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In MRI imaging, two types of external magnetic fields are applied, B0 and B1. Pl...

Oct 8, 2024

In MRI imaging, two types of external magnetic fields are applied, B0 and B1. Please explain the specific utilities of these two fields, and also point what components of a MRI machine are used to generate the fields?

Answer

The external magnetic fields B0 and B1 in MRI imaging serve distinct purposes: B0 is the main magnetic field that aligns the nuclear spins, while B1 is the radiofrequency field used to excite these spins. The components generating these fields include superconducting magnets for B0 and radiofrequency coils for B1.

Solution

a

B0 Field: The B0 field is the primary magnetic field in MRI, typically ranging from 1.5 to 3 Tesla. It aligns the magnetic moments of hydrogen nuclei in the body, which is crucial for obtaining a clear image

b

B1 Field: The B1 field is a radiofrequency (RF) field that is applied perpendicular to the B0 field. It temporarily disturbs the alignment of the hydrogen nuclei, allowing them to emit signals that are detected to create images

c

MRI Components: The B0 field is generated by superconducting magnets, while the B1 field is produced by RF coils that transmit and receive the radiofrequency signals

Key Concept

The roles of B0 and B1 fields in MRI imaging

Explanation

B0 aligns hydrogen nuclei for imaging, while B1 excites them to produce detectable signals.