Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

THRALL - Thom > 15. CT / MR Spine > Flashcards

15. CT / MR Spine Flashcards

1
Q

What do the longitudinal ligaments of the spine do?

A

Support discs (dorsal and ventral)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why is root signature more common in cervical spine?

A

Dorsal long. lig. WIDE and THICK in cervical spine - predisposes to LATERAL disc extrusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where are the intercapital ligaments (in spine and in relation to long. lig.)?

A

T2-T11; Ventral to dorsal long. lig. Buttress dorsal asepct of disc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Interarcuate ligaments are also known as what?

A

Yellow ligaments, ligamentum flavum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where is the conus medullaris located in cats, small and large breed dogs?

A
  • Cats / small breeds: caudal to L6
  • Large breeds: cranial to L6
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe relationship of spinal cord segments to vertebral segments

A
  • Numerically matched EXCEPT C8!!!
  • Tend to be cranial to vertebra
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does the spinal cord diameter : vertebral canal diameter vary between breeds?

A
  • Higher in chondrodystrophic (e.g. dachs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe meninges, their relationships, and assocaited spaces

A
  • Pia mater: tightly adhered to cord, vascular
  • SUBARACHNOID SPACE: Arachnoid trabeculae, and CSF!!
  • Arachnoid membrane: Closely assocaited with Dura
  • SUBDURAL SPACE
  • Dura Mater: Outermost, close association with arachnoid.
  • EPIDURAL SPACE: Contains fat and vertebral venous plexus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where is spinal CSF located? Where does this compartment extend to / communicate with?

A
  • SUBARACHNOID SPACE

Cranially: Intracranial SA space

Caudally: Terminates at filum terminale

  • CENTRAL SPINAL CANAL

Cranially: 4th ventricle

Caudally: Terminates at conus medullaris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where is the basivertebral venous canal located?

A
  • Midportion of vertebral body: y shaped lucency extending towards canal. Dorsal bony protrusion at this level.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

LIGAMENTS! See pic

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How much contrast is injected for CT myelo?

A

25% normal myelo dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the annulus and nucleus made out of?

A

Fibrocartilage

  • Differr in amount of collagen and ground substance

Annulus: More collagen and less ground

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the principal component of the nucleus pulposus?

A

Water (bound to large proteoglycan molecules) = 80-88%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hansen type 1 vs type 2!

A

Type 1: Chondrodystrophic, loss of elasticity, inc collage / mineralisation -> Annulus rupture and extrusion

AGE: PEAK 4-5yrs

Type 2: Nonchondrodystrophic, Fibroid degeneration, annular protrusion and shifting of central nuclear material

AGE: 8-10yrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

DISC CLASSIFICATION ALGORITH

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What imaging features make protrusion / extrusion more likely?

A
  • Protrusion: Paritally degnerate, midline, multiple
  • Extrusion: Degenerate, lateralised / dispersion, single
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a discal cyst?

A
  • MISNOMER: NOW CALLED = COMPRESSIVE HNPE - hydrated nucleus pulposus extrusion, !
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What CT settings should be used to evaluate discs?

A

Thin slices (1-2mm), low pitch (<2) and medium freq algorithm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What percentage of dachsunds have transitional vertebral anatomy?

A

10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

On CT, how does extruded disk material appear in chondrodystrophic dogs?

A
  • Large volume hyperattenuating (200HU)
  • Small volume less hyperattenuating (60HU) -> corresponds to haemorrhage
  • IF CHRONIC: material even more hyper (700HU) as continues to mineralise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the bony ridge seen in the midportion of the vertebral body on CT?

A
  • Most likely = small bony ridge between dorsal vertebral foramina
  • Other suggestion: Mineralisation of dorsal long. lig.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When is CT myelography likely to be required for dx of spinal disease?

A
  • Non-chondrodystrophic (less mineralisation)
  • Chondro with concurretn extradural compression and cord swelling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What features of IVDE are reported on MR?

A
  • attenuation of epidural fat
  • Extradural compression at level of disc space
  • narrowing of disc space
  • Degen of disc
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the incidence of epidural haemorrhage / inflammation in thoracolumbar / lumbosacral disc herniation?

A
  • Approx 5%

=> Typically more caudal lumbar discs, and with migration of material

T2: Hyper or hetero

T1: Hyper, hypo or iso

T2* signal void

Freq CE!

=> No apparent difference in outcome if present

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In what percentage of dogs with disc extrusion do we see CE of disc material / meninges?

A
  • Disc material: 50%
  • Meninges: 40%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What percentage of IVDD is cervical in dogs? Which dogs and where?

A
  • 14-16%
  • Small dogs typically (dachs, beagles): C2-C5
  • Large dogs (Labs, GSDs): C4-5 and C6-7

=> Thick dorsal long lig -> often results in dorsolateral extrusion, and nerve root compression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Where does IVDD most commonly occur in TL spine? Which breed has unique distribution?

A
  • T12-L1
  • GSDs: Can have cranial thoracic discs (despite intercapital ligs!) -> T2-5
29
Q

Name imaging features associated with worse neuro grade and prognosis in TL IVDD?

A
  • Length of compressed cord -> associated with neuro grade (not outcome)
  • Length of T2 IM hyperintensity > L2 associated with poorer outcome in approx 50% patients
30
Q

Name 4 characteristics that can be seen with LS stenosis

A
  • Disc extrusion / protrusion
  • New bone at endplates / articular processes
  • Subluxation
  • Thickening of lig flavum / joint capsule
31
Q

Where is foraminal extrusion most commonly identiifed? What is ganglioneuritis?!

A

C5-C7, rarely reported in L6-S1

  • Rarely, fragements induce mechanical / chemical damage to perineurium +- penetrate root => inflam, thickening. MAY BE MISTAKEN FOR NERVE SHEATH TUMOUR
32
Q

MR differences between compressive and noncompressive ANPE?

A

ANNPE:

  • Narrowed disc space
  • IM hyper dorsal to space (typically non-enhancing)
  • Tract
  • T2w hyper extradural material
  • Loss of NP volume

Compressive HNPE (C3-6 most common):

  • Seagull sign: ventrally positioned extradural T2w hyper, may not suppress on FLAIR
  • IM Hyper above space, non enhancing. Iso to hyper on T2*
  • Materrial may enhance
33
Q

What % of patients with ANNPE have an unsuccessful outcome? Px features?

A

33%

Px:

  • Severity of neuro signs at presentation
  • CS area of IM hyper: If >90%, 92% chance of unsuccessful outcome
34
Q

What features have been described with dural tear?

A
  • Tract crossing spinal cord contiguous with intervertebral disc space
  • Myelography: Leakage from SA -> epirdural space; into disc if traction applied; Into cord
35
Q

Features of disc associated CSM

A
  • Disc bulging / herniation
  • Lig flav hyper (dorsal compression)
  • IM inc signal (* associated with clinically relevant cord compression*, but not px)
  • Vert body abnormalities / spndylosis
36
Q

DDx for T2w IM hyperintensity in CSM? And if T1w hypo concurrently?

A

T2w hyper: Gliosis, oedema, nerve cell loss. In white matter, demyelination, oedema and wallerian degen

w/ T1w hypo: MORE SEVERE CHANGES MAY BE PRESENT -> necrosis, myelomalaxia, spongiform change

37
Q

Osseus associated CSM features:

A
  • NOTE YOUNG dobermans get this too!!! And other large breeds e.g. G Dane
  • Disc degen +- protrusion (occasional)
  • Osteoarthritis of articular process joints and dorsal long lig hyper (C3 - T1; worse at C4-7) -> dorsal compression
  • Synovial cysts

NB: High incidence of features in clinically normal dogs. G Danes can have severe foraminal stenosis without CS, and occasional spinal cord compression

38
Q

List three common cystic lesions of spine; and one uncommon

A

Common:

  • Arachnoid cysts
  • Dermoid / epidermoid cysts
  • Synovial / ganglion cysts

Uncommon:

  • Perineural (Tarlov) -> originate from dorsal nerve root and ganglion sheath. EXTRADURAL (unlike arachnoid diverticula), filled with CSF and contain neural structures
39
Q

List 4 causes of arachnoid diverticula

A

1) Congenital
2) Trauma
3) Arachnoiditis
4) IVDD

IN SUBARACHNOID SPACE -> Communicate freely with CSF

40
Q

Common locations and breeds for SAD?

A

PUGS: Thoracic (typically caudal). A familial type of cervical SAD reported.

ROTTIS: Cervical (typically cranial)

** can be single or multiple**

Located in subarachnoid space, lined by pia and arachnoid

41
Q

MR Features of SAD

A
  • Teardrop shape continguous with SA
  • T1 hypo, T2 hyper and typically null on FLAIR
  • Compression (usually dorsal)
  • IM hyper (Oedema)
  • Syrinx
42
Q

Difference between dermoid and epidermoid cyst / sinus?

A
  • Cyst vs sinus: Discrete if cyst, tract to skin surface if sinus
  • DERMOID = Contain sweat glands, hair follicles, sebaceous glands
  • Epidermoid = Lined by squamous epithelium, contains cholesterol, keratin, epithelial cells. Can cause chemical meningitis if ruptured!
43
Q

Six types of dermoid cyst / sinus (attached Vet Clinics pic - first 4 types)

Which 2 types are associated with neuro abnormalities?

A

See image*

Type 5: True dermoid cyst - closed capsule, no deeper connection or communication with skin

Type 6: Deep tract extends to supraspinois or nuchal lig and contineus deeper as fibrous strand that connects to dura mater

NEURO SIGNS: only 4 and 6 as involve dura mater

44
Q

List 4 causes of neuro signs in association with dermoid cyst

A

1) Infection (abscessation, meningomyelitis etc)
2) Compression
3) Tethered cord
4) Syringomyelia

45
Q

MR features of dermoid cyst

A
  • Invagination of cut tissue
  • Focal roudned or lenticular SC lesion, and tubular tract (variable signal depending on content)
  • Thick capsule if absecess

…MOre depending on appearance. Be familar with diagrams and likely can figure out MR appearance!

46
Q

Name 4 vertebral anomalies associated with dermoid cyst / sinus

A

1) Spina bifida
2) Block vertebrae
3) Incompletel dorsal lamina
4) Fusion of spinous processes

47
Q

MR features of dural connection with dermoid sinus

A
  • Dorsal tenting of meninges
  • Triangular subarachnoid space - point of tether dorsally
  • Dorsal displacement of cord at site of tethering
48
Q

Where are articular process cysts typically located, and in which breed categories?

A
  • Typically cervical and multiple in young GIANT breeds
  • Typically thoracolumbar or lumbosacral in adult and older LARGE breeds
49
Q

In general terms, which tumours are found at extradural, intradural-extramedullary and intramedullary locations?

A
  • Extradural: Vertebra soft tissue tumours
  • Intradural-extramedullary: Nerve sheath or meningioma
  • Intramedullary: Glial, round cell or metastatic (e.g. HSA)
50
Q

List extradural tumours

A

Most common: OSA, CSA IN DOGS; LSA in cats

  • Histio SA
  • MM
  • Mets: TCC, prostatic C
  • Soft tissue: STS, Infiltrative lipoma

No specific CT or MR features with tumour type (except lipoma!)

51
Q

List intradural-extramedullary

A
  • 33% of spinal tumours!
  • Nerve S
  • Meningioma
  • Cats: Lymphoma (most common) -> often have extradural component
  • Rare: Neprhoblastoma
52
Q

Ct features of nerve sheath tumour?

A
  • Muscle atrophy
  • ST mass, iso to muscle
  • CE: uniform, patchy or rimlike
  • May track into foramen /invade canal
  • > Can identify as small as 1cm.
53
Q

What is the golf-tee sign a hallmark of?

A

Intradural-extramedullary lesion

54
Q

Features of nephroblastoma?

A
  • YOUNG dogs (<3)
  • Typically T10-L2 (region of kidneys??)
  • Usually a single mass, although mets reported
  • Enhancing
  • Features of intradural, extramedullary location…..

-

55
Q

List 6 PRIMARY intramedullary tumours of the dog

A
  • EPENDYMOMA (Most common)
  • Astrocytoma (next)
  • Nephroblastoma, chordoma, oligodendroglioma, teratoma
56
Q

List metastatic intramedullary tumours

A

Most common:

  • TCC
  • HSA

Other:

  • Carcinomas (prostatic, mammary, pancreatic)
  • Sarcoma

Even less common in cats -> glial cell usually. More likely cervical spine

57
Q

List three spinal tumours that effect multiple locations

A

HSA

LSA

Histio

58
Q

Describe features of CNS histiocytic sarcoma

A
  • Disseminated vs primary neoplasia
  • Retrievers and Pembroke corgis may be predisposed, with latter suspected to be specifucally preodiscposed to primary form
  • May arise from vertebra, soft tissues around bone, or directly within CNS
  • EXTRADURAL, INTRADURAL / EXTRAMEDULLARY or INTRAMEDULLARY
  • Multiple non specific MR features, but may include meningeal enhancement and dural tail (may be only feature)
59
Q

What is the most common neoplasia of the spinal cord in cats?

A

Lymphoma!

Most commonly extradural, but may be intra or mixed

60
Q

Features of canine spinal lymphoma

A
  • 80% cases multicentric
  • Commonly effects multiple spinal compartments (epidural , paraspinal ST, vertebrae, nerve roots, less commonly cord)
  • MR features….non-specific, however occasionally CAN BE T1w HYPER!

-

61
Q

Features of spinal HSA

A
  • Intramedullary or extraudral (and in 2-3% originating from vertebra)
  • Rarely primarily in epidural space alone
  • May be metastatic, more likely if intramedullary
  • MRI features…. as would expect. T2* void!
62
Q

What percentage of dogs develop myelomalacai after IVDE?

A

10% deep pain neg

63
Q

Features of myelomalacia?

A
  • Cord swelling (length effected may be suggestive)
  • IM Hyper
  • T2* void -> haemorrhage
  • May have T2 hypo on high-field = deoxyhaemoglobin
64
Q

Features of Ischaemic myelopathy

A
  • T2 hyper
  • Usually assymetric
  • Usually grey matter
  • Variable CE
  • May have T2* void with haem
  • AVERAGE Length of T2 hyper:
    1. 8 x C6 or 2.2x L2

=> 20% cases have normal MRI!

65
Q

What two metrics have been associated with poor outcome in ischaemic myelopathy (both 100% sn)?

A

Lesion length : vert ratio > 2

CSA > 67%

66
Q

MR features of disco?

A
  • T1/T2 hypo endplates and bone marrow ; STIR hyper
  • Hyper disc
  • CE of disc, endplates and STs
  • Endplate erosion, or in early stages T2 hyper marrow
  • Compression

Subluxation

67
Q

What feature of syrinx is the strongest predictor of clinical signs?

A

Syrinx WIDTH!

95% CKCS with max width > 0.64cm -> clinical signs

68
Q

Causes of meningomyelitis

A

Infectious

  • Viral: distemper, FIP
  • Bacterial: Staph, pasteurella, actinomyces, nocardia)
  • Fungal: Crypto, blasto, histoplasma, coccidiodes
  • Rickettsiae: Ehrlicia, rickettsia ricketsiae

Parasites: Dirofilaria, angio, toxo

Algae: Prototheca

Noninfecitous

  • GME, pyogranulometsous, SRMA
69
Q

Know your IM HYPER: px features in ANNPE vs ISCHAEMIC vs TL IVDE?

A

ANNPE

>90% CSA -> 92% poor px

Ischaemic - BOTH 100% sensitive for poor outcome

>67% CSA -

>2x vertebral body length -

TL IVDE

Length of T2 IM hyperintensity > L2 associated with poorer outcome in approx 50% patients

THRALL - Thom (40 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions