Flatfield Correction Optimization for Energy Selective X-Ray Imaging With Medipix3

Procz, S.; Pichotka, M.; Lubke, J.; Hamann, Elias; Ballabriga, R.; Blaj, G.; Campbell, M.; Fauler, A.; Mix, Michael; Zwerger, A.; Fiederle, M.

doi:10.1109/tns.2011.2165732

Cited by 18 publications

(9 citation statements)

References 14 publications

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“…This solution needs small corrections for area dilation and air absorption, in addition to a few more detector-specific ones, and needs a separate check of the uniformity of the source. The advantage is that it can be tuned to the energy of interest, and that a sufficient number of photons is easily acquired [146,41,59].…”

Section: Detector Correctionsmentioning

confidence: 99%

Everything SAXS: small-angle scattering pattern collection and correction

Pauw

2013

J. Phys.: Condens. Matter

158

136

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Section: Detector Correctionsmentioning

confidence: 99%

Everything SAXS: small-angle scattering pattern collection and correction

Pauw

2013

J. Phys.: Condens. Matter

158

136

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“…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

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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...

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“…The published experiment was, however, carried out using a single detector assembly. Even later publications dealing with energy-sensitive micro-CT using Medipix and Timepix detectors were based on the use of a single-chip or quad configuration (4 assemblies in 2 by 2 array sharing a common sensor) [8][9][10][11][12][13][14][15][16].…”

Section: Jinst 17 C01028mentioning

confidence: 99%

Multi bin energy-sensitive micro-CT using large area photon-counting detectors Timepix

Dudák¹,

Žemlička²

2022

J. Inst.

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X-ray micro-CT has become a popular and widely used tool for the purposes of scientific research. Although the current state-of-the-art micro-CT is on a high technology level, it still has some known limitations. One of the relevant issues is an inability to clearly identify and quantify specific materials. The mentioned drawback can be solved by the energy-sensitive CT approach. Dual-energy CT, which is already frequently used in human medicine, offers the identification of two different materials; for example, it differentiates an intravenous contrast agent from bone or it can indicate the composition of urinary stones. Resolving a larger number of material components within a single object is beyond the capabilities of dual-energy CT. Such an approach requires a higher number of measurements using different photon energies. A possible solution for multi bin, or so-called spectral CT, is the application of photon-counting detectors. Photon counting technology offers an integrated circuitry capable of resolving the energy of incoming photons in each pixel. Therefore, it is possible to collect data in user-defined energy windows. This contribution evaluates the applicability of the large-area photon-counting detector Timepix for multi bin energy-sensitive micro-CT. It presents an experimental phantom study focused on the simultaneous K-edge-based identification and quantification of multiple contrast agents within a single object. The paper describes the collection of multiple energy bins using the Timepix detector operated in the photon counting mode, explains the data processing, and demonstrates the results obtained from an in-house implemented basis material decomposition algorithm.

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Flatfield Correction Optimization for Energy Selective X-Ray Imaging With Medipix3

Cited by 18 publications

References 14 publications

Everything SAXS: small-angle scattering pattern collection and correction

Everything SAXS: small-angle scattering pattern collection and correction

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

Multi bin energy-sensitive micro-CT using large area photon-counting detectors Timepix

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