A method of X-ray attenuation analysis for approximating the intensity distribution at its point of origin of bremsstrahlung excited in a thick target by incident electrons of constant medium energy

Soole, B W

doi:10.1088/0031-9155/21/3/003

Cited by 24 publications

(22 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…29 This model was modified later on to include the target attenuation. 23 Birch and Marshal 12 adjusted some parameters in the latter model to give good agreement with experimental data. They used Green's formulation 30 for estimating the characteristic radiation with some modifications using experimental measurements.…”

Section: Introductionmentioning

confidence: 94%

“…Early attempts by Silberstein 22 relied on the determination of x-ray spectra from measurement of x-ray attenuation curve. Several groups made every effort to analyze the attenuation data as accurately as possible by different mathematical methods such as analytical modeling, 23 Laplace transform, 24 iterative methods, 11,25 matrix manipulation, 26 and neural networks. 27 Nevertheless, the calculation of x-ray spectra from attenuation curves is subject to errors in two respects.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Assessment of different computational models for generation of x‐ray spectra in diagnostic radiology and mammography

Sarkar

Shahriari

et al. 2005

Medical Physics

View full text Add to dashboard Cite

Different computational methods based on empirical or semi-empirical models and sophisticated Monte Carlo calculations have been proposed for prediction of x-ray spectra both in diagnostic radiology and mammography. In this work, the x-ray spectra predicted by various computational models used in the diagnostic radiology and mammography energy range have been assessed by comparison with measured spectra and their effect on the calculation of absorbed dose and effective dose (ED) imparted to the adult ORNL hermaphroditic phantom quantified. This includes empirical models (TASMIP and MASMIP), semi-empirical models (X-rayb&m, X-raytbc, XCOMP, IPEM, Tucker et al., and Blough et al.), and Monte Carlo modeling (EGS4, ITS3.0, and MCNP4C). As part of the comparative assessment, the K x-ray yield, transmission curves, and half value layers (HVLs) have been calculated for the spectra generated with all computational models at different tube voltages. The measured x-ray spectra agreed well with the generated spectra when using X-raytbc and IPEM in diagnostic radiology and mammography energy ranges, respectively. Despite the systematic differences between the simulated and reference spectra for some models, the student's t-test statistical analysis showed there is no statistically significant difference between measured and generated spectra for all computational models investigated in this study. The MCNP4C-based Monte Carlo calculations showed there is no discernable discrepancy in the calculation of absorbed dose and ED in the adult ORNL hermaphroditic phantom when using different computational models for generating the x-ray spectra. Nevertheless, given the limited flexibility of the empirical and semi-empirical models, the spectra obtained through Monte Carlo modeling offer several advantages by providing detailed information about the interactions in the target and filters, which is relevant for the design of new target and filter combinations and optimization of radiological imaging protocols.

show abstract

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Assessment of different computational models for generation of x‐ray spectra in diagnostic radiology and mammography

Sarkar

Shahriari

et al. 2005

Medical Physics

View full text Add to dashboard Cite

show abstract

“…Silberstein 30,31 recognized the relationship between the attenuation curve, measured with absorbers of various thicknesses, and the energy spectrum. Others subsequently applied different methods of numerical analysis of the attenuation data, including Laplace transform techniques, 32-36 iterative methods, 37-40 modeling, 41,42 and matrix manipulation. 43 Application of catalog or theoretical spectral data is valid only if the x-ray system is well characterized.…”

Section: B Methods To Calculate Energy Spectramentioning

confidence: 99%

Deblurring of x‐ray spectra acquired with a Nal‐photomultiplier detector by constrained least‐squares deconvolution

Skipper

Hangartner

2002

Medical Physics

View full text Add to dashboard Cite

A constrained least-squares technique to correct diagnostic x-ray tube energy spectra for inherent blurring by scintillation detectors was developed. The measured detector response function to monoenergetic sources was used to construct a matrix that modeled the energy broadening in the crystal. This blurring operator, along with an estimate of statistical noise in the count data, comprised the a priori system knowledge required for application of the method. Tungsten anode spectra up to 90 kVp were acquired with a Nal-photomultiplier detector system at a source-to-detector distance of 30 cm. X-ray tube output was collimated at the detector by a 0.5 mm diameter pinhole collimator. Measured Nal spectra were compared to both published reference data and to spectra acquired in our laboratory with a Ge detector system. Application of the constrained least-squares technique involved first defining a criterion function that combined an assessment of the goodness of fit with a weighted measure of the smoothness of the solution. Minimization of this function resulted in the corrected spectrum. While it is not possible to recover the characteristic tungsten peaks, the success of our method in deconvolving the measured spectra was demonstrated by a significant improvement in agreement with reference data. To provide a measure of this agreement, a histogram of the differences between the two curves was generated. The full width at half maximum (FWHM) of the Gaussian distribution fit to the histogram was used to quantify the similarity between the spectra and the reference data, both before and after correction. As spectral agreement improves, the FWHM becomes smaller. We show that application of the constrained least-squares technique improved spectral matching by 20%-60%.

show abstract

“…The initial x-ray beam has been calculated by several groups (6)(7)(8). We follow the method calculated from the electron-electron interaction cross sections (8).…”

Section: Andmentioning

confidence: 99%

Three dimensional modeling of projection radiography

Gray¹,

Inanc²,

Shull³

1992

NDT & E International

View full text Add to dashboard Cite

A method of X-ray attenuation analysis for approximating the intensity distribution at its point of origin of bremsstrahlung excited in a thick target by incident electrons of constant medium energy

Cited by 24 publications

References 12 publications

Assessment of different computational models for generation of x‐ray spectra in diagnostic radiology and mammography

Assessment of different computational models for generation of x‐ray spectra in diagnostic radiology and mammography

Deblurring of x‐ray spectra acquired with a Nal‐photomultiplier detector by constrained least‐squares deconvolution

Three dimensional modeling of projection radiography

Contact Info

Product

Resources

About