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Magnetic resonance imaging is a method of medical examination of a patient, which is advisable to use to scan most parts of the body, systems and organs of a person, including studying the condition of the throat and larynx. These parts of the human body are characterized by the complexity of the structure, the presence of a large number of individual structures and tissues in a limited space, as well as their special significance for human life and health. That is why MRI, as a non-invasive diagnostic technique that does not use X-ray irradiation, is considered one of the most suitable ways to study the complex system formed by the throat and larynx.
Larynx and throat: structural features
The throat refers to the upper part of the respiratory tract. Its main function is to separate food and air entering the oral cavity between the esophagus and trachea. The structure of the throat works in such a way that pieces of food cannot enter the respiratory tract, so they overlap during swallowing.
Anatomically, the throat is divided into the pharynx and larynx. It is the pharynx that, as it were, continues the oral cavity, being behind it, is responsible for the delivery of food and air to the corresponding tracts of the body. Further, the pharynx passes into the respiratory tract – the trachea, through which, during inhalation, air enters the bronchi.
The pharynx has the shape of an inverted cone, expanding upwards. It contains a large number of glands that secrete a special secret that promotes the movement of food into the esophagus, as well as muscle structures responsible for the swallowing process.
The upper part of the pharynx is represented by the nasopharynx. In its lower part there is a soft palate, which covers the nasopharynx during swallowing with an upward movement in order to prevent pieces of food from entering the nasal cavity, and in the upper part there are adenoids, which are soft tissues. Another part of the pharynx is the movable oropharynx. This space behind the oral cavity allows air to pass from the mouth into the respiratory tract, and is also part of the human speech apparatus.
The larynx is located at the level between the third and sixth cervical vertebrae. It contains the vocal cords – the organs through which a person can make sounds. Above the larynx is the hyoid bone, in front of it is formed by the hyoid muscles. The thyroid gland is directly adjacent to the sides of the larynx, and the laryngeal region of the pharynx is in front. The structure of the pharynx is formed by cartilages, which are connected by joints, muscles, ligaments.
All these organs, muscles, cavities together make up a complex, multifunctional system that can be affected by various pathologies and diseases.
In order to be able to identify them at any stage and develop an optimal treatment regimen, doctors use the most accurate and detailed scanning methods, including magnetic resonance imaging.
What is an MRI of the throat and larynx
Magnetic resonance imaging scans organs and tissues in the human body using the properties of a magnetic field and radio waves.
Obtaining an MRI image was made possible thanks to the discovery of the principle of nuclear magnetic resonance.
The entire technique of magnetic resonance scanning is based on measuring the electromagnetic response of hydrogen molecules when they are in a magnetic field of a certain strength. This method allows you to study the deep structures of the human body, based on the saturation of the body’s tissues with hydrogen, and the electromagnetic properties of its nuclei.
By passing electromagnetic pulses through the human body in the area under study, the tomograph captures the data obtained, after which they are processed by a special computer program, which makes up the final image from them – MRI images. Scanning occurs in layers, along sections with a step thickness, on average, 3-5 millimeters. The thickness of the cut is inversely proportional to the strength of the magnetic field of the tomograph – the greater the voltage, the smaller the step of the cut, respectively, the more informative are the results of magnetic resonance imaging.
Indications for MRI of the larynx and throat
Usually, the question of the need for the procedure is decided by the attending physician – an oncologist, therapist, otolaryngologist or pulmonologist.
The obtained results of tomography make it possible to identify the presence or absence of metastases, neoplasms, foci of inflammatory processes, blood clots, abnormalities in the structure and functioning of blood or lymphatic vessels.
The doctor also determines from the pictures what condition the vocal cords and mucous tissues in the larynx and throat are in. The main indications for referring a patient to magnetic resonance imaging of the larynx and throat are:
- suspicion of the presence of tumors;
- detection of anatomical deviations in the structure;
- difficulty swallowing, breathing, passing food;
- inflammatory changes;
- swelling of the neck area;
- trauma to the neck, throat, ligaments;
- upcoming or past operations on the larynx and throat.
When foreign bodies are suspected in these organs, doctors usually prefer to order a CT scan, which gives clearer images of solid objects, their contours, and how they come into contact with soft tissues.
MRI of the thyroid gland as a separate examination is practically not prescribed – if it is necessary to obtain information on this particular organ, the appointment of ultrasound is considered more appropriate. Due to the fact that the gland is located close to the skin and does not overlap with bones or other organs, ultrasound in this case can give doctors a detailed picture of the state of this organ.
Diagnostic capabilities
What do the results of this procedure show? An experienced radiologist in the MRI images of the throat and larynx sees the anatomical features of this area, the structure and condition of the lymphatic and circulatory system, trachea, larynx, soft tissues of the neck.
Pictures taken in three planes clearly define:
- foci of inflammation;
- tumors and metastases;
- pathology of the lymphatic system;
- condition of mucous tissues, vocal cords;
- gross changes in blood vessels;
- mobility, structure and density of cartilage.
MRI is especially often prescribed for suspected tumors. Oncological diseases of the throat confidently hold the dubious “title” of one of the most common types of cancer. After all, it is through the mouth and throat that drinks, food, cigarette smoke, alcohol enter the body – all those products that may contain carcinogenic additives, or are themselves carcinogens. Smokers and those who abuse strong alcohol make up the bulk of patients at risk in this case.
It is thanks to the magnetic resonance imaging of the larynx and throat that doctors are able to establish the presence of cancers even at the earliest stages of their appearance, determine their size and location.
Also, by analyzing the obtained MRI images, it is possible to determine the presence and localization of metastases penetrating from other organs.
What are the contraindications for MRI?
Compared to X-ray methods of scanning the body, magnetic resonance imaging has no limitations associated with the danger of exposure to radiation. For example, MRI without contrast can be done in children and breastfeeding women. Pregnancy is a relative contraindication only during the first trimester – during this period, doctors prefer not to expose the developing fetus to electromagnetic pulses.
However, there are limitations associated with the essence of the procedure. For example, magnetic resonance imaging and fixed metal prostheses, wires, implants, valves, clamps, as well as electrical devices such as pacemakers, in most cases, are incompatible. In the presence of such details in the human body, an MRI is questionable.
The fact is that metal parts, prostheses or implants, when exposed to a magnetic field, heat up and can even come out. In addition, the reason for the limitation associated with the presence of metal parts in the body is that they cause interference in the operation of the equipment and distort the information content of the obtained images. With regard to pacemakers, doctors unambiguously recommend that people who have such a device installed refuse the MRI procedure.
Due to the influence of the magnetic field, the pacemaker can fail, thereby putting the patient’s life at serious risk. Exposing a person to such a risk, even for the sake of very accurate diagnostic results, is unacceptable.
Recently, however, manufacturers of both metal implants and pacemakers have paid attention to this problem, so such products have begun to appear on the medical market, produced taking into account the requirements for compatibility with the magnetic field of tomographs.
In addition, patients with tattoos should be asked if the pigment injected under the skin contains metallic compounds. If the answer to it is in the affirmative, then diagnostics on a magnetic resonance tomograph is not carried out.
The presence of excess weight in a patient is considered a relative contraindication. Many tomographs are not designed for a weight of more than 120-160 kilograms, but in this case there is still a chance to perform a tomography – an open tomograph will cope with this task.
Features of the preparation and implementation of the procedure
Magnetic resonance imaging of the throat and larynx without contrast does not require special preparations. It is necessary to pay increased attention to this stage if an MRI with contrast is planned. In this case, the doctor will first find out if the patient has allergic reactions, if necessary, send him for an allergy test. Women must be sure to report the presence of pregnancy at the time of the tomography.
All metal elements, jewelry and accessories must be removed from yourself and left in the next room.
The patient puts on loose cotton clothes that do not have metal fittings – this can be pajamas brought from home, or things provided by the nurse.
If contrast is needed for the examination, it is administered intravenously after the first scan (native) is performed, after which the table with the patient is rolled out, a contrast agent is injected intravenously and a second scan is performed. A substance that acts as a coloring and contrasting element is prepared on the basis of gadolinium salts.
After the patient is placed on the tomography table, he is fixed with special straps and rollers to ensure his complete immobility. During the scan, the patient lies in a relaxed position. An MRI of the throat and larynx usually takes about 30 minutes. If a stage with contrast is applied, this time is increased to 40-50 minutes.
It is quite noisy inside the cavity of the tomograph, therefore, for the entire period of the procedure, the patient will be asked to use earplugs or headphones. When the scanning process is over, the radiologist takes on the interpretation of the results and drawing up a conclusion. Usually it does not take more than an hour, but in difficult cases, the doctor may need a day to decrypt.
The conclusion received from the radiologist, together with the images printed or stored on digital media, must be provided to the attending physician who made the decision to conduct the examination – based on these data, the doctor will establish a diagnosis, develop a scheme of therapeutic, rehabilitation or preventive measures, depending on whether for what purposes the survey was conducted, and what results it showed.
MRI of the throat and larynx is recognized by doctors as one of the most accurate and modern methods for studying the state of these complex systems in the human body. Due to the fact that the process does not use potentially dangerous X-rays, but the strength of the magnetic field and radio waves, MRI can be performed more often than, for example, computed tomography or radiography.
This procedure has a number of contraindications, so it is very important for the doctor, when prescribing this examination, to find out from the patient all the information about the injuries, diseases, operations, the presence of tattoos or the state of pregnancy, that is, to carry out certain preparatory measures.
The results of MR tomography are distinguished by the accuracy and high quality of the images, and for a more detailed study of the deep state of the tissues and the vascular system, the method of magnetic resonance imaging with contrast can be prescribed.