Repeatability of pig body composition measurements using dual energy X-ray absorptiometry and influence of animal size and subregional analyses

2006 ◽  
Vol 46 (11) ◽  
pp. 1447 ◽  
Author(s):  
D. Suster ◽  
B. J. Leury ◽  
D. J. Kerton ◽  
F. R. Dunshea
Keyword(s):  
Body Composition ◽  
Mineral Content ◽  
Regional Analysis ◽  
Dual Energy ◽  
Whole Body ◽  
Lean Tissue ◽  
Tissue Mass ◽  
X Ray ◽  
Animal Size ◽  
Total Tissue

Fifteen Large White × Landrace male pigs were used to investigate the influence of animal size and subregional analysis technique on dual energy X-ray absorptiometry body composition measurements and their repeatability. Pigs were scanned in triplicate with an Hologic QDR4500A X-ray absorptiometer at the beginning of the study (3 weeks of age, liveweight 5–10 kg) and then every 4 weeks until 19 weeks of age. Measurements made by dual energy X-ray absorptiometry included total tissue mass, lean tissue mass, fat tissue mass and bone mineral content. The QDR4500 software allows the scanned image to be divided into head, arms, legs and trunk using an in-built regional analysis grid that contains algorithms unique to each region. Different regional grid manipulations were performed at each scan to evaluate the effects of incorporating subregions into a whole body analysis over time. The dual energy X-ray absorptiometry measurements were highly repeatable and measurement repeatability improved as animal size increased. When results were averaged across regional grid placement and scan time, the most repeatable measurement was total tissue mass (CV = 0.21%), followed by lean tissue mass (CV = 0.59%), bone mineral content (CV = 2.50%) and fat tissue mass (CV = 2.71%). The placement of the regional analysis grid influenced the repeatability of all measurements except for total weight; however, this influence reduced with increasing animal size. It is recommended that the body of the scan image be positioned in the arm region and the head in the head region of the software regional analysis grid to measure whole body composition in pigs because it provides the most repeatable measure overall. Animal placement into the trunk region or utilising the full regional analysis option as specified by the manufacturer provided less repeatable results.

The accuracy of dual energy X-ray absorptiometry (DXA), weight, and P2 back fat to predict half-carcass and primal-cut composition in pigs within and across research experiments

2004 ◽  
Vol 55 (9) ◽  
pp. 973 ◽  
Author(s):  
D. Suster ◽  
B. J. Leury ◽  
C. D. Hofmeyr ◽  
D. N. D'Souza ◽  
F. R. Dunshea
Keyword(s):  
Mineral Content ◽  
Dual Energy ◽  
Regression Equations ◽  
Lean Tissue ◽  
Large White ◽  
Tissue Mass ◽  
X Ray ◽  
Fat Composition ◽  
Non Destructive ◽  
Total Tissue

A Hologic QDR4500A dual energy X-ray absorptiometer (DXA) was used to measure body composition in 199 half-carcasses ranging from 15 to 48 kg. Half-carcasses were from animals of mixed sex and of either Large White × Landrace or Large White × Landrace × Duroc descent. Half-carcasses were selected from 5 different experiments to evaluate DXA accuracy within and across experiments. Values determined by DXA including total tissue mass, fat tissue mass, lean tissue mass, and bone mineral content, for the half-carcass and the shoulder, loin, belly, and ham primal cuts were evaluated by comparison with manually dissected composition. Relationships between manually dissected values and measurements of weight and backfat at the P2 site were also evaluated. Manually dissected values were strongly related to DXA-derived values, more so than with weight and P2 or a combination of both, particularly in the measurement of fat composition. In contrast to estimates derived from weight and P2, DXA-derived estimates remained accurate even when between-experiment variation was included. However, because DXA estimates were different from manually dissected values, they would need to be adjusted with the use of appropriate regression equations to correct the in-built algorithms. These results demonstrate the efficacy of DXA as a non-destructive method for determining the composition of the half-carcass and primal cuts, and its greater precision than current routinely used methods.

Accuracy of dual energy X-ray absorptiometry, weight, longissimus lumborum muscle depth and GR fat depth to predict half carcass composition in sheep

2007 ◽  
Vol 47 (10) ◽  
pp. 1165 ◽  
Author(s):  
F. R. Dunshea ◽  
D. Suster ◽  
P. J. Eason ◽  
R. D. Warner ◽  
D. L. Hopkins ◽  
...  
Keyword(s):  
Mineral Content ◽  
Dual Energy ◽  
Carcass Composition ◽  
Regression Equations ◽  
Tissue Mass ◽  
X Ray ◽  
Longissimus Lumborum ◽  
The Relationship ◽  
Non Destructive ◽  
Total Tissue

A Hologic QDR4500W dual energy X-ray absorptiometer (DXA) was used to measure body composition in 60 sheep half carcasses ranging from 8 to 28 kg. Half carcasses were from ewes and wethers of mixed genetics. Values determined by DXA, including total tissue mass (TTM), lean tissue mass (LTM), fat tissue mass (FTM) and bone mineral content (BMC), for the half carcass were evaluated by comparison with chemically determined composition. In the case of BMC, the relationship was with chemically determined ash content. Liveweight and chemically determined lean, fat and ash were strongly related to DXA-derived values for TTM, LTM, FTM and BMC, respectively (R2 = 0.999, 0.986, 0.989 and 0.920, respectively). However, because DXA estimates were different from chemically determined values in this sample of carcasses, they needed to be adjusted with the use of appropriate regression equations to correct the in-built algorithms. These data demonstrate the efficacy of DXA as a non-destructive method for determining the composition of the sheep half carcass.

MO047COMPARISON BETWEEN DUAL-ENERGY X-RAY ABSORPTIOMETRY AND BIOELECTRICAL IMPEDANCE FOR BODY COMPOSITION MEASUREMENTS IN ADULTS WITH CHRONIC KIDNEY DISEASE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Natália Tomborelli Bellafronte ◽  
Lorena Vega-Piris ◽  
Paula Garcia Chiarello ◽  
Guillermina Barril Cuadrado
Keyword(s):  
Chronic Kidney Disease ◽  
Body Composition ◽  
Peritoneal Dialysis ◽  
Renal Transplantation ◽  
Bioelectrical Impedance ◽  
Total Sample ◽  
Dual Energy ◽  
Error Tolerance ◽  
Whole Body ◽  
X Ray

Abstract Background and Aims Chronic kidney disease (CKD) patients frequently have an altered body composition driven by metabolic disorders from the uremic syndrome that usually leads to increased protein catabolism, with obesity and muscle impairment being common conditions associated with worse clinical prognosis and high mortality rates. Therefore, with increased mortality and disability rates of CKD patients in the last quarter of a century and the association of a poor body composition with low survival, routine and longitudinal assessment of body composition could improve clinical outcomes. Due to limited availability of reference methods to assess nutritional status, alternative methods are used. In view of the above, our goal was to evaluate the agreement between multifrequency bioelectrical impedance spectroscopy (BIS) and Dual-energy X-ray Absorptiometry (DXA) for assessment of body composition in CKD. Method Cross-sectional and prospective analyses by DXA (Hologic, GE®) and BIS (BCM, Fresenius Medical Care®) in whole-body (BISWB) and segmental (BISSEG) protocols were performed in CKD non-dialysis-dependent, hemodialysis and peritoneal dialysis (for at least 3 months), and renal transplantation (for at least 6 months) adult (18 ≤ age ≤ 60 years old) patients. Measurements were performed consecutively by the same professional after an 8-hour fast, drainage of the peritoneal dialysate and just after the midweek hemodialysis session. Intraclass correlation coefficient (ICC) and Bland-Altman plots were evaluated for agreement analysis in group and individual levels, respectively; linear regression analysis was performed for bias assessment and development of new equations; ROC curve was constructed for diagnosis of inadequate error tolerance (DXA - BIS > ± 2kg). Results A total of 266 patients were included: 137 men (M) and 129 women (W); 81 were in non-dialysis-dependent treatment, 83 in hemodialysis, 24 in peritoneal dialysis, and 80 had renal transplantation. Total sample had a mean age of 47 ± 10 years old. CKD was secondary to systemic arterial hypertension in 29% of the total sample, to glomerulonephritis in 25%, to diabetes mellitus in 10%, to polycystic kidney in 7%, to glomerulosclerosis and systemic syndromes in 8%, and to other causes and unknown etiology in 20%. Fourteen patients (4 M and 10 W) were in automated and 9 (4 M and 5 W) in continuous ambulatory PD. KTx was by living donor in 18 (14 M and 4 W) and by deceased donor in 63 (34 M and 29 W) patients. The agreement with DXA was greater for BISWB than BISSEG; for fat mass (FM) (ICC in M = 0.89; ICC in W = 0.93) than for fat free mass (FFM) (ICC in M = 0.57; ICC in W = 0.52). Bland-Altman plots showed high limits of agreement (FFM: from -9.51 to 15.64kg; FM: from -7.71 to 7.32kg) with greater bias for FFM as muscular mass increases and for FM in extremes of body fat. The agreement was lower when using the prospective data (body change analysis) (ICC for FFM in M = 0.20; ICC for FFM in W = 0.49; ICC for FM in M = 0.46; ICC for FM in W = 0.58). The factors that interfered in bias between methods were extra to intracellular water ratio (ECW/ICW), body mass index, fat mass index, waist circumference, resistance and reactance (adjusted r2 for FFM = 0.90; r2 for FM = 0.87). FFM had poorer agreement in the last tertile of ECW/ICW sample (ICC in M = 0.69, 0.68 and 0.51; ICC in W = 0.71, 0.74 and 0.38 for first, second and third tertiles, respectively). An ECW/ICW cut-off point of > 0.725 for inadequate error tolerance was determined. New prediction equations for FFM (r2 = 0.91) and FM (r2 = 0.89) presented adequate error tolerance in 55% and 63% in the validation sample compared to 30% and 39% of the original equation, respectively. Conclusion For body composition evaluation in CKD, BIS applied using the whole-body protocol, in normal hydration CKD patients is as reliable as DXA; BIS must be used with caution among overhydrated patients with ECW/ICW > 0.725. The newly developed equations are indicated for greater precision.

scholarly journals Skeletal Muscle Mass in Acromegaly Assessed by Magnetic Resonance Imaging and Dual-Photon X-Ray Absorptiometry

2009 ◽  
Vol 94 (8) ◽  
pp. 2880-2886 ◽  
Author(s):  
Pamela U. Freda ◽  
Wei Shen ◽  
Carlos M. Reyes-Vidal ◽  
Eliza B. Geer ◽  
Fernando Arias-Mendoza ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Skeletal Muscle ◽  
Whole Body ◽  
Resonance Imaging ◽  
Lean Tissue ◽  
Tissue Mass ◽  
Lean Tissue Mass ◽  
X Ray ◽  
Igf I ◽  
Active Acromegaly

Context: GH and IGF-I are nitrogen retaining and anabolic, but the impact of long-term exposure to supraphysiological GH and IGF-I, either from endogenous overproduction in acromegaly or exogenous sources, on skeletal muscle (SM) mass is not clear. Objectives: The objectives of the study were to assess SM mass by whole-body magnetic resonance imaging (MRI) in acromegaly and test the hypothesis that dual-energy x-ray absorptiometry (DXA) lean tissue mass-derived estimates of SM accurately estimate true SM mass. Design, Setting, and Patients: The design was a cross-sectional study in 27 acromegaly patients compared with predicted models developed in 315 nonacromegaly subjects and to matched controls. Outcome Measures: Mass of SM from whole-body MRI and lean tissue from DXA were measured. Results: SM mass did not differ from predicted or control values in active acromegaly: 31.75 ± 8.6 kg (acromegaly) vs. 33.06 ± 8.9 kg (predicted); SM was 95.6 ± 12.8% of predicted (range 66.7–122%) (P = 0.088). Lean tissue mass (DXA) was higher in acromegaly than controls: 65.91 ± 15.2 vs. 58.73 ± 13.5 kg (P < 0.0001). The difference between lean tissue mass (DXA) and SM in acromegaly patients was higher than that in controls (P < 0.0001) consistent with an enlarged non-SM lean compartment in acromegaly. SM mass predicted by DXA correlated highly with SM mass by MRI (r = 0.97, P < 0.0001). SM (MRI) to SM (DXA predicted) ratio was 1.018 (range 0.896–1.159), indicating high agreement of these measures of SM. Conclusions: SM mass in active acromegaly patients did not differ from predicted values. SM mass estimated from DXA agreed highly with SM by MRI, supporting the validity of the DXA model in assessing SM in acromegaly and other disorders of GH/IGF-I secretion.

DUAL-ENERGY X-RAY ABSORPTIOMETRY FOR REGIONAL AND WHOLE-BODY COMPOSITION: THE NEW GOLD STANDARD? 481

1996 ◽  
Vol 28 (Supplement) ◽  
pp. 81
Author(s):  
A D Martin ◽  
S B Heymsfield ◽  
W M Kohrt ◽  
T G Lohman
Keyword(s):  
Body Composition ◽  
Gold Standard ◽  
Dual Energy ◽  
Whole Body ◽  
X Ray

Assessment of whole-body composition with dual-energy x-ray absorptiometry.

Radiology ◽  
1992 ◽  
Vol 185 (2) ◽  
pp. 593-598 ◽  
Author(s):  
D O Slosman ◽  
J P Casez ◽  
C Pichard ◽  
T Rochat ◽  
F Fery ◽  
...  
Keyword(s):  
Body Composition ◽  
Dual Energy ◽  
Whole Body ◽  
X Ray

scholarly journals Correlation of a feline muscle mass score with body composition determined by dual-energy X-ray absorptiometry

2011 ◽  
Vol 106 (S1) ◽  
pp. S57-S59 ◽  
Author(s):  
Kathryn E. Michel ◽  
Wendy Anderson ◽  
Carolyn Cupp ◽  
Dorothy P. Laflamme
Keyword(s):  
Body Composition ◽  
Lean Body Mass ◽  
Muscle Mass ◽  
Body Mass ◽  
Body Fat ◽  
Convergent Validity ◽  
Dual Energy ◽  
Rater Agreement ◽  
Lean Tissue ◽  
X Ray

Body condition scoring (BCS) systems primarily assess body fat. Both overweight and underweight animals may have loss of lean tissue that may not be noted using standard BCS systems. Catabolism of lean tissue can occur rapidly, may account for a disproportionate amount of body mass loss in sick cats and can have deleterious consequences for outcome. Therefore, along with evaluation of body fat, patients should undergo evaluation of muscle mass. The aims of the present study were first to evaluate the repeatability and reproducibility of a 4-point feline muscle mass scoring (MMS) system and second to assess the convergent validity of MMS by dual-energy X-ray absorptiometry (DXA). MMS was as follows: 3, normal muscle mass; 2, slight wasting; 1, moderate wasting; 0, severe wasting. For the first aim, forty-four cats were selected for evaluation based on age and BCS, and for the second aim, thirty-three cats were selected based on age, BCS and MMS. Cats were scored by ten different evaluators on three separate occasions. Body composition was determined by DXA. Inter- and intra-rater agreement were assessed using kappa analysis. Correlation between MMS and BCS, age, percentage lean body mass and lean body mass (LBM) was determined using Spearman's rank-order correlation. The MMS showed moderate inter-rater agreement in cats that scored normal or severely wasted (κ = 0·48–0·53). Intra-rater agreement was substantial (κ = 0·71–0·73). The MMS was significantly correlated with BCS (r 0·76, P < 0·0001), age (r − 0·75, P < 0·0001), LBM (g) (r 0·62, P < 0·0001) and percentage LBM (r − 0·49, P < 0·0035). Additional investigation is needed to determine whether the MMS can be refined and to assess its clinical applicability.

Reproducibility of Pediatric Whole Body Bone and Body Composition Measures by Dual-Energy X-Ray Absorptiometry Using the GE Lunar Prodigy

2005 ◽  
Vol 8 (3) ◽  
pp. 298-304 ◽  
Author(s):  
Lauren Margulies ◽  
Mary Horlick ◽  
John C. Thornton ◽  
Jack Wang ◽  
Elli Ioannidou ◽  
...  
Keyword(s):  
Body Composition ◽  
Dual Energy ◽  
Whole Body ◽  
X Ray ◽  
Body Bone
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