MRI thyroid is a hardware method of investigation using a magnetic field used to study this endocrine organ. Scanning allows you to assess the location and size of the lobes and isthmus of the gland, their structure, to identify the presence of inflammatory processes, neoplasms, compression of the gland, to study adjacent organs and tissues. As a rule, it is carried out natively, but if a deeper diagnosis is needed, intravenous contrast agents can be used.
mri thyroid is prescribed to patients with symptoms of damage to this organ if other methods of research are uninformative. Clinical indications include causeless rapid weight gain or weight loss, general metabolic disorders and hormonal imbalance, increased irritability, fatigue and anxiety, sleep disorders – insomnia at night and drowsiness during the day, emotional lability, cardiac arrhythmias, tachycardia. Also, an mri thyroid is necessary in case of an abnormal location of the organ or its enlargement, suspicion of infectious and inflammatory diseases, a tumor or the presence of a foreign body (non-metallic in nature). Less often, tomography is used before surgery in order to study the topographic features of the gland and surrounding structures, or if there is a suspicion of a retrosternal localization of goiter.
The list of absolute contraindications to MRI includes the presence of metallic foreign bodies in the patient’s body (dentures, traumatological and orthopedic metal structures, vascular clips or fragments from live projectiles, etc.), ferrimagnetic or electronic devices (artificial pacemakers, hearing implants). Also, this procedure is not prescribed to women in the first 3 months of pregnancy and patients with tattoos applied using metal-containing dyes. Relative contraindications include severe general condition, mental disorders and phobias (schizophrenia, fear of confined space), heart failure of the II-III st., the second half of pregnancy, the patient’s body weight over 120-140 kg. If it is necessary to perform an mri thyroid with intravenous contrast, allergy to contrast agents, severe renal dysfunction, breastfeeding are added to all of the above. In the latter case, the study is permissible if the patient refrains from feeding for 2 days after the procedure.
Depending on the suspected pathology, other studies are pre-conducted: laboratory tests (general blood and urine analysis, biochemical examination, determination of thyroid and hypothalamus hormone levels, etc.), ultrasound, scintigraphy, etc. If it is planned to use intravenous contrast agents, then the sensitivity of the patient to this drug is necessarily determined, the excretory function of the kidneys is evaluated.
In most cases, thyroid MRI does not require specific preparation. The exceptions are children and persons who are unable to maintain a static position throughout the study – patients with severe pain syndrome, mental disorders and claustrophobia, a tendency to involuntary movements. In such situations, a full-time anesthesiologist performs drug sedation. It is recommended to give up eating 3-6 hours before contrast diagnostics. Immediately before placing the patient in the MRI machine, he is asked to take off all metal objects: jewelry, belts with steel buckles, watches, removable dentures, hairpins, etc. Clothes should not have metal buttons or rivets. If necessary, a gadolinium-based contrast agent is injected intravenously to the patient before being placed in the tomograph.
Methodology of conducting
To conduct an mri thyroid, the subject is placed on a table, the head is fixed and a roller is placed under the neck. Then he is transported inside the MRI machine, and the doctor goes to the next room, from which he monitors the patient’s condition and communicates with him. He also controls the quality of the images received, because any movement of the patient can “lubricate” them. The average duration of an mri thyroid is from 20 to 60 minutes. During the procedure, the subject may feel a slight tingling and a feeling of warmth in the neck, less often – slight discomfort. In most cases, the procedure does not cause complications, after its completion, no restrictions are required. When using intravenous contrast, adverse reactions are sometimes observed in the form of mild nausea, headache or general weakness and drowsiness.
Interpretation of results
In most clinics and diagnostic centers, you can get the result of an mri thyroid “on your hands” already 1 hour after the end of the study. During this time, a conclusion is drawn up in written or printed form, in which the doctor describes in detail the identified deviations from the norm. The resulting images are printed and recorded on a CD. In some institutions, the results may be sent to the e-mail of the patient or the attending physician.
According to the results of mri thyroid, it is possible to establish the general shape of the organ (including in 3D mode), confirm an increase in one or both lobes or the presence of additional ones, identify neoplasms, determine their structure, localization and degree of vascularization, assess the condition of surrounding tissues and compression of the gland (esophagus, trachea, lymph nodes). The technique also makes it possible to diagnose the presence of triiodnegative metastases, infectious, inflammatory and autoimmune disorders. When using contrast agents, minimal pathological changes in blood vessels and gland tissues can be detected. Despite the results obtained, mri thyroid, the final diagnosis is made only by the attending oncologist or endocrinologist, taking into account the combination of the study data with the clinical picture and medical history.
At the moment, the main study for thyroid diseases is ultrasound. Echography allows you to study the organ in sufficient detail due to its surface location. Therefore, in most cases, mri thyroid is used as a diagnostic “reserve” – in situations where ultrasound scanning does not reveal any changes with pronounced clinical disorders. The advantages of MR tomography include the possibility of obtaining a three-dimensional image of the gland, the absence of radiation exposure and the mandatory use of contrast agents, a detailed study of regional lymph nodes. The result of the study, unlike ultrasound, does not depend on the individual abilities of the doctor or the severity of the subcutaneous fat of the patient. Also, mri thyroid is the only method that allows detecting triiodnegative metastases. The disadvantages of this procedure include the high cost and information content equivalent to ultrasound in most diseases.