Leslie Partridge, RRA, MSRT(R) - srpeweb.org

Leslie Partridge, RRA, MSRT(R)

Drawings by: Joshua Tussing, MSRT(R)(N), RRA

OBJECTIVES

Discuss patient screening, pre-procedure assessment and patient education

process.

Review intrathecal contrast administration

Medication interactions

Allergy issues

Selection of appropriate concentration and dosage

Risks

Analyze puncture and procedure techniques, contraindications and

complications

Present myelogram studies to examine anatomy, procedure technique and

pathology.

I have no disclosures.

HISTORY OF MYELOGRAPHY

1920s – air into subarachnoid space for X-ray eval of spinal tumors

1920s-1930s – oil-based lipiodol

1940s – oil based but less viscous iophendylate(Pantopaque)

1950s-1960s – Iodinated water-soluble, ionic

Methiodal (Abrodil), meglumine iothalamate (Conray), meglumineiocarmate (Dimer X)

1970s – first nonionic water-soluble, metrizamide(Amipaque), CT imaging

1980s – MRI use takes over much of spinal imaging

Today – nonionic water soluble

Iohexal (Omnipaque), iopamidol (Isovue)

INDICATIONS

Pathology contacting, displacing

or impinging on thecal sac,

spinal cord or nerve roots

Degenerative changes of disks,

vertebrae or ligamentum flavum

Examine arachnoid cysts,

arachnoiditis, perineural cysts

Preference of referring surgeon

Cannot have an MRI

Radiation therapy planning

Back or neck pain

Extremity weakness,

radiculopathy, paresthesia

Incontinence

Gait disturbance

Trauma

MRI VS MYELOGRAPHYMRI Myelography

Less invasive

No radiation

No intrathecal contrast

Often no contrast

Intramedullary lesions

Tumors, infarction, demyelination

Extramedullary lesions

Meningiomas, nerve sheath tumors

Negatives:

Low osseous detail, CSF pulsation

artifact, motion degradation,

surgical hardware, claustrophobia

Physician involvement

Improved look at osseous structures

Trauma, congenital anomaly, spinal column curvature

Stenosis by bone or soft tissue

Functional

Delayed passage of contrast across severe stenosis

Dynamic - upright, flexion, extension

Post-op spine

Brachial plexus injury

Radiation therapy planning

CSF leak evaluation

Negatives

Contrast, needles, pain, positioning, radiation

PATIENT SCREENING

History

Indication/symptoms, surgeries,

allergies, current status

Medications

Lab studies

Prior imaging studies

Potential contraindications

Elevated intracranial or intraspinal

pressure

Soft tissue infection at/near

puncture site

Systemic infection with likely

bacteremia

Coagulopathy

Uncooperative patient

Pregnancy

Hepatorenal insufficiency

Contrast allergy

History of seizures

PATIENT PREP

Call 2 days prior to exam

Hold blood thinners or meds that decrease seizure threshold

If contrast allergy, verify premedication

NPO for 4 hours before exam

Except necessary medications

Bring medications for after

Bring outside imaging studies or reports

Must have a driver and someone to help them at home for 24 hours

Arrival time

2 hours early if need coags day of

30 minutes early otherwise

CONTRAST ALLERGY

Mild to moderate » 13 hour steroid prep

Emergency » IV steroid prep

Severe or anaphylactic » serious consideration of alternative imaging

IV access

• 50 mg Prednisone, po

13 hours

• 50 mg Prednisone, po

7 hours

• 50 mg Prednisone, po

• 50 mg Benadryl, po

1 hour

• 40 mg Solu-Medrol, IV

• 200 mg Solu-Cortef, IV

• 7.5 mg Decadron, IV

Every 4 hours*, choose one

• 50 mg Benadryl, IV

1 hour

*ACR – IV steroids have not been shown to be

effective if administered less than 4-6 hours before

contrast.

MEDICATION REVIEWMeds that reduce seizure threshold

Antipsychotics

Psychoactives

Muscle relaxants

Antidepressants

Phenothiazines

MAOIs

Tricyclic

CNS stimulants

MEDICATION REVIEW – BLOOD THINNERSMedication Hold

Warfarin/Coumadin/Jantoven 3-5 days, INR < 1.5

Heparin <10,000U no hold; >10,000U 2-4 hours + normal PTT

Restart 1 hour after

Enoxaparin/Lovenox 40mg QD 12 hours; Treatment dose (1-1.5mg/kg or 100mg

Q12 h) 24 hours before + after

Dalteparin/Fragmin Prophylaxis 12 hours; Treatment 24 hours before + after

Dabigatran/Pradaxa 5 days + normal PTT

Fondaparinux/Arixtra <2.5mg QD 48 hours; 5-10 mg 72 hours

Rivaroxaban/Xarelto Hold 18 hours

Apixaban/Eliquis, Abciximab/ReoPro,

Dipyridamole/Persantine

Hold 48 hours

Edoxaban/Savaysa Hold 24 hours

Bivalirudin/Angiomax Hold 2 hours

Aspirin No hold

Clopidogrel/Plavix, Prasugrel/Effient, Aggrenox Hold 7 days

Ticloplidine/Ticlid Hold 14 days

Tirofiban/Aggrastat, Eptifibatide/Integrilin Hold 8 hours

Alteplase/TPA 2 mg dose for catheter no hold; Full dose delay procedure

10 days

PRE PROCEDURE LAB STUDIES

INR <1.5

Platelet count >50,000

PTT <35

Urine pregnancy test

REVIEW OF PRIOR IMAGING

Anatomy

Optimal puncture level

Level and degree of spinal stenosis

Scoliosis or other deformity

Location of the conus

Postsurgical anatomy

Location of hardware

Post-op infection or abscess

Potential complications

Chiari malformation

Myelomeningocele

Low-lying posterior inferior cerebellar artery (PICA)

Tonsillar ectopia

PROCEDURE - INFORMED CONSENT

Explain procedure

Risks and side effects

Pain

Bleeding

Infection

CSF leak

Headache

N/V

Dizziness

Allergic or anaphylactic reaction

Nerve root injury

Seizures

PROCEDURE - SUPPLIES

Myelogram tray

Needle selection

22G 3.5” or 20G 6”

20G-27G

Quincke, beveled

+ stiffness, easy skin penetration and

steerability

- cuts dural fibers, potential for nerve root

injury

Whitacre, conical

+ spreads dural fibers to decrease risks of

bleeding and CSF leak

- harder to steer

PROCEDURE – CONTRAST SELECTION

Non-ionic, iohexal – total volume up to 3g of iodine

17 mL 180

12.75 mL 240

10.2 mL 300

Ionic has potential for neurotoxicity

Lumbar

12-15 mL

Lumbar, Lumbar + Thoracic, Cervical w/CP

10-12 mL

Cervical w/LP, Thoracic + Cervical w/LP, Entire spine, Cisternogram

10 mL

LP PATIENT POSITIONING

Prone Prone, oblique

Less painful, avoiding

paraspinal musculature

Advanced spinal degeneration

or interspinous osteoarthritis

(Baastrup’s)

THORACIC, CERVICAL OR ENTIRE

LP TECHNIQUE

Dural “pop”

Stretches for 5-10 mm

before puncture

Less likely to feel with

smaller gauge needles

CSF flow

Slight, 1-2mm, advancement

after pop

Rotate bevel cranial

Tilt table head up

CONTRAST INJECTION

“Wet-to-wet” connection

Avoid air bubbles

CSF & contrast mixing

Confirms subarachnoid placement

Elevate head of table

Slow injection of 1-2 mL under

continuous fluoro

“wisp of smoke”

Flows freely away from needle

Finish slow injection with

intermittent fluoro looking for

visible nerve roots

CONTRAST INJECTION

Epidural Subdural

Starburst Linear

CERVICAL PUNCTURE

Higher risk of neurologic

complications

Puncture of cord, nerves or vessels

When?

Lumbosacral skin infection, abscess or

mass

Severe spinal stenosis resulting in a block

Lumbar posterior osseous fusion

Contraindications

Tonsillar ectopia

Chiari malformation

Low-lying PICA

Uncooperative patient

Positioning

Supine, prone or lateral

Head and neck stabilized

True lateral imaging

C1-C2 puncture

Posterior 1/3 meets the anterior 2/3

Advance to midline on AP view

Free flow of CSF to ensure subarachnoid

positioning

Intramedullary injection could cause

catastrophic cord injury

CT IMAGING

Roll patient 360o right before scan

Acquired at 0.5-0.625 mm

Reformatted into 2 mm axial, sagittal and coronal planes

Bone

Soft tissue

3D imaging software

Curved planar reformatting for scoliosis

Dual-energy – metal artifact reduction techniques

Delayed scans

CSF leak

Communications between

cysts and CSF

Subdural injection

POST MYELOGRAM PATIENT CARE

Post procedure care area At home

2 hours of bedrest (2-4 hours)

Head elevated 30-45o

Allowed up to bathroom

Back to normal diet

Encourage fluid intake

Medications

None if doing ok; may take personal

meds

Headache or pain

Tylenol or NSAIDs

Stronger if prescribed

N/V

Zofran

Avoid phenothiazines (Phenergan)

No driving for 24 hours

Lay around for 24 hours

Normal diet with extra fluids

Caffeine

Go to ED if

Fever

Stiff neck

Increased pain or N/V

Swelling or drainage at puncture site

Positional headache after 48 hours

ANATOMY

Thecal sac

Smooth margins

Uniform diameter with tapering near termination S1-S3

AP diameter > 10 mm

Spinal cord

Foramen magnum to conus medullaris, L1-L2

Occupies 50-75% of the subarachnoid space

Normal AP diameter = 7 mm

Two areas of fusiform enlargement

Lower C spine

Thoracolumbar junction

Nerve roots

Exit bilaterally through the intervertebral neural foramina

Ventral and dorsal components

SPINAL STENOSIS

Common causes

Bulging or protruded disks

Ligamentum flavum hypertrophy

Facet hypertrophy

Degenerative osteophytes

Spondylolisthesis

Congenital causes

Short pedicles, thick laminae, large

facets

Morquio’s syndrome

Achondroplasia

6 mm

7 mm

8 mm

9 mm

10 mm

SPINAL CORD COMPRESSION

No CSF around the cord

Narrowed AP diameter <7mm

Deformity of cord

Causes

Infection (TB, pyogenic)

Fractures (malignancy, trauma)

Disk disease (HNP, ligament hypertrophy,

osteophytes, facet hypertrophy)

Primary bone disorders (Paget’s disease)

Benign tumors (cysts, lipoma)

Epidural hematoma

FORAMINAL STENOSIS

Common causes

Osteoarthritis of facet joints

Buckling/thickening of

ligamentum flavum

Spondylolisthesis

Lateral herniated discs

Fracture

Post-op scarring

Extradural masses

POST OP SPINE COMPLICATIONS

Recurrent disk herniation

Scarring

Neural foramina stenosis

Neuritis

Arachnoiditis

Lateral recess stenosis (post-

laminectomy)

Dural bulge/pseudomeningocele

Diskitis

Epidural hematoma or abscess

INTRAMEDULLARY LESIONS

Tumor

Astrocytoma

Ependymoma

Hemangioblastoma

Metastases

Demyelinating disease/myelitis

Syringohydromyelia (tumor or

Chiari malformation)

AVM

Trauma

INTRADURAL EXTRAMEDULLARY LESIONS

Nerve sheath tumor

Neurofibroma

Schwannoma

Meningioma

Metastases

Lipoma

Teratoma

Arachnoid cyst

Arachnoiditis/meningitis

AVM/AVF

EXTRADURAL LESIONS

Disk

Metastases

Epidural abscess

Hematoma

Lipomatosis

Synovial cyst

Perineural cyst

1

2

3 4 5

6

7 8

Change patient position if contrast is

not going where you want it to go!

QUESTIONS?

[email protected]

REFERENCES

Boutin, RD, Rupp FW. Myelography.

Harisinghani, MG, Chen JW, et al. Primer of Diagnostic Imaging. Elsevier,

2019.

Harreld JH, McMenamy JM, et al. Myelography: A Primer. Current

Problems in Diagnostic Radiology July/August:149-157, 2011.

Pomerantz, SR. Myelography: modern technique and indications.

Handbook of Clinical Neurology, Vol. 135, p. 449-468. Elsevier, 2016.