Bone Structure Studies at the University of Leeds

Darley, P.J.

doi:10.1097/00004032-200602000-00009

Cited by 8 publications

(12 citation statements)

References 7 publications

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“…This enabled comparison with the results on lumbar vertebrae obtained by others. [ 10 13 ] This comparison also justified the reproducibility of the system employed and reliability of the results obtained for the sternum. In all sternum cases studied, the omnidirectional path-length distribution curves for the trabeculae take the form of an asymmetrical curve with a tail at high path-length values.…”

Section: Resultssupporting

confidence: 56%

“…The values for the surface-to-volume ratios are very close (within ±4%) for sternums and their corresponding third lumbar vertebrae, reflecting the closeness of their mean trabecular path lengths. For sternums (those of 68-year-old man and 77-year-old woman) for which their matching third lumbar vertebrae were not available, data of the third lumbar vertebra of the same age group analyzed by Darley[ 10 ] have been used for comparison, and trends similar to the above results have been found.…”

Section: Methodsmentioning

confidence: 96%

“…The third lumbar vertebra of the same cadaver was also obtained,[ 11 ] where possible, and analyzed to serve as a reference sample and to help confirm that the sternum could be categorized as normal. The results for the lumbar vertebra were compared with corresponding data quoted in the field of bone dosimetry by Darley[ 10 ] and Beddoe. [ 12 13 ]…”

Section: Methodsmentioning

confidence: 99%

“…[ 9 ] Lumbar vertebrae are less difficult to obtain than other bones and their convenient size and shape make it easy to prepare sections and consequently to calculate the omnidirectional path-length distributions and other structural parameters. Darley[ 10 ] studied a wide range of lumbar vertebra from individuals of both sexes aged from birth to 85 years. Beddoe et al .…”

Section: Introductionmentioning

confidence: 99%

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A quantitative analysis of the structure of human sternum

Arbabi¹

2009

J Med Phys

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An extensive study of the human sternum has been carried out to obtain estimates of the omnidirectional path-length distributions and structural parameters for trabeculation and marrow spaces. Data for sternum samples have been collected, using an object plane scanning microscope. These data have been used to produce the omnidirectional path-length distributions and values of structural parameters for the whole sternum. For a typical adult man the mean trabecular and marrow space path lengths are 224 and 1364 μm, respectively. The percentage bone volume is 13.8 and the surface to volume ratio is 190 cm. Data on the structural variations within the whole sternum are presented. They show a percentage difference in bone volume between the manubrium and the body of sternum of about 36%.

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Section: Resultssupporting

confidence: 56%

Section: Methodsmentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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A quantitative analysis of the structure of human sternum

Arbabi¹

2009

J Med Phys

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“…Early studies in trabecular bone dosimetry were performed by F W Spiers and colleagues at the University of Leeds. One of their main achievements was the acquisition of 2D chord-length distributions across thin sections of trabecular spongiosa imaged under contact radiography (Beddoe et al 1976, Darley 1972). These distributions were later used to calculate dose factors (absorbed dose to marrow or endosteum per decay in the volume or on the surfaces of the bone trabeculae) for use in radiological protection of, and dose reconstruction to, the skeletal tissues (Bouchet et al 2000, Eckerman and Stabin 2000, Spiers et al 1978, Stabin and Siegel 2003, Whitwell and Spiers 1976.…”

Section: Skeletal Dosimetrymentioning

confidence: 99%

Image segmentation of trabecular spongiosa by visual inspection of the gradient magnitude

et al. 2006

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Recent advances in physical models of skeletal dosimetry utilize high-resolution 3-dimensional microscopic computed tomography images of trabecular spongiosa. These images are coupled to radiation transport codes to assess energy deposition within active bone marrow and trabecular endosteum. These transport codes rely primarily on the segmentation of the spongiosa images into bone and marrow voxels. Image thresholding has been the segmentation of choice for bone sample images because of its extreme simplicity. However, the ability of the segmentation to reproduce the physical boundary between bone and marrow depends on the selection of the threshold value. Statistical models, as well as visual inspection of the image, have been employed extensively to determine the correct threshold. Both techniques are affected by partial volume effect and can provide unexpected results if performed without care. In this study, we propose a new technique to threshold trabecular spongiosa images based on visual inspection of the image gradient magnitude. We first show that the gradient magnitude of the image reaches a maximum along a surface that remains almost independent of partial volume effect and that is a good representation of the physical boundary between bone and marrow. A computer program was then developed to allow a user to compare the position of the iso-surface produced by a threshold with the gradient magnitude. The threshold that produces the iso-surface that best coincides with the maximum gradient is chosen. The technique was finally tested with a set of images of a true bone sample with different resolutions, as well as with three images of a cube of Duocell aluminium foam of known mass and density. Both tests demonstrate the ability of the gradient magnitude technique to retrieve sample volumes or media volume fractions with 1% accuracy at 30 microm voxel size.

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Anthropomorphic Phantoms and Models of Biological Systems

McParland

2010

Nuclear Medicine Radiation Dosimetry

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Bone Structure Studies at the University of Leeds

Cited by 8 publications

References 7 publications

A quantitative analysis of the structure of human sternum

A quantitative analysis of the structure of human sternum

Image segmentation of trabecular spongiosa by visual inspection of the gradient magnitude

Anthropomorphic Phantoms and Models of Biological Systems

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