Lumbar spine MRI is a diagnostic method that allows you to get an exhaustive picture of the studied area with detailed visualization of anatomical structures.
The lumbar spine includes 5 consecutive vertebrae, which are separated by intervertebral discs. Then it is followed by the sacral section, consisting of 5 vertebrae fused into one common bone, and the coccyx (a rudimentary organ similar in structure to the sacrum, but having smaller dimensions).
In fact, the lumbar region is the lowest mobile part of the human spine, which accounts for the greatest loads, so the causes of back and lower back pain are often associated with it. Bones themselves cannot hurt, but in addition to bone structures in the form of vertebrae and intervertebral discs, the lumbar-sacral section includes ligaments, tendons, nerves, muscles, blood vessels that can be injured as a result of vertebral displacement or degenerative changes in bone-cartilage structures.
The proximity of the lumbar and sacral spine leads to the fact that in order to determine the cause of pain and limitation of spinal mobility in the lumbar region, doctors see it appropriate to examine both departments, so the procedure in most cases is called an MRI of the lumbosacral region.
Usually, a study of the spine is required if the patient complains of back pain closer to the lower back, which prevent a change in the position of the trunk. After the patient tells about the symptoms that have appeared, the doctor already has suspicions about possible pathological processes in the body that cause the appearance of the described clinical picture. With a certain degree of accuracy, the diagnosis can be confirmed by a blood test or spinal cord puncture, but to make a final diagnosis, outline the affected area, see exactly what processes led to the disease and develop a further scheme for solving the problem can only help specialized instrumental studies, one of which is an MRI of the lumbar spine.
Indications for an MRI examination may be:
- suspicion of any pathology and spinal injuries
- suspicion of tumor processes in the lumbar region,
- suspected anomalies in the development of other parts of the spine, for example, cervical or thoracic,
- control of the recovery period after removal of an intervertebral hernia
- identification of the path of metastasis spread after removal of a tumor in the lumbar or sacral region,
- impaired limb mobility in the sacral region,
- leg pain and back pain of unknown etiology
- preparation for the upcoming surgery in the lumbar region and control in the postoperative period,
- diagnosis of multiple sclerosis and determination of the degree of its progression,
- suspicion of syringomyelia – a pathology characterized by the formation of cavities inside the spinal cord
- identification of the causes of circulatory disorders in the lower extremities (risk factors for such disorders may be injuries, inflammatory and degenerative processes in the vertebral region, as a result of which blood vessels are squeezed).
As for diseases of the spine, in addition to injuries (fracture or severe contusion of the vertebral column, its instability), doctors also consider the following pathological processes:
- inflammatory processes in the spinal cord (myelitis),
- infectious inflammation of the bone tissue (osteomyelitis)
- decrease in the density of the bones of the spine (osteoporosis),
- the appearance of spiny growths on the edges of the vertebrae and their proliferation, which violates the mobility of the spine and leads to narrowing of its canal (spondylosis),
- dystrophy of the cartilaginous tissue of the spine (osteochondrosis of the lumbar spine, which is a very common disease in which MRI is very informative, allowing the doctor to determine the extent of the lesion and make predictions of the disease),
- cartilage damage of the joints with the involvement of soft tissues, tendons and bone (osteoarthritis),
- the displacement of the vertebrae (spondylolisthesis),
- pathology of the intervertebral discs (their removal, hernia, protrusion, a chronic pain syndrome in the spine or dorsopathy, inflammation and fusion of the intervertebral joints or ankylosing spondylitis),
- the presence of transitional vertebrae on the border of the lumbar and sacral divisions (if they are asymmetric, there is spinal instability develops lumbar scoliosis, etc.),
- stenosis or narrowing of the vertebral column, which is a consequence of long-term inflammatory and degenerative processes in the spine
- cyst formation in the coccyx area.
MRI gives very valuable information when tumor processes are suspected. The study not only helps to identify the fact of the presence of a tumor, but also to accurately determine its location, size, structure and the presence of metastases to other organs. The procedure can be prescribed even if the tumor was located in other departments, but there is a suspicion that its metastases penetrated into the lumbar spine. MRI allows you to control the quality of the metastasis removal process.
In the diagnosis of intervertebral hernia and spinal instability in the places of transitional vertebrae, MRI with verticalization is very indicative. This study involves studying the state of the spine in a lying and sitting position, when the tomograph table and the magnet rise to an upright position. At the same time, the spine begins to experience a noticeable axial load, and the defects become more pronounced.
MRI of the lumbar spine is one of the diagnostic studies that does not require special preparation for the procedure. The patient will not have to revise his daily routine and food preferences or worry about taking medications. The readings of the tomograph will not depend on what a person ate on the eve of the research or when he visited the toilet. This is one of the advantages of the MRI method.
You do not have to take bedding or special clothes with you for the procedure. Disposable household items are given to the patient at the clinic where the examination is taking place. The patient will also be asked to remove any objects containing metal parts (watches, rings, earrings, bracelets, piercings, etc.) that can interact with the magnetic field, making undesirable changes and threatening to burn tissues.
If the day before the patient did not tell the doctor about the metal objects inside the body (dentures, pacemakers, implants, artificial joints or heart valves, IUDs, etc., including fragments from shells and bullets), it’s time to say it now, indicating the material (if possible) from which the implant or prosthesis is made. Any large metal implants and fragments, as well as electronic devices and implants made of ferromagnetic materials that cannot be removed, will be an obstacle to MRI.
You cannot take keys, payment cards, mobile phones and other electronic devices with you to the procedure. They can be left with their relatives.
The tomograph is a large-sized device in the form of a torus with a retractable table. Some people, for example, those who suffer from claustrophobia, may be afraid of the moment when the table on which they are lying enters the cavity of the device or stays there for a long time. If such a fear is present, it is necessary to tell the doctor about it, who will first make sure that the patient is given a sedative.
In principle, this is the end of the preparation for the examination procedure on the tomograph. But this is only if an MRI is performed without contrast injection. The introduction of contrast chemicals into the body implies special caution.
The patient will have to take blood and urine tests, take a test for allergic reactions. Gadolinium and iron oxide used for MRI are not as strong allergens as contrasts for computed tomography, and yet it is better to be safe so as not to harm a person. A urine test will show the condition of the kidneys, which are primarily affected by drugs, and blood tests will help confirm or reject the presence of hemolytic anemia, in which red blood cells are destroyed (a magnetic field can enhance this process).
If during an MRI without contrast, the patient can eat up to the beginning of the procedure, then the introduction of contrast requires refusal of food and medications at least 3-4 hours before the start of the examination. This will help to avoid unpleasant consequences in the form of nausea and vomiting.
What should I take with me to undergo an MRI of the lumbar spine with or without contrast? There is no mandatory list, but it is recommended to have patient identification documents, an outpatient card, the results of previously conducted spinal examinations (if any), test results, and a doctor’s referral. But even if a person does not have all these documents with him, this is not a reason for refusing to conduct an MRI diagnosis.
Technique of conducting
After the person is ready for the examination, special disposable clothes are put on him, and placed on the tomograph table. The doctor will ask you not to move during the scan, since any movements can distort the overall picture of the study. If a person has difficulty staying in a static position for a long time, which often happens with young children or with severe pain in the spine, his body will be fixed with special straps. As an option, it is possible to administer intravenous anesthesia or take painkillers, which do not affect the truth of the results in any way.
The patient is warned in advance that during the procedure he will be alone in the office where the tomograph is located (although in some cases the presence of relatives or clinic staff is allowed). The doctor and, if necessary, the patient’s relatives will be in another room at this time, in which there is an opportunity to observe what is happening. That is, the doctor will monitor the patient’s condition remotely. In addition to remote visual contact, there is a possibility of two-way voice communication. A microphone is installed in the tomograph, and the patient has the opportunity to call for help or report unpleasant sensations during the procedure. Being in another room, the examinee hears all the doctor’s instructions about the correct behavior during the procedure.
The working device emits a monotonous hum, which can frighten or irritate patients, so the subjects are given special vacuum headphones that help them feel more comfortable.
The table on which the examinee is placed moves inside the tomograph until the part of the body that needs to be scanned is inside the device. After that, the magnetic field is turned on, which is many times larger than the Earth’s magnetic field, and the device begins scanning the affected area.
When asked how long an MRI of the lumbar spine lasts, the answer will be ambiguous. In most cases, everything is limited to 15-20 minutes, but in some cases, the diagnosis may take even 30-40 minutes, depending on the complexity of the pathology. If contrast is introduced, the duration of the procedure will be slightly longer than an MRI without contrast.
MRI of the lumbar spine is usually performed in two projections: axial (transverse) and sagittal (vertical). During the entire procedure, the device, the magnet inside of which wraps around the area under study several times (as laid down in the instructions), takes a series of pictures that allow you to restore a full three-dimensional image of the area under study on the computer screen.
Contraindications to the procedure
Magnetic resonance imaging is one of the safest diagnostic procedures, but this does not mean that this method has no contraindications. However, the limitations on conducting a diagnostic study are not so much related to the pathologies present in the body, as with metals previously embedded in the patient’s body.
There are not so many absolute contraindications to performing an MRI of the lumbar spine without contrast. The procedure is not performed in patients whose body has ferromagnetic implants or metals that can interact with a magnetic field or can cause tissue burns, and electronic devices that support the patient’s vital activity (a magnetic field can have a bad effect on the operation of pacemakers and other similar devices). Ferromagnetic components may have artificial imitators of the middle ear, shell fragments, Ilizarov apparatus and some other implants.
Relative contraindications are considered to be the patient’s use of an insulin pump, portable electrical stimulators of the nervous system, the presence in the body of middle and inner ear implants, imitators of heart valves, hemostatic clips, dental implants and braces made of metals not related to ferromagnets. Some precautions will have to be taken when performing the procedure for patients with heart failure in the decompensation stage, with claustrophobia and inappropriate behavior of the patient (in this case, medication sleep is recommended).
It is undesirable to carry out the procedure of magnetic resonance imaging for patients in very serious condition, as well as pregnant women in the early stages, but if urgent diagnosis of pathologies is necessary, an MRI of the lumbar spine can be performed even in such patients, and it is considered preferable than a popular X-ray or computed tomogram.
An obstacle to MRI can also be the presence of tattoos, for which titanium compounds were used. In this case, there is a risk of tissue burns.
Tomographs used for MRI diagnostics can have a closed or open contour. The device with an open circuit allows the procedure to be performed by both patients with relative contraindications.
If we are talking about MRI with contrast, then it is not carried out to diagnose spinal pathologies in pregnant women at any time (contrast agents can affect fetal development), in patients with hemolytic anemia and severe renal insufficiency (the half-life of the chemical increases and, accordingly, its negative effect on the body). Accordingly, contrast is unacceptable in patients with allergic reactions to the administered drug.
Interpretation of the results of MRI of the lumbosacral spine is carried out after the end of the examination procedure. Although in some clinics it is possible to conduct a tomography with visualization, and already in the process to draw some conclusions about the condition of the spine and surrounding tissues.
To some, the MRI procedure will seem too long in time (if compared with a conventional X-ray), but this is necessary to obtain a three-dimensional image consisting of many separate flat images taken in 0.5-5 mm increments. We will have to wait even longer for the results of the research. Most often, it takes about 60 minutes for a specialist to decipher them, but in the case of multiple or complex fractures, as well as in the presence of tumor processes, the results can be obtained even the next day.
What does an MRI of the lumbosacral spine show? On the image obtained with the help of a magnetic resonance imaging machine, the doctor can see:
- curvature of the spinal column in the lumbosacral region,
- inflammatory processes in various tissues (cartilage, muscles, nerves, etc.),degenerative changes in bone-cartilage tissue (thickening or thinning of cartilage, destruction (decrease in density) of bones, the appearance of growths, reducing the distance between vertebrae, etc.),
- tumors and other neoplasms in the lumbosacral region, which on the MRI image look like a darker round-shaped spot compared to other tissues,
- tumor metastases in the form of clearly defined objects of different shapes surrounded by edematous tissues,
- displacement of the vertebrae relative to the axis
- disturbances of blood flow through the vessels of the pelvic region and lower extremities,
- the presence of voids in the spinal cord.
MRI allows not only to visualize pathology, but also to assess the degree of damage to the spine and adjacent structures, because changes in the structure and position of the bone structures of the spinal column often entail circulatory disorders and the appearance of neurological symptoms due to pinching of nerve fibers.
Hence the pain syndrome with which patients come to a therapist, traumatologist or orthopedist. A person can consult a doctor with complaints of pain, weakness and loss of sensitivity in the legs, and an MRI of the lumbar spine will detect the cause of these symptoms in changes in the structure of the spine in the lumbar and sacrum.
Complications after the procedure
MRI of the lumbar spine is considered a safe procedure that has neither near nor far consequences. It is clear that we are talking about conducting diagnostics taking into account absolute and relative contraindications, as well as requirements for high-quality scanning.
As for unpleasant sensations during the study, they are practically absent. Some patients may feel a slight twitching in the muscles of the body or a slight tingling, which is a variant of the norm and should not frighten the subject.
When MRI is performed with contrast and the introduction of chemicals into the body is required, patients may experience headaches, nausea or vomiting after the procedure, which are associated with the action of “chemistry”, and not a magnetic field. If we are not talking about hypersensitivity of the body to chemotherapy drugs, these symptoms pass quite quickly and have no consequences. In order to reduce the severity of such unpleasant consequences, a test for sensitivity to contrasts is carried out beforehand and a requirement is introduced not to eat 1.5-2 hours before the procedure.
If tattoos are present on the body in an area of the body exposed to a strong magnetic field, the patient may feel a noticeable burning sensation, which is a consequence of tissue burns.
MRI machines do not use ionizing radiation, which can cause various complications after the procedure. But the magnetic field can affect the operation of electronic devices implanted in the body and attract prostheses made of ferromagnetic alloys, so it’s not worth the risk. The doctor should be aware of the possible risks to the same extent as the patient, who is warned about the consequences before the procedure.
Anyway, there is a constant connection between the patient on the tomograph table and the doctor performing the procedure, and the person has the opportunity to report any unpleasant sensations that require stopping the device and medical care.