Determination of the Electronic density and the average atomic number of tissues in man by γ-ray attenuation

Joyet, G.; Baudraz, A.; Joyet, M. L.

doi:10.1007/bf01945218

Cited by 16 publications

(4 citation statements)

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“…The true soft tissue may consist, however, of both lean tissue and fat with nonuniform distribution. The difference between the attenuation coefficients of lean tissue and fat is significant, about 22% and 15% for the x-ray energies of 42 keV and 68 keV, respectively (Joyet et al 1974, Phelps et al 1975, Rao and Gregg 1975. Therefore, if the assumption on uniform soft tissue composition is incorrect, bone density will be over-or under-estimated in the DXA technique.…”

Section: Introductionmentioning

confidence: 99%

Dual energy x-ray laser measurement of calcaneal bone mineral density

et al. 2003

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In dual energy x-ray absorptiometry (DXA) the photon attenuation is assumed to be similar in soft tissue overlying, adjacent to and inside the measured bone. In the calcaneal dual energy x-ray laser (DXL) technique, this assumption is not needed as attenuation by soft tissues at the local bone site is determined by combining DXA and heel thickness measurements. In the present study, 38 subjects were measured with DXL Calscan, Lunar PIXI and Lunar DPX-IQ DXA instruments and Hologic Sahara ultrasound instrument, and the performance and agreement of the instruments were analysed. Furthermore, numerical simulations on the effect of non-uniform fat-to-lean tissue ratio within soft tissue in heel were conducted. In vivo short-term precision (CV%, sCV%) of DXL Calscan (1.24%, 1.48%) was similar to that of Lunar PIXI (1.28%, 1.60%). Calcaneal areal bone mineral densities (BMD, g cm(-2)) measured using DXL Calscan and Lunar PIXI predicted equally well variations in BMD of femoral neck (r2 = 0.63 and 0.52, respectively) or lumbar spine (r2 = 0.61 and 0.64, respectively), determined with Lunar DPX-IQ. BMD values measured with DXL Calscan were, on average, 19% lower (p < 0.01) than those determined with Lunar PIXI. Interestingly, the difference in BMD values between instruments increased as a function of body mass index (BMI) (r2 = 0.17, p < 0.02) or heel thickness (r2 = 0.37, p < 0.01). Numerical simulations suggested that the spatial variation of soft tissue composition in heel can induce incontrollable inaccuracy in BMD when measured with the DXA technique. Theoretically, in contrast to DXA instruments, elimination of the effect of non-uniform soft tissue is possible with DXL Calscan.

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Section: Introductionmentioning

confidence: 99%

Dual energy x-ray laser measurement of calcaneal bone mineral density

et al. 2003

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“… Note : These values were found in the NIST database 24–26 . Air is approximated as zero, as its density is negligible compared to the other materials.…”

Section: Methodsmentioning

confidence: 99%

“…The physical materials mimicked are listed in Table 1. Attenuation at postscatter energies was linearly interpolated between the 60 and 80 keV attenuation values from the National Institute of Standards and Technology (NIST) database 24–26 . Additionally, a separate test set of 200 phantoms containing eight random ellipses was created to test the accuracy and robustness of the algorithm to out‐of‐distribution inputs.…”

Section: Methodsmentioning

confidence: 99%

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Feasibility analysis on simultaneous electron density and attenuation coefficient reconstruction

2021

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Creating a viable reconstruction method for Compton scatter tomography remains challenging. Accounting for scatter attenuation when the underlying attenuation map is not known is particularly challenging, and current mathematical approaches to this vary widely. This work explores a novel approach to joint scatter and attenuation image reconstruction, which leverages the underlying structural similarity between the two images and incorporates a deep learning model in an alternating iterative reconstruction scheme. Methods: A single-view computed tomography (CT) imaging procedure for recording Compton scatter is first described. A joint reconstruction model, which iterates between algebraically reconstructing scatter images and estimating the attenuation via deep learning, is then proposed. This model is tested on both a generated dataset of 2D phantom images designed to mimic human tissues as well as a realistically simulated dataset based on real CT images. Results: Testing results yield convergence of the model and decent reconstruction quality to distinguish crucial features such as tumors and lesions, demonstrating the potential principled utilities of this configuration and deep learning approach. The model achieved a structural similarity index measure of at least 0.82 for scatter and 0.88 for attenuation reconstructions with the realistically simulated dataset. Conclusion:The iterative, deep learning approach outlined in this work shows potential for future efficient medical imaging procedures, reconstructing images with limited scatter information.

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Influence of the chemical composition on gamma ray attenuation by fatty acids

Bhandal

Singh

1992

International Journal of Radiation Applications and Instrumenta

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Determination of the Electronic density and the average atomic number of tissues in man by γ-ray attenuation

Cited by 16 publications

References 1 publication

Dual energy x-ray laser measurement of calcaneal bone mineral density

Dual energy x-ray laser measurement of calcaneal bone mineral density

Feasibility analysis on simultaneous electron density and attenuation coefficient reconstruction

Influence of the chemical composition on gamma ray attenuation by fatty acids

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