Revealing sub‐voxel motions of brain tissue using phase‐based amplified MRI (aMRI)

Terem, Itamar; Ni, Wendy W.; Goubran, Maged; Rahimi, Mahdi; Zaharchuk, Greg; Yeom, Kristen W.; Moseley, Michael E.; Kurt, Mehmet; Holdsworth, Samantha J.

doi:10.1002/mrm.27236

Cited by 63 publications

(68 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Discussionmentioning

confidence: 99%

“…Prior studies by Holdsworth et al and Terem et al dealt with frequency selective Eulerian movement amplification in the brain. Similarly to our results, very small movements were detected using motion amplification, based on Laplacian pyramid or steerable pyramid . The phase amplification used here and in Terem et al allows larger amplification factors and generates less noise compared with the original Eulerian amplification …”

Section: Discussionmentioning

confidence: 99%

“…Recently, subtle brain motions due to cardiac‐induced blood pulsation have been visualized with amplified MRI (aMRI). In aMRI, motion amplification was originally performed on retrospective cardiac‐gated cine images using the Eulerian approach and has been then improved by the implementation of a phase‐based video motion processing …”

Section: Introductionmentioning

confidence: 99%

“…In aMRI, motion amplification was originally performed on retrospective cardiac-gated cine images using the Eulerian approach 10 and has been then improved by the implementation of a phasebased video motion processing. 11 The present study aims to characterize weak or imperceptible liver movements induced by the heartbeat using an HARP image representation with an optical flow quantification method and further to visually emphasize right liver displacements using a motion amplification technique. The method was applied to define the cardiac trigger delay that provides DWI images with minimal signal losses in a given region of the liver.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Assessment of cardiac‐driven liver movements with filtered harmonic phase image representation, optical flow quantification, and motion amplification

Hahn

Absil

Debeir

et al. 2018

Magnetic Resonance in Med

View full text Add to dashboard Cite

Purpose To characterize cardiac‐driven liver movements using a harmonic phase image representation (HARP) with an optical flow quantification and motion amplification method. The method was applied to define the cardiac trigger delay providing minimal signal losses in liver DWI images. Methods The 16‐s breath‐hold balanced‐SSFP time resolved 20 images/s were acquired at 3T in coronal and sagittal orientations. A peripheral pulse unit signal was recorded. Cardiac‐triggered DWI images were acquired after different peripheral pulse unit delays. A steerable pyramid decomposition with multiple orientations and spatial frequencies was applied. The liver motion field‐map was derived from temporal variations of the HARP representation filtered around the cardiac frequency. Liver displacements were quantified with an optical flow method; moreover the right liver motion was amplified. Results The largest displacements were observed in the left liver (feet‐head:3.70 ± 1.06 mm; anterior–posterior: 2.35 ± 0.51 mm). Displacements were statistically significantly weaker in the middle right liver (0.47 ± 0.11 mm; P = 0.0156). The average error was 0.013 ± 0.022 mm (coronal plane) and 0.021 ± 0.041 mm (sagittal plane). The velocity field demonstrated opposing movements of the right liver extremities during the cardiac cycle. DWI signal loss was minimized in regions and instants of smallest amplitude of both velocity and velocity gradient. Conclusion Cardiac‐driven liver movements were quantified with combined cardiac frequency‐filtered HARP and optical flow methods. A motion phase opposition between right liver extremities was demonstrated. Displacement amplitude and velocity were larger in the left liver especially along the vertical direction. Motion amplification visually emphasized cardiac‐driven right liver displacements. The optimal cardiac timing minimizing signal loss in liver DWI images was derived.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Assessment of cardiac‐driven liver movements with filtered harmonic phase image representation, optical flow quantification, and motion amplification

Hahn

Absil

Debeir

et al. 2018

Magnetic Resonance in Med

View full text Add to dashboard Cite

show abstract

“…After the microwire removal, the implant was provided with additional mechanical slack by lowering the Z axis of the stereotaxic frame about 500µm before sealing the implant to the skull. This allowed for decoupling of the direct mechanical constrain between the implant and the brain which is under constant micromotion (35). Using this approach, we did not register any acute or chronic mechanical failure for the NeuroRoots.…”

Section: Implantationmentioning

confidence: 99%

NeuroRoots, a bio-inspired, seamless Brain Machine Interface device for long-term recording

Ferro

Proctor

Gonzalez

et al. 2018

Preprint

View full text Add to dashboard Cite

Minimally invasive electrodes of cellular scale that approach a bio-integrative level of neural recording could enable the development of scalable brain machine interfaces that stably interface with the same neural populations over long period of time. In this paper, we designed and created NeuroRoots, a bio-mimetic multi-channel implant sharing similar dimension (10µm wide, 1.5µm thick), mechanical flexibility and spatial distribution as axon bundles in the brain. A simple approach of delivery is reported based on the assembly and controllable immobilization of the electrode onto a 35µm microwire shuttle by using capillarity and surface-tension in aqueous solution. Once implanted into targeted regions of the brain, the microwire was retracted leaving NeuroRoots in the biological tissue with minimal surgical footprint and perturbation of existing neural architectures within the tissue. NeuroRoots was implanted using a platform compatible with commercially available electrophysiology rigs and with measurements of interests in behavioral experiments in adult rats freely moving into maze. We demonstrated that NeuroRoots electrodes reliably detected action potentials for at least 7 weeks and the signal amplitude and shape remained relatively constant during long-term implantation. This research represents a step forward in the direction of developing the next generation of seamless brain-machine interface to study and modulate the activities of specific subpopulations of neurons, and to develop therapies for a plethora of neurological diseases. Science AdvancesManuscript Template

show abstract

All‐Polymer Fiber Organic Electrochemical Transistor for Chronic Chemical Detection in the Brain

Feng

Fang

Wang

et al. 2023

Adv Funct Materials

View full text Add to dashboard Cite

Continuous and precise monitoring of chemicals in the brain can assist in understanding the working mechanism of the brain and exploring therapeutics for nerve disorders. Organic electrochemical transistors (OECTs) are employed for this purpose due to their high sensitivity from the in situ amplification effect. However, the chronic and stable detection of chemicals in the brain is rarely reported for OECTs. It is possibly due to the chronic inflammation from mechanical mismatch between the device and soft brain tissue as well as the biofouling that hinder the diffusion of chemicals to decrease the sensitivity similar to other implanted devices. Therefore, an all‐polymer fiber OECT (PF‐OECT) is designed, composed solely of conductive polymers and fluorine rubber. The PF‐OECT shows matching modulus with the soft brain tissue and good anti‐biofouling performance. It also demonstrates both high sensitivity and electrochemical stability under dynamic deformations and in complex protein solutions. Finally, the PF‐OECT is implanted into the mouse brain, achieving a stable 14‐day ascorbic acid monitoring. The design strategy of PF‐OECT presents a potential avenue for developing more biomedical devices.

show abstract

Revealing sub‐voxel motions of brain tissue using phase‐based amplified MRI (aMRI)

Cited by 63 publications

References 23 publications

Assessment of cardiac‐driven liver movements with filtered harmonic phase image representation, optical flow quantification, and motion amplification

Assessment of cardiac‐driven liver movements with filtered harmonic phase image representation, optical flow quantification, and motion amplification

NeuroRoots, a bio-inspired, seamless Brain Machine Interface device for long-term recording

All‐Polymer Fiber Organic Electrochemical Transistor for Chronic Chemical Detection in the Brain

Contact Info

Product

Resources

About