Off‐resonance artifact correction for MRI: A review

In magnetic resonance imaging (MRI), inhomogeneity in the main magnetic field used for imaging, referred to as off‐resonance, can lead to image artifacts ranging from mild to severe depending on the application. Off‐resonance artifacts, such as signal loss, geometric distortions, and blurring, can compromise the clinical and scientific utility of MR images. In this review, we describe sources of off‐resonance in MRI, how off‐resonance affects images, and strategies to prevent and correct for off‐resonance. Given recent advances and the great potential of low‐field and/or portable MRI, we also highlight the advantages and challenges of imaging at low field with respect to off‐resonance. In magnetic resonance imaging (MRI), inhomogeneity in the main magnetic field used for imaging, referred to as off‐resonance, can lead to image artifacts ranging from mild to severe depending on the application. Off‐resonance artifacts, such as signal loss, geometric distortions, and blurring, can compromise the clinical and scientific utility of MR images. In this review, we describe sources of off‐resonance in MRI, how off‐resonance affects images, and strategies to prevent and correct for off‐resonance.