Physics Just the Basics Series #11 - K-Space Trajectories Used for Rapid Cardiac MRI-Webinar

Video Transcription

Video Summary

The webinar introduced cardiac MRI k-space sampling, focusing on how magnetic field gradients create different trajectories for collecting data. Presenter Adrienne Campbell-Washburn explained the basics of k-space, including how its center relates to image contrast and its edges to fine detail. She reviewed Cartesian sampling, where k-space is filled line by line, and contrasted it with non-Cartesian approaches such as spiral, radial, rosette, cones, and 3D variants.<br /><br />The lecture highlighted why non-Cartesian methods are valuable: they can be faster, more SNR-efficient, more motion tolerant, and useful for real-time imaging, self-navigation, ultra-short TE imaging, and compressed sensing. Examples included spiral and radial imaging for real-time cine, flow, perfusion, fetal cardiac MRI, MR fingerprinting, and 3D whole-heart imaging.<br /><br />She also discussed artifacts and reconstruction challenges, including streaking, off-resonance blurring, gradient delays, and the need for non-uniform Fourier transforms and gridding. The Q&A covered practical topics such as centric vs linear sampling, compressed sensing benefits, trajectory correction, and field-strength-related off-resonance effects.

Keywords

cardiac MRI

k-space sampling

non-Cartesian trajectories

Cartesian sampling

spiral imaging

radial imaging

compressed sensing

off-resonance artifacts

non-uniform Fourier transform