A5073630730- Medical Imaging Techniques and Applications
- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Advanced MRI Techniques and Applications
- Advanced X-ray and CT Imaging
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Lung Cancer Diagnosis and Treatment
- Digital Radiography and Breast Imaging
- Boron Compounds in Chemistry
- MRI in cancer diagnosis
- Particle Detector Development and Performance
- Advances in Oncology and Radiotherapy
- Radiation Dose and Imaging
- Statistical Methods and Inference
- Complexity and Algorithms in Graphs
- Nuclear reactor physics and engineering
- Parallel Computing and Optimization Techniques
- Radiation Effects and Dosimetry
- Radiomics and Machine Learning in Medical Imaging
- Advanced Graph Theory Research
- Ultrasound and Hyperthermia Applications
KU Leuven
2019-2024
Universitair Ziekenhuis Leuven
2019-2024
AZ Sint-Lucas
2023
Vrije Universiteit Brussel
2014-2018
Huisarts en Wetenschap
2018
Universidad de Colima
2009
Scatter correction is typically done using a simulation of the single scatter, which then scaled to account for multiple scatters and other possible model mismatches. This scaling factor determined by fitting simulated scatter sinogram measured sinogram, only counts along LORs that do not intersect patient body, i.e. 'scatter-tails'. Extending previous work, we propose scale with plane dependent factor, as an additional unknown in maximum likelihood (ML) reconstructions, entire rather than...
In positron emission tomography a scatter estimate is calculated prior to image reconstruction and then added at each MLEM iteration the estimated true counts yield prompts. The absolute scale of usually by matching data for those lines response that do not intersect patient. goal this work explore alternatives tail fitting method. Pursuing method introduced V. Panin 2012 IEEE Medical Imaging Conference case with known attenuation, we scaling factor as an additional voxel, which updated same...
Purpose One of the main sources uncertainty in proton therapy is conversion Hounsfield Units planning CT to (relative) stopping powers. Proton radiography provides range error maps but these can be affected by other errors as well (e.g., residual misalignment). To better understand and quantify uncertainty, it desirable measure individual contributions particularly those associated conversion. Methods A workflow proposed carry out an assessment solely on basis radiographs real tissues...
Objective.Protons offer a more conformal dose delivery compared to photons, yet they are sensitive anatomical changes over the course of treatment. To minimize range uncertainties due variations, new CT acquisition at every treatment session would be paramount enable daily calculation and subsequent plan adaptation. However, series scans results in an additional accumulated patient dose. Reducing radiation thereby decreasing potential risk exposure patients is desirable, however, lowering...
In this paper we derive four sets of sinc-like functions, defined on a finite interval and obeying different boundary conditions. The functions in each set are orthogonal their nodes uniformly distributed the interval. We have applied to solve large class eigenvalue equations, with conditions, both intervals real line, showing that precise numerical results can be obtained efficiently rapidly. A comparison available literature is also performed.
Background and purposeTo obtain an understanding of current practice, professional needs future directions in the field fan-beam CT RT, a survey was conducted. This work presents collected information regarding use imaging for dose calculation structure delineation.Materials methodsAn online institutional distributed to medical physics experts employed at Belgian Dutch radiotherapy institutions assess status, challenges, QA practices CT. A maximum 143 questions covered topics such as scanner...
This work reports on the results of a survey performed use computed tomography (CT) imaging for motion management, surface guidance devices, and their quality assurance (QA). Additionally, it details collected user insights regarding professional needs in CT radiotherapy. The purpose is to understand current practice, future directions field fan-beam radiation therapy (RT).
The 'simultaneous maximum-likelihood attenuation correction factors' (sMLACF) algorithm presented here, is an iterative to calculate the estimate of activity λ and factors a in time-of-flight positron emission tomography, this from data only. Hence sMLACF alternative MLACF algorithm. derived using generalized expectation-maximization principle by introducing appropriate set complete data. resulting iteration step yields simultaneous update which, addition, enforces natural way constraints...
Maximum likelihood expectation-maximization (MLEM) is a popular algorithm to reconstruct the activity image in positron emission tomography. This paper introduces "fundamental equality" for MLEM complete data from which two key properties easily follow that allows us to: 1) prove an elegant and compact way convergence of forward model with fixed background (i.e., counts such as random scatter coincidences) 2) generalize this proof MLEM-3 algorithm. Moreover, we give necessary sufficient...
In time-of-flight (TOF) positron emission tomography (PET) imaging, it is possible to correct for attenuation using only the TOF-PET data. Currently two main iterative algorithms exist this purpose: MLAA [1] and MLACF [2]. addition reconstructing activity image A, reconstructs map μ, whereas correction factors a. While implementing MLACF, one has be careful. Possible pitfalls are: (i) obtaining slice dependent scale factors, (ii) converging local maxima, (iii) unbounded estimates, (iv)...
. In this experimental work we compared the determination of absorbed dose to water using four ionization chambers (ICs), a PTW-34045 Advanced Markus, PTW-34001 Roos, an IBA-PPC05 and PTW-30012 Farmer, irradiated under same conditions in one continuous- two pulsed-scanned proton beams.
In this work, we propose a plane-dependent maximum likelihood (ML) scatter scale estimation from the emission measurements. The scales obtained are validated using Monte Carlo simulation of NEMA-like phantom, and results shown two whole-body patient scans.
In CT-imaging, an optimal compromise between the radiation burden and required image quality for imaging task is needed. this research, we aim to develop a tool simulate lower-dose scans from standard-dose scan. The motivation determine lowest possible dose that still produces sufficient information proton therapy treatment planning. tube current reduction modeled by estimating noise equivalent number of photons in high exposure scan applying thinning technique reduce number. proposed method...
Protons offer a more precise radiation dose delivery compared to photons, however, they are sensitive anatomical changes during the course of treatment. Therefore, CT scan would be paramount at every treatment session enable accurate calculation and subsequent plan adaptation. Nevertheless, series scans results in accumulated additional patient dose. We hypothesize that signal-to-noise ratio provided by conventional protocols is higher than needed for proton therapy calculations. In this...