A fundamental method to determine the signal-to-noise ratio (SNR) and detective quantum efficiency (DQE) for a photon counting pixel detector

Michel, Thilo; Anton, G.; Böhnel, Michael; Durst, Jürgen; Firsching, Markus; Korn, A.; Kreisler, B.; Loehr, A.; Nachtrab, F.; Niederlöhner, D.; Sukowski, Frank; Talla, Patrick Takoukam

doi:10.1016/j.nima.2006.08.115

Cited by 47 publications

(76 citation statements)

References 7 publications

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“…Several detector developers have worked towards the introduction of charge-sharing effects in image quality modelling of PC-HPDs [4][5][6][7][8][9][10][11][12][13][14][15][16]. By simulating charge collection processes in highly segmented PC-HPDs, Tlustos demonstrated how count loss and multiple counting were both decreasing the zero-frequency DQE of PC-HPDs and how multiple counts resulting from charge-sharing effects were acting as a low pass (or anti-aliasing) filter on the image by widening the presampling MTF of the detector [4].…”

Section: Jinst 7 P11028mentioning

confidence: 99%

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Detective quantum efficiency model of single-X-ray-photon counting hybrid pixel detectors

Marchal

Medjoubi

2012

J. Inst.

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A Detective Quantum Efficiency (DQE) model of single-X-ray-Photon Counting Hybrid Pixel Detectors (PC-HPDs) is presented. It applies to PC-HPDs based on semiconductor sensors such as silicon and CdTe pixel sensors. Charge-sharing effects are introduced in the expressions of imaging performance parameters such as large-area gain factor, presampling modulation transfer function and digital noise power spectrum, using the concept of threshold-dependent effective fill-factor. A simple X-ray induced charge distribution approximation is used to derive a practical formula for the threshold-dependent large-area gain factor, i.e. the integral X-ray spectrum which can be indirectly measured with a PC-HPD. This detector model was applied to standard synchrotron X-ray PC-HPDs: MEDIPIX3, PILATUS and XPAD detectors.

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Section: Jinst 7 P11028mentioning

confidence: 99%

“…In their model they approximated the X-ray induced charge cloud by a uniform charge distribution. Another major step consisted in the introduction by Michel et al of a DQE model of PC-HPDs based on the mean and variance of the count multiplicity [5,7]. However this model is restricted to the zero-frequency DQE.…”

Section: Jinst 7 P11028mentioning

confidence: 99%

Detective quantum efficiency model of single-X-ray-photon counting hybrid pixel detectors

Marchal

Medjoubi

2012

J. Inst.

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“…In addition, angiography requires high spatial resolution but the use of small detector elements will result in reabsorption of characteristic and Compton-scatter x rays and therefore charge sharing in near-by elements. This may result in increased image noise [26][27][28][29][30][31][32][33] although fast coincidence detection algorithms, such as that implemented in the Medipix-3 prototype detector, 29 may prevent these effects.…”

Section: Introductionmentioning

confidence: 99%

A theoretical comparison of x-ray angiographic image quality using energy-dependent and conventional subtraction methods

2011

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While the energy-based methods are not necessarily optimized and further improvements are likely, the linearized noise-propagation analysis provides the theoretical framework of a level playing field for optimization studies and comparison with conventional DSA. It is concluded that both dual-energy and photon-counting approaches have the potential to provide similar angiographic image quality to DSA.

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“…Secondly, the charge signal transport is affected by charge sharing. The moving charge cloud also induces electrical pulses on neighboring pixels, [17], again mostly at the funnelshaped bottom part of the pixel field configuration.…”

Section: Methodsmentioning

confidence: 99%

Spectral and spatial resolution of semiconductor detectors in medical X- and gamma ray imaging

Heismann

Henseler

Niederloehner

et al. 2008

2008 IEEE Nuclear Science Symposium Conference Record

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Abstract-In X-and gamma ray based medical systems, detector performance is a key driver for diagnostic quality. Over the last years and decades, indirect conversion scintillator detectors have become the standard for many medical applications including X-ray Radiography, Computed Tomography and SPECT. Recently, direct conversion semiconductor detectors based on CdTe and CdZnTe (CZT) have come into focus, as they might offer improved or additional performance for specific applications. In this paper we use generic physical models to compare the spatial and spectral resolution of both detector types. The spatial resolution is quantified by the Modulation Transfer Function (MTF). We find that the direct conversion of quanta leads to an approximately sinc-like MTF. In comparison, the MTF of a pixelized scintillator detector shows a mid-frequency drop due to optical signal cross-talk.The spectral resolution of both detector types is described by the Detector Response Function (DRF). It yields the probability density D(E, E ) to measure an incoming quantum of energy E as the output energy E . As a general result we find that fluorescence X-ray cross-talk on one hand and charge sharing and optical cross-talk on the other hand significantly influence the DRF in both detector types. We compare the two detector types in a Computed Tomography application. For an integrating scintillator detector, a Poisson excess noise is observed and quantified. For a counting semiconductor detector, we describe the signficant low-energy shift in D(E, E ). The weighting functions of a two bin counting detctor are analyzed and compared to tube-based approaches. The results are summarized to show the trade-off between spectral and spatial resolution in medical imaging with direct conversion detectors.

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A fundamental method to determine the signal-to-noise ratio (SNR) and detective quantum efficiency (DQE) for a photon counting pixel detector

Cited by 47 publications

References 7 publications

Detective quantum efficiency model of single-X-ray-photon counting hybrid pixel detectors

Detective quantum efficiency model of single-X-ray-photon counting hybrid pixel detectors

A theoretical comparison of x-ray angiographic image quality using energy-dependent and conventional subtraction methods

Spectral and spatial resolution of semiconductor detectors in medical X- and gamma ray imaging

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