MRI: What is it?

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“MRI is based upon the science of nuclear magnetic resonance (NMR). Certain atomic nuclei can absorb and emit radio frequency energy when placed in an external magnetic field. In clinical and research MRI, hydrogen atoms are most-often used to generate a detectable radio-frequency signal that is received by antennas in close proximity to the anatomy being examined. Hydrogen atoms exist naturally in people and other biological organisms in abundance, particularly in water and fat. For this reason, most MRI scans essentially map the location of water and fat in the body. Pulses of radio waves excite the nuclear spin energy transition, and magnetic field gradients localize the signal in space. By varying the parameters of the pulse sequence, different contrasts can be generated between tissues based on the relaxation properties of the hydrogen atoms therein.” – wikipedia

Muscles are 79% water.
Brain is made up of about 75 % water.
22% – 31% of bones is made up of water.

MRI contrast agents are a group of contrast media used to improve the visibility of internal body structures in magnetic resonance imaging (MRI). The most commonly used compounds for contrast enhancement are gadolinium-based.

When Rx MRI’s to image muscular skeletal pains, temporomandibular joint, disc, condyle degeneration abnormalities are seen on a non-contrast scan. When looking for certain types of abnormalities, as brain tumors contrast (gadolinium ) is used allowing the tumor to “glow’
on scan.

When scanning temporomandibular joints, surrounding
tendons, ligaments, and cartilage a non contrast MRI scan is typically indicated.