MRI SCANNERS: The Inner Workings MAIN MAGNETIC COIL Creates the main magnetic ﬁeld that surrounds the patient
TRANSCEIVER Sends and receives radio signals that are transformed into images by a computer
Y MAGNETIC COIL Creates a magnetic ﬁeld from top to bottom
X MAGNETIC COIL Creates a magnetic ﬁeld from left to right
Z MAGNETIC COIL Creates a magnetic ﬁeld from head to toe
MRI at the Atomic Level
1. Billions of hydrogen atoms in our bodies continuously spin in random directions.
2. In the strong magnetic ﬁeld of the MRI scanner, the atoms line up.
3. Radio frequency (RF) pulses are directed at the body part being imaged, causing certain protons to spin, or resonate, as they absorb the RF energy.
4. When the radio wave pulse is turned off, these protons release energy, emitting a signal.
5. The computer translates the signals into an image. Different tissues have different signals that are represented by different gradations of gray.
Temple Health - Temple Health Magazine - Spring 2016