Radiology: Spine

Cervical Spine - x-ray views
1. AP
2. AP Open Mouth View (Odontoid) –> to view dens (teeth obscure dens if not open wide)
3. Lateral
–>Need to include T1
–>Need to see preverterbral soft tissues
4. Bilateral Oblique
5. Flexion and Extension
Cervical Spine – x-ray views
Cervical Anatomy
Cervical Anatomy
We will write a custom essay sample on
Radiology: Spine
or any similar topic only for you
Order now
Cervical Spine - AP Open Mouth X Ray
-Dens
-Lateral Masses
-C1/C2 Alignment
–>looking for fx, trauma
Cervical Spine – AP Open Mouth X Ray
Cervical AP X Ray
-Uncovertebral joints (more midline than facet jts)
-Transverse Process (lateral)
-Spinous Processes (midline)
–> looking for bony hypertrophy (excess bone)
Cervical AP X Ray
[uncovertbral joints]
– present from C3 to C7
– (more midline than facet jts)
– allow for flexion and extension, limit lateral flexion in the cervical spine
ISSUES: degenerative changes, hypertrophic arthritis, resulting in foraminal stenosis and nerve compression.
Foraminal stenosis is the most common cause of cervical nerve root pressure.
[uncovertbral joints]
Cervical Lateral X Ray - what is most important to include?
1) Visualize all seven vertebrae (including *C7-T1*)
Cervical Lateral X Ray – what is most important to include?
Lateral X-Ray Alignment (lines)
1. Anterior vertebral line
2. Posterior vertebral line
FACETS
3. Spinolaminar line
4. Spinous processes line
SUBLUXATION or FX
Lateral X-Ray Alignment (lines)
Above vertebral body relationship to below vertebral body
*Anterolisthesis* – above level forward
*Retrololisthesis* – above level behind (measured in mm)
Naming of Misalignment
-Pseudosubluxation of C2 and C3
–>Normal in children
–>Seen in 20% of children under age 8 years
Pseudosubluxation in Cx Vertebrae
Predental Space (Atlanto-Dens)
-AP distance from dens (tip) to C1 body (ant. arch)
-Normal values
–>Adult: 3mm
–>Child: 5mm
Helps look for subluxation.
Predental Space (Atlanto-Dens)
Cervical Spine - Oblique X-ray structures
2 views: R & L views
*1. Neural foramina* = holes (look for size/narrowing)
*2. Facet joints* (angulated)
*3. Pedicles*
Cervical Spine – Oblique X-ray structures
Flexion & Extension X-Ray views (what are you looking for?)
-*Helps detect ligamentous injury* (instability – can’t view on CT/MRI)

Compare Neutral, Flexion, & Ext. views, measuring degrees of antero/retrolisthesis >3mm difference btn. any of those views = INSTABILITY of ligaments

Flexion & Extension X-Ray views (what are you looking for?)
Dens Fracture
-TYPE I (<5%): Fx through tip of dens at insertion of alar ligament (connects dens to occiput); usually *unstable* -TYPE II (> 60%): Fx through base of dens; MOST COMMON FX (often no surgery)

-TYPE III (30%): Subdentate (through body of C2) and does not involve the dens;
-**Unstable** because atlas and occiput can move together

–> Better on CT view

Dens Fracture
Types of Flexion Injuries
*Most common fractures in cx*
1) Anterior subluxation (hyperflex. sprain)
2) Simple wedge fracture
3) Unstable wedge fracture (assoc. w/lig. injury)
4) Unilateral facet dislocation (lig. injury)
5) Bilateral facet dislocation (lig injury)
6) Flexion teardrop fracture (lig injury)
7) Anterior atlantoaxial dislocation
*FOCUS ON FACET DISLOCATIONS*
Types of Flexion Injuries
Jumped Facets (Facet Dislocation: Uni vs. bilateral)
*Facet above is anterior to facet below.*
Widening d/t ligament tear
-Unilateral: <50% anterolisthesis -Bilateral: >50% anterolisthesis
*Jumped facet can be unilateral or bilateral
Jumped Facets (Facet Dislocation: Uni vs. bilateral)
Types of Extension Injuries
1) Hangman’s fracture
2) Extension teardrop fracture
3) Hyperextension w/pre-existing spondylosis (degen.)
Types of Extension Injuries
Hangman's Fracture
HYPEREXTENSION
*Fx involving both pars interarticularis of C2*

Usually anterolisthesis at C2-C3

Hangman’s Fracture
Jefferson Fracture (how to identify on x-rays)
*Burst fracture of C1* – usually involving anterior and posterior arches
IMAGING:
–> looking for indirect sign, change in lat. masses of C1 arch and the dens (L lat mass is further from dens)
*CT much better*
Jefferson Fracture (how to identify on x-rays)
*Requires immediate intervention*
FLEXION:
1) Bilateral facet dislocation
2) Flexion teardrop fracture
3) Wedge fracture with posterior ligamentous rupture

EXTENSION:
1) Odontoid fracture type II
2) Hangman’s fracture
3) Extension teardrop fracture

VERTICAL COMPRESSION:
1) Burst fracture

Unstable cervical fractures
Anatomy of Lumbar Spine Lateral X-Ray
*SPIVA*
Spinous process
Pedicles
Intervertebral disc spaces
Vertebral body height
Alignment
Anatomy of Lumbar Spine Lateral X-Ray
SCOTTY DOG SIGN (lumbar oblique view)
*Better for foramina and pedicle (pars interarticularis fx)*
-Nose = Transverse Process
-Eye = Pedicle
-Front Leg = Inferior articular facet
-Ear = Superior articular facet
-*Neck of dog = Pars Interarticularis –> look for fx (lucency) here!*
SCOTTY DOG SIGN (lumbar oblique view)
(SCOTTY DOG SIGN pic)
Pars Interarticularis fx, often assoc. with *anterolisthesis (typically L4/L5)*
–> young pts <30 y/o, sports/stress-related activity -*Nose* = TP, *Eye* = Pedicle, *Front Leg* = inferior articular facet, *Ear* = Superior articular facet, *Neck* = Pars Interarticularis, *Body* = lamina/SP
(SCOTTY DOG SIGN pic)
-One vertebra slips anterior/posterior
-Forward slippage = ANTEROLISTHESIS
-Backward slippage = RETROLISTHESIS

5 MAJOR TYPES OF SPONDYLOLISTHESIS:
1) *Dysplastic* – caused by defect in formation of part of vertebra (congenital)
2) *Isthmic* -caused by defect in pars interarticularis (spondylolysis)
3) *Degenerative* – caused by arthritic changes
4) *Traumatic* – caused by direct trauma/injury to vertebrae; usually fx of the pedicle, lamina or facet joints
5) *Pathologic* – caused by abnormal bone (eg tumor)

Spondylolisthesis (5 types)
Spondylolisthesis = One vertebra slips anterior/posterior
Spondylolysis = fx of pars interarticularis resulting in A/P slippage
Spondylisis = degenerative disease
Spondylolisthesis vs. vs. Spondylolysis vs. Spondylisis
Spondylolisthesis grades
1: 0 – 25%
2: 25 – 50%
3: 51 – 75%
4: 76 – 100%
5 (Spondyloptosis): >100%

(-pars defect: usually grade 2 or greater, Degenerative: usually grade 1)

Spondylolisthesis grades
Spondylolysis
*Defect of lumbar vertebra at the pars interarticularis (anterior to lamina and posterior to pedicle)
*Typically secondary to stress fx from repetitive injury (MC in young adolescents, who overtrain)
Spondylolysis
1) *Compression/Wedge Fracture*: Anterior part of vertebral body breaks/loses height while posterior part of vertebral body is intact. *Usually stable.*

2) *Axial Burst Fracture*: Vertebra loses height along both anteriorly & posteriorly.
*Unstable*

3) *Chance Fracture*

Types of Tx and Lx Spine Fractures: Flexion Fxs
Wedge Fracture (what part of spine/vertebral body, population?)
AKA Compression fx
Compression fracture along *anterior or lateral vertebral body* secondary to hyperflexion and compression
*Most common within thoracic spine*
*Common in osteoperotic patients*
Wedge Fracture (what part of spine/vertebral body, population?)
Wedge Fracture considered serious if...
-fx involves adjacent vertebra
-anterior wedge >50%
-severe hyperkyphosis
-bone fragments suspected within spinal canal
Wedge Fracture considered serious if…
Chance Fracture
Compression injury separating vertebral body. *UNSTABLE*

Secondary to violent forward flexion -> leads to distraction of posterior elements
–> CLASSIC “SEAT BELT INJURY”

*Common at thoracolumbar junction (T12-L2)*

Chance Fracture
Schmorl's Node
protrusions of the nucleus pulposus of the IV disc through the vertebral body endplate and into the adjacent vertebra.

*Leads to concavity and erosion of bone.*
-Can be inferior, superior or both

*Relatively common especially with increasing age*

Schmorl’s Node
Typical Fx of Sacrum
-not at SI jt
-most are vertical (unless it’s a severe MVA/crush injury –> fragmentation)
Typical Fx of Sacrum
(limited evaluation of spinal cord and nerve roots)
*1. Fractures (including Pars Defects)*
*2. Pre-op & Post-op Spinal Surgery*
– bony anatomy prior to surgery
– surgical hardware alignment & integrity
*3. Characterization of osseous lesion(s)*
– neoplasm/metastases, hemangioma etc.
*4. Unable to get MRI*
– Pacemaker, retained metal fragments, etc
Indications for CT Scan
-Typically *Noncontrast* for spinal imaging
–> Uses *ionizing radiation*
-Multislice axial imaging performed parallel to the disc spaces.
CT Scan
Normal Cervical Spine CT Scan (colors)
See more of the bony and soft tissue structures than x-rays
-white: bone
-gray: fat, muscles, vessels
-black: air
Normal Cervical Spine CT Scan (colors)
CT Scan: Normal C-Spine Vert., C1-6 (axial view)
C1: complete ring
CT Scan: Normal C-Spine Vert., C1-6 (axial view)
CT Scan: Normal Thoracic Spine
– the worse the scoliosis, the worse the image (you won’t see all vert. clearly)
– bone & soft tissue windows (L/R)
CT Scan: Normal Thoracic Spine
CT Scan: Normal Thoracic Spine Vert. (axial view)
[fat around thecal sac = epidural space]
CT Scan: Normal Thoracic Spine Vert. (axial view)
CT Scan: Normal Lumbar Spine Vert. (axial view)
CT Scan: Normal Lumbar Spine Vert. (axial view)
L5 CONGENITAL PARS DEFECT (CT)
L: midline (can’t see fx – not midline structure)
Middle: *more lateral, start to see defect*
R: lateral fx
L5 CONGENITAL PARS DEFECT (CT)
CT Scan: L5 CONGENITAL PARS DEFECT (axial view - what does it do to foramen magnum?)
axial
– *pars interarticularis: horizontally oriented defect/lucency*
(facet jts: obliquely oriented defect/lucency)
*spinal canal more flute-like/champagne shape (instead of round) –> widening due to ant. slippage* (usually accompanies pars defect)
CT Scan: L5 CONGENITAL PARS DEFECT (axial view – what does it do to foramen magnum?)
CT Scan: L5 BURST FRACTURE (what to look for)
– vert. lost height, lots of fx lines
looking for:
1) retropulsion of bone (bone fragment extending back into spinal canal)
2) canal stenosis (esp. in thoracic)
–> MRI imaging
CT Scan: L5 BURST FRACTURE (what to look for)
CT Scan: L5 BURST FRACTURE (axial view)
– CT, soft-tissue window, bad canal stenoisis
CT Scan: L5 BURST FRACTURE (axial view)
CT Scan: L1 OSTEOPENIC COMPRESSION FRACTURE
Across entire vertebral body or anterior portion of vertebral body (rarely posterior vertebral body)

-Around level of conus – might use MRI

CT Scan: L1 OSTEOPENIC COMPRESSION FRACTURE
L1 OSTEOPENIC COMPRESSION FRACTURE - axial (structural change? Sx?)
– flattening of thecal sac –> canal stenosis
Usually asymptomatic – still room in canal
L1 OSTEOPENIC COMPRESSION FRACTURE – axial (structural change? Sx?)
What can happen to Osteopenic Compression fx? (1 mo later)
*KYPHOSIS*
– more loss of vert. height
– retropulsion: causing more SC stenosis? Pt may have more Sx’s
What can happen to Osteopenic Compression fx? (1 mo later)
1) Osteoporosis (most common)
2) Direct acute trauma in healthy vertebra
3) Neoplasms
– Infiltrative neoplasms
(eg multiple myeloma, lymphoma)
– Metastatic neoplams
(eg prostate, breast, lung)
– Primary bone neoplasm
(hemangiomas, giant cell tumors)
Most Common Causes of Vertebral Compression Fractures
1. Conservative Management (if simple fx) for 4-6 wks
-medical management with or without methods of immobility
-medications (NSAIDS and narcotics)
2. Vertebral Augmentation –> If conservative care doesn’t work
Management of Compression Fracture
1) Percutaneous Vertebroplasty (PV)
2) Balloon-assisted Kyphoplasty
-Both involve injection of an acrylic cement under local anesthesia to control pain of vertebral fractures [moving against one another] -85-90% patients have rapid pain relief
Types of Vertebral Augmentation
1) Pain localized to a fracture or tumor
2) Pain after conservative care
3) Fracture <12 months old [otherwise body is already building new bone] 4) Contraindications to medications or requirement for IV narcotics and hospital admission (??)
Vertebral Augmentation – Inclusion criteria
1) Retropulsed Fracture (don’t make worse)
2) Cord compression (don’t make worse)
3) Fever and/or sepsis [don’t want to trap an infection!]
Vertebral Augmentation – Exclusionary Criteria
-Injection of low-viscosity acrylic cement directly into vertebral body using a unipedicle or bipedicle needles

-Objective: treatment of pain (preventing painful motion of vertebral body fragments moving against one another); Stabilizes vertebra = prevent future fx
*DOES NOT RESTORE VERTEBRAL BODY HEIGHT*

Percutaneous Vertebroplasty
Low Complication Rate (1-3.9%)
*Acute Complications*
*Cement leak (biggest issue)
-Cement pulmonary embolism
-Bleeding/hematoma
-Infection
-Neurological deficit (transient or permanent)

*Delayed Complications*
-New fracture at other levels?
–> diminished compliance of vertebra b/c of cement places remaining vertebral bodies at higher risk for fx

Percutaneous Vertebroplasty – Complication Rate and most common complications
Image of cement in vert. body
Image of cement in vert. body
Balloon Kyphoplasty
– Inflation of one or two intravertebral body high pressure balloons to create a cavity in which high-viscosity arcylic cement is then injected
Unipedicle (1 balloon) or bipedicle (2 balloons)
-Usually hospitalization
*Restores height loss*
Balloon Kyphoplasty
-Posterior cortical defect (Injection in that area can make it worse)
-Bone infection such as diskitis with osteomyelitis.
Contraindications for PV or Kyphoplasty
Indication for CT Myelogram
Need CT delineation of soft tissue structures within spinal canal for:
1) Patient who cannot get MRI (pacemaker)
2) Patient with surgical hardware in spine which obscures visualization of spinal canal on MRI and CT scan.
Indication for CT Myelogram
Injection of contrast material into thecal sac under flouroscopic guidance with subsequent CT imaging of the spine
CT MYELOGRAM – Technique
Evaluation for degree of canal stenosis and/or cord compression, disc herniation, arachnoiditis
Most common uses for CT Myelogram
-Bleeding disorder (elevated PTT/INR)
-Less frequently performed due to the invasive nature of the test and associated risks.
CT MYELOGRAM – Contraindication/Relative contraindications:
MRI – soft tissue
CT – bone integrity
MRI vs. CT
*1) DEGENERATIVE DISEASE*
-Disc herniation
-Spinal stenosis and Cord compression
-Nerve Root Impingement (Radiculopathy/Sciatica)
*2) INFECTION* (Discitis/Osteomyelitis, abscesses)
*3) NEOPLASM* (Osseous Metastasis)
*4) DEMYELINATING/INFLAMMATORY* (MS lesions (cervical & thoracic))
*5) TRAUMA*
-Ligamentous rupture
-Epidural/Subdural Hematomas
*6) POSTOPERATIVE SPINE*
-Recurrent disc herniation versus Postoperative
MRI INDICATIONS
-No ionizing radiation
*Contraindications*
– Aneurysm clip
-*Cardiac pacemaker*
– Orbital metallic foreign body, cochlear implant, IVC filter
NO CONTRAST: Patient with EGFR <30 (measure of kidney function) due to increased risk of Nephrogenic Sytemic Fibrosis (NSF)
MRI CONTRAINDICATIONS (for contrast too)
-Degenerative Disease
-Lumbar back pain
-Radiculopathy
-Preoperative Planning
NONCONTRAST MRI used for:
*-Postoperative spine recurrent back pain evaluation*
>> to see granulation tissue vs. recurrent/new disc herniation
– Metastatic Bone disease (bone and spinal cord)
– Spinal Infection (discitis/osteomyelitis, epidural abscess)
CONTRAST ENHANCED MRI:
Extra view b/c so much bony pathology in Cx spine

bone black, fluid bright, *accentuates bony structures*

MRI Cx Spine: Gradient Echo view
*Water: *
T1 hypointense (dark),
T2 & STIR hyperintense (white)
*Fat:*
-T1 & T2 hyperintense (bright),
-STIR hypointense (dark)
*Normal Bone:*
-T1, T2 & STIR hypointense (dark)*
*Sclerotic Bone*
-T1, T2, and STIR markedly hypointense (very dark)*
T1 / T2 / STIR
T2 & STIR: fluid bright
– CSF, thecal sacs

STIR: fat dark (“suppressed”)
T2: fat bright

Normal MRI Lumbar Spine
-Disk space should always be darker than vertebral bodies on T1 (??)
If VB is darker -? abnormal – tumor or degeneration = sclerotic changes
-Disk space will always be bright on T2 & stir (b/c most of the disc is fluid)
General rules of colors of MRI in Spine
Normal MRI Lumbar Spine - Intervertebral Neural Foramina
– keyhole structures at level of disc space
– contain fat & nerve roots
– Look for symmetry in each region (C, T, L)
– T1&2: bright signal (fat) surrounding dark signal (nerve root)
– STIR: vessels around nerve root (a little bright), but fat supressed –> STIR not a great view of foramina
–> looking for any encroachment/narrowing (facet arthropathy, disc herniation, etc)
Normal MRI Lumbar Spine – Intervertebral Neural Foramina
NORMAL MRI LUMBAR SPINE (axial view)
through the disc space
– neural foramena: fat (bright) + n. roots (dark)
NORMAL MRI LUMBAR SPINE (axial view)
*Cervical spine*
– exiting nerve root at disc space is from *level below* (eg at C5-C6, C6 exiting nerve roots noted; at C7-T1, C8 exiting nerve roots noted)
Thoracic & Lumbar spine:
– exiting nerve root at disc space from *level above* (eg at T1-T2, exiting nerve roots are T1)
*Cervical Spine: You have Uncovertebral Joints*
*Thoracic/Lumbar Spine: No uncovertebral joints*
Nerve roots exiting Cervical vs. Tx/Lx Spine
ZYGAPOPHYSEAL (FACET) JOINTS (potential issue)
-Function: carry axial load of body limit range of motion of the spine
*can cause LATERAL CANAL STENOSIS [AKA foramenal stenosis] when hypertrophied from osteoarthritis*
ZYGAPOPHYSEAL (FACET) JOINTS (potential issue)
Spinal Nerves - Intervertebral Neural Foramina
-Foramen through which the spinal nerves exit the spinal canal.
-Within foramen, the motor & sensory nerve roots merge into single Spinal Nerve (sensory and motor fibers). Termed “Exiting Nerve”
Spinal Nerves – Intervertebral Neural Foramina
End of Spinal Cord
Typically terminates at L1-L2 (Conus Medullaris); [but can low or high-lying]
End of Spinal Cord
-Inferior to conus medullaris, thecal sac contains pia-wrapped 3-5 lumbar, 5 sacral and 1 coccygeal nerves

nerves hang like a “horse tail” inferior to L2 within the thecal sac

Cauda Equina
Lumbar spine imaging (thecal sac on CT myelogram, facet joints)
Thecal sac is bright w/contrast! [otherwise only white on CT is bone] – facet jts: should look smooth, like a hamburger bun (inf. is top of bun, sup. is bottom of bun) –> some facet arthropathy seen in these images
Lumbar spine imaging (thecal sac on CT myelogram, facet joints)
Sciatic Nerve
Supplies whole skin of the leg, the muscles of the back of the thigh and those of the leg & foot

Comprised of spinal nerves L4 through S3

Sciatic Nerve
*Degenerative changes of bone marrow* seen on MRIs.
Happens with age and can change from one type to another.
Modic Changes
MODIC CHANGES Type I
-bright: *bone marrow edema & inflammation*
-T1 hypointense (dark) and T2 hyperintense (bright)
MODIC CHANGES Type I
MODIC CHANGES Type II
-Conversion of normal hemopoietic (red) bone marrow into fatty (yellow) marrow

-T1 hyperintense and T2 iso/mildly hyperintense (bright spots) [b/c it’s fat replacing bone marrow!]

MODIC CHANGES Type II
*Subcondral bone sclerosis*
-T1 and T2 hypointense (dark)
MODIC CHANGES Type III
Ring Apophysis (and potential problem)
-“Naked bone” of outer periphery of vertebral body
-Outer fibers of disc (Sharpey’s Fibers) anchor themselves into this region [what attach end-plates to discs below/above] -*Bone spurs (osteophytes) arise form this region* as a result of prolonged pulling/tugging of Sharpey’s fibers (degeneration)
Ring Apophysis (and potential problem)
Disc anatomy (nucleus pulposus, annulus fibrosus)
*Nucleus Pulposus*
-*water-rich* gelatinous center of disc
-bear axial load of body; pivot point for movt

*Annulus Fibrosus*
-more *fibrous* than nucleus, higher collagen / lower water content
-hold in place the highly pressurized nucleus
-outer lamellae = SHARPEY’S FIBERS

Disc anatomy (nucleus pulposus, annulus fibrosus)
DISC Problems anatomy
DISC Problems anatomy
OSTEOPHYTES - MRI (which ones matter?)
Posterior osteophytes. Don’t care about anterior.
Cx>Lx
OSTEOPHYTES – MRI (which ones matter?)
loss of square shape of vertebral body
MRI CERVICAL DDD – Osteophytes
CT Scan: FACET ARTHROPATHY
Facets = Synovial Jts
-Prone to osteoarthritis
-*Osseous overgrowth can results in lateral canal stenosis (neural foraminal stenosis)*
Look for hypertrophic changes in joint space
CT Scan: FACET ARTHROPATHY
Facet Arthropathy - CT SCAN (axial view
Lose the *nice hamburger shape*, excess bone formation
Facet Arthropathy – CT SCAN (axial view
CT Scan: Uncovertebral Hypertrophy (where?)
-exist from C3 to C7
-allow for flexion and extension; limit lateral flexion
-osteophytes (bone spurs) form in response to degeneration to try to maintain stability of spine
-can lead to lateral canal (foraminal stenosis)
[L>R uncovertebral hypertrophy (should be nice kidney-bean shape), and facet hypertrophy]
CT Scan: Uncovertebral Hypertrophy (where?)
MRI: UNCOVERTEBRAL HYPERTROPHY
MRI: UNCOVERTEBRAL HYPERTROPHY
Ligamentum Flavum
-provides stability and protection to spine
-flexible
>> normally thicker when standing or leaning back and thinner when sitting or bending forward
Ligamentum Flavum
Ligamentum Flavum Thickening, & MRI (process and effect)
-natural part of aging process
-Thickening provides additional support when injury or aging occurs but…
-thickened ligament becomes less flexible and weaker and can encroach on spinal canal
Ligamentum Flavum Thickening, & MRI (process and effect)
Calcified Ligamentum Flavum - CT SCAN
Calcified Ligamentum Flavum – CT SCAN
Normal & Abnormal Disc on MRI
ABNORMAL – no water.
Normal & Abnormal Disc on MRI
*Radicular pain:*
-Pain arising from the *spinal root level*
-Sciatica (most common type of radiculopathy)
RADICULOPATHY (most common type)
Specific type of Radiculopathy where pain is caused by impingement/irritation of one of the three lowest lumbar nerve roots (L4, L5 & S1)
Treatment is often nonsurgical unless concurrent cauda equina symptoms present or not responding to conservative therapy
*CAUSES*
-Disc herniation
-Annular tear
Sciatica (causes, treatment)
Normal annulus fibrosus:
-Strong and keeps pressurized nucleus pulposus from escaping outward

Annular Tears/Fissures:
-Separations between one of more of the annular lamellae
-Avulsion of fibers from the vertebral insertion

ANNULAR TEARS (FISSURES)
How to classify Annular tears?
*Modified Dallas Discogram Classification*
[when tear reaches last lamellae = 4] [Grade 5: chemical release, annular tears are NOT A MECHANICAL ISSUE – doesn’t actually leak out]
How to classify Annular tears?
Diagnosis of Annular Tears, & MRI
MRI: can pick up some annular tears, but not all

*Non-Contrast MRI: T2 hyperintensity along annulus*
*Contrast MRI: “lights up” granulation tissue in healing/healed annular disc tear*

Diagnosis of Annular Tears, & MRI
ANNULAR TEAR MRI w/ contrast
R = contrast
ANNULAR TEAR MRI w/ contrast
ANNULAR TEAR imaging (axial view)
ANNULAR TEAR imaging (axial view)
Degenerative disk disease - terminology
free fragment, AKA sequestration
Degenerative disk disease – terminology
DISC BULGE
-Displacement of disc material circumferentially (50-100%) beyond edges of ring apophyses
*CAUSE: LAXITY*
DISC BULGE
CT: L4-L5 DISC BULGE
CT: L4-L5 DISC BULGE
DISC BULGE: MRI
DISC BULGE: MRI
-*Localized (<50%) displacement of disc material beyond limit of disc space* -Disc material mostly nucleus and anulus (but can be other stuff) -What defines borders of Disc Space? (1) Cranio-caudad: vertebral body endplates (2) Anterior-Posterior: outer edges of ring apophyses, exclusive of osteophytes
DISC HERNIATION (borders of disc space)
1) Intravertebral disc herniation (Schmorl’s node) [ant. & sup. into the end-plates; don’t cause much bone pain] 2) Protrusion
3) Extrusion
4) Sequestration
TYPES OF DISC HERNIATIONS
-Greatest distance (in any plane) between edges of disc material beyond disc space is less than distance between edges of disc material at the base in the same plane.
*PLL is ALWAYS intact (contained disc herniation)*
DISC PROTRUSION
2 types of disc protrusions
(1) *Focal*: size of protrusion is <25% of disc circumference (2) *Broad-based*: size of protrusion is 25-50% of disc circumference
2 types of disc protrusions
DISC PROTRUSION graphic
DISC PROTRUSION graphic
DISC PROTRUSIONS imaging
DISC PROTRUSIONS imaging
DISC EXTRUSION Definition
-Dome of herniation is greater in width than base of herniation)
OR
-No continuity exists between the herniated disc material and the disc space

-*PLL is disrupted (uncontained disc herniation)*

DISC EXTRUSION Definition
axial
[compressing exiting nerve root]
DISC EXTRUSION imaging
DISC Extrusion with SEQUESTRATION
-Extruded disc material completely loses continuity with disc space
DISC Extrusion with SEQUESTRATION
DISC Extrusion with SEQUESTRATION images
[disk material that’s contiguous btn levels]
DISC Extrusion with SEQUESTRATION images
-Extruded disc material migrates away from site of extrusion
-Can be contiguous or noncontinguous (sequestration) with disc space [attached or unattached]
DISC EXTRUSION W/MIGRATION
DISC EXTRUSION W/MIGRATION (cont)
DISC EXTRUSION W/MIGRATION (cont)
*1. Central Zone*
-thecal sac
-Right central
-Left central
*2. Subarticular Zone*
-nerve roots
*3. Foraminal Zone*
-Zone between sagittal planes passing through medial and lateral edges of pedicle
*4. Extraforaminal Zone*
-nerve root compression
LOCATION OF DISC HERNIATIONS
BULGE = ligamentous laxity – DOES NOT MIGRATE
Herniation = trauma – PLL can be torn – can migrate
Disc Bulge vs. Disc Herniation
-Immediate referral for MRI or CT
-*Surgical Emergency – immediate surgical consult needed*
CAUSE: Compression of multiple lumbosacral nerve roots below conus medullaris.
Symptoms:
-LB pain
– Sciatica (unilateral or bilateral)
-Saddle sensory disturbances
-Bladder and bowel dysfunction
-Variable lower extremity motor and sensory loss
Cauda Equina Syndrome (cause/sx)
×

Hi there, would you like to get such a paper? How about receiving a customized one? Check it out