Introduction
The paranasal sinuses are hollow spaces within the facial bones of the skull, which are filled with air, arranged around the nasopharynx and lined with nasal mucosa. They are divided into the so-called whereby they stand among themselves and with the nasal passages of the nasal cavity in connection. They serve primarily as resonance chambers when speaking as well as for humidifying, cleaning and warming the air.
- Maxillary sinuses
- Sinuses
- Sphenoid sinus and
- Ethmoidal cells,
MRI or CT imaging of the paranasal sinuses?
Magnetic resonance imaging (MRI) as an imaging method that works with magnetic fields rather than harmful X-rays is particularly suitable for soft tissue imaging and thus also for imaging pathological processes (e.g. sinusitis, tumor formation) in the paranasal sinuses, which involve mucous membrane involvement, among other things. Computer tomography (CT), as a further method for imaging the paranasal sinuses, can also be used to assess the mucous membranes, but is also particularly suitable for bone imaging (e.g. to clarify the anatomical conditions in the paranasal sinus system). In contrast to the MRT, however, it works with X-rays. Both methods can be used equally well, depending on the focus of the question and the indication behind the examination.
Indications
The MRI (and also the CT) serves in imaging for routine overview diagnostics of the paranasal sinuses in the facial skull, whereby especially inflammatory processes and spatial demands of the nasal mucosa, changes in the facial skull bones and the anatomical conditions of the paranasal sinus system can be assessed. The most frequent indication for MRI of the paranasal sinuses is the inflammation of the paranasal sinuses (med. sinusitis).
Especially in the case of chronic sinusitis, the MRI can provide information on the cause of the chronicity, e.g. by detecting any obstruction of the flow of water, etc. etc. In addition, the MRI image is also used for imaging prior to planned invasive surgical interventions on the sinuses, such as punctures or endoscopies.
In general, the most common indications for paranasal sinus MRI are the exclusion of inflammatory or space-occupying processes as well as the monitoring of their progress, imaging of congenital anatomical variants and malformations, overview images prior to surgery and the exclusion of fractures after trauma. In particular, various differential diagnoses can be an indication for an MRI:
- These include inflammations, such as acute or chronic sinusitis (inflammation of the paranasal sinuses)
- Accumulation of mucus or pus in the caves
- Fractures in the midface or frontobasal (basal skull fracture, frontal bone fracture) after trauma
- Benign tumors (e.g. osteomas, polyps, angiofibromas, retention cysts)
- Malignant tumors (e.g. carcinomas, sarcomas, metastases)
- Congenital malformations, such as a narrowing or closure of the posterior nasal opening (choanal stenosis, – atresia), a cleft lip and palate or the Cartagener syndrome
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