1. MYELOGRAPHY and CNS Exams using MRI & CT
Spring 2013

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
Has protective membranes that enclose the brain and spinal cord
Dura Mater- outer most layer
Tough and fibrous
Arachnoid = middle layer
Has appearance of cobwebs
Pia mater = innermost layer
highly vascular and closely adhered to cortex and spinal cord
Subarachnoid space = wide space between arachnoid and pia mater
Filled with CSF
Bathes brain & spinal cord with nutrients
Cushions against shocks and blows

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
General term applied to the 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
These pathologies are demonstrated radiographically as a deformity in the subarachnoid space or an obstruction of the passage of the contrast within the subarachnoid space.
It is also useful in identifying a stenosis or narrowing of the subarachnoid space by watching the dynamic flow patterns of the CSF.

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 and Cisterna Magna

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, and yourself
Varying sizes of spinal needles and needles
Extra syringes and tubing
Cleaning liquid

15. Syringes and 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
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
Since the Prothrombin time (PT) evaluates the ability of blood to clot properly, it can be used to help diagnose bleeding. When used in this instance, it is often used in conjunction with the PTT to evaluate the function of all coagulation factors. Occasionally, the test may be used to screen patients for any previously undetected bleeding problems prior to surgical procedures.
In an adult, a normal count is about 150,000 to 450,000 platelets per microliter of blood. If platelet levels fall below 20,000 per microliter, spontaneous bleeding may occur and is considered a life-threatening risk. Patients who have a bone marrow disease, such as leukemia or another cancer in the bone marrow, often experience excessive bleeding due to a significantly decreased number of platelets (thrombocytopenia). As the number of cancer cells increases in the bone marrow, normal bone marrow cells are crowded out, resulting in fewer platelet-producing cells.
Low number of platelets may be seen in some patients with long-term bleeding problems (e.g., chronic bleeding stomach ulcers), thus reducing the supply of platelets. Decreased platelet counts may also be seen in patients with Gram-negative sepsis.
Individuals with an autoimmune disorder (such as lupus or idiopathic thrombocytopenia purpura (ITP), where the body’s immune system creates antibodies that attack its own organs) can cause the destruction of platelets
Heparin is a medication that is used in hospitals across the world to prevent blood clot formation. Heparin can be given either directly into the bloodstream, or as an injection under the skin. No oral form of heparin is available. To prevent the formation of dangerous blood clots in people who must stay in bed for prolonged periods of time. This can be accomplished with a low daily dose of this medication which is typically given under the skin, which is known to prevent the formation of deep venous thromboses, or DVTs in the deep veins of the legs, thighs, and pelvis. Such blood clots are known as DVTs for short, and are well known to cause strokes and pulmonary embolisms, (PEs) which can be lethal (see below).
To treat pulmonary embolisms: Pulmonary embolisms are blood clots that migrate into the lungs from the heart, or from the deep venous system of the body. Once in the lungs, pulmonary embolisms can block blood flow to large portions of the lung and prevent oxygen-poor, venous blood from being repleted with oxygen. As stated previously, PEs can be lethal.
To prevent the enlargement of high risk blood clots found inside the heart, and other parts of the body, as they can cause pulmonary embolisms or strokes.
To prevent the formation of blood clots during heart surgery, or during surgery of the large arteries.
Coumadin (warfarin) is an anticoagulant (blood thinner). Coumadin reduces the formation of blood clots by blocking the formation of certain clotting factors.
Coumadin is used to prevent heart attacks, strokes, and blood clots in veins and arteries.

17. Radiation Safety Have shields for PT’s, DR and yourself
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

18. Prone & Lateral Flexion
Pillow under abdomen for flexion of spine
Lateral flexion is not commonly used
Widens interspace for easier introduction of needle

19. Scout Images
Cross table lateral
With grid
Closely collimated

20. Myelography Images are taken at
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 contrasCentral 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
t under fluoroscopy
Spot images taken as needed

21. Myelogram overview
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

22. 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

23. 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
Vomiting
Vertigo
Spinal Headache
Neck pain
Due to loss of CSF during puncture
Increased severity upright
Decreased pain when recumbent.
Nerve root damage
Meningitis
Epidural abscess
Contrast reaction (anaphylactic shock)
CSF leak
Hemorrhage
Neck Pain

24. Treatment for Spinal Headache
Initial treatment
Tylenol
Horizontal position
Forced fluids
Caffeine
Persistent headache
If a fever occurs, contact MD
May be indicative of meningitis
Beyond 48 hrs w/o fever (24 hrs if severe)
Blood patch
It can last up to one week.

25. 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

26. Myelogram radiographs

27. Myelograms Images

28. 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
Very common for CTM to be done post- conventional Myelogram.
Gantry is tilted so that images are taken parallel to the plane of the vertebral disks of interest.
CTM demonstrates size, shape and positioning of the spinal cord and nerve roots.
It is extremely useful in determining the extent of dural tears resulting from extravasation of the CSF.

29. 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
Provides excellent anatomic detail.
Allows visualization of the areas of CNS normally obscured by bone
Shows exact demonstration between soft tissue and bone structures

30. MRI basics T1 & T2 images can be taken
Head coil for brain
Body coil and surface coil form spine
IV contrast can be used to enhance tumor
Gadolinium

31. Contraindications to MRI
Pacemakers
Ferromagnetic aneurysm clips
Metallic spinal fusion rods

32. Myelography Using MRI and Conventional methods
MRI is the preferred modality for middle and posterior cranial fossa of brain.
In CT these structures are obscured by bone artifacts
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
MYELOGRAM

33. MRI and Brain imaging Middle and posterior fossa abnormalities
Acoustic neuromas
Pituitary Tumors
Primary and metastatic neoplasms
Hydrocephalus
AVM’s
Brain atrophy

34. Not valuable for diagnosing:
Osseous bone abnormalities of skull
Intracerebral hematomas
Subarachnoid Hemorrhage
CT preferred for these 3 illnesses

35. CT of Brain basics
Useful for demonstrating size, location and configuration of mass lesions and surrounding edema
Assessing cerebral ventricle or cortical sulcus enlargement
Shifting of midline structures caused by mass lesions, cerebral edema, or hematoma

36. Indications for Pre and Post contrast Imaging using CT
Suspected Neoplasms
Suspected metastatic disease
Arteriovenous malformation (AVM)
Demyelinating disease (MS)
Seizure disorder
Bilateral isodense hematomas

37. Indications for Brain scans without Contrast media
Dementia
Craniocerebral trauma
Hydrocephalus
Acute infarcts
Post evacuation follow up of hematomas

38. CT Brain imaging Most often Axial orientation
Gantry degrees to OML
Allows lowest slice to provide an image of both the upper cervical, foramen magnum, and roof of orbit
12-14 slices
8-10 mm slices
3-5 mm slices through post fossa
Depending of PT size
Slice thickness

39. CT Brain imaging (cont)
Coronal imaging
Helpful in evaluation of
Pituitary gland
Sella turcica
Facial bones
Sinuses

40. CT: Modality of choice Modality of choice for the following”
Hematomas
Suspected aneurysms
Ischemic or hemorrhagic strokes
Acute infarcts
Used as initial diagnostic modality for:
Craniocerebral trauma

41. CT of Spine
Useful in diagnosis of vertebral column hemangiomas and lumbar spine stenosis
Often used post-trauma to assess Axis and Atlas fractures and for better demonstration of C7-T1
Clearly demonstrates size, number and locations of fracture fragments of C, T and L spine.

42. Surgery Applications of CT imaging
Greatly assists surgeons in distinguishing neural compression by soft tissue from compression by bone
Post-op
Useful in assessing outcome of surgical procedure

43. MRI vs. CT MRi superior to CT for imaging of posterior fossa
CT has artifacts from bone
MRI is free from bone artifacts
MRI has inability to image calcified structures. CT is superior for calcifications
MRI can detect cerebral infarction earlier than CT.
Both modalities provide similar information on subacute and chronic strokes

44. Diskograms http://www.youtube.com/watch?v=Cf-Ce7K3Qqk
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

45. Lumbar Diskograms

46. Vertebroplasty under Fluoro
Interventional radiology procedure to treat compression fractures or other pathologies in the vertebral bodies
Used when conservative treatment does not work
Done in specials or OR
Trocar needle is advanced through pedicle into the vertebral body under fluoro
Non-ionic contrast media is used to confirm needle placement
Bone cement ( polymethyl methacrylate) is injected into vertebral body using fluoro
AP & LAT images taken post procedure
CT sometimes done as well
Used when severe pain does not improve over a number of weeks of treatment

47. Post Vertebroplasty

48. Kyphoplasty Outline
Trocar needle advanced
Through pedicle, avoiding spinal canal
Biopsies can be taken
Balloon catheter used to expand the compressed vertebral body to near its original height before injection of bone cement
Trocar needle is considered the “working cannula”

49. Pre and Post Kyphoplasty radiographs

50. Complications of Vertebroplasty and Kyphoplasty
Most common: leakage of cement
Less common: pulmonary embolism
Death

51. Success of Vertebroplasty and Kyphoplasty
Success is measured by the pt’s pain reduction and quality of life improvement
Can help reduce hunchback and restore normal curvature
With Kyphoplasty there is a 80-90% success rate

52. Pain Management Epidural Injection Facet Injection
Spinal Cord stimulation
Radiofrequency Neurolysis

53. Considerations of Pain Management Interventional Procedures
Stop NSAID 3 days prior to procedures
With Facet injections no pain relievers 4 hours prior to procedure
Takes days for full results to manifest
Done when conventional treatment has not helped

54. Epidural Place a needle (often with catheter) into epidural space
Used to treat pain as a result of and injured disk affecting spinal nerves
Decreased inflammation & swelling
Done under fluoroscopy with PT awake
Takes minutes
Recovery short
Sterile procedure
Complications
Spinal headache (most common)
Infection
Epidural HematomaCan be done at any level of the spine
Place a needle (often with catheter) into epidural space
Small amount of contrast injected to verify placement
Corticosteroid & anesthetic injected (
Cortisone
Lidocaine

55. Epidural with Catheters

56. Facet Injections Inject needle into facet joint
Inject contrast to verify needle placement
Inject lidocaine or bupivivaine (anesthetic) & corticsteroid (anti-inflammatory)
Indications:
Diagnosis
Therapy
Causes of pain include:
Inflammation, swelling, or arthritis
Awake under fluoro
Takes minutes
Sterile procedure
Complications
Pain at site
Bleeding
Infection
Increase in pain

57. Side effects of Steroids
Fluid retention
Weight gain
Mood swings
Increase in blood pressure
Usually temporary

58. SCS Radiographs Wires placed in epidural space
Delivers low voltage electrical stimulation to the spinal cord
Delivered through 1-2 wires which are carefully placed in epidural space
Electrical signals replace sensation of pain with a tingling sensation
Done in two stages
Trial
Permanent placementDone in OR
Local anesthetic & intravenous sedation
Wires placed in epidural space
PT goes home with wires in place for 1 week to test and see if it helps
If trial period helps permanent generator is placed under skin in OR
Contains generator with battery (some are rechargeable)
Periodically battery is replaced
Others have transmitters & generators

59. SCS With Generator and Transmitter

60. SCS Indications, Benefits & Risks
Reduces rather than eliminates pain
Reduces pain by 50%
Reduces narcotic use
Risks
Infection & bleeding
Paint at insertion site
Nerve injury
Dural puncture or tear
Migration or breakage of wire
Indications:
Chronic pain associated with:
Neuropathic pain
Failed back surgery syndrome
Arachnoiditis
Certain vascular disease

61. Radiofrequency Neurolysis
Helps for 6-24 months
70% of PT’s get relief
Takes about minutes
Can be repeated if pain returns
Uses high frequency radio waves to produce a heat lesion
Lesion ablates or inactivates nerves responsible for transmitting pain
Usually done in L and C spine
Pain can be caused from whiplash or arthritis
Done under fluoro in OR
PT is awake and mildly sedated
Local anesthetic injected
Stimulation test is done to verify needle placement
PT is questioned for tingling or buzzing feeling (as when hitting your funny bone)
Once PT confirms this , they are sedated more
Radio waves are transmitted ablating the nerve
Muscles may spasm or “jump”