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A method for determining skeletal lengths from DXA images.

Chinappen-Horsley U, Blake GM, Fogelman I, Spector TD - BMC Musculoskelet Disord (2007)

Bottom Line: Two methods, linear pixel count (LPC) and reticule and ruler (RET) were used to measure skeletal sizes on DXA images and compared with real clinical measures from 20 subjects and 20 x-rays of the femur and tibia taken in 2003.Although both methods were highly correlated, the LPC inter- and intra-observer error was lower at 1.6% compared to that of RET at 2.3%.This new phenotype will be useful for osteoporosis research for individuals or large-scale epidemiological or genetic studies.

View Article: PubMed Central - HTML - PubMed

Affiliation: King's College London, St Thomas' Hospital Campus, Twin Research & Genetic Epidemiology Unit, Lambeth Palace Road, London, SE1 7EH, UK. usha.chinappen@kcl.ac.uk

ABSTRACT

Background: Skeletal ratios and bone lengths are widely used in anthropology and forensic pathology and hip axis length is a useful predictor of fracture. The aim of this study was to show that skeletal ratios, such as length of femur to height, could be accurately measured from a DXA (dual energy X-ray absorptiometry) image.

Methods: 90 normal Caucasian females, 18-80 years old, with whole body DXA data were used as subjects. Two methods, linear pixel count (LPC) and reticule and ruler (RET) were used to measure skeletal sizes on DXA images and compared with real clinical measures from 20 subjects and 20 x-rays of the femur and tibia taken in 2003.

Results: Although both methods were highly correlated, the LPC inter- and intra-observer error was lower at 1.6% compared to that of RET at 2.3%. Both methods correlated positively with real clinical measures, with LPC having a marginally stronger correlation coefficient (r2 = 0.94; r2 = 0.84; average r2 = 0.89) than RET (r2 = 0.86; r2 = 0.84; average r2 = 0.85) with X-rays and real measures respectively. Also, the time taken to use LPC was half that of RET at 5 minutes per scan.

Conclusion: Skeletal ratios can be accurately and precisely measured from DXA total body scan images. The LPC method is easy to use and relatively rapid. This new phenotype will be useful for osteoporosis research for individuals or large-scale epidemiological or genetic studies.

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Related in: MedlinePlus

A bar graph showing combined population CV% between five bone measurement sites using four different measurement techniques – Real, RET, LPC and X-ray (only performed on femur and tibia). Real measures have the lowest CV% at four out of five sites.
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Figure 5: A bar graph showing combined population CV% between five bone measurement sites using four different measurement techniques – Real, RET, LPC and X-ray (only performed on femur and tibia). Real measures have the lowest CV% at four out of five sites.

Mentions: Twenty real measures and twenty x-rays were compared to LPC and RET. Coefficient of variation between methods showed, as expected, real measures to have the lowest CV% (4.6%) and x-ray measures to have the highest CV% (6.4%). LPC and RET had an average CV% of 5.1% and 5.2% respectively (Figure 5).


A method for determining skeletal lengths from DXA images.

Chinappen-Horsley U, Blake GM, Fogelman I, Spector TD - BMC Musculoskelet Disord (2007)

A bar graph showing combined population CV% between five bone measurement sites using four different measurement techniques – Real, RET, LPC and X-ray (only performed on femur and tibia). Real measures have the lowest CV% at four out of five sites.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2211289&req=5

Figure 5: A bar graph showing combined population CV% between five bone measurement sites using four different measurement techniques – Real, RET, LPC and X-ray (only performed on femur and tibia). Real measures have the lowest CV% at four out of five sites.
Mentions: Twenty real measures and twenty x-rays were compared to LPC and RET. Coefficient of variation between methods showed, as expected, real measures to have the lowest CV% (4.6%) and x-ray measures to have the highest CV% (6.4%). LPC and RET had an average CV% of 5.1% and 5.2% respectively (Figure 5).

Bottom Line: Two methods, linear pixel count (LPC) and reticule and ruler (RET) were used to measure skeletal sizes on DXA images and compared with real clinical measures from 20 subjects and 20 x-rays of the femur and tibia taken in 2003.Although both methods were highly correlated, the LPC inter- and intra-observer error was lower at 1.6% compared to that of RET at 2.3%.This new phenotype will be useful for osteoporosis research for individuals or large-scale epidemiological or genetic studies.

View Article: PubMed Central - HTML - PubMed

Affiliation: King's College London, St Thomas' Hospital Campus, Twin Research & Genetic Epidemiology Unit, Lambeth Palace Road, London, SE1 7EH, UK. usha.chinappen@kcl.ac.uk

ABSTRACT

Background: Skeletal ratios and bone lengths are widely used in anthropology and forensic pathology and hip axis length is a useful predictor of fracture. The aim of this study was to show that skeletal ratios, such as length of femur to height, could be accurately measured from a DXA (dual energy X-ray absorptiometry) image.

Methods: 90 normal Caucasian females, 18-80 years old, with whole body DXA data were used as subjects. Two methods, linear pixel count (LPC) and reticule and ruler (RET) were used to measure skeletal sizes on DXA images and compared with real clinical measures from 20 subjects and 20 x-rays of the femur and tibia taken in 2003.

Results: Although both methods were highly correlated, the LPC inter- and intra-observer error was lower at 1.6% compared to that of RET at 2.3%. Both methods correlated positively with real clinical measures, with LPC having a marginally stronger correlation coefficient (r2 = 0.94; r2 = 0.84; average r2 = 0.89) than RET (r2 = 0.86; r2 = 0.84; average r2 = 0.85) with X-rays and real measures respectively. Also, the time taken to use LPC was half that of RET at 5 minutes per scan.

Conclusion: Skeletal ratios can be accurately and precisely measured from DXA total body scan images. The LPC method is easy to use and relatively rapid. This new phenotype will be useful for osteoporosis research for individuals or large-scale epidemiological or genetic studies.

Show MeSH
Related in: MedlinePlus