Knowing exactly where the instrument is at all times is a special added safety factor. The CT image is shown in 3 different views, to give information in all 3 dimensions. The location of the instrument is also shown in 3 different views. Note that the precise location of the surgical instrument is indicated by where the two lines cross. In the upper left is a frontal view of the instrument removing polyps from the ethmoid sinus.
Upper right is a side view of the ethmoid area and lower left is a horizontal cut.
Commonly a patient has an MRI for a reason unrelated to surgery. They are referred to our group because the MRI shows sinus disease. If the patient doesn't have a clear history of sinus disease, we explain that the MRI is too sensitive and will appear to show horrible disease when only mucus is present. Often, no treatment is needed. Or we will take a CT Scan X-ray.