Chest MRI allows noninvasively studying the condition of the lungs, pleura, mediastinal organs, and soft tissues of the chest. MRI is most informative in the diagnosis of volumetric formations in the lungs and mediastinum and in the assessment of their invasion into surrounding structures. With the help of MRI, it is possible to detect lymph node lesions (with lymphogranulomatosis, tuberculosis, metastatic process, etc.), abnormalities of organ development, pathology of the thoracic aorta (aneurysms, dissections), exudative pleurisy and pericarditis.
Chest MRI is performed after other instrumental studies if the information obtained during diagnostic procedures does not allow making a reliable conclusion about the presence, structure and prevalence of pathological processes in the chest area. Usually, the technique is prescribed after radiography, sometimes after ultrasound and CT. The purpose of chest MRI is to clarify the diagnosis, differentiate various diseases, draw up a program of conservative treatment, prepare for surgery, monitor the effectiveness of therapy or surgical intervention, as well as timely detection of relapses.
An MRI of the chest assesses the condition of the lungs, pleura, organs and tissues of the mediastinum (trachea, esophagus, vessels, lymph nodes, thymus gland, adipose tissue), as well as muscles and subcutaneous adipose tissue. The diagnostic value of MRI in the study of lung tissue depends on the type of pathology, many diseases are better or with the same accuracy determined during CT. Magnetic resonance imaging is less informative in the study of ribs and sternum, but in some cases it is successfully used to detect neoplasms of bone and cartilage structures, to diagnose traumatic injuries and developmental abnormalities.
In oncology, chest MRI is performed during the diagnosis of lung cancer, pleural cancer, tumors originating from rib and sternum tissue (osteomas, chondromas, osteoblastoclastomas, etc.), malignant and benign mediastinal neoplasia. In addition, the study can be assigned to detect metastases of tumors of other localizations in the lung tissue, as well as to assess the involvement of lymph nodes in malignant neoplasms of the chest and some other oncological processes (for example, lymphogranulomatosis). During the procedure, the topology of neoplasias is determined, confirmation or exclusion of germination of neighboring anatomical structures is carried out.
In case of lung atelectasis, chest MRI is performed to clarify the cause of the pathology (compression of the bronchus by a tumor or enlarged lymph node, blockage by a foreign body, collapse of the lung or part of the lung with bronchitis or pneumonia). In some cases, MRI is used for bronchiectatic disease, pleurisy, abscess and gangrene of the lung. The study is effective in diagnosing foci of purulent infection located in soft tissues (for example, under the pectoralis major muscle). Tomography is sometimes prescribed for traumatic injuries of this anatomical zone (for example, when a lung ruptures with the formation of a pneumothorax or hemothorax), for pathological processes that occurred in the long term after injuries, operations, inflammatory and infectious diseases.
Diagnosis is not carried out in the first trimester of pregnancy. Chest MRI is not prescribed in the presence of ferromagnetic implants of any purpose (from plates and spokes used for fixing fractures to vascular clips) and complex electronic devices in the patient’s body. There are limitations due to the load capacity of the equipment and the size of the tomograph tunnel. The listed parameters may vary depending on the type of device. MRI is usually not performed for claustrophobia, hyperkinesis and mental disorders that make it difficult to remain motionless or to understand and follow the doctor’s instructions. If necessary, patients suffering from claustrophobia, MRI is performed in open-type devices or sedatives are prescribed. In conditions that prevent the preservation of immobility, anesthesia, anticonvulsants and other medications are used (depending on the nature of the pathology).
Chest MRI with contrast is contraindicated in the presence of an allergic reaction to gadolinium salts and in diseases of the urinary system with severe renal dysfunction. In addition, contrast studies are not prescribed in the second and third trimester of pregnancy. The lactation period is not considered as a contraindication to contrast chest MRI if the patient refrains from feeding for 48 hours after the procedure is completed (until gadolinium preparations are completely eliminated from the body).
When performing a native chest MRI, no preparation is required. Before the contrast study, laboratory tests are performed to detect kidney dysfunction, a skin test is performed to exclude allergies to gadolinium. The patient presents to the specialist the results of previous diagnostic procedures, doctors’ conclusions and extracts from medical records, removes all metal objects and accessories, leaves them in the next room. In some clinics, at the time of the MRI, the patient is offered to change into disposable underwear, in others it is allowed to perform the study in their own clothes if there are no metal parts in it.
Methodology of conducting
The patient lies on his back on a mobile table, which is either pushed into the tunnel of the equipment (when using a closed-type device), or placed under a hinged block (when using an open-type device). Contrast is administered intravenously, if necessary, an infusion system is installed. Chest MRI is absolutely painless. Some patients note tingling and a feeling of warmth, with the introduction of contrast, slight discomfort is possible. The appearance of pronounced unpleasant sensations during the study is a reason for immediate communication with the diagnostician using a microphone. The duration of the study is from 30 to 60 minutes (sometimes longer), depending on the type of procedure (native or contrast).
The patient can go home immediately after completing an MRI of the chest. When administering anesthetic drugs, the patient is left in a medical institution until the condition normalizes, when using sedatives, support may be required. The conclusion is usually prepared within a day or earlier and given to the patient in printed form. It is possible to write to a disk, USB drive or other electronic media. If deviations from the norm are detected, it is necessary to contact the specialist who sent for the procedure to establish a diagnosis and determine treatment tactics.