Spine imaging Flashcards
results from compromise of the spinal cord itself, due to mechanical compression, intrinsic lesions or inflammatory processes loosely grouped under the term “myelitis”. classic symptoms include bowel and bladder incontinence, spasticity, weakness and ataxia
myelopathy
true or false: myelopathy often presents without a clear sensory level. In such cases screening of the cord from the cervicomedullary junction of the conus is required
true
true or false: spinal cord is less tolerant of injury than the brain due to the small diameter of the spinal canal, resulting in permanent paralysis
true
acute myelopathy is an emergency, because
after 24 hours of acute severe cord compression, chances of full recovery are significantly diminished
due to the impingement or irritation of the spinal nerves within the spinal canal, lateral recess, neural foramen, or along the extraforaminal course of the nerve
radiculopathy
most common cause of radiculopathy are
disc herniations, spinal stenosis, and in the cervical spine, uncovertebral joint spurring
cause of myelopathy
spinal cord compromise
typical disease processes in myelopathy
extramedullary disease; cord compression due to epidural mass effect, cervical spinal stenosis, intramedullary disease: tumor, inflammation, AVMs, SDAVFs
ataxia, bowel and bladder incontinence and babinski sign are neurologic findings in
myelopathy
accuracy of clinical localization of spinal level in myelopathy
poor
urgency of imaging in myelopathy
high significant deficits may occur if severe compression untreated > 24 hours
preferred imaging modality for myelopathy
MR
cause of radiculopathy
spinal nerve compromise
osteophytic spurring (esp cervical spine), disc herniations, lumbar spinal stenosis, extramedullary and paraspinous tumors and inflammatory processes compromising nerve root may present with
radiculopathy
weakness and diminished reflexes in specific muscle groups, dermatomal sensory deficits are seen in
radiculopathy
true or false: accuracy of clinical localization in radiculopathy is quite good
true
urgency for imaging of acute presentations of radiculopathy
low-short delay for conservative tx usually entails little risk
preferred imaging modality for radiculopathy
CT, especially with intrathecal contrast is still excellent, particularly in cervical spine
flexion and extension plain films are helpful for the assessment of
spine stability in spondylolisthesis
in nondegenerative disease, pay careful attention to the integrity of the ____ because its a frequent site of metastasis
pedicles
this imaging modality is used in complex postoperative cases and patients in whom MR is contraindicated due to incompatible implanted device
myelography in conjunction with CT
True or false: ionic contrast agents are absolutely contraindicated for myelography
true; as they can result in severe inflammation, seizures, arachnoiditis and even death
in myelography, intrathecal iodine should not exceed
3 g
preferred puncture site in myelography
midlumbar region, inferior to the posterior elements of L2 or L3
complications of poor needle placement in myelography include
subdural and epidural injection
intradural, intramedullary masses include
ependymoma, astrocytoma, hemangioblastoma, lipoma/epidermoid, syringohydromyelia, intramedullary AVM
intradural, extramedullary masses include
meningioma, schwannoma/neurinoma, neurofibroma, hemangiopericytoma, lipoma/epidermoid, arachnoid cyst, adhesions, drop/leptomeningeal mets, extramedullary AVM
degenerative causes of an extradural impression in the spinal cord
herniated disc, synovial cyst, osteophyte, rheumatoid pannus
nondegenerative causes of extradural impression in the spinal cord
metastasis, abscess, hematoma, primary tumor expansion or invasion, epidural lipomatosis
this MR sequence can help differentiate tumor from fracture zones
DWI– tumors show restricted diffusion
when both clinical and pathologic findings pinpoint a distinct spinal level, the term ____ may be used
transverse myelitis
most common spinal cord “inflammatory” disorder and by far the most freq cause of intramedullary lesions seen on MR
Multiple sclerosis
true or false: when spinal MS predominates, it tends to follow a progressive clinical course, as opposed to the relapsing/remitting pattern more characteristic with brain involvement
true
an autoimmune disorder affecting the spinal cord and optic nerves. the spinal cord lesions are longer than in MS, and the brain is often spared
Devic disease or neuromyelitis optica (NMO)
specific test of NMO is
NMO IgG antibody, which targets the aquaporin 4 protein of astrocytes
in this autoimmune condition, necrotizing arteritis leads to cord ischemia and injury
lupus erythematosus
these have less well-defined margins that discrete plaques of MS and may involve the cord over 4 to 5 VB segments
SLE lesions
collagen-vascular disease that can compromise the spinal cord, although the mechanisms are different. focal inflammatory change termed “pannus” destroys the transverse ligament of C1, allowing the odontoid to slide posteriorly relative to C1. this leads to cord compression, particularly in flexion
Rheumatoid arthritis
neurologic injury in RA is due to ______ rather than a primary intramedullary lesion. this then leads in time to myelomalacia
atlantoaxial instability
shows the classic “bamboo spine” due to extensive bridging of syndesmophytes across multiple vertebral bodies. spine is prone to fracture with even mild trauma due to loss of flexibility
Ankylosing spondylitis
this viral infection can cause cord swelling and enhancement, appearing as spinal levels corresponding to the dermatologic outbreak
Herpes zoster
this viral infection provokes an autoimmune reaction that can damage the cord, and is termed subacute sclerosing panencephalitis
measles
a progressive ascending motor weakness that affects more than one limb, but involves peripheral nerves rather than the spinal cord. this has been seen after vaccinations and evolves over a maximum of 4 weeks. often the spinal nerves enhance
acute inflammatory polyradiculoneuropathy (Guillain-Barre syndrome)
inflammatory conditions involving pia and arachnoid have a similar differential diagnosis whether they involve cerebral or spinal leptomeninges. this condition present as diffuse leptomeningeal granulomatous nodules which typically enhance
Neurosarcoidosis
most common cause of arachnoiditis are
iatrogenic
peak incidence of radiation myelitis is
6-12 months after initial tx
this peaks 6-12 months after initial radiation therapy tx, with affected areas demonstrating increased signal intensity on T2 with variable enhancement
Radiation myelitis
most common cause of spine infection in adults
staph aureus
cause of spine infection with sickle cell disease
Salmonella
true or false: in adults, the disc itself has a relatively poor blood supply, so primary infection is rare. in children however, arteries penetrate the growing disc, providing access for primary hematogeneous primary infection
true
once the arterial vessels on the disc from childhood involute, the most common spinal site of “seeding” is the
vertebral body, particularly near the end plates, which have the richest blood supply
osteolyelitis/discities complex is suspicous for
infection, unusual in neoplasms
it can be difficult, though to distinguish between degenerative endplate changes and early infection. this sign on DWI has been proposed as a useful discriminating sign
Claw sign
true or false: many epidural infections do not have the well-encapsulated “liquid” collections we associate with abscesses elsewhere in the body, and technically are better termed “epidural phlegmon”
true
true or false: epidural infections spread craniocaudally, extending as many as three to four interspaces away from any vertebral abnormality. such distanct extension is unusual with epidural tumor from metastatic neoplasms
true
this is typically due to direct hematogeneous seeding of the CSF, rather than contiguous spread of adjacent vertebral infection, unless there is a disruption of the leptomeninges on a congenital or acquired basis
meningitis
these are rare, and usually result of direct seeding of the cord from overwhelming sepsis
spinal cord abscesses
causes slow collapse of one or usually more vertebral bodies, spreading underneath the longitudinal ligament. result is acute kyphotic or “gibbus” deformity. this angulation, coupled with epidural granulation tissue and body fragments can lead to cord compression. unlike pyogenic infections, the discs can be preserved
Tb of spine or Pott’s disease
in late stages of spinal TB, large paraspinal abscesses without severe pain, frank pus, or fever, occur, leading to the expression of
“cold abscess”
number of vertebrae afftected in infectious process
usually atleast 2 vertebrae around an affected disc (pyogenic) or intact disc with subligamentous spread (Tb or fungus)
portions of vertebrae affected in infectious process
destruction greatest at endplates, posterior elements relatively spared. abnormal marrow signal centered around disc in osteomyelitis/discitis complex
marrow signal changes in infectious process
dec on T1, inc on T2, normal diffusion, abnormal marrow signal centered around disc in osteomyelitis/discitis complex
disc integrity in infectious process
pyogenic: disc involved and enhances; nonpyogenic: disc may be spared
epidural component in infectious process
granulation tissue (best seen post-gad), extends several levels above and below the affected vertebrae
True or false: discogenic vertebral sclerosis can mimic the osteomyelitis complex on T1 (but not on enhanced scans)
true
number of vertebrae affected and pattern in neoplasm
isolated or noncontiguous involvement common
portions of vertebra affected in neoplasm
irregular vertebral body involvement, pedicles typically affected, entire vertebra often infiltrated
marrow signal in neoplasm
dec on T1, inc on T2, restricted diffusion due to “marrow packing”, entire vertebral body usually infiltrated with pathologic compression fracture
disc integrity in neoplasm
spared (prostate cancer an exception)
epidural component in neoplasm
focal mass usually on at level of affected vertebra/e, lymphoma an exception, with more extensive epidural mass
number of vertebrae affected and pattern in osteoporosis
several, showing loss of height to varying degrees
portions of vertebral affected in osteoporosis
anterior wedge deformity of VB, posterior elements spared, portions of VB retain normal marrow even with acute compression fracture
marrow signal in osteoporosis
T1 and T2 normal (unless with fx), diffusion may be increased at fracture plane, portions of VB retain normal marrow even with acute compression fracture
disc integrity in osteoporosis
discs spared
epidural component in osteoporosis
rare, unless acute fracture with hematoma, or retropulsion of fragments
these fungal infections may mimic metastatic tumor in the spine
candida and aspergillus
true or false: coccidiotomycosis, like TB, spares the disc
true
true or false: blastomycosis like actinomycosis, can destroy the discs and ribs
true
this viral infection destroys the anterior horn cells directly
poliomyelitis
myelopathy is seen in this viral infection with vacoular changes in the spinal cord
AIDS
this constitute 25% of all intraspinal lesions in adults, but are rare in children
meningioma
aside from poliomyelitis, this condition also affects the anterior horn cells
amyotrophic lateral sclerosis
two most common primary intramedullary tumors. both are expansile, low in signal intensity on T1, bright on T2, with variable enhancement. both have increased incidence in neurofibromatosis
astrocytomas and ependymomas
primary intramedullary tumor that has longer cord segments favors
astrocytoma
primary intramedullary tumor that has cysts and hemorrhage favors
ependymoma
most common spinal cord tumor in adults. they can be divided into cellular (intramedullary) and myxopapillary (filum terminale) types
ependymomas
true or false: spinal ependymomas are genetically and epidemiologically different from intracranial types
true
these are slow-growing neoplasms arise from ependymal cells lining the central canal of the cord or ependymal cell rests along the filum
ependymomas
tx for spinal ependymomas
resection
spinal astrocytomas occur in the
cervical and upper to midthoracic cord
in this intramedullary tumor, there is fusiform cord widening, hyperintensity on T2 and contrast enhancement often extend over several vertebral body segments
astrocytoma
true or false: spinal astrocytomas have lower histologic grade than astrocytomas in the brain
true
most common spinal cord tumor in children, with peak incidence in the third decade, younger than for ependymomas. they may be exphytic, and at times may even appear largely extramedullary
astrocytoma
it occurs in the spine as well as the posterior fossa, both types have a high association with von Hippel-Lindau syndrome. these rare tumors, with their characteristic densely enhancing nidus, represent 2% of the intraspinal neoplasms. 40% are extramedullay and 20% are multiple. it may be mistaken for an AVM
hemangioblastomas
how to differentiate AVM versus hemangioblastoms
intramedullary AVM typically do not show related cyst, cord expansion or a non-vascular enhancing nodule
refers to dilation of the central canal of the spinal cord, which is lined by ependyma.
syringohydromyelia/hydromyelia
a cavity outside the central canal lined by glial cells
syringomyelia
criteria for a syrinx cavity
well-defined margins and its contents should follow CSF signal intensity
if the “syrinx” borders are indistinct and the signal is brighter than CSF on T1 and darker than CSF on T2, you may be dealing with severe central cord edema or ____ which is related to obstruction of CSF flow
“presyrinx”
most common intradural tumor in the thoracic region and represents roughly 25% of all adult intraspinal tumors. most common in women with an average age of 45
meningioma
usual location of meningioma
extramedullary-intradural
main differential in spinal meningioma, which often will extend out through a neural foramen, and lacks a broad dural base. they are also less vascularized than meningioma, so may undergo cystic necrosis and often extend out the neural foramina
schwannoma
most common intraspinal masses
nerve sheath tumors such as schwannomas and neurofibromas
spinal schwannomas usually originate from the
dorsal nerve roots
frequent finding in spinal schwannomas in the cervical and thoracic regions
extension into the neural foramen
part of this tumor will be intraspinal, and part will be extraspinal, with the waist at the often-expanded bony neural foramen, giving the classic “dumbbell” appearance
schwannoma
spinal neurofibromas may show what associated finding in the spine
dural ectasia
classic cause of spinal intradural-extramedullary metastases is
subarachnoid seeding of primary CNS neoplasms, typically medulloblastomas, ependymomas and germ cell tumors. tumor cells exfoliate into the CSF and “drop” down into the spinal canal, implant on pia, and grow into small nodules, giving rise to the term drop metastasis
malignancy that has the highest rate of infiltration of the meninges of any non-CNS tumor
leukemia
this can cause considerable inflammation, and patients can present with signs of meningeal irritation, leading to the term “carcinomatous meningitis”. they appear classically as multiple intradural nodules, usually adherent to the pial reflections, best seen after gadolinium
Leptomeningeal metastases
differential diagnosis of thicekend leptomeninges includes
carcinomatous and infectious meningitis, postinfectious states such as Guillain-Barre, granulomatous diseases and inflammatory arachnoiditis in postoperative patients
second most common cause of extradural mass, after disc herniations and other degenerative processes
neoplasm
most common extradural masses are
metastases
most metastases, like infection, reach the vertebrae via
arterial seeding
prostate carcinoma may preferentially ascend to the lumbar region via
Batson venous plexus
appearance of spinal metastasis in MR
low signal on T1, high SI on T2 and STIR, diffusion restriction, because of their higher water content as compared with fat
this neoplasms can “stealthily” involve the spinal canal, infiltrating through the neural foramina
round cell tumors such as lymphoma in adults and neuroblastoma in children
leukemia change the appearance of the vertebrae in a characteristic fashion
diffuse, even replacement of the marrow with tumor
solid leukemic infiltrates aka ____, can involve the epidural space and cause cord compression
chloromas
can present as a diffuse and homogeneous low signal in the spine on T1, but more typically shows multiple focal defects
multiple myeloma
differential diagnosis for vertebral plana or totally collapsed vertebral body
solitary plasmacytomas, eosinophilic granuloma, leukemia and severe osteoporosis
true or false: multiple myeloma are missed in technetium bonse scans because they are often “indolent” metabolically. MR is the screening of choice for myeloma patients
true
this is a rare scenario wherein a patient who became paralyzed after major thoracic surgery, such as repair of a thoracic aortic aneuryms. this condition may be suspected
spinal stroke
spinal stroke will appear what in MRI
just like brain infarcts, bright on T2 and DWI, followed by development of myelomalacia
true or false: cavernous malformations of the spinal cord are more dangerous due to lack of plasticity, and even a small hemorrhage can be devastating
true
intramedullary AVMs have a congenital nidus of abnormal vesels within the cord substance, which cause symptoms by hemorrhage or ischemia, because of ____
steal phenomenon
they are congenital spinal AVMs that can grow as vessels dilate and typically present in young patients with hemorrhage, leading to acute paraparesis
Intramedullary AVMs
this is a classic lesion of extramedullary AVM, with a direct connection between an artery and vein without an intervening nidus of congenitally abnormal vasculature
spinal dural arteriovenous fistula (SDAVF)
SDAVF cause symptoms through venous hypertension and congestion of cord with edema due to this process
direct arterial inflow into the local venous system through the fistula, undamped by the resistance of a capillary bed, raises pressure within the coronal venous plexus draining the spinal cord which is valveless
houses the vertebral artery
foramen transversaria
true or false: spinal cord contusions may occur in the absence of spinal fractures, because of hyperflexion or hyperextension, resulting in myelopathy
true
true or false: subdural hematomas are rare in the spine, while epidural hematomas are far more common
true
most posttraumatic bleeding in the spine are arterial or venous?
venous
most common site for root avulsion in the spine is
cervical spine, probably because of its wide range of motion during accidents
nerves typically affected in cervical spine root avulsion
brachial plexus and upper extremities are typically affected
one of the classic causes of nerve root avulsion at the cervicothoracic junction in newborns, which can result in an Erb palsy on the affected side
birth trauma, typically traction on the shoulder
degenerated discs appear what on MR
low SI on T2
annular fiber disruption are show in MR as
high SI on T2
this has been associated with internal disc derangement , which may be a cause of axial back pain, and surgeons may perform discectomy with spinal fushion for tx of IDD
“high-intensity zone”
defined as a localized or focal displacement of disc material involving less than 25% of the periphery of the disc as viewed in axial plain
disc herniation
it involves greater than 25% of the circumference of the disc, and may result from disc degeneration, ligamentous laxity, or bony remodelling
disc bulge
true or false: mild disc bulging at L5-S1 <2 mm is considered a normal variant
true
defined as displaced disc material extending beyond less than 25% of the disc space, with the greatest measure in any plane being less than the measure of the base. it has a broad base at its origin, and does not extend above or below the level of the disc in the sagittal plane
disc protrusion
defined as a herniation where the greatest measure of the herniated material is greater than the base at the site of origin. any disc herniation extending above or below the disc space level should be called this type of herniation
disc extrusion
the presence of extrusion, as the name implies that there is an
annular disruption
extrusion are subclassified as ____ if the displaced disc material has lost continuity with the parent disc
sequestration
this term signifies displacement of the herniated disc material away from the site of the extrusion
migration
location of disc herniation include
central, subarticular, foraminal, extraforaminal and anterior
herniated discs in the craniocaudal direction through a gap in the vertebral body endplate are referred to as intravertebral herniation or
“Schmorl nodes”
enroachment of the bony or soft tissue structures of the spine on one or more of the neural elements, with resulting symptoms
spinal stenosis
classification of stenosis based on anatomy
central canal, lateral recess and neural foramen
lateral herniation or bulge in L4-L5 disc affects what nerve root
L4
posterior disc herniation or bulge in L4-5 affects what nerve root
L5
most common cause of central canal stenosis is ____, this is also the most common cause of lateral recess stenosis
degenerative disease of the facets, with bony arthritis that enroaches on the central canal
most common cause of neural foramen stenosis
DSD of the facets
in the cervical spine, these joints develop degenerative spurs that narrow the foramina anteromedially. these joints are not present in the thoracic and lumbar spine
uncovertebral joints (which help stabilize the vertebrae)
these are bony canals in which the nerve roots lie after they leave the thecal sac and before they enter the neural foramen
lateral recesses
most common cause of enroachment on the lateral recesses
arthritic spurs of the superior articular facet from DJD
these are defects in the bony pars interarticularis, and are found in up to 10% of asymptomatic indivduals, and can be seen on oblique plain films. they can be a source of low back pain and instability
spondylolysis
neck of Scotty dog represents the
pars interarticularis
imaging of choice to detect spondylolysis
CT
on axial images through the midvertebral body, it appears as a break in the normally intact bony ring of the lamina
sponylolysis
refers to forward displacement of one vertebral body on a lower one, occurs from either slippage of 2 vertebral bodies following bilateral spondylolysis or from DJD of the facets with slippage of the facets
spondylolisthesis
spondylolisthesis is most common at what levels
L4-5 and L5-S1
modic type: dark on T1, bright on T2
modic type 1- fibrovascular ingrowth (increased fluid)
modic type: bright on T1, bright on T2
modic type 2- fatty change, chronic irritation
modic type: dark on T1, dark on T2
modic type 3- sclerotic change (end stage)
endplate marrow changes are categorized by
modic types
spondylolisthesis is grades by
Meyerding grading scale
is a common and often unrecognized source of back pain. facet synovitis may be associated with facet effusions. this can be treated with radiofrequency facet denervation of the medial branches of the sinuvertebral nerves, which supply the facet joints
facet disease
synovial cyst may be a complication of
facet disease
synovial cysts are most commonly seen in the
lumbar spine
tx of synovial cyst
minimally invasive image-guided injection into the adjacent facet jpint or directly into the cyst, which may result in cyst rupture in up to one-third of cases
