MRI of the knee: what shows the decoding of the results

The knee is one of the joints that is most often subjected to various injuries and injuries, both in childhood and in the elderly. Fortunately, most often the trauma is limited to abrasion and bruising. But sometimes pain is not released for a long time, or even worse, in such a situation the doctor can prescribe an MRI of the knee joint, to diagnose the pathological condition.

MRI of the knee joint will always help the doctor determine the existence of the problem and prescribe adequate treatment. This type of research is completely safe, and by informativity surpasses most other similar methods.

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Indications for the procedure

With problems with the knee joint, doctors are slow to prescribe procedures such as MRI - this type of research is quite expensive. Therefore, such diagnostics are carried out only if there are strong indications, which include:

• arthritis with a complicated course of infection, of an infectious or rheumatoid origin;
• congenital defect of the knee;
• pronounced inflammatory process associated with a gouty attack;
• Collagen disease, involving the process of knee ligaments;
• meniscopathy;
• complex traumatic injuries of the knee;
• tumor processes of a primary or metastatic nature;
• gonarthrosis;
• chronic unstable condition of the knee;
• unexplained cause of pain in the knee joint;
• damage to ligaments;
• inflammation of the knee capsule;
• preoperative and postoperative period associated with surgical intervention in the knee joint area.

It can not be said that all of the above indications are absolute - in every concrete case the doctor decides everything. With easier pathologies and injuries, MRI can be replaced with radiography, but in complex cases without the help of MRI can not do.

• In case of trauma it will help to determine the localization and extent of damage, stretching, rupture of meniscus, ligamentous apparatus, musculature. This type of diagnosis is appropriate for fractures, fissures, as well as for severe bruises with hemorrhages and bleeding.
• MRI of the knee joint with a meniscus rupture does not require the use of contrast: the meniscus in the image looks like a dark band, and all the lesions are clearly displayed in a white tint. Meniscus rupture can occur with a sharp movement in the lateral direction, or in a direction that goes beyond the scope of the joint.
• When synovitis is carried out because of nonspecific symptoms of the disease. When a synovitis occurs, the doctor who describes the MRI, observes the change in signal intensity in the joint cavity (due to fluid accumulation). This signal has an increased intensity in the T2VI mode, and a reduced intensity in the T1VI mode. If an MRI is performed with the introduction of contrast, the signal from the affected shell will be amplified. Visualization of prolapses hanging inside the capsules of the joint capsule.
• With arthrosis and arthritis can be difficult because of the large accumulation of fluid - effusion. For an accurate diagnosis of MRI of the knee joint is carried out in the frontal projection.
• When the cruciate ligament ruptures, the lack of ligament display is most often demonstrated due to local edema and hemorrhage after injury. An incomplete rupture, which is noticeable in the form of an enlarged cruciate ligament with a hyperintense signal and visible whole fibers, is called interstitial rupture. This image needs to be differentiated from degenerate processes in a whole bunch.

How often can an MRI of the knee be performed?

Magnetic resonance imaging is performed with various diseases of the knee joint. This type of diagnosis is done as often as necessary. In most patients, a primary MRI helps the doctor confirm or deny the diagnosis and start correct and effective treatment. Additional MRI procedures can be assigned to clarify some previously dubious points in diagnosis, as well as to assess the condition of the joint after a surgical procedure, to monitor the effectiveness of the therapy, for a more detailed study using contrasting.

Electromagnetic radiation does not threaten any radiation load on the patient's body - this is its main difference from radiography. Therefore, MRI is allowed to be performed as many times as necessary for adequate treatment. Experts insist: MRI is safe and extremely informative.

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Preparation

To the MRI of the knee joint, there is no need to prepare in advance: you do not need to follow a special diet, take any medications or go hungry. The only need is to leave all metal things at home, including jewelry, watches, and other accessories.

The patient during the procedure will have to take off some of his clothes: so, with the MRI of the knee, these are trousers, tights, a skirt, etc.

Be sure to tell the doctor if you are pregnant, you are allergic to any medications, you suffer from chronic illnesses, you have metal implants or stimulants.

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The device for carrying out the procedure

An MRI device for standard examination of the knee should have a capacity of 1.5 Tesla. If you want a more accurate image of the tissue structure, then you can choose a power from 1 Tesla - but this type of apparatus is more in demand in diagnosing the brain and abdominal organs.

There are also types of closed and open type devices:

• a closed type can have a capacity of 1-3 Tesla;
• Open type (suitable for patients with claustrophobia) has a capacity of up to 0.4 Tesla.

The image is more informative if the magnetic power is greater, so doctors advise choosing an MRI device with 1.5 Tesla power.

It is better, if possible, for the MRI of the knee joint to choose a high-field device - that is, a closed type. It gives a better image than what is obtained on open devices. It is especially important to conduct a qualitative study if necessary to visualize the ligament and tendon system.

Technique of the mRI of the knee

MRI of the knee joint is performed in much the same way as in the MRI examination of other parts of the body. Diagnosis is carried out in stages:

• The patient lies horizontally on a special traveling couch, his limbs and head doctor fixes using belts and / or linings for this purpose. This action is necessary so that the patient does not accidentally produce a movement, which in the future will affect the quality of the image.
• The exit couch is placed inside the tomographic apparatus, and the doctor proceeds to scan, during which constant noise is heard.
• For the convenience of the patient, the internal camera of the scanner is equipped with lighting and ventilation system, as well as a voice connection with which the patient can communicate with the doctor.
• At the end of the study - after about 15 minutes, the patient leaves the device and can return to his usual cases. Sometimes it may take some time to wait for an MRI description if it does not go directly to the treating doctor.

How do the MRI of the knee joint?

• The usual "closed" MRI device looks like a three-dimensional cylindrical tube, with the location of a powerful magnet in a circle. The patient during the diagnosis lies on the pull-out couch, which, with the beginning of the procedure, is pushed into the center of the magnetic radiation. The "open" MRI has a similar principle of action, but in this apparatus the magnet is not in the circumference, but only on the sides of the patient.

An open MRI of the knee joint is suitable for people who suffer from claustrophobia or obesity.

• MRI of the ligaments of the knee joint helps the doctor to consider the problem in different planes. So you can assess not only the existing problem, but also to detect concomitant tissue damage, if any.
• MRI of the right, left knee joint is performed by placing special coils on the affected area. To obtain the correct image, you need to ensure the motion of the trunk and limbs for about a quarter of an hour. If contrast is used, the study time may be extended. During the procedure, the patient should not experience any uncomfortable sensations. Sometimes there may be a feeling of heating the knee - this is an adequate reaction of tissues to the radiation of the magnet.
• MRI of the knee joint with contrast helps to see hemorrhages, bleeding, inflammatory foci, instability of blood supply, tumor formations. The essence of contrasting is that the patient is injected into the vein with special substances that can enhance magnetic resonance. The contrast component diverges through the blood vessels and settles in the tissues: the larger the vascular network in the organ being examined, the clearer the image becomes. In the zone of hemorrhages or injuries, or in the presence of an inflammatory focus, the degree of blood flow will differ from that in healthy areas. With tumor neoplasms, which have their own saturated capillary mesh, contrasting is particularly clear. Before conducting a contrast MRI, you need to make sure that the patient is not allergic to the substance being injected. If there is no allergy, then the use of contrast is absolutely safe: the substance is withdrawn from the body on its own for 1-2 days. Do not use contrasting if the patient suffers from kidney failure or acute inflammation of the urinary tract.

How much do they do on time and what does the MRI of the knee joint show?

The procedure for MRI of the knee joint takes 30 minutes. Direct reading of the MRI information lasts approximately 15 minutes.

MRI is often used for diagnostic purposes, with many diseases in the knee area and with suspicion of them. In some cases, the information obtained with MRI may not be enough to determine the therapeutic tactics. In such situations, the results of magnetic resonance imaging are compared with the data indicated in the medical history, as well as with the information obtained during the physical examination.

MRI of the knee joint helps the doctor to properly examine disorders of the bone and soft tissues - special attention is paid to changes in meniscuses, ligaments, tendons. In many patients, MRI allows to obtain exhaustive information about the altered morphology in the knee joint, which can not be obtained by examining the knee joint with the help of radiography, computed tomography or ultrasound.

In some cases, it may be necessary to use contrasting if the MRI is repeated again. Such an addition, as the introduction of a contrast component, is required for a more pronounced visualization of the joint structures. In most cases, the contrast agent improves the data when it is necessary to check the circulatory system, when diagnosing tumor processes, as well as infectious and inflammatory reactions.

MRI anatomy of the knee joint

Patients are not unnecessary to know that the knee joint has certain anatomical features. It is a complex mechanism that ensures the connection of the hip bone with the patella and the tibia.

Patellar is the anterior articular element, which is known to most people as the "patella". It is also important to consider tendon joints, lateral and cruciate ligaments - that is why the interpretation of the results lasts for a relatively long time, but only so you can put the right diagnosis.

In the joint cavity there are cruciform ligaments that can be damaged with excessive motor amplitude of the knee. The function of the anterior ligament is to protect the ankle from the forward displacement beyond the permissible border. This ligament passes through the joint cavity and unites the parts of the lower segment of the tibia.

On the articular surface there is a cartilaginous tissue forming the menisci. The joint system itself is localized in the knee bursa. This mechanism ensures flexion and extension of the limb under different loads.

Most often, patients with ligament ruptures, with peri-tendon bone fractures, with cartilage trauma and meniscus, use the MRI. The above injuries occur with excessive overload of the knee joint, with excessive motor amplitude in different directions.

This specific pathology, like the dissecting osteochondritis of the knee joint on the MRI, has its own characteristic features. In most patients, epiphysis of the femur is detected, specifically, a medial palette. Near the sites of attachment of the posterior cruciate ligament a defect zone is determined, caused by an aseptic necrotic process. The spongy structure in this zone is not tracked, the boundaries are usually even, relatively clear.

MRI of the knee joint for children

To children of younger age group diagnostic MRT appoint only at presence of strong indications - as a rule, such research spend with application of anesthesia.

If a doctor is required to examine a knee joint in an older child, he first communicates with his parents. It is parents who must discuss in advance with the child all the nuances of the examination, and also convince him that this procedure will not cause any pain or discomfort. If a small patient is afraid of loud sounds, then he must be sure to warn that during the work of the scanner will be noisy: you will have to wear special headphones.

If the doctor can diagnose without resorting to MRI of the knee joint, then it is better not to assign this type of diagnosis. Most babies are difficult to stay for a while in a stationary state. It is to ensure the immobility of small children have to use anesthesia - this is practiced only in extreme irreplaceable situations.

Evaluating the obtained diagnostic image, the doctor takes into account that the norm of MRI of the knee joint in children has its own peculiarities:

• the proliferation of blood vessels in the region of the horn of the medial meniscus;
• small volume of fluid in girls;
• subchondrally altered bone tissue.

In children, it is advisable to carry out MRI-diagnosis of the knee joint on both extremities, even if the child complains of problems with one of the parties.

Contraindications to the procedure

• MRI of the knee joint is not done for patients with permanent metal elements in the body, since the latter can be exposed to a magnetic field, heated and affect the functioning of internal organs. Such elements can become heart stimulants, insulin pumps, implants of teeth and bones, amplifiers of auditory function, etc.
• The procedure is not entirely suitable as a diagnostic study for people who are afraid of an enclosed space. Theoretically, diagnostics in such patients is possible in two versions: with the use of an open device, and also after additional administration of the patient to sedative medications.
• Magnetic resonance imaging is not performed for people with mental disabilities and a tendency to hyperkinesia. Closed procedure is also not suitable for obese people.
• Contrast MRI is not prescribed for pregnancy and breastfeeding, as well as for patients with severe renal failure.

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Complications after the procedure

MRI of the knee joint can not cause unpleasant consequences for the patient's health. On the contrary, this study often allows the correct diagnosis to be made in a timely manner, which will help not only to keep the patient healthy, but also to prevent disability.

MRI of the knee never becomes a cause of complications - on the contrary, this type of research helps to find hidden diseases that cause a lot of unpleasant symptoms that cause a person to experience prolonged discomfort. It is these diseases, if not detected in time, can in time cause serious complications, up to the violation of mobility in the joint and the inability to move normally.

Magnetic resonance imaging is a much safer method than computed tomography or radiography, that is, diagnostic procedures related to radiation radiation.

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Care after the procedure

Special postdiagnostic care for the patient after the procedure is not required. After diagnosis, a person goes home and continues to lead his usual lifestyle.

Description of the conclusion of the MRI of the knee joint is based on the received images, which are carried out in different projections on different sections. The description is made by the attending physician of a rheumatological, traumatological or orthopedic direction.

• MRI allows us to describe the condition of the bone tissues that form the joint: bony outgrowths, neoplasms, lesions-in particular, cracks, tears, are indicated. The use of different sections allows you to track the depth of damage, its dimensions.
• The image perfectly visualizes the structure of the cartilage. You can notice symptoms of meniscopathy, changes in the integrity of the cartilage, microscopic damage. The so-called "articular mouse" is also defined, which is an element of the meniscus that has been detached from it. This condition usually causes a lot of unpleasant symptoms.
• MRI shows in detail the condition of ligaments, capsular articular fibers. Thanks to this, it is easy to determine the presence of rupture of the cruciate ligaments, their detachment from the bone. Diagnosis and violation of the capsule - for example, the presence of cystic formations, inflammatory processes, etc.

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Reviews

Often a person tries to cure a sick joint by resorting to various pills, ointments, compresses, not suspecting that he is not treating the disease at all. To exclude such a situation, you need to do the following: go to a doctor and go through a qualitative diagnosis - for example, magnetic resonance imaging. This method will solve the following problems with the knee:

• difficulties and discomfort during movement;
• uncomfortable ascent and descent on stairs;
• incomprehensible sounds in the form of a crunch or clicks in the knee joint;
• pain in the knee with or after exercise;
• edema and inflammation in the knee joint;
• periodic or persistent pain in the knee joint for no apparent reason.

According to many patients, MRI of the knee joint often helps to find a previously unknown problem, which allows you to go through exactly the treatment that is needed in a particular case.