MRI of the paranasal sinuses: what shows?
MRI of the paranasal sinuses of sinuses may be included in the Protocol of examination of the brain or to execute itself. It is prescribed infrequently, as most of the diseases of the paranasal sinuses (sinusitis, frontal sinusitis) is well diagnosed using x-ray, CT, and ENT-endoscopy. MRI is indispensable in the diagnosis of pathological changes in the nasopharynx, as x-ray examination of this region is uninformative.
In addition to the well-known sinus, in humans there are three pairs of sinuses: frontal, sphenoidal and ethmoidal labyrinth. The maxillary and frontal sinuses located superficially and is arranged relatively simple, so the sinusitis and frontal sinusitis is well possible to detect using conventional radiography. Lattice labyrinth cavity and sphenoid located deeper and is arranged more difficult, therefore, to obtain at least approximate information about the changes in them can only be through a layer-by-layer imaging techniques – CT and MRI.
The nasopharynx is a continuation of the nasal cavity, passing at the level of the lower edge of the palatal curtain in the oropharynx. Pharyngeal wall consists of muscle tissue, on their surface are the nasal (adenoids) and Palatine tonsil. The mucosal surface of the nasopharynx can be viewed visually or with the help of ENT endoscope. As the deep-lying tissues will be able to show only MRI, x-ray methods here is not informative.
MRI is used for imaging of soft tissues, so with this study, you can discover dobrokachestvenno magadane or malignant tumors of the paranasal sinuses to diagnose sinusitis, frontal sinusitis or etmoidit, cysts and polyps of the mucous membrane of the sinuses.
Identified tumors can be measured to determine their relationship with nearby structures, and using the contrast, even to assess the intensity of blood flow in them and to determine the topography of blood vessels. While on the CT we see only the darkening gamerboy sinus, which allows to suspect sinusitis, MRI will show its type and cause.
At the same time, bone tissue, poor in water, on magnetic resonance scans is visible. Therefore, anomalies in the structure of bones and other damage are best explored using x-ray computed tomography. CT may show mucosal thickening or darkening of the sinus, however, to determine exactly what caused the change, will not work.
MRI of the sinuses shows the smallest changes in soft tissues and allows you to explore them as detailed as possible, but to assess lesions of bone structures better to use CT. For examination of the nasopharynx will only fit MRI
When prescribed magnetic resonance scan of the sinuses?
Usually an MRI of the sinuses is prescribed in cases when all other methods of examination did not give any result or the resulting information needs to be clarified. Research shows if:
- The patient has persistent headaches, the origin of which is unclear. If the results of the preliminary examination, the pathology of ENT organs is not revealed, it is advisable to get an MRI of the paranasal sinuses together with the examination of the brain.
- There is a suspicion of the presence of benign or malignant tumors of the sinuses – is an MRI with contrast. The study will show the exact boundaries of the tumor and its relationship with the surrounding tissues. The type of filling in contrast we can assume the nature of the tumor.
- The CT scan shows changes detected in the mucosa of the sinuses, but failed to establish their nature. Magnetic resonance scan will show what caused the shading sinus: polyp, cyst or liquid content, will help to distinguish the swelling of the mucous membrane from polosnogo sprawl.
- With persistent recurrent course sinusitis or sinusitis. Possible aggravation causes a small polyp, obstructing the ostium of the sinus or cyst is a barely visible small diameter, which was not detected by CT.
What diseases will help to identify?
In the description of the magnetic resonance research never indicated the name of the disease, as it is an auxiliary method study. The diagnosis is determined only by the doctor. Conclusion write with the expectation that it will read the doctor, so many terms can be confusing.
- Allergic and non-allergic rhinitis.
- Chronic sinusitis, sinusitis, etmoidit, sphenoidal or pansinusitis.
- Polyps and cysts of the mucous membrane of the sinuses and nasopharynx and a cyst of Thornwald.
- Retropharyngeal abscess.
- Benign and malignant tumors of the mucous membrane of the sinuses and nasopharynx.
- The presence of adenoid growths and the degree of hypertrophy of nasal tonsils.
Preparation and use restrictions of the study
If the contrast is not planned, no training required. Otherwise 6 hours before the procedure have nothing to eat or drink. Clothing it is advisable to choose without metal inclusions, they typically are made from magnetized materials. For the same reason, patients with a decorative jewellery or piercings, please remove them. Entering the magnetic field, metal objects are heated, which can cause soreness. In addition, they create noise in the image and make the study useless.
Dental implants, titanium plate for osteosynthesis of the jaws, and braces, and tires most often, is not magnetized. In this case, the question of whether the test is solved with the doctor individually. It is impossible to conduct MRI of patients after clipping of cerebral vessels with pacemakers without magnetic protection and non-magnetic cochlear implant.