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Non-invasive methods for the determination of body and carcass composition in livestock: dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging and ultrasound: invited review.

Scholz AM, Bünger L, Kongsro J, Baulain U, Mitchell AD - Animal (2015)

Bottom Line: The preference for a specific technique depends on the target animal species or carcass, combined with technical and practical aspects such as accuracy, reliability, cost, portability, speed, ease of use, safety and for in vivo measurements the need for fixation or sedation.The techniques rely on specific device-driven signals, which interact with tissues in the body or carcass at the atomic or molecular level, resulting in secondary or attenuated signals detected by the instruments and analyzed quantitatively.CT, MRI and US can provide volume data, whereas only DXA delivers immediate whole-body composition results without (2D) image manipulation.

View Article: PubMed Central - PubMed

Affiliation: 1Livestock Center Oberschleißheim,Ludwig-Maximilians-University Munich,Sankt-Hubertusstrasse 12,85764 Oberschleißheim,Germany.

ABSTRACT
The ability to accurately measure body or carcass composition is important for performance testing, grading and finally selection or payment of meat-producing animals. Advances especially in non-invasive techniques are mainly based on the development of electronic and computer-driven methods in order to provide objective phenotypic data. The preference for a specific technique depends on the target animal species or carcass, combined with technical and practical aspects such as accuracy, reliability, cost, portability, speed, ease of use, safety and for in vivo measurements the need for fixation or sedation. The techniques rely on specific device-driven signals, which interact with tissues in the body or carcass at the atomic or molecular level, resulting in secondary or attenuated signals detected by the instruments and analyzed quantitatively. The electromagnetic signal produced by the instrument may originate from mechanical energy such as sound waves (ultrasound - US), 'photon' radiation (X-ray-computed tomography - CT, dual-energy X-ray absorptiometry - DXA) or radio frequency waves (magnetic resonance imaging - MRI). The signals detected by the corresponding instruments are processed to measure, for example, tissue depths, areas, volumes or distributions of fat, muscle (water, protein) and partly bone or bone mineral. Among the above techniques, CT is the most accurate one followed by MRI and DXA, whereas US can be used for all sizes of farm animal species even under field conditions. CT, MRI and US can provide volume data, whereas only DXA delivers immediate whole-body composition results without (2D) image manipulation. A combination of simple US and more expensive CT, MRI or DXA might be applied for farm animal selection programs in a stepwise approach.

No MeSH data available.


Related in: MedlinePlus

Differences in NMR proton characteristics depending on body temperature (left: lambin vivo ~37°C, right: lamb carcass chilled <8°C, freesoftware DicomWorks, ©Philippe PUECH).
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fig2: Differences in NMR proton characteristics depending on body temperature (left: lambin vivo ~37°C, right: lamb carcass chilled <8°C, freesoftware DicomWorks, ©Philippe PUECH).

Mentions: A combination of magnetic field produced either by a ferromagnetic, electromagnetic orsuperconducting system with a field strength between 0.1 and 7 T and so-called gradientcoils with a corresponding RF frequency (Larmor frequency) sequence creates a number ofcross-sectional images with a 3D voxel definition for the x-,y- and z-axis direction. A Fourier transformation helpsin recalculating the signal information from the spectral domain into pixel (orvoxel)-wise signal intensity values in a ‘gray scale domain’ visible on the ‘computer’screen. For a T1-weighted sequence with a TR (time between two consecutive RF pulsesignals or between successive excitations) of 300 ms and a TE (time between echoes=betweenmiddle of exciting RF pulse signal and middle of spin echo production) of 17 ms, the fattissue containing pixels have rather high signal intensities, whereas the non-fat pixelsshow lower signal intensities. This pattern, however, changes on chilled objects (Monziolset al., 2005 and 2006). As shown in Figure 2, a T1-weighted sequence would show dark pixels (low signal intensity)for fat tissue and brighter pixels for lean meat tissue (relatively higher signalintensity).Figure 2


Non-invasive methods for the determination of body and carcass composition in livestock: dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging and ultrasound: invited review.

Scholz AM, Bünger L, Kongsro J, Baulain U, Mitchell AD - Animal (2015)

Differences in NMR proton characteristics depending on body temperature (left: lambin vivo ~37°C, right: lamb carcass chilled <8°C, freesoftware DicomWorks, ©Philippe PUECH).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492221&req=5

fig2: Differences in NMR proton characteristics depending on body temperature (left: lambin vivo ~37°C, right: lamb carcass chilled <8°C, freesoftware DicomWorks, ©Philippe PUECH).
Mentions: A combination of magnetic field produced either by a ferromagnetic, electromagnetic orsuperconducting system with a field strength between 0.1 and 7 T and so-called gradientcoils with a corresponding RF frequency (Larmor frequency) sequence creates a number ofcross-sectional images with a 3D voxel definition for the x-,y- and z-axis direction. A Fourier transformation helpsin recalculating the signal information from the spectral domain into pixel (orvoxel)-wise signal intensity values in a ‘gray scale domain’ visible on the ‘computer’screen. For a T1-weighted sequence with a TR (time between two consecutive RF pulsesignals or between successive excitations) of 300 ms and a TE (time between echoes=betweenmiddle of exciting RF pulse signal and middle of spin echo production) of 17 ms, the fattissue containing pixels have rather high signal intensities, whereas the non-fat pixelsshow lower signal intensities. This pattern, however, changes on chilled objects (Monziolset al., 2005 and 2006). As shown in Figure 2, a T1-weighted sequence would show dark pixels (low signal intensity)for fat tissue and brighter pixels for lean meat tissue (relatively higher signalintensity).Figure 2

Bottom Line: The preference for a specific technique depends on the target animal species or carcass, combined with technical and practical aspects such as accuracy, reliability, cost, portability, speed, ease of use, safety and for in vivo measurements the need for fixation or sedation.The techniques rely on specific device-driven signals, which interact with tissues in the body or carcass at the atomic or molecular level, resulting in secondary or attenuated signals detected by the instruments and analyzed quantitatively.CT, MRI and US can provide volume data, whereas only DXA delivers immediate whole-body composition results without (2D) image manipulation.

View Article: PubMed Central - PubMed

Affiliation: 1Livestock Center Oberschleißheim,Ludwig-Maximilians-University Munich,Sankt-Hubertusstrasse 12,85764 Oberschleißheim,Germany.

ABSTRACT
The ability to accurately measure body or carcass composition is important for performance testing, grading and finally selection or payment of meat-producing animals. Advances especially in non-invasive techniques are mainly based on the development of electronic and computer-driven methods in order to provide objective phenotypic data. The preference for a specific technique depends on the target animal species or carcass, combined with technical and practical aspects such as accuracy, reliability, cost, portability, speed, ease of use, safety and for in vivo measurements the need for fixation or sedation. The techniques rely on specific device-driven signals, which interact with tissues in the body or carcass at the atomic or molecular level, resulting in secondary or attenuated signals detected by the instruments and analyzed quantitatively. The electromagnetic signal produced by the instrument may originate from mechanical energy such as sound waves (ultrasound - US), 'photon' radiation (X-ray-computed tomography - CT, dual-energy X-ray absorptiometry - DXA) or radio frequency waves (magnetic resonance imaging - MRI). The signals detected by the corresponding instruments are processed to measure, for example, tissue depths, areas, volumes or distributions of fat, muscle (water, protein) and partly bone or bone mineral. Among the above techniques, CT is the most accurate one followed by MRI and DXA, whereas US can be used for all sizes of farm animal species even under field conditions. CT, MRI and US can provide volume data, whereas only DXA delivers immediate whole-body composition results without (2D) image manipulation. A combination of simple US and more expensive CT, MRI or DXA might be applied for farm animal selection programs in a stepwise approach.

No MeSH data available.


Related in: MedlinePlus