This document provides information about myelography, a radiographic procedure used to examine the spinal cord and surrounding structures. It begins with definitions of key terms like myelogram and spinal cord anatomy. It then describes the meninges layers surrounding the spinal cord and details the standard myelography procedure, which involves injecting water-soluble contrast into the thecal sac between the L3-L5 vertebrae under fluoroscopy. Post-procedure monitoring and potential complications are also outlined.

1. MyelographyMyelography

2. MyelogramMyelogram
Myelogram: Myel/o means spinal cord
or bone marrow – gram: …………
 Note DO NOT confuse for my/o, which means muscle)
The spinal cord is part of the Nervous
System. Therefore, this a study focused
on the spinal cord anatomy which could
be affected by the bony anatomy of the
spine.

3. Basic Spinal Cord AnatomyBasic Spinal Cord Anatomy
For description, the central nervous
system (CNS) is divided into
◦ Brain
◦ Spinal cord
CNS tissue composed of two main
portions
◦ Gray matter = outer portion or cortex
◦ White matter = inner portion

4. Spinal CordSpinal Cord
Slender, elongated structure
Consists of an inner gray
cellular substance and an
outer white fibrous
substance
◦ Gray substance forms H-shape
seen on transverse section
Extends from the brain
to the L1-L2 space
Conus medullaris = pointed
end of spinal cord

5. SPINAL CORDSPINAL CORD
Gray substance forms H-shape seen on
transverse section

6. SPINAL CORDSPINAL CORD
Filum terminale =
delicate fibrous portion
that connects the
terminal tip to the first
coccygeal segment

7. Spinal CordSpinal Cord
Connected to 31 pairs of spinal nerves
◦ Arise from roots on each side of cord
◦ Transmitted through intervertebral and sacral
foramina
Cauda equina refer to spinal nerves

8. MeningesMeninges
Three continuous, protective membranes
that enclose the brain and spinal cord
Pia mater = inner sheath; highly
vascular and closely adhered
Arachnoid = delicate central sheath
Subarachnoid space = wide space
between arachnoid and pia mater
◦ Continuous with ventricular system

9. MeningesMeninges
Subarachnoid cisterns = areas of
subarachnoid space that are increased in
width
Cisterna magna = widest of subarachnoid
cisterns
◦ Located in lower posterior fossa between
base of cerebellum and dorsal surface of
medulla oblongata

10. MeningesMeninges
Dura mater = outermost meningeal
layer; strong, fibrous
◦ Separated from arachnoid by subdural space
◦ Separated from vertebral periosteum by
epidural space
◦ These spaces do not communicate with
ventricular system

11. MeningesMeninges
◦ Dural sac (Thecal sac) =
encloses cauda equina

12. Myelography (procedure)Myelography (procedure)
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 (sterile
procedure)
Puncture made at L2-L3 or L3-L4 space
◦ May also be introduced into cisterna magna at C1 and
occipital bone (this is no longer standard procedure
in USA)

13. Standard ProcedureStandard Procedure
Standard procedure is the most
common way to proceed in a
determined area or region.
In USA, myelograms are commonly
done injecting in the thecal sac using a
Sprotte Needle. (this is a blunt needle
that has been replacing the spinal
needle)
Water soluble contrast

14. Thecal SacThecal Sac
Commonly located
between L3 and L5
Made by the outermost
meninge
Which is the ?
Dura mater =
outermost meningeal
layer; strong, fibrous

15. MyelographyMyelography
Usually performed as outpatient basis
◦ Patients held for recovery after procedure for
4 to 8 hours, then released to go home
MRI often used instead
Myelography still used for patients with
contraindications for MRI
◦ Pacemakers and metal fusion rods

16. MyelographyMyelography
Contrast is generally water-soluble, nonionic,
and preservative free iodinated medium
Invasive Procedure
Room should be prepared by RT before patient
arrival
◦ Table and equipment (FL IR) cleaned
◦ Footboard and shoulder supports attached
◦ Radiographic equipment checked
◦ Image intensifier locked to prevent accidental contact
with sterile field or spinal (Sprote) needle

17. MyelographyMyelography
Premedication rarely needed (allergies)
Patient should be well hydrated
Procedural details, including table
movement and sensations, should be
explained
Scout images made: AP & Lat
Prone position usually used for spinal
puncture
◦ Lateral with spine flexed may also be used

18. MyelographyMyelography
Local anesthesia given at puncture site
Spinal needle inserted
CSF usually withdrawn and sent to
laboratory
Contrast injected and needle removed
Table angle and gravity used to move
contrast under fluoroscopy
Spot images taken as needed (protocol)

19. MyelographyMyelography
If contrast is moved into cervical area,
head is positioned in acute extension to
prevent contrast from entering
ventricular system (varies depending on
T, L and/or C spine
◦ Acute extension compresses cisterna magna
and is the only position that will prevent
contrast from entering ventricles

20. MyelographyMyelography
Postprocedure monitoring required
◦ Head and shoulders elevated 30 to 45
degrees
◦ Bed rest for several hours (Dr instructions)
◦ Fluid encouraged (caffeine not recommended)
◦ Puncture site checked before release

21. MyelographyMyelography
Instructions for a possible contrast reaction
Instructions for a possible spinal headache

22. Spinal Cord AnatomySpinal Cord Anatomy
Transverse section of spinal cord