MRI FAQs
At the molecular level, the human body is composed of Hydrogen atoms that have a random spin direction. However, when you are placed in the strong magnetic field of a MRI scanner, the Hydrogen atoms align in the same direction as the magnetic field. When a radiofrequency wave generated by the MRI scanner is transmitted, the Hydrogen atoms will produce a signal. These signals are processed by a computer to create an image of internal structures and organs.
Both MRI and CT create cross-sectional images of the body. The main difference is that MRI uses strong magnetic and radio waves to produce images, where as a CT scanner uses ionizing radiation. Both modalities are used to diagnose different types of medical conditions.
The MRI Technologist will ensure that you are as comfortable as possible during the MRI exam. Our MRI scanners are open on both ends, well lit, and there is a fan for air circulation. There is a two-way intercom for communication between you and the MRI technologist. Additionally, the MRI Technologist will provide the patient with an emergency call bell that can be used at any time during the procedure.
The tapping or knocking noise heard during the MRI scan is created when “gradient coils” inside the scanner are switched on and off to measure the signal reflecting from the patient’s body.
Although MRI scans may be focused on one specific area of the body, it is important that the MRI technologist is aware of any devices that are inside or outside of the patient’s body. Upon entering the MRI scan room you are exposed to a strong magnetic field that can affect certain metallic devices. These devices can interfere with the scan and can cause injury to the patient. It is very important to inform the MRI technologist if you have a pacemaker or other implanted electronic device, a history of heart surgery or brain surgery, aneurysm clips, shrapnel, or a history of getting metallic fragments in your eyes.