magnetic resonance

Thân thiện

A doctor reviews a magnetic resonance image of a patient's knee.

Definition

Noun: 1. A physical phenomenon: The absorption or emission of electromagnetic radiation by electrons, atoms, or nuclei when they are placed in a strong, static magnetic field and exposed to a second, oscillating magnetic field at a specific resonant frequency. This occurs due to the quantum mechanical property of spin.

Usage

• Magnetic resonance is the fundamental principle behind important medical imaging and analytical techniques.
• The study of magnetic resonance allows scientists to understand the structure of molecules.
• The signal in an MRI machine is generated by magnetic resonance.

Examples in Use

Advanced Usage & Related Terms

• Nuclear Magnetic Resonance (NMR): A specific type of magnetic resonance involving the nuclei of atoms. It is the core technology behind MRI and a major analytical technique in chemistry and biochemistry.
• Magnetic Resonance Imaging (MRI): A non-invasive medical imaging technology that uses the principles of nuclear magnetic resonance to generate detailed anatomical and physiological images of the body.
• Electron Paramagnetic Resonance (EPR) / Electron Spin Resonance (ESR): A type of magnetic resonance involving unpaired electrons, used to study chemical species with free radicals or transition metal ions.
• Functional MRI (fMRI): An MRI procedure that measures brain activity by detecting changes in blood flow, relying on the magnetic resonance signal.

Variants and Related Words

• Resonance (n): In physics, the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force is equal or close to a natural frequency of the system on which it acts. Magnetic resonance is a specific type of resonance.
• Magnetic (adj): Having the properties of a magnet; of or relating to magnetism or a magnet.

Synonyms & Near-Synonyms

• Magnetic resonance phenomenon
• Spin resonance (a more technical term emphasizing the quantum spin property)

Notes on Meaning

• Core Concept: The term almost always refers to the underlying physical phenomenon. In common usage, it is frequently part of the compound terms "MRI" or "NMR," which refer to the applied technologies. The definition provided is for the isolated term "magnetic resonance."
• "Nuclear" Omission: In medical contexts, the word "nuclear" is often dropped from "Nuclear Magnetic Resonance Imaging" to form "Magnetic Resonance Imaging (MRI)" to avoid patient concerns, even though the technology is based on nuclear spin.

Học thuật

Noun

1. resonance of electrons or atoms or molecules or nuclei to radiation frequencies as a result of space quantization in a magnetic field