MRI Parallel Imaging Artifacts

Parallel imaging artifact is a type of artifact that can occur in magnetic resonance imaging (MRI) when using parallel imaging techniques. Parallel imaging is a method used to accelerate MRI scans by simultaneously acquiring data from multiple receiver coils. However, it can introduce artifacts such as the following:

Noise amplification artifact: Due to the reconstruction of high-frequency information from the aliased signal, the noise is amplified.

Geometric distortion artifact: Due to the sensitivity of the coil array and image reconstruction methods, there can be errors in the image geometry.

Ghosting artifact: Due to incomplete phase correction, there can be residual ghosts in the image.

Signal loss artifact: Due to variations in coil sensitivity, the signal can be lost in certain regions of the image.

Parallel imaging(ipat) artifact MRI

Here are some strategies to minimize or avoid parallel imaging artifacts :

Increase signal-to-noise ratio (SNR): Higher SNR can help mitigate artifacts. Techniques such as using larger field-of-view (FOV), increasing the number of signal averages, or utilizing higher magnetic field strengths can enhance SNR and reduce artifacts.

parallel imaging and SNR

Number of receiver coils : Increasing the number of receiver coils to improve the signal-to-noise ratio and reduce the amount of aliasing

Reconstruction algorithms: Appropriate reconstruction algorithms designed for parallel imaging, such as sensitivity encoding (SENSE) or generalized autocalibrating partially parallel acquisitions (GRAPPA), can help reduce artifacts. These algorithms exploit the


  • Barmet, C., et al. (2008). “Parallel imaging in MRI.” NMR in Biomedicine 21(3): 24-35.
  • Griswold, M. A., et al. (2002). “Generalized autocalibrating partially parallel acquisitions (GRAPPA).” Magnetic Resonance in Medicine 47(6): 1202-1210.
  • Pruessmann, K. P., et al. (1999). “SENSE: sensitivity encoding for fast MRI.” Magnetic Resonance in Medicine 42(5): 952-962.