Characterisation of materials: determining density using X-ray microtomography

Abstract The authors have previously published a method of beam hardening correction for X-ray microtomography that allows accurate determination of mineral concentration in hard tissue. This uses a multi-element calibration carousel for making experimental X-ray attenuation measurements to optimise the parameters in a model of X-ray transmission and detection. From this, a calibration curve is generated to convert the X-ray polychromatic X-ray projection data to that which would be expected with monochromatic X-rays. Furthermore, the calibration curve can be modified according to the known composition of the specimen. Here, this is tested using different materials to assess its accuracy in determining their density. Generally, errors in density of around 1–2% were obtained. When modelling the conventional use of an aluminium step wedge, much larger errors are seen. The technique can be used to measure and map density or concentration in cases where this would be difficult with other methods.

[1]  A. Boyde,et al.  Deciduous enamel defects in low-birth-weight children: correlated X-ray microtomographic and backscattered electron imaging study of hypoplasia and hypomineralization , 1994, Anatomy and Embryology.

[2]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[3]  R. Brooks,et al.  Beam hardening in X-ray reconstructive tomography , 1976 .

[4]  J. Sijbers,et al.  A model-based correction method for beam hardening artefacts in X-ray microtomography , 2003 .

[5]  G. R. Davis,et al.  Mineral concentration gradients in rat femoral diaphyses measured by X-ray microtomography , 2004, Calcified Tissue International.

[6]  S. Dover,et al.  Three-dimensional distribution of mineral in bone at a resolution of 15 micron determined by x-ray microtomography. , 1984, Metabolic bone disease & related research.

[7]  S Prohaska,et al.  Stereological measures of trabecular bone structure: comparison of 3D micro computed tomography with 2D histological sections in human proximal tibial bone biopsies , 2005, Journal of microscopy.

[8]  Quanhong Zhang,et al.  A Novel Beam Hardening Correction Method for Computed Tomography , 2007, 2007 IEEE/ICME International Conference on Complex Medical Engineering.

[9]  J. H. Hubbell,et al.  XCOM: Photon Cross Section Database (version 1.2) , 1999 .

[10]  J. C. Elliott,et al.  X‐ray microtomography , 1982, Journal of microscopy.

[11]  G. Herman.  Correction for beam hardening in computed tomography. , 1979, Physics in medicine and biology.

[12]  A Odgaard,et al.  Three-dimensional methods for quantification of cancellous bone architecture. , 1997, Bone.

[13]  David Mills,et al.  Multi-species beam hardening calibration device for x-ray microtomography , 2012, Optics & Photonics - Optical Engineering + Applications.

[14]  S. Majumdar,et al.  Quantitative Assessment of Bone Tissue Mineralization with Polychromatic Micro-Computed Tomography , 2008, Calcified Tissue International.

[15]  Graham R. Davis,et al.  X-ray microtomography scanner using time-delay integration for elimination of ring artefacts in the reconstructed image , 1997 .

[17]  S. Dover,et al.  Computed tomography part II: The practical use of a single source and detector , 1994 .

[18]  TOR Hildebrand,et al.  Quantification of Bone Microarchitecture with the Structure Model Index. , 1997, Computer methods in biomechanics and biomedical engineering.

[19]  David Mills,et al.  Quantitative high contrast X-ray microtomography for dental research. , 2013, Journal of dentistry.

[20]  G. Poludniowski.  Calculation of x-ray spectra emerging from an x-ray tube. Part II. X-ray production and filtration in x-ray targets. , 2007, Medical physics.