Theoretical performance comparison of a Compton-scatter aperture and parallel-hole collimator

Clinthorne, N.H.; Ng, Chor-Yi; Hua, Chia‐Ho; Gormley, J.E.; LeBlanc, J.W.; Wilderman, S.J.; Rogers, W.L.

doi:10.1109/nssmic.1996.591443

Cited by 17 publications

(6 citation statements)

References 3 publications

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“…Comparison to simulation data. Recall that equation (6) and most of the following discussion assumed (incorrectly) independence for different pixels of the events "a pixel is crossed by n lines". To confirm that the confidences we estimated under this assumption are not vastly optimistic, we simulate a large number of random background fields and compare the statistics of these samples to our theoretical estimates.…”

Section: A Probabilistic Discussionmentioning

confidence: 99%

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Detecting small low emission radiating sources

Allmaras

Darrow

Hristova

et al. 2013

Inverse Problems &Amp; Imaging

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The article addresses the possibility of robust detection of geometrically small, low emission sources on a significantly stronger background. This problem is important for homeland security. A technique of detecting such sources using Compton type cameras is developed, which is shown on numerical examples to have high sensitivity and specificity and also allows to assign confidence probabilities of the detection. 2D case is considered in detail

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Section: A Probabilistic Discussionmentioning

confidence: 99%

“…The most significant of these is the dramatic increase of sensitivity -Compton cameras are reported to count orders of magnitude more photons than Anger cameras [6,24]. Another advantage is the flexibility of geometrical design [33,34], which even allows for hand-held devices [17,23].…”

Section: Compton Camerasmentioning

confidence: 99%

Detecting small low emission radiating sources

Allmaras

Darrow

Hristova

et al. 2013

Inverse Problems &Amp; Imaging

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“…The rest of the geometrical parameters of the two simulated SPECT systems are optimized based on the well-established uniform Cramer-Rao bound approach [26][27][28][29][30], which evaluates the resolution-variance tradeoff for each specific system parameter-set to choose a preferred parameter value. Below is a brief description of the approach.…”

Section: Geometrical Parameters Of Matrices Spectmentioning

confidence: 99%

“…Following the system performance characterization method in [27], the variance bound B and corresponding bias-gradient length δ for the n-th voxel in the vector θ, which is a uniform image distributed over the entire FOV, are respectively expressed as:…”

Section: Geometrical Parameters Of Matrices Spectmentioning

confidence: 99%

Self-Collimating SPECT With Multi-Layer Interspaced Mosaic Detectors

Quan

Lyu

et al. 2021

IEEE Trans. Med. Imaging

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Conventional singlephoton emission computed tomography (SPECT) relies on mechanical collimation whose resolution and sensitivity are interdependent, the best performance a SPECT system can attain is only a compromise of these two equally desired properties. To simultaneously achieve high resolution and sensitivity, we propose to use sensitive detectors constructed in a multi-layer interspaced mosaic detectors (MATRICES) architecture to accomplish part of the collimation needed. We name this new approach selfcollimation.We evaluate three self-collimating SPECT systems and report their imaging performance: 1) A simulated human brain SPECT achieves 3.88% sensitivity, it clearly resolves 0.5-mm and 1.0-mm hot-rod patterns at noise-free and realistic count-levels, respectively; 2) a simulated mouse SPECT achieves 1.25% sensitivity, it clearly resolves 50-μm and 100-μm hot-rod patterns at noise-free and realistic count-levels, respectively; 3) a SPECT prototype achieves 0.14% sensitivity and clearly separates 0.3-mm-diameter point sources of which the center-to-center neighbor distance is also 0.3 mm. Simulated contrast phantom studies show excellent resolution and signal-to-noise performance.The unprecedented system performance demonstrated by these 3 SPECT scanners is a clear manifestation of the superiority of the self-collimating approach over conventional mechanical collimation. It represents a potential paradigm shift in SPECT technology development.

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“…The Uniform CR Bound has been used to calculate fundamental limits in estimator performance in medical imaging [Z-31, comparing the performance of different medical imaging modalities [4], among other applications.…”

Section: Introductionmentioning

confidence: 99%

Bias-resolution-variance tradeoffs for single pixel estimation tasks using the uniform Cramer-Rao bound

Kragh

Hero

2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149)

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Previously we introduced the Uniform Cram&-Rao (CR) Bound as a lower bound on the variance of biased estimators, along with the concept of the delta-sigma tradeoff curve. For an estimator whose variance lies on this curve, lower variance can only be achieved at the price of increased estimator bias gradient norm, and vice versa.However, for single pixel estimation, one can specify a variety of different estimator point response functions that have identical bias-gradient norm but with widely different resolution properties. This has lead to some counter-intuitive results and interpretation difficulties when using the Uniform CR Bound in performance studies of imaging systems.We now extend this tradeoff concept by introducing the 2nd-moment of the point response function as a measure of resolution for single-pixel estimation tasks. We derive an expression for the delta-gamma-sigma tradeoff surface. This surface specifies an "unachievable region" of estimator variance. For estimators that lie on this surface, lower variance can only be achieved at the price of increased bias gradient norm and/or decreased estimator resolution. We present a method for computing this surface for linear gaussian inverse problems.

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Theoretical performance comparison of a Compton-scatter aperture and parallel-hole collimator

Cited by 17 publications

References 3 publications

Detecting small low emission radiating sources

Detecting small low emission radiating sources

Self-Collimating SPECT With Multi-Layer Interspaced Mosaic Detectors

Bias-resolution-variance tradeoffs for single pixel estimation tasks using the uniform Cramer-Rao bound

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