radiology

1. MYELOGRAPHY

2. Meninges
 Membranes that enclose the brain
and spinal cord
 Dura Mater- outer layer
 Arachnoid = middle layer
 Pia mater = innermost layer
 Subarachnoid space = wide
space between arachnoid and
pia mater

3. Subarachnoid space
 Wide space between arachnoid and pia mater
 Filled with CSF
 Bathes brain & spinal cord with nutrients
 Cushions against shocks and blows
 Where contrast is injected for myelograms

4. CSF Information
 Total adult CSF volume is 150 ml
 50% intracranial
 50% spinal
 Adult opening pressure is normally 7-15 cm
fluid
 >18 abnormal
 Young adults slightly higher <18-20

5. Spinal Cord Diameter
 AP diameter is 7mm through C7
 C7 to conus medullaris is 6mm
 At conus it is 7mm
 Cord size is considered abnormal if it is over
8mm or under 6mm

6. Myelography
 radiologic examination of the CNS structures situated
in the vertebral canal
 Requires contrast introduction into the subarachnoid
space by spinal puncture
 Puncture made at L2-L3 or L3-L4 space
 May also be introduced into cisterna magna at C1 and
occipital bone

7. Myelography
 Contrast is generally
water-soluble,
nonionic, iodinated
medium
OMNIPAQUE
ISOVUE

8. Contrast Precautions
 Verify it is the correct contrast
 Non-ionic iodinated contrast
 Omnipaque or Isovue
 Correct concentration
 180 and 300 common
 Check expiration date
 Keep contrast vial in room until procedure is
complete

9. Puncture made at L2-L3 or L3-L4
space

10. Spinal needle injection

11. MYELOGRAM WITH CONTRAST

12. Room should be prepared by RT
before patient arrival
 Table and equipment cleaned
 Footboard and shoulder
supports attached
 Radiographic equipment
checked
 Image intensifier locked to
prevent accidental contact
with sterile field or spinal
needle
 Tray setup
FOOT
BOARD
SHOULDER
PADS
Hand grips

13. MYELOGRAM TRAY

14. Additional items
 Blankets
 Sterile towels
 Sodium bicarbonate (if not in tray)
 Non-ionic iodinated contrast media
 Sterile gloves for DR
 Shields for PT, DR, anyone else in room
 Varying sizes of spinal needles and needles
 Extra syringes and tubing
 Cleaning liquid

15. Syringes and Spinal Needles
Syringes
Spinal
Needles
(covered)
More Spinal Needles (uncovered)

16. PRE- Procedure :Myelography
 Premedication rarely needed
 Patient should be well hydrated
 Check orders, obtain history, labs results (if necessary),
and previous exams
 Informed consent:
 Risks, benefits alternatives
 Procedural details, including table movement and
sensations should be explained, and get pt into a gown

17. Contraindications and Considerations
 PT < 15.0 seconds
 Preferable to reschedule exam if below 15
 Platelets >100,000
 If below 50,000 a platelet transfusion may be indicated
before procedure
 Heparin stopped 4 hours before
 Can be restarted 2 hrs after procedure
 Usually given as IP
 Coumadin stopped 3-4 days before
 Usually OP
 Labs usually indicated

18. Radiation Safety
 Have shields for PT’s, DR
 Question LMP and the possibility of being pregnant
 Use cardinal rules
 Time
 Distance
 Shielding
 ALARA
 Use pulse if possible
 Save the last image on screen when possible

19. Prone &
Lateral Flexion
 Prone
 Pillow under abdomen
for flexion of spine
 Lateral flexion
 Widens interspace for
easier introduction of
needle

20. Scout Images
 Cross table lateral
 With grid
 Closely collimated

21. Myelography
 Local anesthesia given at puncture
site
 Lidocaine and sodium bicarbonate
 Spinal needle inserted (pressure
obtained)
 CSF usually withdrawn and sent to
laboratory
 Contrast injected and needle
removed
 9-12 ml
 Table angle and gravity used to
move contrast under fluoroscopy
 Spot images taken as needed

22. Spot Films
 Central ray vertical or horizontal using CR or film
screen cassettes
 Images are taken at
 Site of blockage
 Level of distortion
 If conus medullaris is area of concern:
 Lay pt supine
 Central ray at T12- L1
 Use 10x12 cassette and collimate tightly

23. Myelogram overview

24. Myelography
 If contrast is moved into cervical area, head is
positioned in acute extension to prevent
contrast from entering ventricular system
 Acute extension compresses cisterna magna and
is the only position that will prevent contrast from
entering ventricles

25. Myelography
 Usually performed as outpatient basis
 Common for CT myelography (CTM) to be used with
conventional Myelogram
 MRI often used instead
 Myelography and CTM still used for patients with
contraindications for MRI
 Pacemakers and metal fusion rods

26. Post procedure: Myelography
 Monitoring required
 Head and shoulders elevated 30 to 45 degrees
 Bed rest for several hours
 Fluid encouraged
 Puncture site checked before release

27. Possible Complications from
Myelography
 Vomiting
 Vertigo
 Neck Pain
 Spinal Headache
 Due to loss of CSF
during puncture
 Increased severity
upright
 Decreased pain when
recumbent.

28. More Severe Complications
 Nerve root damage
 Meningitis
 Epidural abscess
 Contrast reaction (anaphylactic shock)
 CSF leak
 Hemorrhage

29. Treatment for Spinal Headache
 Initial treatment
 NSAIDS
 Horizontal position
 Forced fluids
 Caffeine
 Persistent headache
 If a fever occurs,
 May be indicative of
meningitis
 Beyond 48 hrs w/o
fever (24 hrs if severe)
 Blood patch

30. Blood Patch
 Sterily injecting a
small amount of
patient’s blood into the
epidural space
 Clot will occur over
hole
 Usually will stop
headache immediately
 1st patch is 70%
effective
 2nd patch is 95%
effective

31. Myelogram radiographs

32. Myelograms Images

33. CTM
 Performed after intrathecal injection
 Can be performed at any level of vertebral column
 Multiple slices taken (1.5 – 3mm)
 Gantry is tilted
 Windowing allows for density and contrast changes
 Can obtain images with small amounts of contrast
 Can be done 4 hours after initial injection

34. CTM

35. MRI of Spinal Cord and CSF flow
 Non-invasive
 Provides anatomic detail of brain, spinal cord,
intravertebral disc spaces, and CSF within
subarachnoid space
 Does not require intrathecal injection
 Does not have bone artifacts

36. Myelography Using MRI and
Conventional methods
MYELOGRAM

37. Preference of MRI
 Spinal cord
 Allows direct visualization of spinal cord, nerve
roots, and surrounding CSF
 Can be done in various planes
 Aid in diagnosis and treatment of neurodisorders

38. Usefulness of MRI
 Assessing
demyelinating disease
 Such as MS
 Spinal cord
compression
 Postradiation therapy
changes of spinal cord
tumors
 Herniated disks
 Congenital
abnormalities of
vertebral column
 Metastatic disease
 Paraspinal masses

39. Diskography and Nucleography
 Radiologic exam of individual intervertebral
disks
 Small amount of water soluble iodinated contrast
injected into center of disk double needle entry
 Pt’s given local anesthetic
 So pt is alert and communicate with DR about pain
when needle and contrast are inserted
 Used to investigate disk lesions
 Ruptured nucleus pulpous
 Has been largely replaced by CTM and MRI

40. Diskograms

41. Lumbar Diskograms

42. THANKS