Patients sometimes worry about claustrophobia in the scanners. CT scanners are well tolerated as the scanner does not have a long tunnel. However, an MRI of your shoulder or neck does involve “going into the tunnel” which some patients find difficult. For your foot or ankle MRI you will not “go right in” and so claustrophobia is not a problem. Lying still for the duration of the scan, and the noise, are points to be aware of. The scanning team will ask you to complete a safety check before the scan. A pacemaker is one common reason for not being able to have an MRI. In some instances you will have dye injected to make the scan even more sensitive and some patients need a routine blood check prior to this, just to make sure the dye is safe for your kidneys.
ULTRASOUND
Ultrasound is a particularly useful way of diagnosing tendon, ligament and nerve disorders. An ultrasound can be made as the foot moves – like a video. Other scans produce still pictures only.
Ultrasound guided injections may be recommended at the time of the scan. With the ultrasound guidance, the injection can be very reliably sited at the correct spot.
CT SCAN
This is a detailed set of X-rays which are turned into three-dimensional images by the computer. A CT scan is very good at showng bones, but gives less information about tendons and ligaments.
MRI SCAN
This scan does not use X-rays. It is especially good for looking at the tendons and ligaments in the foot and ankle. Sadly an MRI scan of the ankle does not include toes, and an MRI of the foot does not show the ankle or heel. Occasionally, therefore, two scans may be needed.
