K-space, short for "k-space trajectory imaging," is a type of imaging technique used in MRI (magnetic resonance imaging). In k-space imaging, data is collected in the spatial frequency domain rather than the spatial domain, allowing for faster image acquisition and improved signal-to-noise ratio. K-space data is collected in a grid pattern, with each point representing a different spatial frequency. By sampling data in this way, MRI machines can reconstruct images from the collected k-space data using Fourier transforms. K-space imaging is widely used in MRI for various applications, including dynamic imaging, functional MRI, diffusion imaging, and spectroscopy. The technique has enabled significant advancements in MRI technology, allowing for faster and more detailed imaging of the human body.