Comparison of three applications of ConTraSPECT

Laurette, I.; Clackdoyle, Rolf; Welch, Andrew; Natterer, Frank; Gullberg, Grant T.

doi:10.1109/23.819297

Cited by 28 publications

(18 citation statements)

References 11 publications

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“…Using Helgason's consistency formula, the attenuation map is adjusted to the emission data using nonlinear least squares. As reported in [35,21], the six variables are sometimes difficult to optimize simultaneously, and the best results are obtained by fixing the attenuation coefficient after some initial steps, and optimizing the 5 shape parameters subsequently. As mentioned in the introduction, since Helgason's formula is only valid over…”

Section: Existing Methodsmentioning

confidence: 99%

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Attenuation correction using SPECT emission data only

Gourion

Noll

Gantet

et al.

2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)

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A major step towards quantitative SPECT imaging may be achieved if attenuation, scatter and blurring effects are accounted for in the reconstruction process. Here we consider an approach which simultaneously estimates the unknown attenuation coefficient and the emission source using the emission data only. This leads to an inverse mathematical problem which could no longer be solved via iterative procedures like the well-known EM-algorithm. Instead, a regularization approach based on nonlinear optimization techniques is used. We present a successful strategy of the analytic type, and we test it in a simulated case study.

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Section: Existing Methodsmentioning

confidence: 99%

“…In particular, we implemented (cf. [16]) the ConTraSPECT method of [35,21], which corrects for attenuation using a dummy attenuation map…”

Section: Existing Methodsmentioning

confidence: 99%

Attenuation correction using SPECT emission data only

Gourion

Noll

Gantet

et al.

2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310)

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“…Reconstruction of the attenuation map using only ECT projection data [4][5][6] ECT projection data contain both the emission distribution and attenuation map information. Consequently, in principle, both the emission distribution and the attenuation map can be estimated from ECT projection data alone, without using TCT projection data.…”

Section: Introductionmentioning

confidence: 99%

“…Typical techniques that have been presented include sinogram extrapolation [1] and an algebraic method [2]. Successive approximation [3] and model fitting [4,6,7] have been used. In X-ray CT, studies of image reconstruction from various incomplete projection data were made in the 1980s.…”

Section: Introductionmentioning

confidence: 99%

Attenuation map reconstruction using topology constrained labeling

Kudo

Nakamura

2003

Electron Comm Jpn Pt II

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SUMMARYIn order to derive a quantitative reconstructed image in various types of emission CT (ECT), such as SPECT and PET, it is necessary to examine the gamma ray attenuation coefficient distribution inside the body, called the attenuation map, by transmission CT (TCT), and to apply attenuation correction. This paper proposes a new method in which the attenuation map is reconstructed from the incomplete TCT projection data or ECT projection data. The conventional attenuation map reconstruction method is performed, assuming that each pixel of the attenuation map takes a continuous value. In the proposed method, in contrast, the attenuation map is reconstructed by region segmentation in which the pixel value takes only discrete values. The problem is formulated as a labeling problem in which the label image minimizing the energy function is to be determined. In order to avoid local minima, the solution is derived by stochastic relaxation. In the conventional formulation of image region segmentation, however, the search space for the solution is too wide, and it is difficult to derive an accurate attenuation map if the measured data are incomplete. Consequently, this paper proposes topology constrained labeling, in which topology constraints, that is, a priori information on the topology (the number of regions and the connection relations among the regions) of the attenuation map to which the region segmentation is applied, are used, and the solution search space is constrained. Simulation experiments, as well as an experiment using the actual PET data, were performed, and the effectiveness of the topology constrained labeling has been demonstrated.

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“…84 Without a transmission scan, elliptical as well as nonconvex spline curves were sought, as well as sinogram regions for truncation compensation of transmission data. 214 The influence of count rates, attenuation coefficients, and photopeak scatter was studied in Ref. 215.…”

Section: Spect-specific Studiesmentioning

confidence: 99%

Attenuation correction in emission tomography using the emission data—A review

Berker

2016

Medical Physics

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The problem of attenuation correction (AC) for quantitative positron emission tomography (PET) had been considered solved to a large extent after the commercial availability of devices combining PET with computed tomography (CT) in 2001; single photon emission computed tomography (SPECT) has seen a similar development. However, stimulated in particular by technical advances toward clinical systems combining PET and magnetic resonance imaging (MRI), research interest in alternative approaches for PET AC has grown substantially in the last years. In this comprehensive literature review, the authors first present theoretical results with relevance to simultaneous reconstruction of attenuation and activity. The authors then look back at the early history of this research area especially in PET; since this history is closely interwoven with that of similar approaches in SPECT, these will also be covered. We then review algorithmic advances in PET, including analytic and iterative algorithms. The analytic approaches are either based on the Helgason-Ludwig data consistency conditions of the Radon transform, or generalizations of John's partial differential equation; with respect to iterative methods, we discuss maximum likelihood reconstruction of attenuation and activity (MLAA), the maximum likelihood attenuation correction factors (MLACF) algorithm, and their offspring. The description of methods is followed by a structured account of applications for simultaneous reconstruction techniques: this discussion covers organ-specific applications, applications specific to PET/MRI, applications using supplemental transmission information, and motion-aware applications. After briefly summarizing SPECT applications, we consider recent developments using emission data other than unscattered photons. In summary, developments using time-of-flight (TOF) PET emission data for AC have shown promising advances and open a wide range of applications. These techniques may both remedy deficiencies of purely MRI-based AC approaches in PET/MRI and improve standalone PET imaging. C

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Comparison of three applications of ConTraSPECT

Cited by 28 publications

References 11 publications

Attenuation correction using SPECT emission data only

Attenuation correction using SPECT emission data only

Attenuation map reconstruction using topology constrained labeling

Attenuation correction in emission tomography using the emission data—A review

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