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Cross-calibration of pencil-beam (DPX-NT) and fan-beam (QDR-4500C) dual-energy X-ray absorptiometry for sarcopenia.

Ito K, Tsushita K, Muramoto A, Kanzaki H, Nohara T, Shimizu H, Nakazawa T, Harada A - Nagoya J Med Sci (2015)

Bottom Line: Muscle mass can be calculated by dual-energy X-ray absorptiometry (DXA), but results differ between devices produced by different manufactures.The conversion formulas were as follows: lumbar BMD, Y = -0.08 + 1.16X (X = QDR-4500C, Y = DPX-NT), femoral neck BMD, Y = -0.015 + 1.11X, and ASMI Y = 0.92 + 0.90X.There is excellent comparability between the DPX-NT and the QDR-4500C DXA units.

View Article: PubMed Central - PubMed

Affiliation: National Center for Geriatrics and Gerontology, Obu, Japan ; Department of Orthopaedic Surgery, Nagoya University Hospital, Graduate School of Medicine, Nagoya, Japan.

ABSTRACT
Sarcopenia, defined as the loss of muscle mass accompanied by weakness, is an important factor leading to frailty and is a growing concern in the aging Japanese society. Muscle mass can be calculated by dual-energy X-ray absorptiometry (DXA), but results differ between devices produced by different manufactures. Thus, cross-calibration is needed to compare body composition results in multicenter trials or when scanners are replaced. The purpose of this study was to perform an in vivo calibration of total body scans between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA units. A total 30 subjects (15 women, 15 men, mean age = 35 years, range 22-49 years) were recruited. The lumbar bone mineral density (BMD), femoral neck BMD, appendicular fat and lean body mass, and the appendicular skeletal muscle mass index (ASMI) were highly correlated (r = 0.979-0.993, r(2) = 0.889-0.977). The conversion formulas were as follows: lumbar BMD, Y = -0.08 + 1.16X (X = QDR-4500C, Y = DPX-NT), femoral neck BMD, Y = -0.015 + 1.11X, and ASMI Y = 0.92 + 0.90X. There is excellent comparability between the DPX-NT and the QDR-4500C DXA units. However, cross-calibration equations are required to assess muscle volume, fat, and ASMI in multicenter studies investigating sarcopenia.

No MeSH data available.


Related in: MedlinePlus

Bland–Altman plot of the difference between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA devices according to the mean values. The regression line is shown.
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fig1: Bland–Altman plot of the difference between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA devices according to the mean values. The regression line is shown.

Mentions: This difference between the two instruments was also apparent in the Bland–Altman analysis (Table 2). The lumbar BMD was 0.16 g/cm2 higher, the femur BMD 0.082 g/cm2 higher, the lean mass in the arm 27.85 g higher, fat in the leg 396.15 g lower, and the ASMI was 0.23 kg/m2 higher in DPX-NT than in QDR-4500C; all these differences and average were correlated. The lean mass of the leg was 287.95 g higher, and fat in the arm was 192.21 g lower in DPX-NT than in QDR-4500C, but these differences and average were not correlated. Figure 1 shows the differences between the mean values in the pencil-beam and fan-beam DXA instruments.


Cross-calibration of pencil-beam (DPX-NT) and fan-beam (QDR-4500C) dual-energy X-ray absorptiometry for sarcopenia.

Ito K, Tsushita K, Muramoto A, Kanzaki H, Nohara T, Shimizu H, Nakazawa T, Harada A - Nagoya J Med Sci (2015)

Bland–Altman plot of the difference between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA devices according to the mean values. The regression line is shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664596&req=5

fig1: Bland–Altman plot of the difference between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA devices according to the mean values. The regression line is shown.
Mentions: This difference between the two instruments was also apparent in the Bland–Altman analysis (Table 2). The lumbar BMD was 0.16 g/cm2 higher, the femur BMD 0.082 g/cm2 higher, the lean mass in the arm 27.85 g higher, fat in the leg 396.15 g lower, and the ASMI was 0.23 kg/m2 higher in DPX-NT than in QDR-4500C; all these differences and average were correlated. The lean mass of the leg was 287.95 g higher, and fat in the arm was 192.21 g lower in DPX-NT than in QDR-4500C, but these differences and average were not correlated. Figure 1 shows the differences between the mean values in the pencil-beam and fan-beam DXA instruments.

Bottom Line: Muscle mass can be calculated by dual-energy X-ray absorptiometry (DXA), but results differ between devices produced by different manufactures.The conversion formulas were as follows: lumbar BMD, Y = -0.08 + 1.16X (X = QDR-4500C, Y = DPX-NT), femoral neck BMD, Y = -0.015 + 1.11X, and ASMI Y = 0.92 + 0.90X.There is excellent comparability between the DPX-NT and the QDR-4500C DXA units.

View Article: PubMed Central - PubMed

Affiliation: National Center for Geriatrics and Gerontology, Obu, Japan ; Department of Orthopaedic Surgery, Nagoya University Hospital, Graduate School of Medicine, Nagoya, Japan.

ABSTRACT
Sarcopenia, defined as the loss of muscle mass accompanied by weakness, is an important factor leading to frailty and is a growing concern in the aging Japanese society. Muscle mass can be calculated by dual-energy X-ray absorptiometry (DXA), but results differ between devices produced by different manufactures. Thus, cross-calibration is needed to compare body composition results in multicenter trials or when scanners are replaced. The purpose of this study was to perform an in vivo calibration of total body scans between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA units. A total 30 subjects (15 women, 15 men, mean age = 35 years, range 22-49 years) were recruited. The lumbar bone mineral density (BMD), femoral neck BMD, appendicular fat and lean body mass, and the appendicular skeletal muscle mass index (ASMI) were highly correlated (r = 0.979-0.993, r(2) = 0.889-0.977). The conversion formulas were as follows: lumbar BMD, Y = -0.08 + 1.16X (X = QDR-4500C, Y = DPX-NT), femoral neck BMD, Y = -0.015 + 1.11X, and ASMI Y = 0.92 + 0.90X. There is excellent comparability between the DPX-NT and the QDR-4500C DXA units. However, cross-calibration equations are required to assess muscle volume, fat, and ASMI in multicenter studies investigating sarcopenia.

No MeSH data available.


Related in: MedlinePlus