Energy and spatial distribution of multiple order Compton scatter in SPECT: a Monte Carlo investigation

Floyd, Carey E.; Jaszczak, R.J.; Harris, C.C.; Coleman, R. Edward

doi:10.1088/0031-9155/29/10/005

Cited by 120 publications

(44 citation statements)

References 11 publications

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“…The distribution of scattered photons in SPECT has been studied extensively (Floyd et al, 1984;Frey and Tsui, 1991), and it is well known that the SRF contains a small peaked component surrounded by long, substantial tails. In terms of the frequency response, the scatter component of SPECT projection data tends to be dominated by low frequency information, though there is some higher frequency information present.…”

Section: A Coarse-grid Scatter Modelingmentioning

confidence: 99%

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

et al. 1998

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Accurate scatter compensation in SPECT can be performed by modeling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using RBSC for fully 3D compensation has resulted in prohibitively long reconstruction times. In this work we propose two new methods that can be used in conjunction with existing methods to achieve marked reductions in RBSC reconstruction times. The first method, Coarse-Grid Scatter Modeling, significantly accelerates the scatter model by exploiting the fact that scatter is dominated by low frequency information. The second method, Intermittent RBSC, further accelerates the reconstruction process by limiting the number of iterations during which scatter is modeled. The fast implementations were evaluated using a Monte Carlo simulated experiment of the 3D MCAT phantom with Tc-99m tracer, and also using experimentally acquired data with Tl-201 tracer. Results indicated that these fast methods can reconstruct, with fully 3D compensation, images very similar to those obtained using conventional RBSC methods, and in reconstruction times that are an order of magnitude shorter. Using these methods, fully 3D iterative reconstruction with RBSC can be performed well within the realm of clinically realistic times (under 10 minutes for 64 × 64 × 24 image reconstruction).

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Section: A Coarse-grid Scatter Modelingmentioning

confidence: 99%

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

et al. 1998

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“…For example, in the case of a srnall 99mTc line source deep in a homogeneous water medium, the Compton-scattered photons detected in the photopeak window are primarily those which scattered once (87%) or twice (12%) [45,152] wit h t hird and higher orders o d y cont ributing 1%. If one wanted to use this method for the calculation of scatter in a lower energy window, such as for down scatter from *Tc into the primary *OfTl window (70keV), the higher order scatter events would play a greater role.…”

Section: First Scatter Angle (Degrees)mentioning

confidence: 99%

Analytical calculation of photon distributions in SPECT projections

Wells

Celler

Harrop

1998

IEEE Trans. Nucl. Sci.

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In this work is presented a method for analytically cdculating the distribution of photons detected in SPECT projections. The technique is appLicabIe to sources in homogeneous and non-homogeneous media. The photon distribution (primary, first and second order Compton scatter, and first order Rayleigh scatter) is computed using precdculated camera-dependent lookup tables in conjunction with an attenuation map of the scattering object aad a map of the activity distribution.The resdts of the technique are in excellent agreement with those of Monte Carlo simulation and experimental phantom studies. It has b e n validated with respect to sources in both homogeneous and noa-homogeneous media.Compared with a similar andyticd technique, it offers a factor of 40-60 decrease in the cdculation time for higher order Compton scatter distributions. For small sources, it improves on computation tirne required by Monte Carlo simulators by a factor of 20-150.Finally, this method has been applied to the problem of correcting for cross-taik in 1231-99mT~ dual-isotope SPECT studies. It has demonstrated the ability to accurately reproduce the shape of the cross-talk distribution and to reproduce the absolute activity of the sources to within 7%, dowing accurate removai of cross-talk contamination. Abstract. . 11

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“…In clinical practice, the single method unaniCorrespondence to: E Bonnin mously adopted to address this problem is conventional 20% energy window acquisition, which takes into account only the photons detected using a spectral window centred on the emission energy of the radioisotope. Part of the scattered photons is thus excluded from scintigraphic images, but some photons that have scattered once or even twice may be detected within this window [1]. Many other methods of scatter correction have therefore been proposed [e.g.…”

Section: Introductionmentioning

confidence: 99%

“…However, due to the limited energy resolution of the camera, scattered photons are also detected within the 20% energy window [1]. PW is in fact not really a scatter correction but rather an expedient means of limiting the detection of scattered photons.…”

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confidence: 99%

A comparative study of scatter correction methods for scintigraphic images

et al. 1994

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Phantom studies have demonstrated that factor analysis of medical image sequences using target apex-seeking (FAMIS-TAS) applied to spectral scintigraphic image sequences is an efficient adaptive scatter correction method. We assessed the improvement in quality of clinical images using FAMIS-TAS as compared with two other scatter correction techniques: conventional 20% photopeak window (PW) and scatter window subtraction (SWS). Thirty normal technetium-99m hydroxymethylene diphosphonate bone scans were processed. Bone to soft tissue contrasts and signal-to-noise and contrast-to-noise ratios were measured. The overall image quality was evaluated using an observer testing questionnaire submitted to four physicians. Quantitative parameters showed that FAMIS-TAS images displayed the best bone to soft tissue contrasts and contrast-to-noise ratios, but the lowest signal-to-noise ratios. PW images presented the lowest contrasts and contrast-to-noise ratios, and the highest signal-to-noise ratios. SWS gave intermediate results. According to the observer testing results, PW images showed the lowest bone to soft tissue contrasts and the highest signal-to-noise ratios. FAMIS-TAS images showed the lowest signal-to-noise ratios. The images processed by the three methods displayed the same anatomical information.

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Energy and spatial distribution of multiple order Compton scatter in SPECT: a Monte Carlo investigation

Cited by 120 publications

References 11 publications

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction

Analytical calculation of photon distributions in SPECT projections

A comparative study of scatter correction methods for scintigraphic images

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