ABSTRACT Measurements of molecular cross sections of coherently scattered photons were obtained b... more ABSTRACT Measurements of molecular cross sections of coherently scattered photons were obtained by means of powder diffraction data analysis in the interval χ=0–6.4 nm−1 (χ=sin(θ/2)/λ; where θ is the scattering angle and λ the incident wavelength in units of nm). Accurate correction procedures were applied to the raw diffraction data. Data for fat and PMMA (polymethyl methacrylate)—reported in a previous analysis (Tartari A, Casnati E, Bonifazzi C, Baraldi C, 1997b. Phys. Med. Biol. 42, 2551–2560.—were found to agree quite well when compared to the results obtained with different quality of beams and analysis techniques. Investigation on bony tissue is presented for the first time, and a simple model has been carried out in order to segment the mineral and non-mineral components. Finally, a basic set of curves for the linear differential scattering coefficient is proposed in order to simulate photons scattering by tissue in terms of linear combination of such curves.
Lecture Notes in Control and Information Sciences, 1996
ABSTRACT We present a regularization technique for solving inverse ill-posed problems which arise... more ABSTRACT We present a regularization technique for solving inverse ill-posed problems which arise in many fields of applied optics and electrodynamics when one has to deal with restoration of images. Numerical results for electron scattering and free-electron-laser data are shown and the problem of reconstructing a planar image from its line integrals in computerized Compton and X-ray diffraction tomographies is addressed.
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149), 2000
ABSTRACT The use of a dedicated gamma camera for scintimammography with breast under compression ... more ABSTRACT The use of a dedicated gamma camera for scintimammography with breast under compression can improve the detection of sub centimeter cancers. Unfortunately, detectors based on PSPMT show a poor energy resolution that would not be able to discriminate tumors in the posterior portion of the breast where the scattering of photons, coming from the chest, is particularly prominent. In this paper we introduce the modified truncated SVD (mTSVD) based deconvolution as a numerical approach to enhance the energy resolution. Tc99m calibration spectra were used to numerically describe the detector response function; the degree of ill-posedness of the numerical problem was carefully study in order to perform the deconvolution of ROI, in different breast position, by a unique response function. Eight ROI spectra from breast phantom and two from a patient study were analyzed, respectively. For each or them the energy resolution, after the deconvolution, was about 1.7 times improved. The results shown that the mTSVD based deconvolution can represent an useful tool to increase the energy resolution in scintimammography, and to improve the image quality by further suppression of the Compton scattering
ABSTRACT The authors investigate a technique for the characterisation of biological tissues, base... more ABSTRACT The authors investigate a technique for the characterisation of biological tissues, based on energy analysis of Compton scattered photons. The incident beam consists of 59.54 keV photons and a backscatter geometry is used. Compared to the technique based on the ratio of photons coherently scattered due to the Rayleigh effect and those incoherently scattered due to the Compton effect, the present technique provides similar results for mineral content evaluation, with an error lower than 1%. However it allows the determination of fat content in a soft tissue matrix - even in the cases in which the Rayleigh peaks is not measurable - although the error can rise up to 3%.
IEEE Symposium Conference Record Nuclear Science 2004., 2004
The use of dedicated gamma camera, with high intrinsic spatial resolution can raise the detection... more The use of dedicated gamma camera, with high intrinsic spatial resolution can raise the detection of sub centimeter cancers in Scintimammography. The recent development of new gamma imagers based on scintillation array with high spatial resolution has strongly improved the SNR of the resulting images; however, Compton scattering contamination is the main drawback in Scintimammography, since it limits the sensitivity
ABSTRACT Measurements of molecular cross sections of coherently scattered photons were obtained b... more ABSTRACT Measurements of molecular cross sections of coherently scattered photons were obtained by means of powder diffraction data analysis in the interval χ=0–6.4 nm−1 (χ=sin(θ/2)/λ; where θ is the scattering angle and λ the incident wavelength in units of nm). Accurate correction procedures were applied to the raw diffraction data. Data for fat and PMMA (polymethyl methacrylate)—reported in a previous analysis (Tartari A, Casnati E, Bonifazzi C, Baraldi C, 1997b. Phys. Med. Biol. 42, 2551–2560.—were found to agree quite well when compared to the results obtained with different quality of beams and analysis techniques. Investigation on bony tissue is presented for the first time, and a simple model has been carried out in order to segment the mineral and non-mineral components. Finally, a basic set of curves for the linear differential scattering coefficient is proposed in order to simulate photons scattering by tissue in terms of linear combination of such curves.
Lecture Notes in Control and Information Sciences, 1996
ABSTRACT We present a regularization technique for solving inverse ill-posed problems which arise... more ABSTRACT We present a regularization technique for solving inverse ill-posed problems which arise in many fields of applied optics and electrodynamics when one has to deal with restoration of images. Numerical results for electron scattering and free-electron-laser data are shown and the problem of reconstructing a planar image from its line integrals in computerized Compton and X-ray diffraction tomographies is addressed.
2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149), 2000
ABSTRACT The use of a dedicated gamma camera for scintimammography with breast under compression ... more ABSTRACT The use of a dedicated gamma camera for scintimammography with breast under compression can improve the detection of sub centimeter cancers. Unfortunately, detectors based on PSPMT show a poor energy resolution that would not be able to discriminate tumors in the posterior portion of the breast where the scattering of photons, coming from the chest, is particularly prominent. In this paper we introduce the modified truncated SVD (mTSVD) based deconvolution as a numerical approach to enhance the energy resolution. Tc99m calibration spectra were used to numerically describe the detector response function; the degree of ill-posedness of the numerical problem was carefully study in order to perform the deconvolution of ROI, in different breast position, by a unique response function. Eight ROI spectra from breast phantom and two from a patient study were analyzed, respectively. For each or them the energy resolution, after the deconvolution, was about 1.7 times improved. The results shown that the mTSVD based deconvolution can represent an useful tool to increase the energy resolution in scintimammography, and to improve the image quality by further suppression of the Compton scattering
ABSTRACT The authors investigate a technique for the characterisation of biological tissues, base... more ABSTRACT The authors investigate a technique for the characterisation of biological tissues, based on energy analysis of Compton scattered photons. The incident beam consists of 59.54 keV photons and a backscatter geometry is used. Compared to the technique based on the ratio of photons coherently scattered due to the Rayleigh effect and those incoherently scattered due to the Compton effect, the present technique provides similar results for mineral content evaluation, with an error lower than 1%. However it allows the determination of fat content in a soft tissue matrix - even in the cases in which the Rayleigh peaks is not measurable - although the error can rise up to 3%.
IEEE Symposium Conference Record Nuclear Science 2004., 2004
The use of dedicated gamma camera, with high intrinsic spatial resolution can raise the detection... more The use of dedicated gamma camera, with high intrinsic spatial resolution can raise the detection of sub centimeter cancers in Scintimammography. The recent development of new gamma imagers based on scintillation array with high spatial resolution has strongly improved the SNR of the resulting images; however, Compton scattering contamination is the main drawback in Scintimammography, since it limits the sensitivity
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Papers by Agostino Tartari