Fast CdTe and CdZnTe Semiconductor Detector Arrays for Spectroscopic X-Ray Imaging

Brambilla, A.; Ouvrier-Buffet, P.; Gonon, G.; Rinkel, Jean; Moulin, Vincent; Boudou, Caroline; Verger, L.

doi:10.1109/tns.2012.2226910

Cited by 48 publications

(30 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main drawback of pixellated CZT detectors is represented by the spectral and spatial distortions caused by charge-sharing and cross-talk phenomena. The effects of these phenomena on the response of CZT/CdTe pixel detectors have been studied extensively through both theoretical Guerra et al, 2008;Iniewski et al, 2007;Xu et al, 2011) and experimental approaches (Brambilla et al, 2012(Brambilla et al, , 2013Bolotnikov et al, 2016;Kim et al, 2011;Kuvvetli et al, 2007;Meuris et al, 2009;Veale et al, 2014b).…”

Section: Charge Sharing and Cross Talk In Pixellated Czt Detectorsmentioning

confidence: 99%

“…High-flux radiation-induced polarization phenomena (Abbene et al, 2016;Sellin et al, 2010;Strassburg et al, 2011) depend mainly on the characteristics of the detectors and high bias voltage operation, and good charge-transport properties (mobility lifetime products of holes and electrons) are required. The mitigation of the effects of dead-time, pile-up and charge sharing is, generally, the main task of pulse mode electronics and encouraging results are obtained through both analogue (Barber et al, 2015;Iwanczyk et al, 2009;Taguchi et al, 2010) and digital approaches (Brambilla et al, 2013;Streicher et al, 2015). A common strategy, widely used by several groups (Barber et al, 2015;Brambilla et al, 2013;Iwanczyk et al, 2009;Ogawa et al, 2012), is to perform a fast shaping analysis on the detector pulses (i.e.…”

Section: Introductionmentioning

confidence: 99%

“…The mitigation of the effects of dead-time, pile-up and charge sharing is, generally, the main task of pulse mode electronics and encouraging results are obtained through both analogue (Barber et al, 2015;Iwanczyk et al, 2009;Taguchi et al, 2010) and digital approaches (Brambilla et al, 2013;Streicher et al, 2015). A common strategy, widely used by several groups (Barber et al, 2015;Brambilla et al, 2013;Iwanczyk et al, 2009;Ogawa et al, 2012), is to perform a fast shaping analysis on the detector pulses (i.e. the output pulses from the charge-sensitive preamplifier, CSP), thus providing shaped pulses with very short time widths (less than 500 ns).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Digital fast pulse shape and height analysis on cadmium–zinc–telluride arrays for high-flux energy-resolved X-ray imaging

et al. 2018

View full text Add to dashboard Cite

Cadmium-zinc-telluride (CZT) arrays with photon-counting and energy-resolving capabilities are widely proposed for next-generation X-ray imaging systems. This work presents the performance of a 2 mm-thick CZT pixel detector, with pixel pitches of 500 and 250 µm, dc coupled to a fast and low-noise ASIC (PIXIE ASIC), characterized only by the preamplifier stage. A custom 16-channel digital readout electronics was used, able to digitize and process continuously the signals from each output ASIC channel. The digital system performs on-line fast pulse shape and height analysis, with a low dead-time and reasonable energy resolution at both low and high fluxes. The spectroscopic response of the system to photon energies below (Cd source) and above (Am source) the K-shell absorption energy of the CZT material was investigated, with particular attention to the mitigation of charge sharing and pile-up. The detector allows high bias voltage operation (>5000 V cm) and good energy resolution at moderate cooling (3.5% and 5% FWHM at 59.5 keV for the 500 and 250 µm arrays, respectively) by using fast pulse shaping with a low dead-time (300 ns). Charge-sharing investigations were performed using a fine time coincidence analysis (TCA), with very short coincidence time windows up to 10 ns. For the 500 µm pitch array (250 µm pitch array), sharing percentages of 36% (52%) and 60% (82%) at 22.1 and 59.5 keV, respectively, were measured. The potential of the pulse shape analysis technique for charge-sharing detection for corner/border pixels and at high rate conditions (250 kcps pixel), where the TCA fails, is also shown. Measurements demonstrated that significant amounts of charge are lost for interactions occurring in the volume of the inter-pixel gap. This charge loss must be accounted for in the correction of shared events. These activities are within the framework of an international collaboration on the development of energy-resolved photon-counting systems for high-flux energy-resolved X-ray imaging (1-140 keV).

show abstract

Section: Charge Sharing and Cross Talk In Pixellated Czt Detectorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Digital fast pulse shape and height analysis on cadmium–zinc–telluride arrays for high-flux energy-resolved X-ray imaging

et al. 2018

View full text Add to dashboard Cite

show abstract

“…We assumed that the detector can stop all X-ray photons with high count rates and ideally recorded the energy of each hitting photon assuming perfect absorption. Although the geometry and materials of the detector may provide the possibility of stopping all incoming X-rays, perfect recording of the energy of all photons is not quite realistic and hence the f(E) and w(E) in Equation (4) need to be experimentally determined for the given photon-counting detector [36][37][38][39][40][41]. In addition, we simplified all sources of noise by adding only Poisson noise to the detected photons.…”

Section: Discussionmentioning

confidence: 99%

K-edge ratio method for identification of multiple nanoparticulate contrast agents by spectral CT imaging

Ghadiri¹,

Ay²,

Shiran³

et al. 2013

BJR

View full text Add to dashboard Cite

Objective: Recently introduced energy-sensitive X-ray CT makes it feasible to discriminate different nanoparticulate contrast materials. The purpose of this work is to present a K-edge ratio method for differentiating multiple simultaneous contrast agents using spectral CT. Methods: The ratio of two images relevant to energy bins straddling the K-edge of the materials is calculated using an analytic CT simulator. In the resulting parametric map, the selected contrast agent regions can be identified using a thresholding algorithm. The K-edge ratio algorithm is applied to spectral images of simulated phantoms to identify and differentiate up to four simultaneous and targeted CT contrast agents. Results: We show that different combinations of simultaneous CT contrast agents can be identified by the proposed K-edge ratio method when energy-sensitive CT is used. In the K-edge parametric maps, the pixel values for biological tissues and contrast agents reach a maximum of 0.95, whereas for the selected contrast agents, the pixel values are larger than 1.10. The number of contrast agents that can be discriminated is limited owing to photon starvation. For reliable material discrimination, minimum photon counts corresponding to 140 kVp, 100 mAs and 5-mm slice thickness must be used. Conclusion: The proposed K-edge ratio method is a straightforward and fast method for identification and discrimination of multiple simultaneous CT contrast agents. Advances in knowledge: A new spectral CT-based algorithm is proposed which provides a new concept of molecular CT imaging by non-iteratively identifying multiple contrast agents when they are simultaneously targeting different organs.Despite remarkable advances in diagnostic and therapeutic procedures during the past two decades, annual reports still indicate that cancer remains a challenging disease all over the world. To reduce the morbidity and mortality caused by cancer and many other diseases, endeavours spanning technological innovations in imaging systems to the development of nanoparticulate (NP) materials aim at improving clinical diagnosis and therapy planning. Numerous high-atomic-number agents have been investigated for X-ray imaging applications, such as bismuth [1] [11]. Moreover, NP CT contrast agents proved to be promising in the context of molecular imaging owing to their higher diagnostic efficacy than current contrast agents [12][13][14]. Targetability and high circulation time in vivo make it possible to use multiple contrast agents simultaneously and integrate multiple phases of diagnostic imaging in a single scan. This may decrease CT radiation dose, drug dose and diagnosis time, with higher sensitivity and specificity [12].Although the use of multiple high-atomic-number contrast agents may improve the efficiency of clinical diagnosis, it would require differentiation of the contrast agents used simultaneously. However, owing to the wide range of atomic numbers and concentrations in the body, conventional CT that uses an integrating detection system is unlike...

show abstract

“…For the models presented below, the following parameter are needed: The Multix ME100 detector's pixel has an area of 0.8 × 0.8 mm 2 and an active crystal thickness of 3 mm thickness. 6 The bias voltage is assumed to be set to around 1200 V. 5 With these parameters, we are able to calculate the needed response matrices.…”

Section: Escape Peaks Charge Sharing and Weighting Potential Cross Talkmentioning

confidence: 99%

Spectral correction algorithm for multispectral CdTe x-ray detectors

Christensen

Kehres

et al. 2017

Radiation Detectors in Medicine, Industry, and National Security XVIII

View full text Add to dashboard Cite

Fast CdTe and CdZnTe Semiconductor Detector Arrays for Spectroscopic X-Ray Imaging

Cited by 48 publications

References 20 publications

Digital fast pulse shape and height analysis on cadmium–zinc–telluride arrays for high-flux energy-resolved X-ray imaging

Digital fast pulse shape and height analysis on cadmium–zinc–telluride arrays for high-flux energy-resolved X-ray imaging

K-edge ratio method for identification of multiple nanoparticulate contrast agents by spectral CT imaging

Spectral correction algorithm for multispectral CdTe x-ray detectors

Contact Info

Product

Resources

About