Rotary scanning acquisition in ultra‐low‐field MRI. Issue 6 (30th June 2015) - Hsu, Yi‐Cheng
Abstract : Purpose: To develop a method of achieving large field of view (FOV) imaging with a smaller amount of data in ultra‐low‐field (ULF) MRI. Theory: In rotary scanning acquisition (RSA), data from the imaging object is acquired at multiple angles by rotating the object or the scanner. RSA is similar to radial‐trajectory acquisition but simplifies the measurement and image reconstruction when concomitant fields are nonnegligible. Methods: RSA was implemented to achieve large FOV with only three localized superconductive quantum interference device (SQUID) sensors at the ULF‐MRI field of 50 μT. Results: Simulations suggest benefits of RSA, including reduced concomitant field artifacts, large FOV imaging, and SNR improvement. Experimental data demonstrate the feasibility of reconstructing large FOV images using only three SQUID sensors with 33% of the amount of data collected using a Cartesian trajectory. Conclusion: RSA can be useful in low‐field, low‐weight, or portable MRI to generate large FOV images with only a few sensors. Magn Reson Med 75:2255–2264, 2016. © 2015 Wiley Periodicals, Inc.