Nicholas W. Marshall
Katholieke Universiteit Leuven
Imaging phantomOpticsPhysicsBiomedical engineeringTomosynthesisArtificial intelligenceOptical transfer functionAutomatic exposure controlKermaMaterials scienceMammographyDigital mammographyDigital Breast TomosynthesisNuclear medicineComputer visionComputer scienceImage qualityMedicineDetective quantum efficiencyDetector
133Publications
23H-index
1,418Citations
Publications 133
Newest
#1Liesbeth Vancoillie (Katholieke Universiteit Leuven)H-Index: 3
#2Lesley Cockmartin (Katholieke Universiteit Leuven)H-Index: 10
Last. Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
view all 4 authors...
Purpose null The aim of this study is to perform a test object-based comparison of the imaging performance of digital mammography (DM), digital breast tomosynthesis (DBT), and synthetic mammography (SM). null Methods null Two test objects were used, the CDMAM and the L1-structured phantom. Small-detail detectability was assessed using CDMAM and the microcalcification simulating specks in the L1-structured background. Detection of spiculated and non-spiculated mass-like objects was assessed using...
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#1Frédéric Bemelmans (Katholieke Universiteit Leuven)H-Index: 2
#2Nicholas W. Marshall (Katholieke Universiteit Leuven)H-Index: 23
Last. Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
view all 10 authors...
PURPOSE To assess if single shot acquisitions with solid-state dosimeters as well as Robson's method could replace ionization chambers for tube output and HVL measurements, saving medical physicists time. MATERIAL AND METHODS The energy responses of 4 solid-state dosimeters with automatic calculation of HVL were compared to ionization chamber measurements. Five anode/filter combinations were tested: Mo/Mo, Mo/Rh, Rh/Rh, W/Rh and W/Ag, from 24kVp to 35kVp. Tube output was measured free in air. HV...
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#1An Dedulle (Katholieke Universiteit Leuven)H-Index: 1
#2Niki Fitousi (Katholieke Universiteit Leuven)H-Index: 3
Last. Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
view all 5 authors...
Patient dose management systems can be part of a department's quality management tools to estimate items such as the radiation burden in specific groups or list dose outliers for further follow up. Patient size information could improve both aspects, but is not generally available. A new metric is proposed to estimate patient size for thorax and abdominal projection radiography from parameters available in thedicomheader and therefore accessible by dose management software. The tested hypothesis...
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#1Kristina Tri Wigati (UI: University of Indonesia)H-Index: 1
#2Nicholas W. Marshall (Katholieke Universiteit Leuven)H-Index: 23
Last. Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
view all 12 authors...
Purpose: The relevance of presampling modulation transfer function (MTF) measurements in digital mammography (DM) quality control (QC) is examined. Two studies are presented: a case study on the impact of a reduction in MTF on the technical image quality score and analysis of the robustness of routine QC MTF measurements. Approach: In the first study, two needle computed radiography (CR) plates with identical sensitivities were used with differences in the 50% point of the MTF (fMTF0.5) larger t...
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#1Liesbeth Vancoillie (Katholieke Universiteit Leuven)H-Index: 3
#2Katrien Houbrechts (Katholieke Universiteit Leuven)
Last. Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
view all 7 authors...
Aim: To develop, validate and apply a pipeline for breast cancer voxel model generation from patient digital breast tomosynthesis (DBT) cases for cancer type specific virtual clinical trials (VCT). Methods: Input cancer cases were retrieved from wide-angle DBT systems. Three aspects of the creation process were investigated: (1) The impact of the limited z-resolution of DBT on the shape of the voxel model using circularity measurements (i.e. ratio of diameters between input and result after simu...
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#1Katrien Houbrechts (Katholieke Universiteit Leuven)
#2Liesbeth Vancoillie (Katholieke Universiteit Leuven)H-Index: 3
Last. Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
view all 5 authors...
Aim: Compare an in-house developed hybrid simulation framework and the FDA’s total simulation framework VICTRE in an exercise to simulate realistic DBT images. Methods: Three different set-ups were investigated in increasing order of difficulty: (1) A simple object insert simulated in homogeneous backgrounds. (2) The same simple test object in a breast phantom to investigate the impact of a non-homogeneous background. (3) The simple test object replaced with clinically relevant lesions (spiculat...
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#1Lesley Cockmartin (Katholieke Universiteit Leuven)H-Index: 10
#2Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
Last. Nicholas W. Marshall (Katholieke Universiteit Leuven)H-Index: 23
view all 3 authors...
This study explores candidate metrics for use in a vendor-neutral Quality Control (QC) protocol for dual energy based (‘spectral’) contrast-enhanced digital mammography (DE-CEDM). The physical metrics were chosen for their anticipated link with clinical image quality. An extra criterion was that limiting values can be applied to these metrics. The following DE-CEDM characteristics were tested: (1) signal produced by test object inserts versus their iodine concentration for different breast tissu...
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#2Johan Coolen (Katholieke Universiteit Leuven)H-Index: 17
Last. Jeroen Desmet (Katholieke Universiteit Leuven)H-Index: 1
view all 9 authors...
Purpose: We describe the creation of computational models of lung pathologies indicative of COVID-19 disease. The models are intended for use in virtual clinical trials (VCT) for task-specific optimization of chest x-ray (CXR) imaging. Approach: Images of COVID-19 patients confirmed by computed tomography were used to segment areas of increased attenuation in the lungs, all compatible with ground glass opacities and consolidations. Using a modeling methodology, the segmented pathologies were con...
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#1M Dehairs (Katholieke Universiteit Leuven)H-Index: 3
#2Hilde Bosmans (Katholieke Universiteit Leuven)H-Index: 58
Last. Nicholas W. Marshall (Katholieke Universiteit Leuven)H-Index: 23
view all 4 authors...
This study investigates the exposure parameters and required x-ray tube output when performing neurological procedures on a hybrid Angio-MR concept system proposed by Siemens Healthineers. The x-ray part of this system uses a longer source to detector distance than conventional (C-arm) systems and will have a fixed amount of filtration. Additionally, as the x-ray source is situated inside a magnetic field, the focal spot size and shape may be slightly distorted. In order to compare the Angio-MR ...
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#1M DehairsH-Index: 3
#2Hilde BosmansH-Index: 58
Last. Nicholas W. MarshallH-Index: 23
view all 3 authors...
This work compared the impact of x-ray tube performance and automatic dose rate control (ADRC) parameter selection on system imaging efficiency of two Siemens angiography systems: a Siemens Megalix x-ray tube installed on an Artis Zee system (denoted 'MEGALIX') and a newer generation Gigalix x-ray tube installed on an Artis Q (denoted 'GIGALIX'). A method was used that accounted for two potential sources of bias in this comparison: differences in radiation output between the x-ray tubes and diff...
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