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 Experiment Videos

Using flow relaxography to elucidate flow relaxivity

J H Lee1, X Li, M K Sammi

  • 1Chemistry Department, Brookhaven National Laboratory, Upton, New York, 11973, USA.jlee@bnl.gov

Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|January 15, 1999
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Magnetic susceptibility shift selected imaging (MESSI) and localized (1)H(2)O spectroscopy in living plant tissues.

NMR in biomedicine·2000
Same author

Resting brain metabolic activity in a 4 tesla magnetic field.

Magnetic resonance in medicine·2000
Same author

Determination of the MRI contrast agent concentration time course in vivo following bolus injection: effect of equilibrium transcytolemmal water exchange.

Magnetic resonance in medicine·2000
Same author

Measurements of human brain ethanol T(2) by spectroscopic imaging at 4 T.

Magnetic resonance in medicine·2000
Same author

4.0 T water proton T1 relaxation times in normal human brain and during acute ethanol intoxication.

Alcoholism, clinical and experimental research·2000
Same author

Equilibrium transcytolemmal water-exchange kinetics in skeletal muscle in vivo.

Magnetic resonance in medicine·1999
Same journal

Localization-driven exchange contrast in diffusion exchange spectroscopy.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

4.5 Tesla superconducting miniature magnet in liquid nitrogen.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Folding and unfolding dynamics of a DNA aptamer studied by heteronuclear <sup>1</sup>H-<sup>13</sup>C correlation zz-exchange spectroscopy.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Multi-spin control from one-spin pulses.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Altering MRI rotating frame relaxations by changing the truncation level of Hyperbolic Secant pulse.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Effects of proton exchange on the lifetimes of long-lived states in aliphatic chains.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
See all related articles

Researchers explored the inflow effect in NMR, finding that fluid relaxation time depends on the RF pulse volume, not detection volume. This allows noninvasive flow rate measurement and stationary T1 extrapolation in flowing fluids.

Area of Science:

  • Magnetic Resonance Imaging (MRI)
  • Fluid Dynamics
  • Biophysics

Background:

  • Nuclear Magnetic Resonance (NMR) flow studies are crucial for medical imaging.
  • Understanding the inflow effect is key to accurate flow quantification.
  • Existing methods face challenges in distinguishing flowing from non-flowing spins.

Purpose of the Study:

  • To investigate the theoretical and experimental linear dependence of NMR signal relaxation time on flow rate.
  • To introduce and validate a new quantitative method called flow relaxography.
  • To explore implications for noninvasive flow measurement and stationary signal extrapolation.

Main Methods:

  • Theoretical modeling of the inflow effect in flowing fluids.
  • Phantom sample experiments using a novel flow relaxography technique.

Related Experiment Videos

  • Quantitative analysis of the relationship between relaxation time and flow parameters.

    • Main Results:

    • Confirmed that longitudinal flow relaxivity (r1F) is primarily determined by the RF perturbation volume, not detection volume.
    • Demonstrated that r1F can be approximated by the reciprocal of half the inversion volume.
    • Successfully measured flow rate (Fv) and extrapolated to intrinsic T1 values in phantom studies.

    Conclusions:

    • Flow relaxography offers a new approach for NMR flow studies and medical MRI.
    • Adjusting inversion slice thickness can noninvasively measure flow rate.
    • It is possible to determine intrinsic fluid T1 values without stopping flow.