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Publications (10 of 14) Show all publications
Chen, H. (2016). Characterization and Optimization of Silicon-strip Detectors for Mammography and Computed Tomography. (Doctoral dissertation). STOCKHOLM: KTH Royal Institute of Technology
Open this publication in new window or tab >>Characterization and Optimization of Silicon-strip Detectors for Mammography and Computed Tomography
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The goal in medical x-ray imaging is to obtain the image quality requiredfor a given detection task, while ensuring that the patient dose is kept as lowas reasonably achievable. The two most common strategies for dose reductionare: optimizing incident x-ray beams and utilizing energy informationof transmitted beams with new detector techniques (spectral imaging). Inthis thesis, dose optimization schemes were investigated in two x-ray imagingsystems: digital mammography and computed tomography (CT).

In digital mammography, the usefulness of anti-scatter grids was investigatedas a function of breast thickness with varying geometries and experimentalconditions. The general conclusion is that keeping the grid is optimalfor breasts thicker than 5 cm, whereas the dose can be reduced without a gridfor thinner breasts.

A photon-counting silicon-strip detector developed for spectral mammographywas characterized using synchrotron radiation. Energy resolution, ΔE/Ein, was measured to vary between 0.11-0.23 in the energy range 15-40 keV, which is better than the energy resolution of 0.12-0.35 measured inthe state-of-the-art photon-counting mammography system. Pulse pileup hasshown little effect on energy resolution.

In CT, the performance of a segmented silicon-strip detector developedfor spectral CT was evaluated and a theoretical comparison was made withthe state-of-the-art CT detector for some clinically relevant imaging tasks.The results indicate that the proposed photon-counting silicon CT detector issuperior to the state-of-the-art CT detector, especially for high-contrast andhigh-resolution imaging tasks.

The beam quality was optimized for the proposed photon-counting spectralCT detector in two head imaging cases: non-enhanced imaging and Kedgeimaging. For non-enhanced imaging, a 120-kVp spectrum filtered by 2half value layer (HVL) copper (Z = 29) provides the best performance. Wheniodine is used in K-edge imaging, the optimal filter is 2 HVL iodine (Z = 53)and the optimal kVps are 60-75 kVp. In the case of gadolinium imaging, theradiation dose can be minimized at 120 kVp filtered by 2 HVL thulium (Z =69).

Place, publisher, year, edition, pages
STOCKHOLM: KTH Royal Institute of Technology, 2016. p. viii, 73
Series
TRITA-FYS, ISSN 0280-316X ; 0280-316X
Keywords
mammography, anti-scatter grid, photon-counting, spectral computed tomography, silicon strip, ASIC, energy resolution, Compton scatter, material decomposition, K-edge imaging
National Category
Medical Engineering
Research subject
Medical Technology
Identifiers
urn:nbn:se:kth:diva-184092 (URN)978-91-7595-919-1 (ISBN)
Public defence
2016-04-22, FA 31, ROSLAGSTULLSBACKEN 21, KTH, STOCKHOLM, 09:00 (English)
Opponent
Supervisors
Note

QC 20160401

Available from: 2016-04-01 Created: 2016-03-23 Last updated: 2016-04-01Bibliographically approved
Chen, H., Danielsson, M. & Xu, C. (2016). Size-dependent scanning parameters (kVp and mAs) for photon-counting spectral CT system in pediatric imaging: simulation study. Physics in Medicine and Biology, 61(11)
Open this publication in new window or tab >>Size-dependent scanning parameters (kVp and mAs) for photon-counting spectral CT system in pediatric imaging: simulation study
2016 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 61, no 11Article in journal (Refereed) Published
Abstract [en]

We are developing a photon-counting spectral CT detector with small pixel size of 0.40.5 mm2, o ering a potentialadvantage for better visualization of small structures in pediatric patients. The purpose of this study is to determinethe patient size dependent scanning parameters (kVp and mAs) for pediatric CT in two imaging cases: adipose imagingand iodinated blood imaging.Cylindrical soft-tissue phantoms of diameters between 10-25 cm were used to mimic patients of di erent ages from 0-15 y. For adipose imaging, a 5-mm-diameter adipose sphere was assumed as an imaging target, while an iodinated bloodsphere of 1 mm in diameter was assumed in the case of iodinated imaging. By applying the geometry of a commercial CTscanner (GE LightSpeed VCT), simulations were carried out to calculate the detectability index,d02, with tube potentialsvarying from 40 to 140 kVp. The optimal kVp for each phantom in each imaging case was determined such that the dose-normalized detectability index,d02=dose, is maximized. With the assumption that image quality in pediatric imagingis required the same as in typical adult imaging, the value of mAs at optimal kVp for each phantom was selected toachieve a reference detectability index that was obtained by scanning an adult phantom (30 cm in diameter) in a typicaladult CT procedure (120 kVp and 200 mAs) using a modeled energy-integrating system.For adipose imaging, the optimal kVps are 50, 60, 80, and 120 kVp, respectively, for phantoms of 10, 15, 20, and25-cm in diameter. The corresponding mAs values required to achieve the reference detectability index are only 9%,23%, 24%, and 54% of the mAs that is used for adult patients at 120 kVp, for 10, 15, 20, and 25-cm-diameter phantoms,respectively. In the case of iodinated imaging, a tube potential of 60 kVp was found optimal for all phantoms investigated,and the mAs values required to achieve the reference detectability index are 2%, 9%, 37%, and 109% of the adult mAs.The results also indicate that with the use of respective optimal kVps, the photon-counting spectral system o ers up to30% higherd02=dose than the modeled energy-integrating system for adipose imaging, and 70% for iodinated imaging.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2016
Keywords
photon counting, spectral CT, silicon-strip detector, pediatric imaging, detectability index
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-184605 (URN)10.1088/0031-9155/61/11/4105 (DOI)000377427700014 ()2-s2.0-84971515147 (Scopus ID)
Note

QC 20160706

Available from: 2016-04-01 Created: 2016-04-01 Last updated: 2017-11-30Bibliographically approved
Liu, X., Chen, H., Bornefalk, H., Danielsson, M., Karlsson, S., Persson, M., . . . Huber, B. (2015). Energy Calibration of a Silicon-Strip Detector for Photon-Counting Spectral CT by Direct Usage of the X-ray Tube Spectrum. IEEE Transactions on Nuclear Science, 62(1), 68-75
Open this publication in new window or tab >>Energy Calibration of a Silicon-Strip Detector for Photon-Counting Spectral CT by Direct Usage of the X-ray Tube Spectrum
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2015 (English)In: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 62, no 1, p. 68-75Article in journal (Refereed) Published
Abstract [en]

The variation among energy thresholds in a multibin detector for photon-counting spectral CT can lead to ring artefacts in the reconstructed images. Calibration of the energy thresholds can be used to achieve homogeneous threshold settings or to develop compensation methods to reduce the artefacts. We have developed an energy-calibrationmethod for the different comparator thresholds employed in a photon-counting silicon-strip detector. In our case, this corresponds to specifying the linear relation between the threshold positions in units of mV and the actual deposited photon energies in units of keV. This relation is determined by gain and offset values that differ for different detector channels due to variations in the manufacturing process. Typically, the calibration is accomplished by correlating the peak positions of obtained pulse-height spectra to known photon energies, e. g. with the aid of mono-energetic x rays from synchrotron radiation, radioactive isotopes or fluorescence materials. Instead of mono-energetic x rays, the calibrationmethod presented in this papermakes use of a broad x-ray spectrum provided by commercial x-ray tubes. Gain and offset as the calibration parameters are obtained by a regression analysis that adjusts a simulated spectrum of deposited energies to ameasured pulse-height spectrum. Besides the basic photon interactions such as Rayleigh scattering, Compton scattering and photo-electric absorption, the simulation takes into account the effect of pulse pileup, charge sharing and the electronic noise of the detector channels. We verify the method for different detector channels with the aid of a table-top setup, where we find the uncertainty of the keV-value of a calibrated threshold to be between 0.1 and 0.2 keV.

Keywords
Calibration, computed tomography, Monte-Carlo simulation, photon-counting, silicon-strip detector, spectral CT
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-161964 (URN)10.1109/TNS.2014.2373641 (DOI)000349672700008 ()2-s2.0-84923304829 (Scopus ID)
Note

QC 20150407

Available from: 2015-04-07 Created: 2015-03-20 Last updated: 2017-12-04Bibliographically approved
Liu, X., Chen, H., Bornefalk, H., Danielsson, M., Karlsson, S., Persson, M., . . . Huber, B. (2015). Modelling the channel-wise count response of a photon-counting spectral CT detector to a broad x-ray spectrum. In: Medical Imaging 2015: Physics of Medical Imaging: . Paper presented at Conference on Medical Imaging - Physics of Medical Imaging, FEB 22-25, 2015, Orlando, FL. , 9412, Article ID 941215.
Open this publication in new window or tab >>Modelling the channel-wise count response of a photon-counting spectral CT detector to a broad x-ray spectrum
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2015 (English)In: Medical Imaging 2015: Physics of Medical Imaging, 2015, Vol. 9412, article id 941215Conference paper, Published paper (Refereed)
Abstract [en]

Variations among detector channels in CT very sensitively lead to ring artefacts in the reconstructed images. For material decomposition in the projection domain, the variations can result in intolerable biases in the material line integral estimates. A typical way to overcome these effects is to apply calibration methods that try to unify spectral responses from different detector channels to an ideal response from a detector model. However, the calibration procedure can be rather complex and require excessive calibration measurements for a multitude of combinations of x-ray shapes, tissue combinations and thicknesses. In this paper, we propose a channel-wise model for a multibin photon-counting detector for spectral CT. Predictions of this channel-wise model match well with their physical performances, which can thus be used to eliminate ring artefacts in CT images and achieve projection-basis material decomposition. In an experimental validation, image data show significant improvement with respect to ring artefacts compared to images calibrated with flat-fielding data. Projection-based material decomposition gives basis material images showing good separation among individual materials and good quantification of iodine and gadolinium contrast agents. The work indicates that the channel-wise model can be used for quantitative CT with this detector.

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-170713 (URN)10.1117/12.2081776 (DOI)000355581700038 ()2-s2.0-84943327631 (Scopus ID)978-1-62841-502-5 (ISBN)
Conference
Conference on Medical Imaging - Physics of Medical Imaging, FEB 22-25, 2015, Orlando, FL
Note

QC 20150706

Available from: 2015-07-06 Created: 2015-07-03 Last updated: 2015-07-06Bibliographically approved
Chen, H., Xu, C., Persson, M. & Danielsson, M. (2015). Optimization Of Beam Quality For Photon-Counting Spectral Computed Tomography In Head Imaging: Simulation Study. Journal of Medical Imaging, 2(4), 043504-1-043504-16, Article ID 043504.
Open this publication in new window or tab >>Optimization Of Beam Quality For Photon-Counting Spectral Computed Tomography In Head Imaging: Simulation Study
2015 (English)In: Journal of Medical Imaging, ISSN 2329-4302, E-ISSN 2329-4310, Vol. 2, no 4, p. 043504-1-043504-16, article id 043504Article in journal (Refereed) Published
Abstract [en]

Head computed tomography (CT) plays an important role in the comprehensive evaluation of acutestroke. Photon-counting spectral detectors, as promising candidates for use in the next generation of x-ray CTsystems, allow for assigning more weight to low-energy x-rays that generally contain more contrast information.Most importantly, the spectral information can be utilized to decompose the original set of energy-selectiveimages into several basis function images that are inherently free of beam-hardening artifacts, a potential ad-vantage for further improving the diagnosis accuracy. We are developing a photon-counting spectral detector forCT applications. The purpose of this work is to determine the optimal beam quality for material decomposition intwo head imaging cases: nonenhanced imaging and K-edge imaging. A cylindrical brain tissue of 16-cm diam-eter, coated by a 6-mm-thick bone layer and 2-mm-thick skin layer, was used as a head phantom. The imagingtarget was a 5-mm-thick blood vessel centered in the head phantom. In K-edge imaging, two contrast agents,iodine and gadolinium, with the same concentration (5mg∕mL) were studied. Three parameters that affect beamquality were evaluated: kVp settings (50 to 130 kVp), filter materials (Z¼13to 83), and filter thicknesses [0 to 2half-value layer (HVL)]. The image qualities resulting from the varying x-ray beams were compared in terms oftwo figures of merit (FOMs): squared signal-difference-to-noise ratio normalized by brain dose (SDNR2∕BD) andthat normalized by skin dose (SDNR2∕SD). For nonenhanced imaging, the results show that the use of the 120-kVp spectrum filtered by 2 HVL copper (Z¼29) provides the best performance in both FOMs. When iodine isused in K-edge imaging, the optimal filter is 2 HVL iodine (Z¼53) and the optimal kVps are 60 kVp in terms ofSDNR2∕BD and 75 kVp in terms of SDNR2∕SD. A tradeoff of 65 kVp was proposed to lower the potential riskof skin injuries if a relatively long exposure time is necessarily performed in the iodinated imaging. In the case ofgadolinium imaging, both SD and BD can be minimized at 120 kVp filtered with 2 HVL thulium (Z¼69). Theresults also indicate that with the same concentration and their respective optimal spectrum, the values ofSDNR2∕BD and SDNR2∕SD in gadolinium imaging are, respectively, around 3 and 10 times larger thanthose in iodine imaging. However, since gadolinium is used in much lower concentrations than iodine in theclinic, iodine may be a preferable candidate for K-edge imaging.

Place, publisher, year, edition, pages
SPIE, 2015
Keywords
photon counting, spectral computed tomography, material decomposition, K-edge imaging
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:kth:diva-184602 (URN)10.1117/1.JMI.2.4.043504 (DOI)000374235100015 ()
Note

QC 20160401

Available from: 2016-04-01 Created: 2016-04-01 Last updated: 2017-11-30Bibliographically approved
Chen, H., Cederström, B., Xu, C., Persson, M., Karlsson, S. & Danielsson, M. (2014). A photon-counting silicon-strip detector for digital mammography with an ultrafast 0.18-mu m CMOS ASIC. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 749, 1-6
Open this publication in new window or tab >>A photon-counting silicon-strip detector for digital mammography with an ultrafast 0.18-mu m CMOS ASIC
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2014 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 749, p. 1-6Article in journal (Refereed) Published
Abstract [en]

We have evaluated a silicon-strip detector with a 0.18-mu m CMOS application specific integrated circuits (ASIC) containing 160 channels for use in photon-counting digital mammography. Measurements were performed at the Elettra light source using monochromatic X-ray beams with different energies and intensities. Energy resolution, Delta E/E-in, was measured to vary between 0.10 and 0.23 in the energy range of 15-40 keV. Pulse pileup has shown little effect on energy resolution.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Mammography, Charge sharing, ASIC, Energy resolution
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-145253 (URN)10.1016/j.nima.2014.02.033 (DOI)000334075000001 ()2-s2.0-84896521372 (Scopus ID)
Note

QC 20140516

Available from: 2014-05-16 Created: 2014-05-15 Last updated: 2017-12-05Bibliographically approved
Liu, X., Bornefalk, H., Chen, H., Danielsson, M., Karlsson, S., Persson, M., . . . Huber, B. (2014). A Silicon-Strip Detector for Photon-Counting Spectral CT: Energy Resolution From 40 keV to 120 keV. IEEE Transactions on Nuclear Science, 61(3), 1099-1105
Open this publication in new window or tab >>A Silicon-Strip Detector for Photon-Counting Spectral CT: Energy Resolution From 40 keV to 120 keV
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2014 (English)In: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 61, no 3, p. 1099-1105Article in journal (Refereed) Published
Abstract [en]

We are developing a segmented silicon-strip detector for spectral computed tomography. The detector operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we determine the energy resolution of a detector module using monoenergetic x-rays from 40 keV to 120 keV, provided at the European Synchrotron Radiation Facility, Grenoble. For each incident x-ray energy, pulse height spectra at different input photon fluxes are obtained. We investigate changes of the energy resolution due to charge sharing between pixels and pulse pileup. The different incident energies are used to channel-wise calibrate the pulse-height response in terms of signal gain and offset and to probe the homogeneity of the detector module. The detector shows a linear pulse-height response in the energy range from 40 keV to 120 keV. The gain variation among the channels is below 4%, whereas the variation of the offsets is on the order of 1 keV. We find an absolute energy resolution (sigma(E)) that degrades from 1.5 keV to 1.9 keV with increasing x-ray energy from 40 keV to 100 keV. With increasing input count rate, sigma(E) degrades by approximately 4 . 10(-3) keV Mcps(-1) mm(2), which is, within error bars, the same for the different energies. The effect of charge sharing on the width of the response peak is found to be negligible.

Keywords
Computed tomography, energy resolution, photon-counting, silicon strip detector, spectral CT
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-148323 (URN)10.1109/TNS.2014.2300153 (DOI)000337905600006 ()2-s2.0-84903277926 (Scopus ID)
Note

QC 20140807

Available from: 2014-08-07 Created: 2014-08-05 Last updated: 2017-12-05Bibliographically approved
Liu, X., Bornefalk, H., Chen, H., Danielsson, M., Karlsson, S., Persson, M., . . . Huber, B. (2014). Characterization of a silicon strip detector for photon-counting spectral CT using monoenergetic photons from 40 keV to 120 keV. In: Medical Imaging 2014: Physics of Medical Imaging. Paper presented at Medical Imaging 2014: Physics of Medical Imaging; San Diego, CA; United States; 17 February 2014 through 20 February 2014 (pp. 90333O). SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Characterization of a silicon strip detector for photon-counting spectral CT using monoenergetic photons from 40 keV to 120 keV
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2014 (English)In: Medical Imaging 2014: Physics of Medical Imaging, SPIE - International Society for Optical Engineering, 2014, p. 90333O-Conference paper, Published paper (Refereed)
Abstract [en]

Background: We are developing a segmented silicon strip detector that operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. In this work, we determine the energy resolution of the detector using monoenergetic x-ray radiation from 40 keV to 120 keV. We further investigate the effects of pulse pileup and charge sharing between detector channels that may lead to a decreased energy resolution. Methods: For each incident monochromatic x-ray energy, we obtain count spectra at different photon fluxes. These spectra corresponds to the pulse-height response of the detector and allow the determination of energy resolution and charge-sharing probability. The energy resolution, however, is influenced by signal pileup and charge sharing. Both effects are quantified using Monte Carlo simulations of the detector that aim to reproduce the conditions during the measurements. Results: The absolute energy resolution is found to increase from 1.7 to 2.1 keV for increasing energies 40 keV to 120 keV at the lowest measured photon flux. The effect of charge sharing is found to increase the absolute energy resolution by a factor of 1.025 at maximum. This increase is considered as negligibly small. The pileup of pulses leads to a deterioration rate of the energy resolution of 4 · 10-3 keV Mcps-1 mm2, corresponding to an increase of 0.04keV per 10 Mcps increase of the detected count rate.

Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2014
Series
Progress in Biomedical Optics and Imaging, ISSN 1605-7422 ; 9033
Keywords
energy resolution, photon counting, pulse pileup, silicon strip detector, spectral CT
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-146702 (URN)10.1117/12.2042862 (DOI)000338775800127 ()2-s2.0-84901611429 (Scopus ID)978-081949826-7 (ISBN)
Conference
Medical Imaging 2014: Physics of Medical Imaging; San Diego, CA; United States; 17 February 2014 through 20 February 2014
Note

QC 20140613

Available from: 2014-06-13 Created: 2014-06-13 Last updated: 2014-09-08Bibliographically approved
Persson, M., Huber, B., Karlsson, S., Liu, X., Chen, H., Xu, C., . . . Danielsson, M. (2014). Energy-resolved CT imaging with a photon-counting silicon-strip detector. Physics in Medicine and Biology, 59(22), 6709-6727
Open this publication in new window or tab >>Energy-resolved CT imaging with a photon-counting silicon-strip detector
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2014 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 59, no 22, p. 6709-6727Article in journal (Refereed) Published
Abstract [en]

Photon-counting detectors are promising candidates for use in the next generation of x-ray computed tomography (CT) scanners. Among the foreseen benefits are higher spatial resolution, better trade-off between noise and dose and energy discriminating capabilities. Silicon is an attractive detector material because of its low cost, mature manufacturing process and high hole mobility. However, it is sometimes overlooked for CT applications because of its low absorption efficiency and high fraction of Compton scatter. The purpose of this work is to demonstrate that silicon is a feasible material for CT detectors by showing energy-resolved CT images acquired with an 80 kVp x-ray tube spectrum using a photon-counting silicon-strip detector with eight energy thresholds developed in our group. We use a single detector module, consisting of a linear array of 50 0.5 x 0.4 mm detector elements, to image a phantom in a table-top lab setup. The phantom consists of a plastic cylinder with circular inserts containing water, fat and aqueous solutions of calcium, iodine and gadolinium, in different concentrations. By using basis material decomposition we obtain water, calcium, iodine and gadolinium basis images and demonstrate that these basis images can be used to separate the different materials in the inserts. We also show results showing that the detector has potential for quantitative measurements of substance concentrations.

Keywords
photon counting, spectral CT, material decomposition, siliconstrip detector
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-157026 (URN)000344091000005 ()2-s2.0-84908587151 (Scopus ID)
Note

QC 20141205

Available from: 2014-12-05 Created: 2014-12-04 Last updated: 2017-05-19Bibliographically approved
Persson, M., Huber, B., Karlsson, S., Liu, X., Chen, H., Xu, C., . . . Danielsson, M. (2014). Energy-resolved CT imaging with a photon-counting silicon-strip detector. In: Medical Imaging 2014: Physics of Medical Imaging. Paper presented at Medical Imaging 2014: Physics of Medical Imaging; San Diego, CA; United States; 17 February 2014 through 20 February 2014 (pp. 90333L). SPIE - International Society for Optical Engineering
Open this publication in new window or tab >>Energy-resolved CT imaging with a photon-counting silicon-strip detector
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2014 (English)In: Medical Imaging 2014: Physics of Medical Imaging, SPIE - International Society for Optical Engineering, 2014, p. 90333L-Conference paper, Published paper (Refereed)
Abstract [en]

Photon-counting detectors are promising candidates for use in the next generation of x-ray CT scanners. Among the foreseen benefits are higher spatial resolution, better trade-off between noise and dose, and energy discriminating capabilities. Silicon is an attractive detector material because of its low cost, mature manufacturing process and high hole mobility. However, it is sometimes claimed to be unsuitable for use in computed tomography because of its low absorption efficiency and high fraction of Compton scatter. The purpose of this work is to demonstrate that high-quality energy-resolved CT images can nonetheless be acquired with clinically realistic exposure parameters using a photon-counting silicon-strip detector with eight energy thresholds developed in our group. We use a single detector module, consisting of a linear array of 50 0.5 × 0.4 mm detector elements, to image a phantom in a table-top lab setup. The phantom consists of a plastic cylinder with circular inserts containing water, fat and aqueous solutions of calcium, iodine and gadolinium, in different concentrations. We use basis material decomposition to obtain water, calcium, iodine and gadolinium basis images and demonstrate that these basis images can be used to separate the different materials in the inserts. We also show results showing that the detector has potential for quantitative measurements of substance concentrations.

Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2014
Series
Progress in Biomedical Optics and Imaging, ISSN 1605-7422 ; 9033
Keywords
Computed tomography, material decomposition, material quantification, photon-counting, silicon-strip detector, spectral CT
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:kth:diva-146705 (URN)10.1117/12.2043519 (DOI)000338775800124 ()2-s2.0-84901628831 (Scopus ID)978-081949826-7 (ISBN)
Conference
Medical Imaging 2014: Physics of Medical Imaging; San Diego, CA; United States; 17 February 2014 through 20 February 2014
Note

QC 20140613

Available from: 2014-06-13 Created: 2014-06-13 Last updated: 2014-09-08Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8560-3262

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