Related Experiment Video
Updated: Jan 28, 2026
10:05
In vivo 19F MRI for Cell Tracking
Published on: November 25, 2013
15.4K
Markerless high-frequency prospective motion correction for neuroanatomical MRI
Robert Frost1,2, Paul Wighton1, F Işık Karahanoğlu1,2
1Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts.
Magnetic Resonance in Medicine
|March 2, 2019
Summary
Markerless head tracking enables prospective motion correction (PMC) during MRI. High-frequency, within-echo-train PMC significantly reduces motion artifacts in neuroimaging, improving accuracy.
Area of Science:
- Medical Imaging
- Neuroimaging
- Biomedical Engineering
Background:
- Head motion is a significant source of artifacts in neuroanatomical MRI.
- Prospective motion correction (PMC) aims to minimize these artifacts by adjusting imaging parameters in real-time.
- High-frequency motion correction during echo trains is crucial for sequences with long acquisition times.
Purpose of the Study:
- To integrate markerless head motion tracking with prospectively corrected neuroanatomical MRI sequences.
- To investigate the efficacy of high-frequency motion correction within imaging echo trains.
Main Methods:
- A commercial 3D surface tracking system was used for markerless head motion estimation.
- Imaging field of view (FOV) was adapted during MPRAGE and T2 SPACE sequences based on real-time motion tracking.
- Within-echo-train PMC (updating FOV every <50 ms) was compared to before-echo-train PMC (updating once per TR).
- Continuous-motion experiments with phantoms and in vivo were conducted.
Main Results:
- Markerless tracking demonstrated high accuracy in estimating head pose compared to MR image registration.
- Within-echo-train PMC significantly reduced motion artifacts compared to before-echo-train PMC.
- T2 SPACE sequences were more sensitive to motion during echo trains than MPRAGE.
- Morphometry estimates using FreeSurfer on within-echo-train PMC MPRAGE images were the most accurate.
Conclusions:
- Markerless head tracking is a viable method for implementing PMC in neuroimaging.
- High-frequency, within-echo-train PMC effectively reduces motion sensitivity in long echo train sequences.
- This technique enhances the accuracy of neuroanatomical MRI and subsequent morphometric analysis.
Related Concept Videos
01:15Distance Corrections
282
To achieve precise distance measurements, especially in surveying and construction, certain corrections must be applied to account for potential sources of error like the standardization errors, temperature variations, and slope adjustments.Standardization error emerges when measurement equipment undergoes changes, such as wear, repairs, or weather impacts. To address this, surveyors compare the equipment’s readings to a standard. This process identifies any deviation that might lead to...
282
01:20Power Factor Correction
532
The power transmission to a factory involves the transfer of apparent power, a combination of active and reactive power. The power factor measures how effectively electrical power is converted into useful work output. The ratio of the real power (KW) that does the work to the apparent power (KVA) supplied to the circuit.
532
01:21Frequency-dependent Selection
23.8K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
23.8K
01:22Equation of Motion: General Plane motion
569
In the context of a rigid body's movement within a general plane, it is important to understand that this motion is typically triggered by external forces or couple moments exerted onto it. This principle can be explained through Newton's second law, which stipulates the translational motion of the body's center of mass along each axis.
Moreover, the body's center of mass experiences a rotational effect as a result of these couple moments. This rotation can be articulated as the...
Moreover, the body's center of mass experiences a rotational effect as a result of these couple moments. This rotation can be articulated as the...
569
01:14NMR Spectrometers: Resolution and Error Correction
1.1K
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
1.1K
01:24Absolute Motion Analysis- General Plane Motion
557
Visualize a drone, with its propellers spinning rapidly, hovering mid-air. The fascinating movements and operations of this drone can be comprehended by applying the principle of general plane motion.
As the drone's propellers rotate, an upward force is generated that counteracts the force of gravity, enabling the drone to lift off from the ground. This initial movement of the drone is along a straight path, representing a form of translational motion. In this phase, every point on the...
As the drone's propellers rotate, an upward force is generated that counteracts the force of gravity, enabling the drone to lift off from the ground. This initial movement of the drone is along a straight path, representing a form of translational motion. In this phase, every point on the...
557