Magnetic resonance imaging (MRI) allows for visualization of the sinuses. It provides images of soft tissue without using ionizing radiation like CT scans. MRI creates computer generated cross-sectional views of the sinuses through radio waves and a magnet. MRI studies provide information on body functions like congestion. For example, MRI studies can show normal variation of congestion and decongestion in the nasal passageways. MRI imaging of the sinuses may also be helpful in distinguishing sinus infection and inflammation from cancer.
MRI has some disadvantages as compared to CT evaluation of sinusitis. The test lasts for 1 hour. Any body movement can distort the pictures. Those with cardiac pacemakers or other metallic implants cannot have an MRI due to the magnetic effect on metal. The MRI scan is much more expensive than CT for evaluation of sinusitis. It is generally less sensitive in evaluating bone than CT images. CT scans give a more accurate assessment of the space in the sinuses, the facial bones and the bones of the skull.
If you experience claustrophobia, you may have difficulty getting a CT or MRI of the sinuses. These images require lying on a table with a scanning device placed over your head. You must remain still. The examination may last 10 - 20 minutes for CT scans and 60 minutes for MRI. If you have reservations about this test, an open MRI may be easier.