The Making of an MRI

THE MAKING OF AN MRI MRIS BY THE NUMBERS 30 million MRIS performed per year in the U.S. . 22% brain - 32% head, neck, and spine 9% vascular and cardiac systems 13% breast, chest, pelvis, and abdomen 24% limbs 30 minutes or less to complete most MRI scans MRI COMPONENTS -Superconducting magnet • Large magnet that takes up most of the space in the MRI machine. • Creates a powerful magnetic field. • 5,000-20,000 gauss – strength of a superconducting magnet's field. • That's up to 40,000 times stronger than the Earth's magnetic field! • Made with superconducting material to minimize electrical resistance. . -452.4° F – temperature of liquid helium used to chill the superconducting material. Gradient magnets • 3 magnets used to create a variable magnetic field. · Analyzes very specific locations within the patient's body. • 180-270 gauss – strength of a gradient magnet's field. Coils • Transmit radiofrequency pulse into the area being scanned and also may receive signal from the body. • Different coils for different body parts. -Computer system • Generates images from the data collected during the scan. Patient table • Comfortable table where patients lie during the scan. • Moves patients in and out of the machine. MRI SCANNING STEPS Patient reclines on table and is moved into MRI machine Patient is moved into active magnetic field Hydrogen atoms within the patient's body align in response to magnetic field Radiofrequency pulse is directed through coils into body part being scanned Radiofrequency causes protons in certain hydrogen atoms to spin at a specific frequency Gradient magnets alter the magnetic field, allowing the machine to scan very precise sections of the body Radiofrequency pulse is turned off, causing hydrogen protons to release absorbed energy Coils detect released energy and send data to computer, which generates MRI images Provided by: concord imaging Sources: www.medtronic.com/patients/essential-tre mor/living-with/mri-scan/index.htm science.howstuffworks.com/mri.htm www.radiologysanantonio.com