EchoMRIThe 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 research
was done under a grant from the National Institutes of Health, which wants to
know if the new technology could have future applications for human paediatric
use.
Standard MRI systems are commonly used to scan and visualise tissue
in humans. However, when used for body composition analysis, imaging systems are
subject to substantial error rates caused by the interpretation of visual images
using software that relies on population averages.
EchoMRI uses a new
type of QMR methodology to obtain body composition results. Its measurement
principle depends on the density of hydrogen nuclei and the physical state of
the tissue.
Accuracy
ARS animal scientist Alva
Mitchell at the Animal Biosciences and Biotechnology Laboratory in Beltsville,
Md., tested the device, developed by Echo Medical Systems, to determine
EchoMRI's precision and accuracy in piglets as compared to dual x-ray (DXA)
technology and chemical analysis.
Twenty-five piglets, each weighing
between 3.5 pounds and 8 pounds, were screened live, anesthetised, and
post-mortem, using a prototype EchoMRI device for infants. The piglets were also
scanned using DXA and then subjected to chemical analysis.
After DXA
scans, EchoMRI screenings, and chemical analyses were completed, EchoMRI was
found to be a precise and accurate method suitable for measuring piglet whole
body composition, total body fat, lean tissue mass, free water mass, and total
body water. While these studies were conducted on piglets, EchoMRI may be
transferable to market-weight pigs.
ConvenientEchoMRI allows for measurements to be
conducted in only a few minutes without anesthesia or sedation, is
radiation-free, and does not require the subject to remain completely
motionless. This facilitates convenient, low-stress repeated tracking of small
changes in body composition and can be advantageous to researchers to optimize
feed utilization. It could also help researchers identify high-value hogs for
breeding.
ARS is a scientific research agency of the US Department of
Agriculture.
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