Indications and contraindications for MRI with myelography
The procedure is carried out for the following purposes:
- search for the causes of neurological disorders (weakness, numbness, pain in the limbs);
- diagnosis of arachnoiditis;
- exclusion of spinal column tumors;
- search for areas of damage to the spinal nerve roots;
- detection of spinal canal stenosis;
- diagnosis of herniated intervertebral discs;
- exclusion of tumors and infections of the spinal canal and nerve roots.
Patients with discogenic myelopathy, syringomyelia, compression fracture of the spine, spinal cord injuries, and spinal osteochondrosis are referred for MRI with myelography.
Research cannot be carried out:
- during pregnancy;
- if the patient cannot remain still during the scan;
- with exacerbation of diseases of the heart, liver, kidneys;
- in case of severe arthritis;
- during feverish conditions;
- if the patient has congenital anomalies or spinal injuries that prevent the administration of a contrast agent;
- for inflammation of the skin in the injection area;
- in case of previous operations on the spinal column.
Main services of Dr. Zavalishin’s clinic:
- consultation with a neurosurgeon
- treatment of spinal hernia
- brain surgery
- spine surgery
Myelography
Yagnikov S.A., Semchenkova M.L., Kornyushenkov E.A., Vilkovysky I.F. Kusenkov S.A., Sedov S.V., Krivova Yu.V.
Contrast spondylography is indicated for animals with progressive neurological symptoms to determine the level of spinal cord compression. In some observations, this type of research allows a final diagnosis to be made for the animal. Complications with this type of research in our clinic are 2.5% (in 1 animal out of 40). Animals undergo a suboccipital puncture with the introduction of a contrast agent into the cerebellocerebral cistern and/or lumbar puncture at the level of L IV-V or L V-VI.
The study is performed under general anesthesia. After administration of a contrast agent, the animal undergoes an X-ray examination of a certain part of the spinal column. Normally in dogs, the contrast agent is distributed in two contrasting columns from the first cervical (CI) to the third sacral vertebra (S III).
Rice. 1. X-ray of the cervical spine in a lateral projection. Free passage of the contrast column from CI to Th I.
Rice. 2. X-ray of the thoracic spinal column in a lateral projection. Free passage of the contrasting column.
Rice. 3. X-ray of the lumbar and sacral parts of the spinal column in a lateral projection. Free passage of the contrast column up to S III.
Rice. 4. X-ray of the lumbar spinal column in a lateral projection. Free passage of the contrast column in the presence of first-order osteophytes on the ventral surface of L II – L III. The presence on plain radiographs of osteophytes on the ventral surface of the vertebral bodies without neurological symptoms corresponding to this level is not always the cause of neurological symptoms. What does this x-ray show?
Rice. 5. X-ray of the lumbar spinal column in a lateral projection. Free passage of the contrast column in the presence of first-order osteophytes on the ventral surface LI - L II - L III. The presence on plain radiographs of osteophytes on the ventral surface of the vertebral bodies without neurological symptoms corresponding to this level is not always the cause of neurological symptoms. What does this x-ray show?
Rice. 6. X-ray of the lumbar spinal column in a lateral projection. Ankylosing spondylosis of the lumbar spine. Free passage of the contrasting column. The presence of osteophytes on the ventral surface of the vertebral bodies on plain radiographs, without neurological symptoms corresponding to this level, is not always the cause of neurological symptoms. What does this x-ray show?
Rice. 7. X-ray of the cervical spine in a lateral projection. Dorsal displacement of the ventral contrast column. Disc herniation C III – C IV according to Hansen type I.
Rice. 8. X-ray of the lumbar spinal column in a lateral projection. Dorsal displacement of the ventral contrast column. Disc herniation L II - L III according to Hansen type II.
Rice. 9. X-ray of the thoracic and lumbar spine of a dachshund in a lateral projection. Complete blocking of the contrast column at level L I – L II . Disc herniation according to Hansen type I, at level L I - L II .
Rice. 10. X-ray of the thoracic and lumbar spine of a dachshund in a lateral projection. When performing a suboccipital puncture on this animal, the contrast column stopped at the atypical level Th VIII – Th IX . Based on the medical history, the stop of the contrast agent at an atypical level was a consequence of ascending edema of the spinal cord. To determine the “true” level of intervertebral disc displacement, the animal underwent a lumbar puncture with the introduction of a contrast agent. Complete blocking of the contrast column at level L I – L II . Disc herniation according to Hansen type I, at level L I - L II .
Rice. 11. X-ray of the thoracic spinal column in a lateral projection. In the presence of spinal cord edema, lumbar puncture allows injection of a contrast agent, which helps to visualize the site of spinal cord compression on an x-ray.
Rice. 12. X-ray of the lumbar spinal column in a lateral projection. In myelomalacia of the spinal cord, the contrast agent spreads along the entire perimeter of the spinal canal in the form of a contrast shadow .
Rice. 13. X-ray of the lumbar spinal column in a lateral projection. The entry of the contrast agent into the epidural space causes the arched shape of the ventral contrast column. This study is of little information.
Rice. 14. X-ray of the lumbar spinal column in lateral and ventro-dorsal projections. Blocking of the contrast column at the level of L V -VI and L VII – S I. This radiographic picture is typical for compression of spinal nerves at the level L VII - S I , due to intervertebral disc herniation, lig hypertrophy. flavum, and a decrease in the lumbosacral angle.
Rice. 15 and 16. X-ray of the cervical and lumbar spine in a lateral projection. Blocking of the contrast column at level C IV-V and at level L IV-V with a dovetail divergence of the contours of the contrast column is typical for tumors of the epidural space.
Conclusion: Myelography in dogs and cats is an accessible research method that allows one to determine the level of spinal cord compression.
The frequency of complications leading to the death of the animal is 1-2.5%.
Preparation for MRI of the spine with myelography
You must complete your last meal 8 hours before the test. If the cervical spine is to be examined, you need to take a sedative to suppress the swallowing reflex (prescribed by your doctor). Before MRI of the lumbar region with myelography, it is necessary to give a cleansing enema.
Before the examination, the doctor explains what the procedure is and how it will take place. He clarifies that the patient is not allergic to iodine, asks what medications the person is taking, whether he has circulatory problems or chronic diseases (asthma, epilepsy, diabetes, kidney pathologies).
Benefits of MRI
MRI of the brain and spinal cord is always preferable to other diagnostic methods. It allows not only to perform myelography with three-dimensional reconstruction, but it can also be used to perform MR myelography in diffusion tractography mode, which makes it possible to study pathways that are affected in many pathologies (for example, ALS, multiple sclerosis). For demyelinating diseases, MRI is the only option for visualizing lesions; Before the advent of MRI, this diagnosis was made only when significant clinical manifestations appeared.
Such excellent information content is due to the fact that the spinal cord is a soft tissue structure, and MRI, as is known, reveals its full diagnostic potential precisely when scanning soft tissues.
Whether surgical intervention is required or whether surgery can be done without surgery, myelography of the spine will help determine the indications.
A significant advantage to the above is the fact that during magnetic resonance scanning there is no exposure to ionizing X-ray radiation, which allows MRI of the spinal cord to be performed on children.
How does MRI with myelography work?
The puncture site is disinfected and numbed. A special needle penetrates the subarachnoid space under the control of a tomograph. A contrast agent is injected, the needle is removed, and the puncture site is treated. The patient lies face down, the doctor adjusts the tilt of the table to evenly distribute the contrast in the human tissues. After this, a magnetic resonance imaging scan is performed, which takes up to 30 minutes. The entire MRI with myelography procedure lasts up to 90 minutes.
After the procedure, the patient is observed in the clinic room for 2–4 hours. An increased drinking regimen was recommended for him in order to quickly remove the contrast agent. During the first 2 days, increased physical activity is contraindicated; bending the body is not recommended.
MRI with myelography is what allows the doctor to learn about the state of the spinal structures, cerebrospinal fluid, and detect cysts, tumors and pathological changes. The results obtained help plan effective treatment and prevention.
The advantages of MRI with myelography include the following:
- Contrast allows you to examine in detail all structures that are poorly visualized with conventional radiography;
- MRI with spinal myelography provides more diagnostic information than computed tomography and standard magnetic resonance imaging;
- After the study, no traces of radiation remain in the body.
Sign up for diagnostics at the Department of Neurosurgery of the City Clinical Hospital named after. A.K. Eramishantsev by phone numbers listed on the website.
How is myelography performed?
Myelography is usually performed on an outpatient basis.
During the examination, the patient lies face down on the table. The doctor uses a fluoroscope to obtain images on a monitor in real time, which allows them to see the spine and find the most appropriate point for injecting contrast.
Typically, contrast material is injected into the spinal canal at the level of the lower lumbar spine, which is considered the safest and most convenient. In rare cases, contrast may be injected at the level of the upper cervical spine if the doctor considers it safer or useful for the study.
At the puncture site, the doctor disinfects the skin and numbs it with a local anesthetic. Depending on the location of the puncture, at the time of needle insertion the patient is positioned on his side, on his stomach or in a sitting position. Under fluoroscope control, the doctor advances the needle deep into the tissue until it is in the subarachnoid space. This can be confirmed by the appearance of several drops of cerebrospinal fluid at the free end of the needle. If necessary, the doctor removes a small sample of the fluid and sends it for laboratory testing. After this, a contrast material is injected through the needle, the needle is removed, and the skin is disinfected again. The patient is then placed on the table, usually in the prone position.
Under fluoroscope guidance, the radiologist begins to slowly tilt the table, which allows the contrast material to spread up or down the subarachnoid space, highlighting the contours of the spinal cord and nerve roots. As the table changes positions, the doctor monitors the flow of contrast using a fluoroscope, paying special attention to those parts of the spinal cord that are of greatest interest. To obtain x-rays, the doctor asks the patient to turn on his side. When taking a photo, it is extremely important to remain as still as possible, which will reduce the risk of blurring the image. After completing the examination, the table returns to a horizontal position and the patient can turn over onto his back. You should wait for some time while the doctor analyzes the received images.
Often, immediately after receiving the results of myelography, while the contrast material is still in the spinal canal, a CT scan is performed. This combined study is called CT myelography.
Myelography generally takes 30 to 60 minutes. The need for a CT scan adds another 15-30 minutes to the total examination time.
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