TU-G-110-04: Material Decomposition in Cardiovascular CT Imaging with Photon Counting Detector

2011 ◽  
Vol 38 (6Part30) ◽  
pp. 3785-3785
Author(s):  
P Baturin ◽  
Y Alivov ◽  
S Molloi
Keyword(s):  
Photon Counting ◽  
Ct Imaging ◽  
Material Decomposition ◽  
Photon Counting Detector ◽  
Cardiovascular Ct

scholarly journals Feasibility of unconstrained three-material decomposition: imaging an excised human heart using a prototype silicon photon-counting CT detector

2020 ◽  
Vol 30 (11) ◽  
pp. 5904-5912 ◽  
Author(s):  
Fredrik Grönberg ◽  
Johan Lundberg ◽  
Martin Sjölin ◽  
Mats Persson ◽  
Robert Bujila ◽  
...  
Keyword(s):  
Photon Counting ◽  
Rate Capability ◽  
Silicon Detector ◽  
Dual Energy ◽  
Material Decomposition ◽  
Clinical Value ◽  
Photon Counting Detector ◽  
Tomography System ◽  
Iodinated Contrast ◽  
Iodinated Contrast Agent

Abstract Rationale and objectives The purpose of this study was to evaluate the feasibility of unconstrained three-material decomposition in a human tissue specimen containing iodinated contrast agent, using an experimental multi-bin photon-counting silicon detector. It was further to evaluate potential added clinical value compared to a 1st-generation state-of-the-art dual-energy computed tomography system. Materials and methods A prototype photon-counting silicon detector in a bench-top setup for x-ray tomographic imaging was calibrated using a multi-material calibration phantom. A heart with calcified plaque was obtained from a deceased patient, and the coronary arteries were injected with an iodinated contrast agent mixed with gelatin. The heart was imaged in the experimental setup and on a 1st-generation state-of-the-art dual-energy computed tomography system. Projection-based three-material decomposition without any constraints was performed with the photon-counting detector data, and the resulting images were compared with those obtained from the dual-energy system. Results The photon-counting detector images show better separation of iodine and calcium compared to the dual-energy images. Additional experiments confirmed that unbiased estimates of soft tissue, calcium, and iodine could be achieved without any constraints. Conclusion The proposed experimental system could provide added clinical value compared to current dual-energy systems for imaging tasks where mix-up of iodine and calcium is an issue, and the anatomy is sufficiently small to allow iodine to be differentiated from calcium. Considering its previously shown count rate capability, these results show promise for future integration of this detector in a clinical CT scanner. Key Points • Spectral photon-counting detectors can solve some of the fundamental problems with conventional single-energy CT. • Dual-energy methods can be used to differentiate iodine and calcium, but to do so must rely on constraints, since solving for three unknowns with only two measurements is not possible. Photon-counting detectors can improve upon these methods by allowing unconstrained three-material decomposition. • A prototype photon-counting silicon detector with high count rate capability allows performing unconstrained three-material decomposition and qualitatively shows better differentiation of iodine and calcium than dual-energy CT.

Impact of photon counting detector spectral distortion on virtual non-contrast CT imaging

2020 ◽  
Author(s):  
Mang Feng ◽  
Xu Ji ◽  
Ran Zhang ◽  
Jessica R. Miller ◽  
Guang-Hong Chen ◽  
...  
Keyword(s):  
Photon Counting ◽  
Ct Imaging ◽  
Spectral Distortion ◽  
Photon Counting Detector ◽  
Contrast Ct

scholarly journals Multi-energy CT imaging for large patients using dual-source photon-counting detector CT

2020 ◽  
Vol 65 (17) ◽  
pp. 17NT01
Author(s):  
Shengzhen Tao ◽  
Jeffrey F Marsh ◽  
Ashley Tao ◽  
Greg J Michalak ◽  
Kishore Rajendran ◽  
...  
Keyword(s):  
Photon Counting ◽  
Ct Imaging ◽  
Photon Counting Detector ◽  
Dual Source

scholarly journals High resolution X-ray micro-CT imaging of fibrin scaffold using large area single photon counting detector

2018 ◽  
Vol 13 (12) ◽  
pp. C12006-C12006 ◽  
Author(s):  
D. Vavřík ◽  
D. Kytýř ◽  
S. Mühleder ◽  
M. Vopálenský ◽  
P. Beneš ◽  
...  
Keyword(s):  
High Resolution ◽  
Single Photon ◽  
Photon Counting ◽  
Ct Imaging ◽  
Micro Ct ◽  
Large Area ◽  
Single Photon Counting ◽  
X Ray ◽  
Photon Counting Detector ◽  
Fibrin Scaffold

Virtual monochromatic imaging reduces beam hardening artefacts in cardiac interior photon counting computed tomography: a phantom study with cadaveric specimens

2021 ◽  
Author(s):  
Satu Irene Inkinen ◽  
Mikael Asko Kaarlo Juntunen ◽  
Juuso Heikki Jalmari Ketola ◽  
Kristiina Korhonen ◽  
Pasi Sepponen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Coronary Artery ◽  
Ex Vivo ◽  
Cardiac Computed Tomography ◽  
Photon Counting ◽  
High Energy ◽  
Ct Imaging ◽  
Material Decomposition ◽  
Beam Hardening ◽  
Selection Of

Abstract In interior cardiac computed tomography (CT) imaging, the x-ray beam is collimated to a limited field-of-view covering the heart volume, which decreases the radiation exposure to surrounding tissues. Spectral CT enables the creation of virtual monochromatic images (VMIs) through a computational material decomposition process. This study investigates the utility of VMIs for beam hardening (BH) reduction in interior cardiac CT, and further, the suitability of VMIs for coronary artery calcium (CAC) scoring and volume assessment is studied using spectral photon counting detector CT (PCD-CT). Ex vivo coronary artery samples (N=18) were inserted in an epoxy rod phantom. The rod was scanned in the conventional CT geometry, and subsequently, the rod was positioned in a torso phantom and re-measured in the interior PCD-CT geometry. The total energy (TE) 10-100 keV reconstructions from PCD-CT were used as a reference. The low energy 10-60 keV and high energy 60-100 keV data were used to perform projection domain material decomposition to polymethyl methacrylate and calcium hydroxylapatite basis. The truncated basis-material sinograms were extended using the adaptive detruncation method. VMIs from 30-180 keV range were computed from the detruncated virtual monochromatic sinograms using filtered back projection. Detrending was applied as a post-processing method prior to CAC scoring. The results showed that BH artefacts from the exterior structures can be suppressed with high (≥100 keV) VMIs. With appropriate selection of the monoenergy (46 keV), the underestimation trend of CAC scores and volumes shown in Bland-Altman (BA) plots for TE interior PCD-CT was mitigated, as the BA slope values were -0.02 for the 46 keV VMI compared to -0.21 the conventional TE image. To conclude, spectral PCD-CT imaging using VMIs could be applied to reduce BH artefacts interior CT geometry, and further, optimal selection of VMI may improve the accuracy of CAC scoring assessment in interior PCD-CT.

scholarly journals A Ring Artifact Correction Method: Validation by Micro-CT Imaging with Flat-Panel Detectors and a 2D Photon-Counting Detector

Sensors ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 269 ◽  
Author(s):  
Mohamed Eldib ◽  
Mohamed Hegazy ◽  
Yang Mun ◽  
Myung Cho ◽  
Min Cho ◽  
...  
Keyword(s):  
Method Validation ◽  
Photon Counting ◽  
Correction Method ◽  
Ct Imaging ◽  
Micro Ct ◽  
Flat Panel ◽  
Artifact Correction ◽  
Photon Counting Detector ◽  
Ring Artifact ◽  
Flat Panel Detectors

scholarly journals Material Decomposition in Low-Energy Micro-CT Using a Dual-Threshold Photon Counting X-Ray Detector

2021 ◽  
Vol 9 ◽  
Author(s):  
Rasmus Solem ◽  
Till Dreier ◽  
Isabel Goncalves ◽  
Martin Bech
Keyword(s):  
Decomposition Method ◽  
Photon Counting ◽  
Low Energy ◽  
Linear Attenuation Coefficient ◽  
Micro Ct ◽  
Material Decomposition ◽  
Beam Hardening ◽  
X Ray ◽  
Photon Counting Detector ◽  
Organic Tissue

Material decomposition in computed tomography is a method for differentiation and quantification of materials in a sample and it utilizes the energy dependence of the linear attenuation coefficient. In this study, a post-image reconstruction material decomposition method is constructed for a low-energy micro-CT setup using a photon counting x-ray detector. The low photon energy range (4–11 keV) allows for K-edge contrast separation of naturally occurring materials in organic tissue without the need of additional contrast agents. The decomposition method was verified using a phantom and its capability to decompose biomedical samples was evaluated with paraffin embedded human atherosclerotic plaques. Commonly, the necessary dual energy data for material decomposition is obtained by manipulating the emitted x-ray spectrum from the source. With the photon counting detector, this data was obtained by acquiring two energy window images on each side of the K-edge of one material in the sample. The samples were decomposed into three materials based on attenuation values in manually selected regions. The method shows a successful decomposition of the verification phantom and a distinct distribution of iron, calcium and paraffin in the atherosclerotic plaque samples. Though the decompositions are affected by beam hardening and ring artifacts, the method shows potential for spectral evaluation of biomedical samples.

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