MYELOGRAM

The Outline

DEFINITION

CM ( TYPE, INJECTION PROCESS, PUNCTURE

POSITIONS)

IMAGING TECHNIQUE

PATIENT PREPARATION

CONVENTIONAL RADIOGRAPHS POSITIONS

INDICATION & CONTRAINDICATION

BENEFITS & RISKS

LIMITATIONS

What is a myelogram?A myelogram is a radiographic

study combining the use of a contrast medium with a fluoroscopy to evaluate abnormalities of the spinal cord and its nerve root branches.

usually completed within 30 to 60 minutes

Contrast Medium Types,1. oil-based,

2. water-soluble,

3. air-contrast.

Currently, Non ionic, water soluble iodine-based media

Dosage,Generally 6-17 ml Recommended by manufacturer and varies

with the medium concentration.

Injection of Contrast Medium

where? into the subarachnoid space. Lumbar Puncture (L3-L4) Cervical Puncture (C1-C2)

The radiologist looks at the spine under fluoroscopy to find the best location to position the needle.

The skin is cleaned, then numbed with local

anesthetic. The needle is inserted and the contrast medium is

injected through it into the subarachnoid space.

Body position for lumbar puncture:

1. Prone position.

2. Left lateral position, with spine flexed to widen the interspinous space.

Body position for cervical puncture:

1. Erect position.

2. Prone position, with the head flexed to open the interspinous space.

Puncture Positions

Imaging Technique1. After injection, the table is tilted slowly to allow

the CM to reach different levels in the spinal canal. (A footrest and shoulder straps or supports will keep the patient from sliding)

2. under fluoroscopy, spot films are taken by the radiologist in different positions.

3. the table tilt is adjusted to concentrate the CM in the interested area.

4. Conventional x-ray images is taken by the technologist as requested.

patient prparation Remove any metal objects or clothing that might

interfere with the x-ray images.

Injectable sedative-muscle relaxant at 1 hour before the examination, to reduce anxiety and relax the patient.

Solid foods are avoided for several hours before the exam.

Increase patients fluid intake the day before a scheduled myelogram.

Position images(B)

>Horizontal beam lateral Cp: c4-c5

>Swimmer’s lateral-horizontal beamCp: c7

2 -THORACIC MYELOGRAPHY

>Lateral decubitus (RT & LT)>Lateral-vertical beam (RTor LT)

Cp : T7

1 -CERVICAL MYELOGRAPHY

CERVICAL MYELOGRAM

LATERAL VIEW

C-2

THECAL SAC

POST OF FUSION

C-5-6

C-3-4 DISC

IODINATED CONTRAST IN THECAL

SAC

CERVICAL MYELOGRAMLATERAL VIEW

Position images(B) cont.

3 -LUMBAR MYELOGRAPHY

With the patient prone, arms flexed above headTable tilted , concentrated CM in interested area.

cp: to L3

CR: Horizontal beam

>ALL in Suspended respiration

NERVE ROOTS

THECAL SAC

LUMBAR MYELOGRAMAP VIEW

IODINATED

CONTRAST IN

THECAL SAC

indications

Spinal cord tumersCystsSpinal nerve root injury.compression of the spinal cord by a herniated

disc.

ContraindicationsBlood in the CSF.Increase intracranial pressure.Decreased platelet count, or patients

on anticoagulation Arachnoditis

Benefits• Obstruction and abnormalities are easily seen and

well defined on X-rays Accurate diagnosis.

• Myelography is relatively safe and painless.

• X-rays usually have no side effects in the diagnostic range.

Risks

• The effective radiation dose from this procedure is about the same as the average person receives from background radiation in 16 months.

• Allergic reaction to the contrast dye.• slight risk of infection(needle)• headache may follow the myelography due to the

leakage of a small amount of CSF from the needle insertion site.

Benefits outweighs

Limitations of Myelography It’s only sees inside the spinal canal and the very proximal

nerve roots. Abnormalities outside these areas may be better imaged with MRI.

 

It may be difficult to inject contrast material in patients with structural defects of the spine or some forms of spinal injury.

Myelography usually is avoided during pregnancy ( If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby).

 

This procedure has largely been replaced by non-

invasive MRI or CT procedures

DONE BY;

ALAA SHATHAEIDAHNORA