Contents
Magnetic resonance imaging of the foot is used to identify possible abnormalities of the congenital or acquired nature of a part of the lower limb. Despite the relatively modest size in relation to other functional areas of the body, it is the foot that acts as a support when walking. It consists of 26 bones that have a complex structure. If at least one of the bones fails or the nearest tissues and blood vessels are damaged, this leads to a significant deterioration in the quality of life.
Due to the fact that classical examination methods such as x-rays or ultrasound are not able to provide high-quality visualization, people turn to MRI of the foot for help. Some mistakenly believe that this testing format can only provide data on possible damage to bone structures. But what the MRI scan shows is much broader. We are talking about the image of the surrounding soft tissues, which are muscles, tendons, ligaments, blood vessels, nerves. Also, the study is able to reflect the picture of the state of health of the joints.
Advantages of the technique
The most important advantage of the method is the ability to visualize even small anatomical structures. They cannot be found on the x-ray image due to the poor detail of the latter.
Also, many patients are interested in what is better: computed tomography or MRI. But CT involves the use of X-rays, which can adversely affect health. In addition, often the study must be carried out with the use of a contrast agent, which can be a significant allergen and can turn into toxins when accumulated in cells. Magnetic resonance imaging does not have a radiation load on the body, and the contrast agent, used if necessary, has a different allergic effect, since other substances form the basis.
The principle of examination is based on sequential scanning of a given structural formation. Each equipment model has its own average step for image capture. Usually it does not exceed 5 millimeters, which is less than that of a classic CT scanner. This allows you to get an improved final quality of the “images”.
Also, some patients are interested in the question of whether they can use both popular diagnostic formats to confirm the results. In most cases, a transcript of the MRI report is sufficient. If the doctor has a suspicion of a pathology of bone tissue and blood vessels, then it would be useful to do a CT scan or angiography. But, as evidenced by the reviews of numerous patients, MRI is usually enough.
Parents of children usually appreciate the technique for its non-invasive approach, which means that it is painless for the baby. But doctors prefer magnetic resonance scanning due to the fact that it provides information immediately on almost all structures of the lower parts of the legs.
At the same time, if you calculate how much one generalized procedure costs and add up the cost of ultrasound, X-ray and CT, then a single analysis will be an order of magnitude cheaper. It even takes less time than three different diagnostics.
In addition to obtaining information about problems in the part of the foot itself, the result will tell about the condition of the ankle joint, which is difficult to achieve from other diagnostic analogues.
But even a standard bone fracture is not always possible to study thoroughly with the help of X-rays, which is especially important for fragment injuries. Hence the desire to use a special tomograph that will catch even the slightest anomalies that other imaging options cannot handle.
Indications and contraindications
In society, it is generally accepted that the main reason for issuing a referral for an MRI is the suspicion of oncological neoplasms of a malignant or benign nature. But the capabilities of the new generation of medical equipment are much wider, as they help to establish the features of a tumor of any etiology. At the same time, the picture will tell about the exact location of the focus, the degree of damage to surrounding tissues and structures.
High-precision visualization will also shed light on the state after:
- fracture;
- stretching;
- dislocation;
- pinched nerve.
Sometimes doctors send patients for examination who have pain in the foot area, but the source of its origin could not be established by other means. For the same reason, a person may ask the attending physician for an appointment for a procedure if he has severe pain in the ankle area for no apparent reason.
Persistent swelling, as well as any restrictions on the normal mobility of the specified part of the lower limb, indicate the need to go to undergo this high-tech testing.
If the patient is already registered with a surgeon or traumatologist, then from time to time he will have to go under a magnetic resonance type scanner. Passing the study will become part of the program for monitoring the health and dynamics of recovery of those who have the following ailments:
- arthritis;
- arthrosis;
- circulatory problems.
Even the most minor anomalies of the heel will be in full view. But not everyone will be able to pass such a useful examination. Those who suffer from the fear of closed spaces may experience some discomfort when entering the tomograph tunnel.
Unlike a CT scan, a magnetic one lasts an order of magnitude longer, which can be cause for panic.
This can be avoided by contacting clinics that use models of open-type devices. And when examining particularly difficult patients, the doctor can decide on the spot to put the victim into a medical sleep or prescribe general anesthesia.
Such a radical decision is explained by the fact that only complete immobility during the manipulation can guarantee the excellent quality of the final image.
The risk group for those who, in case of urgent need, may be prescribed sedatives for the test, except for those suffering from claustrophobia, are:
- children;
- aged people;
- patients with mental disorders;
- people with uncontrolled seizures.
For the same reason, MRI is carefully prescribed to patients in extremely serious condition, since it is not clear how they will behave in an unfamiliar environment. Even open side surfaces do not always help here.
The presence of metal components in the body is considered an absolute contraindication. It can be either a pacemaker or some kind of bone substitute like a supporting pin. Moreover, electrical devices built into the body, such as internal hearing aids, are prohibited even taking into account the fact that the lower limb will be examined. But for metal supports of such severity is not provided. If they do not interact with the territory of influence of the magnetic field, then the absolute contraindication turns into a relative one.
In practice, this means that with the predominance of benefits, all possible harm is leveled. The final decision in such problematic scenarios should be made by the attending specialist, knowing the characteristics of his ward.
Other relative prohibitions include:
- renal failure;
- liver failure;
- the period of breastfeeding.
All of the above covers only situations where the doctor insists on the obligatory involvement of the contrast stage. The danger lies in the fact that when the components of the contrast solution accumulate in the body, they turn into toxins. When the kidneys and liver do not have time to remove the elements of the remedy, this negatively affects the general condition of the body.
Despite the fact that the dosage of the drug is harmless to healthy people, for newborns during lactation, milk with its components can become the cause of an incomprehensible malaise. Therefore, experts insist on refusing breastfeeding for at least two days after the manipulation. All this time, milk must be expressed and poured out.
But during pregnancy, it’s not so easy to get off. This is especially true in the early stages of fetal development, when it is better to replace MRI with a more gentle analogue – ultrasound.
The final contraindication also affects contrasting. It’s about an allergic reaction. If the patient is not sure how the body will react to an unfamiliar remedy, then it is worth insisting on conducting a control allergic test. Depending on the result, a decision will be made: to use a different version of the study, or to change the drug or take antihistamines.
How is the appointment going?
To obtain a high-quality image, technology is attracted by the capabilities of an innovative device – a magnetic resonance tomograph. Its action is based on the physical properties of the electromagnetic field, which explains the name of the technique itself. The detectors capture the reverse reaction of hydrogen ions, which are contained in the examined tissues of the foot.
Since all tissues have different indicators of hydrogen atoms, which is explained by their different structuring, the visualization takes on a detailed outline.
Outwardly, the tomograph looks like a capsule, inside of which a medical couch with the subject enters. The studied area is placed in a special coil with built-in sensors. After activation of the tomograph, an electromagnetic field is generated inside the capsule.
To get a quality result, you have to wait about half an hour. But such an expectation is worth it, since it does not imply a violation of the integrity of tissues. Due to almost zero harm for most potential patients, the technique is widely used even for diagnosing diseases among children.
Upon completion of the manipulation, the radiologist will provide the patient with tomograms, which are successive thin sections made in different projections. All data is recorded on a digital medium, where a written conclusion is attached.
The procedure does not require a special preparatory stage. The only exception is the use of contrast, which indicates the need to refrain from eating approximately five hours before the appointment.
The doctor will warn you in advance that only clothes that do not have metal components should be worn for examination, and jewelry should also be removed. But sometimes private diagnostic rooms offer visitors to change into disposable gowns for convenience. In hospitals, people are given special cotton pajamas with ties or buttons.
How to decipher the conclusion?
Usually, the results of the study are transmitted directly to the office of the attending physician. But if the analysis was taken in a private medical center, then all the information in encrypted form is transferred to the client’s hands. To decipher, that is, to explain what each described point of the conclusion means and what disease the deviations indicate, the doctor should.
Most often, after passing a magnetic resonance test, a person is found to:
- plantar fasciitis;
- oncological diseases;
- infection;
- arthrosis and arthritis;
- Sever’s disease;
- flat feet;
- congenital anomalies;
- the so-called diabetic foot;
- foreign bodies;
- heel spur.
The symptoms that indicate the above deviations from the norm vary significantly from case to case. But most often, people who “endured to the last” turn to the diagnostic room for help. But heel spurs at an early stage of development are much easier to treat.
The most striking sign of plantar fasciitis is considered to be a beak-shaped growth that is deployed on the calcaneus. It is impossible to recognize the lesion from the inside with the naked eye, which makes the use of MRI necessary. The picture will fix the inflammatory process when the connective tissue is stretched throughout the entire plantar part of the foot, and it will reveal swelling of the surrounding tissues. It acts as a protective shield for the metatarsal bones and joints, so its failure should be treated immediately.
Unlike the outdated X-ray and ultrasound, the use of a magnetic tomograph makes it possible to recognize oncological processes on the foot even at the initial stage of development. In the picture, this is expressed in the darkening of the problem area of uXNUMXbuXNUMXbthe tissue.
If the initial examination showed a similar picture, then it is better to do a second analysis, but with contrasting. The solution promotes the differentiation of a tumor of a benign and malignant sample. He will also advise:
- distinctive features of structural education;
- size, volume and degree of damage;
- area of inflammation.
Based on the data obtained, the specialist will decide in favor of an alternative or surgical treatment format.
Initially, infectious lesions of bone and soft tissues were difficult to recognize. But after the invention of the magnetic resonance apparatus, abscesses began to be diagnosed at an early stage, which reduced the percentage of serious complications. In the final image, they are presented as a cavity formation, which has a clear outline.
When a purulent process is found in the victim, the magnetic effect helps to deal with his stage of destruction. The latter is characteristic of osteomyelitis.
But most patients are forced to consult a doctor for help with unbearable pain of arthrotic or arthritic origin. The reason for this is damage to the metatarsal joints, such as bursitis, which indicates inflammation of the periarticular bag of the calcaneus or Achilles tendon.
Due to their small size, it is problematic to interpret their anomalies from an x-ray. The same rule applies to the small joints of the fingers.
Despite the fact that flat feet can be determined even with the naked eye, if the examination is carried out by an experienced expert, only an MRI will confirm the verdict thoroughly. Due to invisible deformities of the metatarsal, heel joints and the joint of the first finger, it turns out to determine the exact type of this anomaly:
- longitudinal, which is a congenital deviation;
- transverse, which is an acquired pathology.
Much less often, epiphysitis of the calcaneus is found in the victims. The disease belongs to the professional class, which is typical for young athletes under the age of 15 years. Due to regular microtraumas of the heel, in the future this results in a serious pathology, which can be detected by modernized diagnostics.
Separately, doctors consider cases of the so-called diabetic foot. Outwardly, the manifestations of the disease cover chronic ulcers in the foot area. But since this disease is very insidious, it often affects the metatarsal part of the lower limb, affecting not only soft tissues.
To give an accurate assessment of the severity of the condition, detailed visualization is indispensable. Its results will be the decisive argument in favor of limb amputation or preference for alternative therapy. In the picture, it will be possible to consider the inflammatory process with the localization of the peritarsal, tarsal, calcaneal and digital bones.
With special care, a tomograph is involved to search for the exact location of a foreign body that somehow got into the foot. The method has proven itself well, but on the condition that the foreign body does not have metal components.
But even the highest quality picture in good resolution cannot be the only reason for making a definite diagnosis. The doctor is obliged to take into account the complaints of the ward, his medical history, hereditary predisposition and current state of health.