Proton Density Imaging
Proton Density Imaging - Related Videos
09:40
Proton Exchange Membrane Fuel Cells
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2023
Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University The United States consumes a large amount of energy – the current rate is around 97.5 quadrillion BTUs annually. The vast majority (90%) of this energy comes from non-renewable fuel sources. This energy is used for electricity (39%), transportation (28%), industry (22%), and residential/commercial use (11%). As the world has a limited supply of these non-renewable sources, the United States (among others) is...
08:26
Quantitative Mapping of Specific Ventilation in the Human Lung using Proton Magnetic Resonance Imaging and Oxygen as a Contrast Agent
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Cited by 3 •
2019
Specific ventilation imaging is a functional magnetic resonance imaging technique that allows for quantification of regional specific ventilation in the human lung, using inhaled oxygen as a contrast agent. Here, we present a protocol to collect and analyze specific ventilation imaging data.
07:38
Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane
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Cited by 4 •
2015
The first part of this article shows how to select mutant cell lines expressing vesicular Na+/H+ exchangers at their plasma membrane. The second part provides protocols based on intracellular pH measurements and fast ion uptake, which are used to determine the ion selectivity and the kinetic parameters of these exchangers.
08:42
Density Gradient Ultracentrifugation
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2023
Density gradient ultracentrifugation is a common technique used to isolate and purify biomolecules and cell structures. This technique exploits the fact that, in suspension, particles that are more dense than the solvent will sediment, while those that are less dense will float. A high-speed ultracentrifuge is used to accelerate this process in order to separate biomolecules within a density gradient, which can be established by layering liquids of decreasing density in a centrifuge tube. The...
03:03
Generating an Ultra-Low-Density Neuronal Culture Using a High-Density Neuronal Feeder Layer
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2025
This video demonstrates the method for culturing ultra-low-density neurons in the presence of a high-density neuronal feeder layer. It establishes a co-culture of varying-density neurons, ensuring close physical proximity. The growth factors secreted by high-density neurons help neuronal survival and growth, maintaining ultra-low-density neurons for a longer time period.
FAQs
These timing choices reduce the influence of longitudinal and transverse relaxation, so differences in signal arise more strongly from the amount of hydrogen nuclei in tissue. The result is anatomical contrast that is less dominated by T1 or T2 effects, helping preserve subtle structural differences for clinical interpretation.
After radiofrequency excitation, aligned protons release a signal as they return toward equilibrium. When relaxation effects are limited by sequence timing, signal intensity more closely reflects the local concentration of hydrogen nuclei, chiefly associated with tissue water and fat. Variations in that concentration can therefore produce anatomical contrast between tissue regions.
Its contrast is designed to minimize, rather than emphasize, the effects of T1 and T2 relaxation. Consequently, image differences are more closely linked to proton concentration and tissue structure than to the distinct relaxation behavior highlighted by T1- or T2-weighted sequences. This makes it a complementary contrast rather than a replacement.
During a medical MRI examination, it can be acquired as one sequence among complementary contrasts. Clinicians then assess its anatomical detail together with other MRI images rather than interpreting it in isolation. This combined approach can improve assessment of musculoskeletal injury or disease by adding information related to proton concentration and tissue structure.
The technique is especially useful for visualizing cartilage, menisci, ligaments, and tendons, where subtle structural differences may be clinically relevant. Its relatively limited relaxation weighting supports anatomical assessment of these tissues, and the resulting images can complement other sequences when evaluating suspected injury or disease.
Because its relatively low T1 and T2 weighting supplies a different basis for anatomical contrast, it can add information not emphasized in sequences dominated by relaxation effects. In medicine, this complementary role helps clinicians examine tissue structure more fully when assessing musculoskeletal injury and disease.