Academic literature on the topic 'Dual energy cone beam CT'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Dual energy cone beam CT.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Dual energy cone beam CT"
Han, C., and J. Baek. "Dual‐energy approach to reduce cone‐beam artefacts in a circular orbit cone‐beam CT system." Electronics Letters 56, no. 13 (June 2020): 648–50. http://dx.doi.org/10.1049/el.2020.0544.
Full textAhn, Sohyun, Sam Ju Cho, Ki Chang Keum, Sang Gyu Choi, and Rena Lee. "Analysis of Beam Hardening of Modulation Layers for Dual Energy Cone-beam CT." Progress in Medical Physics 27, no. 1 (2016): 8. http://dx.doi.org/10.14316/pmp.2016.27.1.8.
Full textTang, Zhiwei, and Guangshu Hu. "Dual energy CT imaging in cone-beam micro-CT for improved attenuation coefficient measurement." Tsinghua Science and Technology 16, no. 4 (August 2011): 352–57. http://dx.doi.org/10.1016/s1007-0214(11)70051-7.
Full textSchröder, Lukas, Uros Stankovic, Simon Rit, and Jan-Jakob Sonke. "Image quality of dual-energy cone-beam CT with total nuclear variation regularization." Biomedical Physics & Engineering Express 8, no. 2 (February 4, 2022): 025012. http://dx.doi.org/10.1088/2057-1976/ac4e2e.
Full textSchyns, Lotte E. J. R., Isabel P. Almeida, Stefan J. van Hoof, Benedicte Descamps, Christian Vanhove, Guillaume Landry, Patrick V. Granton, and Frank Verhaegen. "Optimizing dual energy cone beam CT protocols for preclinical imaging and radiation research." British Journal of Radiology 90, no. 1069 (January 2017): 20160480. http://dx.doi.org/10.1259/bjr.20160480.
Full textGang, Grace J., Wojciech Zbijewski, J. Webster Stayman, and Jeffrey H. Siewerdsen. "Cascaded systems analysis of noise and detectability in dual-energy cone-beam CT." Medical Physics 39, no. 8 (July 31, 2012): 5145–56. http://dx.doi.org/10.1118/1.4736420.
Full textSkaarup, Mikkel, Jens M. Edmund, and Ivan Vogelius. "[P261] Image quality assessment of filtered dual energy cone beam CT for radiotherapy." Physica Medica 52 (August 2018): 174–75. http://dx.doi.org/10.1016/j.ejmp.2018.06.540.
Full textMen, Kuo, Jian-Rong Dai, Ming-Hui Li, Xin-Yuan Chen, Ke Zhang, Yuan Tian, Peng Huang, and Ying-Jie Xu. "A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique." BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/858907.
Full textGranton, P. V., S. I. Pollmann, N. L. Ford, M. Drangova, and D. W. Holdsworth. "Implementation of dual- and triple-energy cone-beam micro-CT for postreconstruction material decomposition." Medical Physics 35, no. 11 (October 16, 2008): 5030–42. http://dx.doi.org/10.1118/1.2987668.
Full textZbijewski, W., J. Stayman, Y. Ding, P. Prakash, A. Machado, J. Carrino, and J. Siewerdsen. "TU-G-110-02: Contrast-Enhanced Dual-Energy Cone-Beam CT for Musculoskeletal Radiology." Medical Physics 38, no. 6Part30 (June 2011): 3784. http://dx.doi.org/10.1118/1.3613243.
Full textDissertations / Theses on the topic "Dual energy cone beam CT"
Vilches, Freixas Gloria. "Dual-energy cone-beam CT for proton therapy." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI099/document.
Full textProton therapy is a promising radiation treatment modality that uses proton beams to treat cancer. Current treatment planning systems rely on an X-ray computed tomography (CT) image of the patient's anatomy to design the treatment plan. The proton stopping-power ratio relative to water (SPR) is derived from CT numbers (HU) to compute the absorbed dose in the patient. Protons are more vulnerable than photons to changes in tissue SPR in the beam direction caused by movement, misalignment or anatomical changes. In addition, inaccuracies arising from the planning CT and intrinsic to the HU-SPR conversion greatly contribute to the proton range uncertainty. In clinical practice, safety margins are added to the treatment volume to account for these uncertainties at the expense of losing organ-sparing capabilities. The use of dual-energy (DE) in proton therapy was first suggested in 2009 to better estimate the SPR with respect to single-energy X-ray imaging. The aim of this thesis work is to investigate the potential improvement in determining proton SPR using DE to reduce the uncertainty in predicting the proton range in the patient. This PhD work is applied to a new imaging device, the Imaging Ring (IR), which is a cone-beam CT (CBCT) scanner developed for image-guided radiotherapy (IGRT). The IR is equipped with a fast kV switching X-ray source, synchronized with a filter wheel, allowing for multi-energy CBCT imaging. The first contribution of this thesis is a method to calibrate a model for the X-ray source and the detector response to be used in X-ray image simulations. It has been validated experimentally on three CBCT scanners. Secondly, the investigations have evaluated the factors that have an impact on the outcome of the DE decomposition process, from the acquisition parameters to the post-processing. Both image- and projection-based decomposition domains have been thoroughly investigated, with special emphasis on projection-based approaches. Two novel DE decomposition bases have been proposed to estimate proton SPRs, without the need for an intermediate variable such as the effective atomic number. The last part of the thesis proposes an estimation of proton SPR maps of tissue characterization and anthropomorphic phantoms through DE-CBCT acquisitions with the IR. A correction for X-ray scattering has been implemented off-line, and a routine to linearly interpolate low-energy and high-energy sinograms from sequential and fast-switching DE acquisitions has been proposed to perform DE material decomposition in the projection domain with real data. DECT-derived SPR values have been compared with experimentally-determined SPR values in a carbon-ion beam
Dong, Xue. "Novel methods for scatter correction and dual energy imaging in cone-beam CT." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51903.
Full textCarlini, Gianluca. "Artefatti di ricostruzione nella tomografia computerizzata con raggi X." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16933/.
Full textJhan, Kai-Jie, and 詹凱傑. "Metal artifact reduction by dual-energy method in dental cone beam CT." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/x7hwu9.
Full text慈濟科技大學
放射醫學科學研究所
104
Abstract Purpose: The aim of this study was to improve metal artifact reduction by dual-energy method in cone-beam computed tomography (CBCT) Methods: We used Monte Carlo simulation software (GATE) to simulate CBCT system and cylindrical phantom. Virtual monochromatic CT (VMCT) based on the dual-energy technique was conducted to reduce metal artifacts in CBCT. A cylindrical phantom with 7 different rod inserts which simulates head set-ups was used to investigate the efficacy VMCT on improving the metal artifact of CBCT. Results: The results CNR showed a decline of as the energy ratio becomes better. Noise as the energy is increased and there is a tendency for improvement. % Diff affected artifacts at least 70 keV. Conclusions: Based on CNR, Noise, %Diff results, We suggest the best energy of 70keV. We have demonstrated the feasibility of improving the image quality by dual-energy method in cone-beam computed tomography (CBCT). Our research results should be able to provide a route to reach a high level of diagnostic image quality for CBCT imaging in Department of Dentistry.
Zhu, Jiahua. "Dual energy image reconstruction and systems for application in proton therapy treatment planning." Thesis, 2017. http://hdl.handle.net/2440/119696.
Full textThesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Physical Sciences, 2017.
Li, Hao. "Investigation of Imaging Capabilities for Dual Cone-Beam Computed Tomography." Diss., 2013. http://hdl.handle.net/10161/8062.
Full textA bench-top dual cone-beam computed tomography (CBCT) system was developed consisting of two orthogonally placed 40x30 cm
Compared with single CBCT, the DCBCT presented: 1) a decrease in uniformity by 1.9% in axial view and 1.1% in the longitudinal view, as averaged for four energies (80, 100, 125 and 150 kVp); 2) comparable or slightly better contrast to noise ratio (CNR) for low-contrast objects and comparable contrast for high-contrast objects; 3) comparable spatial resolution; 4) comparable CT number linearity with R
One of the major challenges for clinical implementation of four-dimensional (4D) CBCT is the long scan time. To investigate the 4D imaging capabilities of the DCBCT system, motion phantom studies were conducted to validate the efficiency by comparing 4D images generated from 4D-DCBCT and 4D-CBCT. First, a simple sinusoidal profile was used to confirm the scan time reduction. Next, both irregular sinusoidal and patient-derived profiles were used to investigate the advantage of temporally correlated orthogonal projections due to a reduced scan time. Normalized mutual information (NMI) between 4D-DCBCT and 4D-CBCT was used for quantitative evaluation.
For the simple sinusoidal profile, the average NMI for ten phases between two single 4D-CBCTs was 0.336, indicating the maximum NMI that can be achieved for this study. The average NMIs between 4D-DCBCT and each single 4D-CBCT were 0.331 and 0.320. For both irregular sinusoidal and patient-derived profiles, 4D-DCBCT generated phase images with less motion blurring when compared with single 4D-CBCT.
For dual kV energy imaging, we acquired 80kVp projections and 150 kVp projections, with an additional 0.8 mm tin filtration. The virtual monochromatic (VM) technique was implemented, by first decomposing these projections into acrylic and aluminum basis material projections to synthesize VM projections, which were then used to reconstruct VM CBCTs. The effect of the VM CBCT on metal artifact reduction was evaluated with an in-house titanium-BB phantom. The optimal VM energy to maximize CNR for iodine contrast and minimize beam hardening in VM CBCT was determined using a water phantom containing two iodine concentrations. The linearly-mixed (LM) technique was implemented by linearly combining the low- (80kVp) and high-energy (150kVp) CBCTs. The dose partitioning between low- and high-energy CBCTs was varied (20%, 40%, 60% and 80% for low-energy) while keeping total dose approximately equal to single-energy CBCTs, measured using an ion chamber. Noise levels and CNRs for four tissue types were investigated for dual-energy LM CBCTs in comparison with single-energy CBCTs at 80, 100, 125 and 150kVp.
The VM technique showed a substantial reduction of metal artifacts at 100 keV with a 40% reduction in the background standard deviation compared with a 125 kVp single-energy scan of equal dose. The VM energy to maximize CNR for both iodine concentrations and minimize beam hardening in the metal-free object was 50 keV and 60 keV, respectively. The difference in average noise levels measured in the phantom background was 1.2% for dual-energy LM CBCTs and equivalent-dose single-energy CBCTs. CNR values in the LM CBCTs of any dose partitioning were better than those of 150 kVp single-energy CBCTs. The average CNRs for four tissue types with 80% dose fraction at low-energy showed 9.0% and 4.1% improvement relative to 100 kVp and 125 kVp single-energy CBCTs, respectively. CNRs for low contrast objects improved as dose partitioning was more heavily weighted towards low-energy (80kVp) for LM CBCTs.
For application of the dual-energy technique in the kilovoltage (kV) and megavoltage (MV) range, we acquired both MV projections (from gantry angle of 0° to 100°) and kV projections (90° to 200°) with the current orthogonal kV/MV imaging hardware equipped in modern linear accelerators, as gantry rotated a total of 110°. A selected range of overlap projections between 90° to 100° were then decomposed into two material projections using experimentally determined parameters from orthogonally stacked aluminum and acrylic step-wedges. Given attenuation coefficients of aluminum and acrylic at a predetermined energy, one set of VM projections could be synthesized from two corresponding sets of decomposed projections. Two linear functions were generated using projection information at overlap angles to convert kV and MV projections at non-overlap angles to approximate VM projections for CBCT reconstruction. The CNRs were calculated for different inserts in VM CBCTs of a CatPhan phantom with various selected energies and compared with those in kV and MV CBCTs. The effect of overlap projection number on CNR was evaluated. Additionally, the effect of beam orientation was studied by scanning the CatPhan sandwiched with two 5 cm solid-water phantoms on both lateral sides and an electronic density phantom with two metal bolt inserts.
Proper selection of VM energy (30keV and 40keV for low-density polyethylene (LDPE), polymethylpentene (PMP), 2MeV for Delrin) provided comparable or even better CNR results as compared with kV or MV CBCT. An increased number of overlap between kV and MV projections demonstrated only marginal improvements of CNR for different inserts (with the exception of LDPE) and therefore one projection overlap was found to be sufficient for the CatPhan study. It was also evident that the optimal CBCT image quality was achieved when MV beams penetrated through the heavy attenuation direction of the object.
In conclusion, the performance of a bench-top DCBCT imaging system has been characterized and is comparable to that of a single CBCT. The 4D-DCBCT provides an efficient 4D imaging technique for motion management. The scan time is reduced by approximately a factor of two. The temporally correlated orthogonal projections improved the image blur across 4D phase images. Dual-energy CBCT imaging techniques were implemented to synthesize VM CBCT and LM CBCTs. VM CBCT was effective at achieving metal artifact reduction. Depending on the dose-partitioning scheme, LM CBCT demonstrated the potential to improve CNR for low contrast objects compared with single-energy CBCT acquired with equivalent dose. A novel technique was developed to generate VM CBCTs from kV/MV projections. This technique has the potential to improve CNR at selected VM energies and to suppress artifacts at appropriate beam orientations.
Dissertation
Giles, William. "Cross-Scatter in Dual-Cone X-ray Imaging: Magnitude, Avoidance, Correction, and Artifact Reduction." Diss., 2012. http://hdl.handle.net/10161/5794.
Full textOnboard cone beam computed tomography (CBCT) has become a widespread means of three-dimensional target localization for radiation therapy; however, it is susceptible to metal artifacts and beam-hardening artifacts that can hinder visualization of low contrast anatomy. Dual-CBCT provides easy access to techniques that may reduces such artifacts. Additionally, dual-CBCT can decrease imaging time and provide simultaneous orthogonal projections which may also be useful for fast target localization. However, dual-CBCT will suffer from large increases in scattered radiation due to the addition of the second source.
An experimental bench top dual CBCT system was constructed so that each imaging chain in the dual CBCT system mimics the geometry of gantry-mounted CBCT systems commonly used in the radiation therapy room. The two systems share a common axis of rotation and are mounted orthogonally. Custom control software was developed to ensure reproducible exposure and rotation timings. This software allows the implementation of the acquisition sequences required for the cross scatter avoidance and correction strategies studied.
Utilizing the experimental dual CBCT system cross scatter was characterized from 70-145 kVp in projections and reconstructed images using this system and three cylindrical phantoms (15cm, 20cm, and 30cm) with a common Catphan core. A novel strategy for avoiding cross-scatter in dual-CBCT was developed that utilized interleaved data acquisition on each imaging chain. Contrast and contrast-to-noise-ratio were measured in reconstructions to evaluate the effectiveness of this strategy to avoid the effects of cross scatter.
A novel correction strategy for cross scatter was developed wherein the cross scatter was regularly sampled during the course of data acquisition and these samples were used as the basis for low- and high- frequency corrections for the cross-scatter in projections. The cross scatter sampling interval was determined for an anthropomorphic phantom at three different sites relevant to radiation therapy by estimating the angular Nyquist frequency. The low frequency portion of the cross scatter distribution is interpolated between samples to provide an estimate of the cross scatter distribution at every projection angle and was then subtracted from the projections.
The high-frequency portion of the correction was applied after the low-frequency correction was applied. The novel high-frequency correction utilizes the fact that a direct estimate of the high-frequency components was obtained in the cross scatter samples. The high-frequency components of the measured cross scatter were subtracted from the projections in the Fourier domain, a process referred to as spectral subtraction. Each projection is corrected using the cross scatter sample taken at the closest projection angle. In order to apply this correction in the Fourier domain the high-frequency component of the cross scatter must be approximately stationary. To improve the stationarity of the high-frequency cross scatter component a novel two-dimensional, overlapping window was developed. The spectral subtraction was then applied in each window and the results added to form the final image.
The effectiveness of the correction techniques were evaluated by measuring the contrast and contrast-to-noise-ratio in an image quality phantom. Additionally, the effect of the high-frequency correction on resolution was measured using a line pair phantom.
Cross scatter in dual CBCT was shown for large phantoms to be much higher than forward scatter which has long been known to be one of the largest degrading factors of image quality in CBCT. This results in large losses of contrast and CNR in reconstructed images. The interleaving strategy for avoiding cross scatter during projection acquisition showed similar performance to cross scatter free acquisitions, however, does not acquire projections at the maximum possible rate. For those applications in which maximizing the acquisition rate of projections is important, the low- and high-frequency corrections effectively mitigated the effects of cross scatter in the dual CBCT system.
Dissertation
Book chapters on the topic "Dual energy cone beam CT"
Kamarianakis, Zacharias, D. Soimu, K. Bliznakova, and N. Pallikarakis. "Microcalcification Detection using Digital Tomosynthesis, Dual Energy Mammography and Cone Beam Computed Tomography: A Comparative Study." In IFMBE Proceedings, 660–63. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-89208-3_157.
Full textConference papers on the topic "Dual energy cone beam CT"
Fang, Chengyijue, Gongming Xu, and Lei Zhu. "Single scan dual energy cone beam CT using a rotating filter." In Physics of Medical Imaging, edited by Hilde Bosmans and Guang-Hong Chen. SPIE, 2020. http://dx.doi.org/10.1117/12.2549498.
Full textCho, Seungryong, Emil Sidky, Junguo Bian, and Xiaochuan Pan. "Dual-energy cone-beam micro-CT for animal imaging: preliminary study." In Medical Imaging, edited by Jiang Hsieh and Michael J. Flynn. SPIE, 2007. http://dx.doi.org/10.1117/12.713243.
Full textJiang, Xiao, Hehe Cui, Zihao Liu, and Lei Zhu. "Residual W-shape network (ResWnet) for dual-energy cone-beam CT imaging." In Seventh International Conference on Image Formation in X-Ray Computed Tomography (ICIFXCT 2022), edited by Joseph Webster Stayman. SPIE, 2022. http://dx.doi.org/10.1117/12.2646505.
Full textMaass, Clemens, Rainer Grimmer, and Marc Kachelrieß. "Material decomposition with inconsistent rays (MDIR) for cone-beam dual energy CT." In SPIE Medical Imaging. SPIE, 2010. http://dx.doi.org/10.1117/12.844546.
Full textZbijewski, W., G. Gang, A. S. Wang, J. W. Stayman, K. Taguchi, J. A. Carrino, and J. H. Siewerdsen. "Noise reduction in material decomposition for low-dose dual-energy cone-beam CT." In SPIE Medical Imaging, edited by Robert M. Nishikawa and Bruce R. Whiting. SPIE, 2013. http://dx.doi.org/10.1117/12.2008431.
Full textMin, Jonghwan, Taewon Lee, Kyong-Woo Kim, Gyuseong Cho, and Seungryong Cho. "Low-dose dual-energy cone-beam CT using a total-variation minimization algorithm." In SPIE Medical Imaging, edited by Norbert J. Pelc, Ehsan Samei, and Robert M. Nishikawa. SPIE, 2011. http://dx.doi.org/10.1117/12.877914.
Full textZavala-Mondragon, Luis A., Fons van der Sommen, Danny Ruijters, Klaus J. Engel, Heidrun Steinhauser, and Peter H. N. de With. "Robust Algorithm for Denoising of Photon-Limited Dual-Energy Cone Beam CT Projections." In 2020 IEEE 17th International Symposium on Biomedical Imaging (ISBI). IEEE, 2020. http://dx.doi.org/10.1109/isbi45749.2020.9098442.
Full textLiu, Stephen Z., Magdalena Herbst, Thomas Weber, Sebastian Vogt, Ludwig Ritschl, Steffen Kappler, Jeffrey H. Siewerdsen, and Wojciech Zbijewski. "Dual-energy cone-beam CT with three-material decomposition for bone marrow edema imaging." In Seventh International Conference on Image Formation in X-Ray Computed Tomography (ICIFXCT 2022), edited by Joseph Webster Stayman. SPIE, 2022. http://dx.doi.org/10.1117/12.2646391.
Full textWang, Zhilei, Hao Zhou, Shan Gu, and Hewei Gao. "Dual-energy head cone-beam CT using a dual-layer flat-panel detector: physics-based material decomposition." In Seventh International Conference on Image Formation in X-Ray Computed Tomography (ICIFXCT 2022), edited by Joseph Webster Stayman. SPIE, 2022. http://dx.doi.org/10.1117/12.2647334.
Full textLiu, Stephen Z., Chumin Zhao, Magdalena Herbst, Thomas Weber, Sebastian Vogt, Ludwig Ritschl, Steffen Kappler, Jeffrey H. Siewerdsen, and Wojciech Zbijewski. "Feasibility of dual-energy cone-beam CT of bone marrow edema using dual-layer flat panel detectors." In Physics of Medical Imaging, edited by Wei Zhao and Lifeng Yu. SPIE, 2022. http://dx.doi.org/10.1117/12.2613211.
Full text