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132 results on '"Schilham, Arnold M. R."'

7. Computed tomography-based calcium scoring in cadaver leg arteries: Influence of dose, reader, and reconstruction algorithm

Author

Anatomie, Fysica Radiologie, Cancer, Beeldverwerking ISI, Brain, Circulatory Health, Researchgr. Systems Radiology, Infection & Immunity, Regenerative Medicine and Stem Cells, Arts-assistenten Radiologie, Onderzoek Beeld, Structure and Connections, de Jong, Daan J, van der Star, Simone, Bleys, Ronald L A W, Schilham, Arnold M R, Kuijf, Hugo J, de Jong, Pim A, Kok, Madeleine, Anatomie, Fysica Radiologie, Cancer, Beeldverwerking ISI, Brain, Circulatory Health, Researchgr. Systems Radiology, Infection & Immunity, Regenerative Medicine and Stem Cells, Arts-assistenten Radiologie, Onderzoek Beeld, Structure and Connections, de Jong, Daan J, van der Star, Simone, Bleys, Ronald L A W, Schilham, Arnold M R, Kuijf, Hugo J, de Jong, Pim A, and Kok, Madeleine

Published
2022

17. Radiation dose reduction for CT assessment of urolithiasis using iterative reconstruction : A prospective intra-individual study

Author

den Harder, Annemarie M, Willemink, Martin J, van Doormaal, Pieter J, Wessels, Frank J, Lock, M T W T, Schilham, Arnold M R, Budde, Ricardo P J, Leiner, Tim, de Jong, Pim A, den Harder, Annemarie M, Willemink, Martin J, van Doormaal, Pieter J, Wessels, Frank J, Lock, M T W T, Schilham, Arnold M R, Budde, Ricardo P J, Leiner, Tim, and de Jong, Pim A

Published
2018

18. Emphysema quantification using chest CT : influence of radiation dose reduction and reconstruction technique

Author

den Harder, Annemarie M, de Boer, Erwin, Lagerweij, Suzanne J, Boomsma, Martijn F, Schilham, Arnold M R, Willemink, Martin J, Milles, Julien, Leiner, Tim, Budde, Ricardo P J, de Jong, Pim A, den Harder, Annemarie M, de Boer, Erwin, Lagerweij, Suzanne J, Boomsma, Martijn F, Schilham, Arnold M R, Willemink, Martin J, Milles, Julien, Leiner, Tim, Budde, Ricardo P J, and de Jong, Pim A

Published
2018

19. Emphysema quantification using chest CT: influence of radiation dose reduction and reconstruction technique

Author

Researchgr. Systems Radiology, Circulatory Health, Fysica Radiologie, Cancer, Arts-assistenten Radiologie, Researchgr. Cardiovasculaire Radiologie, Infection & Immunity, den Harder, Annemarie M, de Boer, Erwin, Lagerweij, Suzanne J, Boomsma, Martijn F, Schilham, Arnold M R, Willemink, Martin J, Milles, Julien, Leiner, Tim, Budde, Ricardo P J, de Jong, Pim A, Researchgr. Systems Radiology, Circulatory Health, Fysica Radiologie, Cancer, Arts-assistenten Radiologie, Researchgr. Cardiovasculaire Radiologie, Infection & Immunity, den Harder, Annemarie M, de Boer, Erwin, Lagerweij, Suzanne J, Boomsma, Martijn F, Schilham, Arnold M R, Willemink, Martin J, Milles, Julien, Leiner, Tim, Budde, Ricardo P J, and de Jong, Pim A

Published
2018

24. Aortic Valve and Thoracic Aortic Calcification Measurements : How Low Can We Go in Radiation Dose?

Author

van Hamersvelt, Robbert Willem, den Harder, Annemarie M, Willemink, Martin J, Schilham, Arnold M R, Lammers, Jan-Willem J, Nathoe, Hendrik M, Budde, Ricardo P J, Leiner, Tim, de Jong, Pim A, van Hamersvelt, Robbert Willem, den Harder, Annemarie M, Willemink, Martin J, Schilham, Arnold M R, Lammers, Jan-Willem J, Nathoe, Hendrik M, Budde, Ricardo P J, Leiner, Tim, and de Jong, Pim A

Published
2017

25. Accuracy of bone mineral density quantification using dual-layer spectral detector CT: a phantom study

Author

Beeldverwerking ISI, Circulatory Health, Fysica Radiologie, Cancer, Researchgr. Cardiovasculaire Radiologie, MS Radiologie, Researchgr. Systems Radiology, Arts-assistenten Radiologie, van Hamersvelt, Robbert W, Schilham, Arnold M R, Engelke, Klaus, den Harder, Annemarie M, de Keizer, Bart, Verhaar, Harald J, Leiner, Tim, de Jong, Pim A, Willemink, Martin J, Beeldverwerking ISI, Circulatory Health, Fysica Radiologie, Cancer, Researchgr. Cardiovasculaire Radiologie, MS Radiologie, Researchgr. Systems Radiology, Arts-assistenten Radiologie, van Hamersvelt, Robbert W, Schilham, Arnold M R, Engelke, Klaus, den Harder, Annemarie M, de Keizer, Bart, Verhaar, Harald J, Leiner, Tim, de Jong, Pim A, and Willemink, Martin J

Published
2017

26. Radiation dose reduction in pediatric great vessel stent computed tomography using iterative reconstruction: A phantom study

Author

Researchgr. Cardiovasculaire Radiologie, Circulatory Health, Onderzoek Beeld, MS Radiologie, Researchgr. Systems Radiology, Fysica Radiologie, Cancer, Cardiologie onderzoek 1, Regenerative Medicine and Stem Cells, Child Health, den Harder, Annemarie M, Suchá, Dominika, van Doormaal, Pieter J, Budde, Ricardo P J, de Jong, Pim A, Schilham, Arnold M R, Breur, JMPJ, Leiner, Tim, Researchgr. Cardiovasculaire Radiologie, Circulatory Health, Onderzoek Beeld, MS Radiologie, Researchgr. Systems Radiology, Fysica Radiologie, Cancer, Cardiologie onderzoek 1, Regenerative Medicine and Stem Cells, Child Health, den Harder, Annemarie M, Suchá, Dominika, van Doormaal, Pieter J, Budde, Ricardo P J, de Jong, Pim A, Schilham, Arnold M R, Breur, JMPJ, and Leiner, Tim

Published
2017

27. Aortic Valve and Thoracic Aortic Calcification Measurements: How Low Can We Go in Radiation Dose?

Author

Beeldverwerking ISI, Circulatory Health, Researchgr. Cardiovasculaire Radiologie, Onderzoek Beeld, Arts-assistenten Radiologie, Fysica Radiologie, Cancer, Infection & Immunity, Cardiologie, Team Medisch, MS Radiologie, Researchgr. Systems Radiology, van Hamersvelt, Robbert Willem, den Harder, Annemarie M, Willemink, Martin J, Schilham, Arnold M R, Lammers, Jan-Willem J, Nathoe, Hendrik M, Budde, Ricardo P J, Leiner, Tim, de Jong, Pim A, Beeldverwerking ISI, Circulatory Health, Researchgr. Cardiovasculaire Radiologie, Onderzoek Beeld, Arts-assistenten Radiologie, Fysica Radiologie, Cancer, Infection & Immunity, Cardiologie, Team Medisch, MS Radiologie, Researchgr. Systems Radiology, van Hamersvelt, Robbert Willem, den Harder, Annemarie M, Willemink, Martin J, Schilham, Arnold M R, Lammers, Jan-Willem J, Nathoe, Hendrik M, Budde, Ricardo P J, Leiner, Tim, and de Jong, Pim A

Published
2017

29. Pulmonary nodule volumetry at different low computed tomography radiation dose levels with hybrid and model-based iterative reconstruction : A within patient analysis

Author

Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, EPA, Schilham, Arnold M R, Lammers, Jan Willem J, Luijk, Bart, Budde, Ricardo P J, Leiner, Tim, De Jong, Pim A., Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, EPA, Schilham, Arnold M R, Lammers, Jan Willem J, Luijk, Bart, Budde, Ricardo P J, Leiner, Tim, and De Jong, Pim A.

Published
2016

30. Finding the optimal dose reduction and iterative reconstruction level for coronary calcium scoring

Author

Willemink, Martin J., den Harder, Annemarie M., Foppen, Wouter, Schilham, Arnold M R, Rienks, R, Laufer, Ward, Nieman, Koen, de Jong, Pim A., Budde, Ricardo P J, Nathoe, Hendrik M., Leiner, Tim, Willemink, Martin J., den Harder, Annemarie M., Foppen, Wouter, Schilham, Arnold M R, Rienks, R, Laufer, Ward, Nieman, Koen, de Jong, Pim A., Budde, Ricardo P J, Nathoe, Hendrik M., and Leiner, Tim

Published
2016

31. Effect of radiation dose reduction and iterative reconstruction on computer-aided detection of pulmonary nodules : Intra-individual comparison

Author

Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, Evert-Jan P A, Milles, Julien, Schilham, Arnold M R, Lammers, Jan Willem, De Jong, Pim A., Leiner, Tim, Budde, Ricardo P J, Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, Evert-Jan P A, Milles, Julien, Schilham, Arnold M R, Lammers, Jan Willem, De Jong, Pim A., Leiner, Tim, and Budde, Ricardo P J

Published
2016

32. Finding the optimal dose reduction and iterative reconstruction level for coronary calcium scoring

Author

Circulatory Health, Onderzoek Beeld, Researchgr. Cardiovasculaire Radiologie, Arts-assistenten Radiologie, Radiologie, Fysica Radiologie, Cardiologie, Aios en Stafsecr. Cardiologie, MS Radiologie, Cardiovasculaire Immunologie, Willemink, Martin J., den Harder, Annemarie M., Foppen, Wouter, Schilham, Arnold M R, Rienks, R, Laufer, Ward, Nieman, Koen, de Jong, Pim A., Budde, Ricardo P J, Nathoe, Hendrik M., Leiner, Tim, Circulatory Health, Onderzoek Beeld, Researchgr. Cardiovasculaire Radiologie, Arts-assistenten Radiologie, Radiologie, Fysica Radiologie, Cardiologie, Aios en Stafsecr. Cardiologie, MS Radiologie, Cardiovasculaire Immunologie, Willemink, Martin J., den Harder, Annemarie M., Foppen, Wouter, Schilham, Arnold M R, Rienks, R, Laufer, Ward, Nieman, Koen, de Jong, Pim A., Budde, Ricardo P J, Nathoe, Hendrik M., and Leiner, Tim

Published
2016

33. Submillisievert coronary calcium quantification using model-based iterative reconstruction: A within-patient analysis

Author

Circulatory Health, Researchgr. Cardiovasculaire Radiologie, Beeldverwerking ISI, Arts-assistenten Radiologie, Fysica Radiologie, Researchgr. Systems Radiology, MS Radiologie, Cardiologie, Brain, den Harder, Annemarie M, Wolterink, Jelmer M, Willemink, Martin J, Schilham, Arnold M R, de Jong, Pim A, Budde, Ricardo P J, Nathoe, Hendrik M, Išgum, Ivana, Leiner, Tim, Circulatory Health, Researchgr. Cardiovasculaire Radiologie, Beeldverwerking ISI, Arts-assistenten Radiologie, Fysica Radiologie, Researchgr. Systems Radiology, MS Radiologie, Cardiologie, Brain, den Harder, Annemarie M, Wolterink, Jelmer M, Willemink, Martin J, Schilham, Arnold M R, de Jong, Pim A, Budde, Ricardo P J, Nathoe, Hendrik M, Išgum, Ivana, and Leiner, Tim

Published
2016

34. Pulmonary nodule volumetry at different low computed tomography radiation dose levels with hybrid and model-based iterative reconstruction: A within patient analysis

Author

Onderzoek Beeld, Circulatory Health, Researchgr. Cardiovasculaire Radiologie, Arts-assistenten Radiologie, Beeldverwerking ISI, MS Radiologie, Fysica Radiologie, Infection & Immunity, Longziekten, Researchgr. Systems Radiology, Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, EPA, Schilham, Arnold M R, Lammers, Jan Willem J, Luijk, Bart, Budde, Ricardo P J, Leiner, Tim, De Jong, Pim A., Onderzoek Beeld, Circulatory Health, Researchgr. Cardiovasculaire Radiologie, Arts-assistenten Radiologie, Beeldverwerking ISI, MS Radiologie, Fysica Radiologie, Infection & Immunity, Longziekten, Researchgr. Systems Radiology, Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, EPA, Schilham, Arnold M R, Lammers, Jan Willem J, Luijk, Bart, Budde, Ricardo P J, Leiner, Tim, and De Jong, Pim A.

Published
2016

35. Effect of radiation dose reduction and iterative reconstruction on computer-aided detection of pulmonary nodules: Intra-individual comparison

Author

Onderzoek Beeld, Circulatory Health, Arts-assistenten Radiologie, Beeldverwerking ISI, MS Radiologie, Fysica Radiologie, Longziekten, Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, Evert-Jan P A, Milles, Julien, Schilham, Arnold M R, Lammers, Jan Willem, De Jong, Pim A., Leiner, Tim, Budde, Ricardo P J, Onderzoek Beeld, Circulatory Health, Arts-assistenten Radiologie, Beeldverwerking ISI, MS Radiologie, Fysica Radiologie, Longziekten, Den Harder, Annemarie M., Willemink, Martin J., Van Hamersvelt, Robbert W., Vonken, Evert-Jan P A, Milles, Julien, Schilham, Arnold M R, Lammers, Jan Willem, De Jong, Pim A., Leiner, Tim, and Budde, Ricardo P J

Published
2016

37. Image quality of conventional images of dual‐layer SPECTRAL CT: A phantom study.

Author

van Ommen, Fasco, Bennink, Edwin, Vlassenbroek, Alain, Dankbaar, Jan Willem, Schilham, Arnold M. R., Viergever, Max A., and de Jong, Hugo W. A. M.

Subjects
IMAGE quality analysis, TOMOGRAPHY image quality, STANDARD deviations, TRANSFER functions, PHOTONS
Abstract

Purpose: Spectral CT using a dual layer detector offers the possibility of retrospectively introducing spectral information to conventional CT images. In theory, the dual‐layer technology should not come with a dose or image quality penalty for conventional images. In this study, we evaluate the influence of a dual‐layer detector (IQon Spectral CT, Philips Healthcare) on the image quality of conventional CT images, by comparing these images with those of a conventional but otherwise technically comparable single‐layer CT scanner (Brilliance iCT, Philips Healthcare), by means of phantom experiments. Methods: For both CT scanners, conventional CT images were acquired using four adult scanning protocols: (a) body helical, (b) body axial, (c) head helical, and (d) head axial. A CATPHAN 600 phantom was scanned to conduct an assessment of image quality metrics at equivalent (CTDI) dose levels. Noise was characterized by means of noise power spectra (NPS) and standard deviation (SD) of a uniform region, and spatial resolution was evaluated with modulation transfer functions (MTF) of a tungsten wire. In addition, contrast‐to‐noise ratio (CNR), image uniformity, CT number linearity, slice thickness, slice spacing, and spatial linearity were measured and evaluated. Additional measurements of CNR, resolution and noise were performed in two larger phantoms. Results: The resolution levels at 50%, 10%, and 5% MTF of the iCT and IQon showed small, but significant differences up to 0.25 lp/cm for body scans, and up to 0.2 lp/cm for head scans in favor of the IQon. The iCT and IQon showed perfect CT linearity for body scans, but for head scans both scanners showed an underestimation of the CT numbers of materials with a high opacity. Slice thickness was slightly overestimated for both scanners. Slice spacing was comparable and reconstructed correctly. In addition, spatial linearity was excellent for both scanners, with a maximum error of 0.11 mm. CNR was higher on the IQon compared to the iCT for both normal and larger phantoms with differences up to 0.51. Spatial resolution did not change with phantom size, but noise levels increased significantly. For head scans, IQon had a noise level that was significantly lower than the iCT, on the other hand IQon showed noise levels significantly higher than the iCT for body scans. Still, these differences were well within the specified range of performance of iCT scanners. Conclusions: At equivalent dose levels, this study showed similar quality of conventional images acquired on iCT and IQon for medium‐sized phantoms and slightly degraded image quality for (very) large phantoms at lower tube voltages on the IQon. Accordingly, it may be concluded that the introduction of a dual‐layer detector neither compromises image quality of conventional images nor increases radiation dose for normal‐sized patients, and slightly degrades dose efficiency for large patients at 120 kVp and lower tube voltages. [ABSTRACT FROM AUTHOR]

Published
2018
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40. Hybrid and Model-Based Iterative Reconstruction Techniques for Pediatric CT

Author

Onderzoek Beeld, Arts-assistenten Radiologie, MS Radiologie, Fysica Radiologie, den Harder, Annemarie M., Willemink, Martin J., Budde, Ricardo P. J., Schilham, Arnold M. R., Leiner, Tim, de Jong, Pim A., Onderzoek Beeld, Arts-assistenten Radiologie, MS Radiologie, Fysica Radiologie, den Harder, Annemarie M., Willemink, Martin J., Budde, Ricardo P. J., Schilham, Arnold M. R., Leiner, Tim, and de Jong, Pim A.

Published
2015

41. Achievable dose reduction using iterative reconstruction for chest computed tomography: A systematic review

Author

Onderzoek Beeld, Researchgr. Cardiovasculaire Radiologie, Arts-assistenten Radiologie, Radiologie, Zorgeenheid Vaatchirurgie Medisch, Fysica Radiologie, MS Radiologie, Researchgr. Systems Radiology, den Harder, Annemarie, Willemink, Martin J., De Ruiter, Quirina M B, Schilham, Arnold M R, Krestin, Gabriel P., Leiner, Tim, de Jong, Pim A., Budde, Ricardo P J, Onderzoek Beeld, Researchgr. Cardiovasculaire Radiologie, Arts-assistenten Radiologie, Radiologie, Zorgeenheid Vaatchirurgie Medisch, Fysica Radiologie, MS Radiologie, Researchgr. Systems Radiology, den Harder, Annemarie, Willemink, Martin J., De Ruiter, Quirina M B, Schilham, Arnold M R, Krestin, Gabriel P., Leiner, Tim, de Jong, Pim A., and Budde, Ricardo P J

Published
2015

43. Radiation dose reduction for CT assessment of urolithiasis using iterative reconstruction: A prospective intra-individual study.

Author

den Harder, Annemarie M., Willemink, Martin J., van Doormaal, Pieter J., Wessels, Frank J., Lock, M. T. W. T., Schilham, Arnold M. R., Budde, Ricardo P. J., Leiner, Tim, and de Jong, Pim A.

Subjects
RADIATION doses, URINARY calculi, COMPUTED tomography, ULTRASONIC imaging, UROLOGY, DIAGNOSIS, SOCIETIES, ALGORITHMS, DIAGNOSTIC imaging, DIGITAL image processing, LONGITUDINAL method, COMPUTERS in medicine, URINARY organs
Abstract

Objective: To assess the performance of hybrid (HIR) and model-based iterative reconstruction (MIR) in patients with urolithiasis at reduced-dose computed tomography (CT).Methods: Twenty patients scheduled for unenhanced abdominal CT for follow-up of urolithiasis were prospectively included. Routine dose acquisition was followed by three low-dose acquisitions at 40%, 60% and 80% reduced doses. All images were reconstructed with filtered back projection (FBP), HIR and MIR. Urolithiasis detection rates, gall bladder, appendix and rectosigmoid evaluation and overall subjective image quality were evaluated by two observers.Results: 74 stones were present in 17 patients. Half the stones were not detected on FBP at the lowest dose level, but this improved with MIR to a sensitivity of 100%. HIR resulted in a slight decrease in sensitivity at the lowest dose to 72%, but outperformed FBP. Evaluation of other structures with HIR at 40% and with MIR at 60% dose reductions was comparable to FBP at routine dose, but 80% dose reduction resulted in non-evaluable images.Conclusions: CT radiation dose for urolithiasis detection can be safely reduced by 40 (HIR)-60 (MIR) % without affecting assessment of urolithiasis, possible extra-urinary tract pathology or overall image quality.Key Points: • Iterative reconstruction can be used to substantially lower the radiation dose. • This allows for radiation reduction without affecting sensitivity of stone detection. • Possible extra-urinary tract pathology evaluation is feasible at 40-60% reduced dose. [ABSTRACT FROM AUTHOR]

Published
2018
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44. Accuracy of bone mineral density quantification using dual-layer spectral detector CT: a phantom study.

Author

Hamersvelt, Robbert, Schilham, Arnold, Engelke, Klaus, Harder, Annemarie, Keizer, Bart, Verhaar, Harald, Leiner, Tim, Jong, Pim, Willemink, Martin, van Hamersvelt, Robbert W, Schilham, Arnold M R, den Harder, Annemarie M, de Keizer, Bart, Verhaar, Harald J, de Jong, Pim A, and Willemink, Martin J

Subjects
BONE density, COMPUTED tomography, MEDICAL protocols, HYDROXYAPATITE, DUAL-energy X-ray absorptiometry, THERAPEUTICS
Abstract

Objectives: To investigate the accuracy of bone mineral density (BMD) quantification using dual-layer spectral detector CT (SDCT) at various scan protocols.Methods: Two validated anthropomorphic phantoms containing inserts of 50-200 mg/cm3 calcium hydroxyapatite (HA) were scanned using a 64-slice SDCT scanner at various acquisition protocols (120 and 140 kVp, and 50, 100 and 200 mAs). Regions of interest (ROIs) were placed in each insert and mean attenuation profiles at monochromatic energy levels (90-200 keV) were constructed. These profiles were fitted to attenuation profiles of pure HA and water to calculate HA concentrations. For comparison, one phantom was scanned using dual energy X-ray absorptiometry (DXA).Results: At both 120 and 140 kVp, excellent correlations (R = 0.97, P < 0.001) were found between true and measured HA concentrations. Mean error for all measurements at 120 kVp was -5.6 ± 5.7 mg/cm3 (-3.6 ± 3.2%) and at 140 kVp -2.4 ± 3.7 mg/cm3 (-0.8 ± 2.8%). Mean measurement errors were smaller than 6% for all acquisition protocols. Strong linear correlations (R2 ≥ 0.970, P < 0.001) with DXA were found.Conclusions: SDCT allows for accurate BMD quantification and potentially opens up the possibility for osteoporosis evaluation and opportunistic screening in patients undergoing SDCT for other clinical indications. However, patient studies are needed to extend and translate our findings.Key Points: • Dual-layer spectral detector CT allows for accurate bone mineral density quantification. • BMD measurements on SDCT are strongly linearly correlated to DXA. • SDCT, acquired for several indications, may allow for evaluation of osteoporosis. • This potentially opens up the possibility for opportunistic osteoporosis screening. [ABSTRACT FROM AUTHOR]

Published
2017
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45. Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study.

Author

Hamersvelt, Robbert, Willemink, Martin, Jong, Pim, Milles, Julien, Vlassenbroek, Alain, Schilham, Arnold, Leiner, Tim, van Hamersvelt, Robbert W, Willemink, Martin J, de Jong, Pim A, and Schilham, Arnold M R

Subjects
COMPUTED tomography, GADOLINIUM, IMAGING phantoms, REPRODUCIBLE research, ATTENUATION coefficients, CHEMICAL elements, HEART, RESEARCH evaluation, PILOT projects
Abstract

Objectives: The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations.Methods: The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.0, 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.1, 10.6, 15.7, 20.7 and 26.3 mg/mL). Images were acquired using a novel 64-detector row SDCT system at 120 and 140 kVp. Acquisitions were repeated five times to assess reproducibility. Regions of interest (ROIs) were drawn on three slices per insert. A spectral plot was extracted for every ROI and mean attenuation profiles were fitted to known attenuation profiles of water and pure gadolinium using in-house-developed software to calculate gadolinium concentrations.Results: At both 120 and 140 kVp, excellent correlations between scan repetitions and true and measured gadolinium concentrations were found (R > 0.99, P < 0.001; ICCs > 0.99, CI 0.99-1.00). Relative mean measurement errors stayed below 10% down to 2.0 mg/mL true gadolinium concentration at 120 kVp and below 5% down to 1.0 mg/mL true gadolinium concentration at 140 kVp.Conclusion: SDCT allows for accurate quantification of gadolinium at both 120 and 140 kVp. Lowest measurement errors were found for 140 kVp acquisitions.Key Points: • Gadolinium quantification may be useful in patients with contraindication to iodine. • Dual-layer spectral detector CT allows for overall accurate quantification of gadolinium. • Interscan variability of gadolinium quantification using SDCT material decomposition is excellent. [ABSTRACT FROM AUTHOR]

Published
2017
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46. Coronary Artery Calcification Scoring with State-of-the-Art CT Scanners from Different Vendors Has Substantial Effect on Risk Classification

Author

Willemink, Martin J., primary, Vliegenthart, Rozemarijn, additional, Takx, Richard A. P., additional, Leiner, Tim, additional, Budde, Ricardo P. J., additional, Bleys, Ronald L. A. W., additional, Das, Marco, additional, Wildberger, Joachim E., additional, Prokop, Mathias, additional, Buls, Nico, additional, de Mey, Johan, additional, Schilham, Arnold M. R., additional, and de Jong, Pim A., additional

Published
2014
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50. Fast Noise Reduction in Computed Tomography for Improved 3-D Visualization.

Author

Schaap, Michiel, Schilham, Arnold M. R., Zuiderveld, Karel J., Prokop, Mathias, Vonken, Evert-Jan, and Niessen, Wiro J.

Subjects
*ANISOTROPY, *TOMOGRAPHY, *DIFFUSION processes, *THREE-dimensional imaging, *MEDICAL radiography
Abstract

Computed tomography (CT) has a trend towards higher resolution and higher noise. This development has increased the interest in anisotropic smoothing techniques for CT, which aim to reduce noise while preserving structures of interest. However, existing smoothing techniques are slow, which makes clinical application difficult. Furthermore, the published methods have limitations with respect to preserving small details in CT data. This paper presents a widely applicable speed optimized framework for anisotropic smoothing techniques. A second contribution of this paper is an extension to an existing smoothing technique aimed at better preserving small structures of interest in CT data. Based on second-order image structure, the method first determines an importance map, which indicates potentially relevant structures that should be preserved. Subsequently an anisotropic diffusion process is started. The diffused data is used in most parts of the images, while structures with significant second-order information are preserved. The method is qualitatively evaluated against an anisotropic diffusion method without structure preservation in an observer study to assess the improvement of 3-D visualizations of CT series and quantitatively by determining the reduction of the difference between low and high dose CT scans of in vitro carotid plaques. [ABSTRACT FROM AUTHOR]

Published
2008
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