense or slightly hypointense to spinal cord
○ Hemorrhage hyperintense
• T2WI
○ Hyperintense relative to spinal cord
○ Focal hypointensity: Hemosiderin
– Cap sign: Hemosiderin at cranial or caudal margin
○ Surrounding cord edema
• T2* GRE
○ Hypointensity (hemorrhage)
• T1WI C+
○ Tumor enhancement patterns
– Intense, well-delineated homogeneous enhancement
(50%)
– Nodular, peripheral, or heterogeneous enhancement
– Minimal or no enhancement (rare)
Imaging Recommendations
• Protocol advice
○ Sagittal, axial T2WI and T1WI MR ± gadolinium
DIFFERENTIAL DIAGNOSIS
Astrocytoma
• May be indistinguishable from ependymoma
○ Often longer, ± holocord
○ More often eccentric, infiltrative with indistinct margins
• Hemorrhage uncommon
Hemangioblastoma
• Cyst with enhancing highly vascular nodule
○ Flow voids often prominent
• Extensive surrounding edema relative to tumor size
• 1/3 with von Hippel-Lindau disease
Demyelinating Disease
• Multiple sclerosis
• Acute disseminated encephalomyelitis
Neoplasms, Cysts, and Other Masses
• Ill-defined
• Typically < 2 vertebral segments in length
Idiopathic Transverse Myelitis
• Cord expansion less pronounced than ependymoma
• Centrally located,3-4 vertebral segments in length
• Variable enhancement
PATHOLOGY
General Features
• Etiology
○ Arises from ependymal cells of central cord canal
• Genetics
○ Ependymoma associated with neurofibromatosis type 2
(NF2)
– Deletions, translocations of chromosome 22
• Associated abnormalities
○ Superficial siderosis
○ NF2
• 4 subtypes: Cellular, papillary, clear cell, tanycytic
○ Cellular most common intramedullary tumor subtype
Staging, Grading, & Classification
• Most WHO grade II
Gross Pathologic & Surgical Features
• Soft red or grayish-purple mass
• Well circumscribed
• Cystic change common
Microscopic Features
• Immunohistochemistry: Positive for GFAP, S100, vimentin
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Neck or back pain
• Other signs/symptoms
○ Progressive paraparesis
Demographics
• Age
○ 35-45 years
• Epidemiology
○ Ependymomas: 4% of all primary central nervous system
neoplasms in adults (30% spinal)
○ Most common primary spinal cord tumor in adults
Natural History & Prognosis
• Metastasis rare
• 5-year survival: 85%
Treatment
• Grade II ependymomas may be observed carefully after
imaging confirms complete resection
• Grade III tumors require adjuvant radiation treatment
• Surgical resection
○ Gross total resection in > 85% of cases
• Radiotherapy for subtotal resection or recurrent disease
○ Typical doses of radiation therapy range from 4,000-
5,400 cGy
293
Myxopapillary Ependymoma
KEY FACTS
TERMINOLOGY
• Slow-growing glioma arising from ependymal cells of
conus, filum terminale, cauda equina
IMAGING
• Usually spans 2-4 vertebral segments
○ May fill entire lumbosacral thecal sac
• Ovoid, lobular, sausage-shaped
• CT/radiographs
○ ± osseous canal expansion, thinned pedicles, vertebral
scalloping
○ May enlarge, extend through neural foramina
• T1WI: Isointense→ hyperintense to cord
Neoplasms, Cysts, and Other Masses
• T2WI: Almost always hyperintense to cord
○ Hypointensity at tumor margin = hemosiderin
• T1WI C+: Intense enhancement
TOP DIFFERENTIAL DIAGNOSES
• Nerve sheath tumor
(Left) Sagittal graphic shows a
multilevel cauda equina
myxopapillary ependymoma.
The mass is vascular with old
intratumoral hemorrhage &
acute subarachnoid
hemorrhage along the dorsal
conus. Indolent tumor growth
has enlarged spinal canal &
remodeled posterior vertebral
cortex. (Right) Coronal T1WI
MR shows a well-delineated,
intradural extramedullary
mass in the lumbar spine ſt.
The lesion is predominantly
isointense with cord & nerves.
Almost 70% of filum terminale
masses are ependymomas,
mostly the myxopapillary-type.
• Intradural metastases
• Meningioma
• Paraganglioma
PATHOLOGY
• WHO grade I
• May have local seeding or subarachnoid dissemination
• Subarachnoid hemorrhage
CLINICAL ISSUES
• Symptoms mimic disc herniation
• Back pain most common
• Other issues include paraparesis, radiculopathy, or bladder
and bowel dysfunction
DIAGNOSTIC CHECKLIST
• Slow tumor growth may delay diagnosis
• Always image conus in patients presenting with back pain
294
(Left) Sagittal T2WI MR
reveals an extensive intradural
tumor distorting the conus st
and cauda equina .
Myxopapillary ependymomas
are unique in their
intracellular and perivascular
accumulation of
proteinaceous mucin, which
appears T1/T2 hyperintense.
(Right) Sagittal T1WI C+ MR
exhibits avid homogeneous
tumor enhancement ſt. Note
diffuse intradural tumor
seeding . Smaller tumors
tend to displace the cauda
equina nerve roots, whereas
large tumors often compress
or encase them.
Hemangioblastoma
KEY FACTS
Neoplasms, Cysts, and Other Masses
TERMINOLOGY
• Low-grade, capillary-rich neoplasms of cerebellum and
spinal cord that occur sporadically or in setting of von
Hippel-Lindau (VHL) syndrome
IMAGING
• Thoracic > cervical > lumbar, sacral
• Subpial and posterior aspect of spinal cord but can arise in
any cord location
• Usually shows intense and uniform contrast enhancement
• Large lesions have vessel flow voids
• Often associated with intraspinal cyst
• Extensive syrinx suggests hemangioblastoma (HB)
• Spinal cord thickening remote from tumor and without
syrinx
TOP DIFFERENTIAL DIAGNOSES
• Arteriovenous malformation
• Cavernous malformation
• Hypervascular cord neoplasms
○ Ependymoma
○ Astrocytoma
○ Vascular metastasis
• Intradural extramedullary tumors
PATHOLOGY
• WHO grade I
• No malignant degeneration
CLINICAL ISSUES
• 68% of spinal hemangioblastomas are sporadic (32% VHLassociated)
○ Multiple HBs indicate VHL syndrome
• Patients with suspected hemangioblastoma and VHL
should undergo contrast-enhanced MR imaging of entire
neural axis to exclude multiple lesions
• Symptoms: Sensory > motor > pain
(Left) Sagittal graphic depicts
a focal intramedullary mass
ſt in the cervical cord with
prominent feeding vessels,
adjacent cysts , and cord
expansion with edema. (Right)
Low-power H&E shows typical
stromal cells (neoplastic
component of the tumor) with
pale vacuolated cytoplasm
(clear cells) containing lipid
droplets.
(Left) Sagittal T1WI C+ MR
shows a focal enhancing mass
in the dorsal cervical cord at
the C4 level ſt. Distinct
appearances of spinal
hemangioblastoma have been
described, including associated
cyst/syrinx st, diffuse cord
enlargement, exophytic
morphology with minimal
spinal cord reaction, and
extramedullary location.
(Right) T2WI MR displays a
peripheral cystic component
and focal mass ſt with edema
enlarging the cervical cord .
The ring of hypointensity st
suggests susceptibility due to
prior hemorrhage.
295
Spinal Cord Metastases
KEY FACTS
TERMINOLOGY
• Metastatic lesion from primary carcinoma in another organ
(including brain)
IMAGING
• Focal, enhancing cord lesion(s) with extensive edema
• Typically small (< 1.5 cm)
• T1WI: Enlarged cord
• T2WI/PD/STIR:Focal high signal represents diffuse edema
○ Rarely syrinx
• T1W C+: Focal enhancement
○ Rim sign: Intense, thin rim of peripheral enhancement
Neoplasms, Cysts, and Other Masses
around enhancing lesion
○ Flame sign:Ill-defined, flame-shaped region of
enhancement at superior/inferior margins
• T2* GRE: Hypointensity due to hemorrhagic components
TOP DIFFERENTIAL DIAGNOSES
• Demyelinating disease
(Left) Metastases to skeleton,
epidural space, & cord is
shown. Hemorrhagic
intramedullary metastasis
expands cord. Rapid onset of
symptoms is characteristic for
intramedullary spinal cord
metastatic (ISCM) disease.
Asymmetric dysfunction of
spinal cord mimicking BrownSéquard is reported in 30-40%
of ISCM disease but is
exceptional in epidural spinal
cord compression patients.
(Right) Sagittal T1WI C+ MR
shows enhancing non-small
cell metastasis to the conus
ſt. Note slight enhancement
of cauda equina roots st.
○ Multiple sclerosis
○ Acute disseminated encephalomyelitis
• Primary cord tumor
• Inflammatory granuloma
○ Tuberculosis
○ Sarcoidosis
• Inflammatory myelitis
CLINICAL ISSUES
• Brown-Séquard syndrome
• Rapidly progressive flaccid paraparesis
• Intramedullary spinal cord metastatic heralds poor
prognosis
• Pain
DIAGNOSTIC CHECKLIST
• Full craniospinal imaging when focal cord lesion found
• Edema out of proportion to focal small cord lesion suggests
metastasis, even if solitary
296
(Left) Sagittal MR shows a T1hyperintense intramedullary
lesion ſt. This ill-defined
enhancing lesion st on T1WI
C+ FS MR was found to be a
melanoma metastasis. There is
extensive intramedullary
edema . Note the vertebral
metastasis . (Right) Sagittal
T1WI C+ MR reveals direct
extension of glioma from
the brainstem inferiorly into
the cervical cord. There are
multiple foci of abnormal
enhancement within the
brainstem st. Spinal
metastases of glioblastoma
multiforme usually occurs late
in the course of the disease.
Primary Melanocytic Neoplasms/Melanocytoma
KEY FACTS
Neoplasms, Cysts, and Other Masses
TERMINOLOGY
• Uncommon neoplasms derived from normal
leptomeningeal melanocytes
• Morphologic spectrum from low-grade melanocytoma to
melanocytic tumor of intermediate differentiation to
malignant melanoma
○ Distinct from other melanotic lesions, such as
meningioma, schwannoma, melanoma
IMAGING
• Most common presentation is intradural enhancing mass
showing T1 hyperintensity, not fat suppressing
○ Rarely intramedullary
• MR
○ T1WI: Isointense to hyperintense intradural lesion
– Signal relates to paramagnetic free radicals in melanin,
with shortening of T1, T2
○ T2WI: Isointense to hypointense to normal cord
○ T2* GRE: May show blooming of low signal related to
melanin susceptibility effect
○ T1WI C+: Heterogeneous enhancement
TOP DIFFERENTIAL DIAGNOSES
• Hemorrhagic cord neoplasm
• Cavernous malformation
• Arteriovenous malformation
• Pigmented intradural extramedullary tumors
○ Malignant melanoma, meningioma, schwannoma
CLINICAL ISSUES
• Progressive back pain, extremity numbness, weakness
• Progressive, low-grade lesions curable by resection
• Can be locally invasive
• Treatment
○ Total tumor resection is optimal to prevent recurrence
○ Adjuvant radiotherapy after incomplete resection
(Left) Tight nests of bland,
slightly spindled cells are key
features of melanocytoma.
Sparsely pigmented or
amelanotic tumors may be
misinterpreted as
meningioma. (Right) Sagittal
T1 C+ MR shows there is
homogeneous, marked
enhancement of a T1
hyperintense intramedullary
lesion ſt in the conus
medullaris.
(Left) Sagittal nonenhanced
T1 MR (left) shows a primary
intramedullary melanocytoma
of the cord with intrinsic T1
shortening ſt that is
characteristic of melanin.
Sagittal T2 MR (right) shows
focal low signal . (Courtesy
P. Hildenbrand, MD.) (Right)
Sagittal T1 MR shows a welldelineated intramedullary
mass in the lower thoracic
cord that demonstrates high
T1 ſt (left) and low T2 signal
st (right). There is
surrounding cord edema .
297
CSF Flow Artifact
KEY FACTS
TERMINOLOGY
• CSF flow-related phenomenon due to time of flight (TOF)
effects and turbulent flow
IMAGING
• Location: Intrathecal, subarachnoid space
○ Most prominent in cervical and thoracic spine
• Low or high signal intensity
• Ill-defined margins
TOP DIFFERENTIAL DIAGNOSES
• Vascular malformation, type I dural arteriovenous fistula
• Vascular malformation, type IV arteriovenous fistula
Neoplasms, Cysts, and Other Masses
• CSF drop metastases
CLINICAL ISSUES
• TOF effects
○ Dark CSF signal
(Left) Sagittal STIR MR shows
an ill-defined signal void in the
dorsal subarachnoid space of
the thoracic spine st. This
artifact is due to a
combination of respiratoryand cardiac-related pulsatile
CSF flow superimposed on
cranially directed bulk CSF
flow. There is also
contribution from turbulent
CSF flow moving from the
ventral to dorsal subarachnoid
space. This complex CSF
motion results in phase
incoherence leading to signal
loss. (Right) Axial T2WI MR
confirms the CSF flow artifact
st.
○ Positive relationship between CSF velocity and TOF
losses
○ Typically occurs in spin-echo or fast spin-echo imaging
• Flow-related enhancement produces bright CSF signal
• Turbulent flow
○ Abnormally dark signal intensity
• Ghosting artifact motion
○ Periodic motion, such as CSF pulsation, cardiac motion,
and respiratory motion
DIAGNOSTIC CHECKLIST
• Flow artifacts frequently have bizarre nonanatomic
appearance
• Cross-reference other imaging planes and compare with
faster imaging sequences (GRE, true FISP) that reduce
superimposed flow phenomenon
Ghosting artifacts in phase-encoding direction often
•
accompany TOF- and FRE-related signal changes, help point
out true nature of those changes
298
(Left) Axial T1WI MR depicts
isointense CSF flow artifact
dorsal to the thoracic cord in
the subarachnoid space ſt.
(Right) Sagittal T1WI MR
exhibits syringomyelia in the
cervical cord ſt. CSF flow
dynamics are altered because
of the cerebellar tonsillar
ectopia . The turbulent flow
results in a broader spectrum
of proton velocities, which
result in more rapid dephasing
and signal loss. There is also a
positive relationship between
CSF velocity and time of flight
losses.
CSF Flow Artifact
Neoplasms, Cysts, and Other Masses
TERMINOLOGY
Definitions
• CSF flow-related phenomenon due to time-of-flight (TOF)
effects, turbulent flow
IMAGING
General Features
• Location
○ Intrathecal, subarachnoid space
○ More prominent in cervical and thoracic spine
Imaging Recommendations
• Protocol advice
○ Turbulence dephasing ↓ by shorter TE sequences and
smaller voxel volume (decreased slice thickness or higher
matrix)
○ Flow-related enhancement (FRE) ↓ by applying
saturation bands or by using ultrafast techniques, such as
true FISP
○ BLADE shown to be superior to turbo spin-echo
sequences
○ ↓ ghosting artifact by ↑ number of excitations
○ T1 FLAIR at 3T and 1.5T shows superior CSF nulling,
better conspicuity of normal anatomic structures and
degenerative and metastatic lesions, and improved
image contrast
MR Findings
• T1WI
○ Hyperintense relative to CSF
• T2WI
○ Hypointense relative to CSF
○ Ill-defined margins
• FLAIR
○ CSF flow artifacts at 3T > 1.5T
– Crosstalk between each inversion pulse
• T2* GRE
○ Resistant to TOF loss because of short TE
• T1 FLAIR
○ Relatively short TI/TR pair to produce effective nulling of
CSF signal, achieve heavy T1 weighting, and optimize
contrast between abnormal tissues and cord/bone
marrow
DIFFERENTIAL DIAGNOSIS
Vascular Malformation, Type I Dural Arteriovenous
Fistula
• Dilated pial veins cover abnormally enlarged, hyperintense
distal cord
Vascular Malformation, Type IV Arteriovenous
Fistula
• Intradural extra-/perimedullary arteriovenous fistula with
multiple well-defined serpentine flow voids on ventral or
dorsal surface of cord
CSF Drop Metastases
• Administer intravenous contrast, image in multiple planes if
necessary
PATHOLOGY
General Features
• Etiology
○ Pulsatile to-and-fro movement of CSF due to expansion
and contraction of brain produced by expansion and
contraction of intracranial vessels associated with cardiac
cycle
– Results in significant motion-related effects that can
alter visualized signal of CSF
CLINICAL ISSUES
Demographics
• Age
○ More prominent in pediatric patients
Natural History & Prognosis
• TOF effects
○ Dark CSF signal
– More pronounced with faster proton velocity, thinner
slices, longer TE, and imaging plane perpendicular to
flow
– Typically occurs in spin-echo or fast spin-echo imaging
○ Single-shot fast spin-echo (SS FSE): TOF loss during
systole without TOF loss in diastole
○ Relationship between CSF velocity and TOF losses
○ Laminar flow: Peripherally located protons move at
slower velocity → reduction in TOF losses
• FRE produces bright CSF signal
○ Bright signal from unsaturated protons flowing into slice
replace outflowing, partially saturated protons during TR
○ Seen on more slices with single slice acquisition
techniques in which every slice is entry slice
• Turbulent flow
○ Abnormal dark signal intensity
○ Varied flow velocities and directions → more rapid
dephasing and signal loss, intravoxel dephasing
• Ghosting artifact motion
○ Periodic motion, such as CSF pulsation, cardiac motion,
and respiratory motion
○ Phase-encoding direction
○ Bright if in phase or dark if out of phase with background
signal
DIAGNOSTIC CHECKLIST
Image Interpretation Pearls
• Flow artifacts frequently have bizarre nonanatomic
appearance
SELECTED REFERENCES
1. Lavdas E et al: Reduction of motion, truncation and flow artifacts using
BLADE sequences in cervical spine MR imaging. Magn Reson Imaging.
33(2):194-200, 2015
2. Kwon JW et al: Three-dimensional isotropic T2-weighted cervical MRI at 3T:
comparison with two-dimensional T2-weighted sequences. Clin Radiol.
67(2):106-13, 2012
3. Lisanti C et al: Normal MRI appearance and motion-related phenomena of
CSF. AJR Am J Roentgenol. 188(3):716-25, 2007
299