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This study introduces a fast, precise method for correcting head motion during MRI scans using navigator-based feedback control. The technique achieves high accuracy with minimal calibration, improving image quality for in vivo human head imaging.

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Area of Science:

  • Medical Imaging
  • Neuroimaging
  • Magnetic Resonance Imaging (MRI)

Background:

  • Motion artifacts are a significant challenge in Magnetic Resonance Imaging (MRI), particularly in head scans.
  • Existing motion correction techniques often require extensive calibration, long acquisition times, or complex processing.
  • Precise and efficient motion correction is crucial for high-quality diagnostic imaging.

Purpose of the Study:

  • To develop a navigator-based method for real-time, rigid-body motion correction in 3D MRI of the human head.
  • To achieve high precision and accuracy in motion detection and correction with minimal acquisition and calibration overhead.
  • To enable simple and fast processing for practical clinical application.

Main Methods:

  • Integration of a short orbital navigator (2.3 ms) into a 3D gradient echo sequence.
  • Determination of head rotation and translation using linear regression with a complex-valued model.
  • Implementation of run-time scan correction via servo control, optionally including global phase and field offset correction.

Main Results:

  • Stable motion control was achieved, both with and without reference navigator acquisition.
  • Accurate detection of motion and global B0 changes was demonstrated in phantom studies.
  • In vivo imaging showed motion detection with micrometer and millidegree precision, successfully correcting millimeters of motion with excellent image quality.

Conclusions:

  • The combination of linear regression and feedback control provides effective prospective motion correction for head MRI.
  • The technique offers high precision, accuracy, short navigator readouts, and fast computation.
  • Minimal demand for reference data makes this method suitable for routine clinical use.