USDA/ARS Children's Nutrition Research Center

Quantitative Magnetic Resonance

Master
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Please read the QMR Request and Use Procedures for information about the access and use of this system.

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Capabilities

Media Component
 EchoMRI-100® QMR instrument
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The MMRU is equipped with an EchoMRI-100® QMR instrument that provides precise measurements of total body fat, lean mass, and body water in live mice up to 100 g in weight. The instrument determines the extent to which the protons present in lean and fat tissue perturb a magnetic field. This has been calibrated so that the output can be interpreted in terms of fat and lean masses (see References). The technique is noninvasive, nondestructive, does not require that the animal be sedated and causes no pain or stress. The measurement can be made in two to four minutes and does not require that the mouse be anesthetized or sedated.

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Body Composition Measurement Method

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The instrument determines the extent to which the protons present in lean and fat tissue perturb a magnetic field. This has been calibrated so that the output can be interpreted in terms of fat and lean masses. The technique is noninvasive, nondestructive, does not require that the animal be sedated and causes no pain or stress.

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Measurement Procedure

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To perform these measurements the mouse is placed in a Plexiglas tube that is appropriate for its size (6 cm in diameter and restrained to a length of approximately 1-3 cm according to the size of the mouse) and is placed in the instrument's magnetic field. The measurements are controlled via a keyboard attached to the instrument computer.  Readings are taken over a period of 2 to 4 minutes, after which the mouse is removed and returned to its cage.