Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
Time-Domain Interpretation of PD Control01:07

Time-Domain Interpretation of PD Control

Proportional-Derivative (PD) control is a widely used control method in various engineering systems to enhance stability and performance. In a system with only proportional control, common issues include high maximum overshoot and oscillation, observed in both the error signal and its rate of change. This behavior can be divided into three distinct phases: initial overshoot, subsequent undershoot, and gradual stabilization.
Consider the example of control of motor torque. Initially, a positive...
Frequency-Domain Interpretation of PD Control01:24

Frequency-Domain Interpretation of PD Control

Proportional-Derivative (PD) controllers are widely used in fan control systems to improve stability and performance. A fan control system can be effectively represented using a Bode plot to illustrate the impact of a PD controller through its transfer function. The Bode plot visually conveys how PD control modifies the fan's response across various frequencies, providing a frequency domain interpretation of the controller's behavior.
The proportional control gain, combined with the system's...
Perceptual Constancy01:12

Perceptual Constancy

Perceptual constancy is the ability to recognize that objects remain consistent and unchanged even when their appearance varies due to changes in sensory input. There are four main types of perceptual constancy: size constancy, shape constancy, color constancy, and brightness constancy.
Size constancy is the recognition that an object remains the same size, even when its image on the retina changes. For instance, a bus is perceived to be large enough to carry people, even if it looks tiny from...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Structural and Physicochemical Features of Oral PROTACs.

Journal of medicinal chemistry·2024
Same author

Compulsory treatment of drug users in Asia: designed to torture?

International journal of prisoner health·2024
Same author

NerveTracker: a Python-based software toolkit for visualizing and tracking groups of nerve fibers in serial block-face microscopy with ultraviolet surface excitation images.

Journal of biomedical optics·2024
Same author

Acceptable performance of blood biomarker tests of amyloid pathology - recommendations from the Global CEO Initiative on Alzheimer's Disease.

Nature reviews. Neurology·2024
Same author

Understanding the important characteristics of neighbourhoods to facilitate ageing in place and longevity.

Australasian journal on ageing·2024
Same author

Diversity, resistance and vector competence of endophilic anophelines from southern Ghana.

MalariaWorld journal·2024
Same journal

Highly Articulated Robotic Probe for Minimally Invasive Surgery.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference·2010
Same journal

Combined peripheral and cortical neural stimulation in motor neurorehabilitation.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference·2008
Same journal

Embedded assessment algorithms within home-based cognitive computer game exercises for elders.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference·2008
Same journal

Digital signal processing of the wideband external pulse recorded during cuff deflation: a new way to measure blood pressure.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference·2008
Same journal

Immune cells detection of the in vivo rejecting heart in USPIO-enhanced magnetic resonance imaging.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference·2008
Same journal

wHospital: a web-based application with digital signature for drugs dispensing management.

Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference·2007
See all related articles

Related Experiment Video

Updated: Jun 20, 2026

Topographical Estimation of Visual Population Receptive Fields by fMRI
06:02

Topographical Estimation of Visual Population Receptive Fields by fMRI

Published on: February 3, 2015

Using the Perceptual Difference Model (PDM) to Optimize GRAPPA Reconstruction.

Donglai Huo1, David Wilson

  • 1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH.

Conference Proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference
|February 7, 2007
PubMed
Summary
This summary is machine-generated.

Optimizing Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) in MRI significantly enhances image quality. Specific calibration region settings reduce noise and artifacts, potentially cutting scan time by 16% for comparable image quality.

More Related Videos

Generalized Psychophysiological Interaction (PPI) Analysis of Memory Related Connectivity in Individuals at Genetic Risk for Alzheimer's Disease
09:38

Generalized Psychophysiological Interaction (PPI) Analysis of Memory Related Connectivity in Individuals at Genetic Risk for Alzheimer's Disease

Published on: November 14, 2017

Photorealistic Learned Landscapes for Augmented Reality
06:54

Photorealistic Learned Landscapes for Augmented Reality

Published on: June 27, 2025

Related Experiment Videos

Last Updated: Jun 20, 2026

Topographical Estimation of Visual Population Receptive Fields by fMRI
06:02

Topographical Estimation of Visual Population Receptive Fields by fMRI

Published on: February 3, 2015

Generalized Psychophysiological Interaction (PPI) Analysis of Memory Related Connectivity in Individuals at Genetic Risk for Alzheimer's Disease
09:38

Generalized Psychophysiological Interaction (PPI) Analysis of Memory Related Connectivity in Individuals at Genetic Risk for Alzheimer's Disease

Published on: November 14, 2017

Photorealistic Learned Landscapes for Augmented Reality
06:54

Photorealistic Learned Landscapes for Augmented Reality

Published on: June 27, 2025

Area of Science:

  • Magnetic Resonance Imaging (MRI)
  • Medical Imaging
  • Image Reconstruction

Background:

  • Parallel imaging techniques accelerate MRI acquisition by undersampling k-space.
  • Generalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) is a widely used parallel imaging reconstruction method.
  • Image quality in GRAPPA is sensitive to calibration region selection and sampling schemes.

Purpose of the Study:

  • To quantitatively evaluate the impact of different GRAPPA calibration regions and sampling schemes on image quality.
  • To identify optimal GRAPPA reconstruction parameters for improved image quality and efficiency.
  • To validate the use of the Perceptual Difference Model (PDM) for assessing parallel MRI quality.

Main Methods:

  • Utilized the Perceptual Difference Model (PDM) for quantitative image quality assessment.
  • Systematically varied calibration region location and width in GRAPPA reconstructions.
  • Compared image quality metrics across different GRAPPA parameter settings.

Main Results:

  • Optimal GRAPPA reconstruction achieved with calibration region at 0.8 of phase encoding direction and 20% width.
  • Minimizing the outer region factor further improved image quality.
  • Optimized GRAPPA parameters led to a 16% reduction in acquisition time for equivalent image quality.

Conclusions:

  • Specific GRAPPA calibration parameters significantly impact image quality and reconstruction efficiency.
  • PDM is a reliable tool for optimizing parallel MRI acquisition protocols.
  • Optimized GRAPPA protocols can reduce scan times without compromising diagnostic image quality.