Scientists at USDA’s Agricultural Research Service (ARS) are testing an advanced magnetic resonance imaging (MRI)-based device they say can accurately and precisely measure total body fat in piglets using the principles of quantitative magnetic resonance (QMR).
The new device, called EchoMRI, was tested by ARS researchers to measure not only total body fat, but lean tissue mass, free water mass and total body water in piglets.
The work was done with a grant from the National Institutes of Health, which wants to know if the new technology could be used in human pediatrics.
Standard MRI tests are commonly used to scan and analyze human tissue. But when used for body composition analysis, imaging systems are often substantially in error due to the interpretation of visual images using software that relies on population averages.
EchoMRI uses a new type of QMR methodology for body composition results that depends on the density of hydrogen nuclei and the physical properties of the tissue.
ARS scientists tested the device in piglets vs. dual x-ray (DXA) technology and chemical analysis. The 25 piglets weighing 3.5-8 lb. were screened live and at necropsy using a prototype EchoMRI device for infants. The piglets were also scanned using DXA and then subjected to chemical analysis.
Of the three methods tested, EchoMRI was found to be an accurate means of measuring piglets’ total body composition, total body fat, lean tissue mass, free water mass and total body water. While conducted on piglets, similar results could be obtained on market hogs, according to ARS researchers.
EchoMRI obtains measurements in only a few minutes without anesthesia or sedation, is radiation-free and does not require the subject to remain completely motionless.
Thus, repeated tracking of small changes in body composition could be helpful to researchers to optimize feed use and identify high-value breeding stock.