What is a magnetic resonance imaging (MRI) scan?
The MRI scan gives us a high-resolution image of the brain. In conjunction with other tests it can help localize the brain region responsible for the patient’s seizures. In patients with certain types of epilepsy, the MRI abnormalities can be fairly subtle. The expertise of a neuroradiologist trained to detect these abnormalities is often needed. In patients with suspected temporal lobe epilepsy, special MRI techniques are needed to maximize the probability these abnormalities will be detected.
Magnetic Resonance Imaging (MRI) is a way of obtaining images of the body. MRI is a very safe imaging modality with no known harmful effects. Unlike other imaging techniques, such as X-ray and CT, MRI does not use x-rays. Instead, MRI uses a strong magnetic field and radio waves to produce images of any part of the body in any direction. Although MRI is capable of imaging any part of the body, it is particularly good for demonstrating structures such as the brain, spinal cord, muscles, ligaments and cartilage. To ascertain if it is a safe for you to enter the strong magnetic field, you will be sent an MRI Safety Screening Form to complete.
An MRI scan uses a powerful magnet to take pictures of the inside of your body. This is an excellent test because it allows your doctor to see your body in narrow slices, each about one quarter of an inch thick. For example, imagine that you are slicing a loaf of bread and taking a picture of each slice. It can view slices from the bottom (axial), front (coronal), or sides (sagittal), depending on what your doctor needs to see. MRI can also be used to view veins and arteries, called magnetic resonance angiography (MRA). Standard MRI can t see fluid that is moving, such as blood in an artery, and this creates flow voids that appear as black holes on the image. The MRA uses a contrast dye (gadolinium) injected into the patient s vein to help the computer see the arteries and veins. The contrast is also used to view tumors and arteriovenous malformations (AVMs).
