Final answer:
Gradient echo (GRE) MRI is a medical imaging technique that creates detailed images of internal tissues using gradient magnetic fields along with the main magnetic field. It leverages the magnetization of hydrogen nuclei and Maxwell's equations. GRE MRI is essential for detecting diseases in soft tissue and uses technologies like MEG and MCG for diagnostics.
Step-by-step explanation:
Gradient echo (GRE) MRI is a type of magnetic resonance imaging (MRI) that uses gradient fields along with the main magnetic field to produce detailed images of the internal tissues and organs of the human body. This technique is highly sensitive to differences in the tissue composition, flow, and blood properties. GRE MRI scans are useful in detecting and characterizing various diseases and abnormalities within the body's soft tissues, especially since soft tissues contain a high percentage of water molecules, and consequently, hydrogen atoms.
The phenomenon of MRI imaging is based on hydrogen nuclei within the body. When these nuclei are placed within a powerful magnetic field, they become magnetized, aligning with the field. Radiofrequency (RF) pulses are then applied to perturb this alignment, causing the nuclei to emit magnetic signals as they return to their original state. These signals are subsequently recorded by sensors within the MRI machine, which, with the help of a computer, are converted into highly detailed images of the body's internal structures.
The process of MRI is grounded in Maxwell's equations, which are the fundamental equations of electromagnetism. These equations explain the behavior of electric and magnetic fields and how they are influenced by objects, including the human body tissues. Advanced applications of magnetic fields in medicine include magnetoencephalogram (MEG), which measures the brain's magnetic field, and magnetocardiogram (MCG), a recording of the heart's magnetic field. Both are important diagnostics tools that rely on the principles of magnetism as described by Maxwell's equations.