Automatic compensation of motion artifacts in MRI

• Published in: Magnetic resonance in medicine Vol. 41; no. 1; pp. 163 - 170
• Main Authors: Atkinson, David, Hill, Derek L.G., Stoyle, Peter N.R., Summers, Paul E., Clare, Stuart, Bowtell, Richard, Keevil, Stephen F.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01.01.1999; Williams & Wilkins
• Subjects: Algorithms; autofocus; Biological and medical sciences; Brain - anatomy & histology; Entropy; Humans; Infant; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging - standards; Medical sciences; Miscellaneous. Technology; motion correction; Movement; Phantoms, Imaging; post-processing; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Shoulder - anatomy & histology; Signal Processing, Computer-Assisted; Human; Image quality; Evaluation; Motion; Signal processing; Artefact; Error correction; Technique; Nuclear magnetic resonance imaging
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/(SICI)1522-2594(199901)41:1<163::AID-MRM23>3.0.CO;2-9

Patient motion during the acquisition of a magnetic resonance image can cause blurring and ghosting artifacts in the image. This paper presents a new post‐processing strategy that can reduce artifacts due to in‐plane, rigid‐body motion in times comparable to that required to re‐scan a patient. The algorithm iteratively determines unknown patient motion such that corrections for this motion provide the best image quality, as measured by an entropy‐related focus criterion. The new optimization strategy features a multi‐resolution approach in the phase‐encode direction, separate successive one‐dimensional searches for rotations and translations, and a novel method requiring only one re‐gridding calculation for each rotation angle considered. Applicability to general rigid‐body in‐plane rotational and translational motion and to a range of differently weighted images and k‐space trajectories is demonstrated. Motion artifact reduction is observed for data from a phantom, volunteers, and patients. Magn Reson Med 41:163‐170, 1999. © 1999 Wiley‐Liss, Inc.