Pulsfältgradient

Pulsfältgradient refers to a technique used in magnetic resonance imaging (MRI) and spectroscopy to encode spatial information. In simple terms, it involves applying magnetic field gradients that vary in time and space. These gradients cause the precession frequency of the magnetic moments of the atomic nuclei, such as hydrogen protons, to become dependent on their location within the magnetic field.

By applying these pulsed gradients in specific sequences, it becomes possible to measure how the signal from the MRI scanner changes depending on the position of the nuclei. This allows for the creation of detailed images of internal body structures or the analysis of molecular environments. The strength, duration, and direction of the gradient pulses are precisely controlled to achieve the desired spatial encoding.

A key application of pulsed field gradients is in diffusion-weighted imaging (DWI), a type of MRI that is highly sensitive to the diffusion of water molecules. Areas with restricted water movement, such as those affected by stroke or tumors, will produce a different signal compared to healthy tissue when pulsed field gradients are applied. This makes pulsed field gradient techniques invaluable tools in medical diagnostics and scientific research.