Frequently Asked QuestionsCommon MRI and Imaging Questions
Common Questions You Might Have
1. Why is an MRI so noisy?
The sounds that come from the MRI scanner are actually vibrations. An MRI machine consists of one large electromagnet, called the main magnet, and three smaller electromagnets called gradients. To make an image, current is rapidly applied to the gradient coils which cause them to interact with the main magnet with great force. This creates the “banging” sound commonly associated with the machine. At Hope Imaging, we provide ear plugs and/or headphones to patients during the exam. While these often don’t completely cancel out all the noise, they do help. Patients wearing headphones may listen to their choice of music during the scan.
2. Why is there such a big concern about medical devices and metal in or on my body?
Most scanners used in medical imaging have a main magnetic field strength of 1.5 Tesla, which is approximately 30,000 times the earth’s magnetic pull. This powerful magnetic field is always on – even when images are not being taken – and is attracted to certain metals. This means that the closer an external object gets to the center of the magnet, the stronger the pull. This pull can cause objects to move suddenly and potentially create a projectile that can cause injury to anyone close by. Metal in the body can also be affected by the magnetic pull unless it is anchored in bone and is nonferrous. For this reason, any type of metal, including shrapnel, bullets, and metal flecks from grinding, that could be embedded in your body, especially the eyes, needs to be evaluated.
3. How long will the test take?
The actual exam time depends on the type of test ordered. Some exams are as short as 20 minutes while others are close to an hour. Each scan takes between 2-5 minutes. Just like taking a picture with a camera, if the patient moves, the images will be blurry and the entire scan will have to be repeated, which means a longer exam time.
4. What if I am nervous or anxious?
Our MRI staff and technologists are experienced caring healthcare professionals who answer any and all patient questions to help them relax and make it through the exam comfortably.