Knee MRI is a method of non-invasive diagnostic examination of the knee joint area using electromagnetic waves and a constant magnetic field to obtain a high-precision layered image. It is used to identify inflammatory and destructive processes, anomalies of the structure of the joint, is used in the diagnosis of damage to the meniscus and ligamentous apparatus, complex fractures, dislocations and fractures. The study is indicated for the visualization of tumors and during the preoperative preparation of patients.
Indications
The technique is used in the diagnosis of many diseases of the knee joint, its forming bones, ligaments, articular cavity and cartilage, as well as soft tissues. The indication may be complaints of pain of any nature, localized in the joint area, and inflammatory changes detected by the results of previous studies or noticeable during examination. Fractures, dislocations, damage to the meniscus and ligaments of the knee joint can also be detected by MRI.
Arthritis, arthrosis, and associated inflammatory and destructive changes in the surrounding tissues are clearly visible on knee MRI. The technique allows differential diagnosis of bursitis, synovitis, tendinitis. The study is used to visualize tumors and tumor-like formations, in particular, Becker’s cysts. The pictures show anomalies of the knee joint development, deformities and structural changes caused by various diseases. In this and some other cases, an examination of both joints is indicated. Knee MRI is used to prepare patients for and after arthroscopy, as well as to monitor the effectiveness of conservative and surgical treatment.
Contraindications
The study is contraindicated in the presence of any metal and electronic structures in the patient’s body: an artificial pacemaker, pacemaker, pins in the limbs, etc. Allergy to gadolinium makes it impossible to MRI the knee joint with contrast, with allergic reactions to other substances, the study is carried out after hyposensitization. If the informative value of the technique is significantly reduced without contrasting, it is preferable to choose another diagnostic method. The same applies to chronic renal failure, when the introduction of contrast poses a danger to the patient due to impaired renal function.
The first trimester of pregnancy is an absolute contraindication to MRI, at later stages the risks are determined individually. Overweight of the patient is a relative contraindication, since it is possible to study in open-type tomographs with increased load capacity. Problems of maintaining immobility of the limb often accompany mental disorders and epilepsy. In this case, other diagnostic procedures or the use of anesthesia are recommended, if there is a need for an MRI. Sedatives are prescribed to patients with claustrophobia. In case of severe somatic disease, it is recommended to postpone the examination until the condition stabilizes.
Preparation
Special preparation for knee MRI is not required. When using a contrast agent, the procedure is performed on an empty stomach. The introduction of a contrast agent involves an additional assessment of the state of the kidneys with the help of tests and sometimes ultrasound. Also, an allergological history is found out in advance. in advance.
Methodology of conducting
Knee MRI can be performed in a closed-type device when the patient is lying on a couch in the center of the tunnel, and his whole body is under the influence of an electromagnetic field. When examining the knee joint, it is possible to use special low-floor tomographs or devices for MRI of the extremities. The patient must remain motionless throughout the procedure, which lasts an average of 30 minutes. The duration of the study increases if it is necessary to study two joints and use contrast. During the scanning process, the examined area may heat up slightly, this is considered the norm. Complications due to contrast or metal objects in the examination area are rarely observed. The result is prepared within a day and given to the patient, if desired or if necessary – together with a digital copy.
Advantages
Radiography and CT allow to visualize the bone base and partly the ligamentous apparatus, therefore they are widely used for the diagnosis of fractures, dislocations, suspected arthrosis of the knee joint and other lesions. CT with contrast is usually prescribed if a tumor process is suspected. Knee MRI joint is more often used when soft tissues are affected, which are clearly visible during the study.
Ultrasound of the knee joint is one of the most inexpensive imaging methods and gives an idea of soft tissues, as well as MRI. For this reason, ultrasound is widely used in the primary diagnosis of soft tissue injuries and inflammatory processes in the knee joint cavity. In addition, joint operations are often performed under ultrasound control. It is preferable to carry out MRI when the information obtained as a result of other diagnostic methods turned out to be insufficient, or it is necessary to establish the exact localization of the process.
