A5018656975- Advanced Radiotherapy Techniques
- Advanced X-ray and CT Imaging
- Medical Imaging Techniques and Applications
- Radiation Dose and Imaging
- Lung Cancer Diagnosis and Treatment
- Nuclear Physics and Applications
- Radiomics and Machine Learning in Medical Imaging
- Molecular Junctions and Nanostructures
- Surface Chemistry and Catalysis
- Medical Image Segmentation Techniques
- Breast Cancer Treatment Studies
- Advanced Vision and Imaging
- Clinical practice guidelines implementation
- Endometrial and Cervical Cancer Treatments
- Radiation Therapy and Dosimetry
- Surface and Thin Film Phenomena
- Artificial Intelligence in Healthcare and Education
- COVID-19 diagnosis using AI
- SARS-CoV-2 detection and testing
- Force Microscopy Techniques and Applications
- Photoacoustic and Ultrasonic Imaging
- Chemotherapy-induced cardiotoxicity and mitigation
- Nasal Surgery and Airway Studies
- Advanced X-ray Imaging Techniques
- Injury Epidemiology and Prevention
Centre Hospitalier de l’Université de Montréal
2014-2024
Université de Montréal
2013-2023
University of Ontario Institute of Technology
2022
Hôpital Notre-Dame
2014-2018
École de Technologie Supérieure
2014
National Physical Laboratory
2014
Polytechnique Montréal
2008-2011
Regroupement Québécois sur les Matériaux de Pointe
2008-2011
McGill University
2008
Institut National de la Recherche Scientifique
2008
Single tetracyanoethyelene (TCNE) molecules on Cu(111) are reversibly switched among five states by applying voltage pulses with the tip of a scanning tunneling microscope. A pronounced Kondo resonance in spectroscopy indicates that one is magnetic. Side bands appear at energies which correspond to inter- and intramolecular vibrational modes. Density functional theory suggests molecular deformation changes occupancy TCNE's orbitals, thus producing magnetic state.
The interaction of the strong electron-acceptor tetracyanoethylene (TCNE) with Cu(100) surface has been studied scanning tunneling microscopy experiments and first-principles density functional theory calculations. We compare two different adsorption models experimental results show that molecular self-assembly is caused by a structural modification rather than formation coordination network diffusing Cu adatoms. Surface atoms become highly buckled chemisorption TCNE accompanied partial...
There is an increasing interest in the evaluation of lung function from physiological images radiation therapy treatment planning to reduce extent postradiation toxicities. The purpose this work was retrieve reliable functional information contrast-enhanced dual-energy computed tomography (DECT) for new applications therapy. obtained by DECT also compared with other methods using single-energy CT (SECT) and single-photon emission (SPECT) CT. differential between left right lung, as well...
Purpose: To evaluate the reliability of common sinogram‐based DECT reconstruction methods for radiotherapy tissue characterization and to advantage combining them with a stoichiometric calibration. Methods: The method defined by Alvarez Macovski [“Energy‐selective reconstructions in x‐ray computerized tomography,” Phys. Med. Biol. 21, – (1976)] is adapted XCOM photon cross sections database also generalized two‐material decomposition method. A theoretical framework developed using test...
We report a detailed investigation of the self-assembly organic semiconductor rubrene on low-index (100) and (110) facets copper by scanning tunneling microscopy (STM) supported density functional theory (DFT) calculations. Rubrene adsorbs in orientations depending substrate symmetry, resulting different self-assembled motifs. STM images point to an asymmetric adsorption geometry, DFT calculations further suggest that molecule twisted conformation.
Purpose The purpose of this study was to develop and validate accurate methods for determining iodine content virtual noncontrast maps physical parameters, such as electron density, in the context radiotherapy. Methods A simulation environment is developed compare three allowing extracting composition: (a) two‐material decomposition, (b) three‐material decomposition with conservation volume constraint, (c) eigentissue decomposition. allows comparing performance using iodine‐based contrast...
This work introduces a 2D motion prediction algorithm for lung tumors applied to dynamic MR images that combines intrafractional tumor deformations. It is developed in the context of MR-linac treatments and evaluates uniform patient-specific margins about gross volume optimize coverage. Seven early stage non-small cell cancer patients were imaged treatment position with 1.5 T magnetic resonance using balanced steady-state free precession sequence one minute at rate four per second instructed...
Purpose: This study introduces a novel autocontouring algorithm based on particle filter for lung tumors. It is validated dynamic magnetic resonance (MR) images and developed in the context of MR‐linac treatments. Methods: A sequential Monte Carlo method called used as main structure combined with Otsu's thresholding technique to contour tumors MR images. Four non‐small cell cancer (NSCLC) patients were imaged 1.5 T 60 s at rate 4 images/s asked breathe normally. Prior treatment, some image...
3D-printed alternatives to standard flocked swabs were rapidly developed provide a response the unprecedented and sudden need for an exponentially growing amount of diagnostic tools fight COVID-19 pandemic. In light anticipated shortage, hospital-based 3D-printing platform was implemented in our institution production nasopharyngeal oropharyngeal sampling based on freely available, open-source design provided community by University South Florida’s Health Radiology Northwell System teams as...
Iterative reconstruction is well-established in diagnostic multidetector computed tomography (MDCT) for dose reduction and image quality enhancement. Its application to cone beam (CBCT) only emerging warrants a quantitative evaluation.Several phantoms canine head specimen were imaged using commercially available small-field CBCT scanner. Raw projection data reconstructed the Feldkamp-Davis-Kress (FDK) method with different filters, including denoising via total variation (TV) minimization...
Purpose To compare cardiac doses of different whole-breast optimization schemes including free-breathing (FB) tangential radiotherapy (TRT), deep-inspiration breath-hold (DIBH) TRT, and FB helical tomotherapy (HT). Methods Early-stage left-sided breast cancer patients who underwent breast-conserving surgery followed by adjuvant were included in the study. Planning images DIBH CT scans acquired same supine treatment position with both arms abducted. A hypofractionated regimen 42.5 Gy 16...
Purpose: An improvement in tissue assignment for low-dose rate brachytherapy (LDRB) patients using more accurate Monte Carlo (MC) dose calculation was accomplished with a metallic artifact reduction (MAR) method specific to dual-energy computed tomography (DECT). Methods: The proposed MAR algorithm followed four-step procedure. first step involved applying weighted blend of both DECT scans (I H/L) generate new image Mix). This action minimized Hounsfield unit (HU) variations surrounding the...
The influence of π-interactions in thin layers stacked polymers has been studied with first-principles DFT calculations and STM simulations. Improving π–π coupling between polymeric the stack contributes to enlarging size contrasts attenuating fine atomic structure features topmost superficial polymer layer. In addition, tunneling transport within is strongly influenced by distance separating stack. Consequently, it appears very difficult determine structural properties (stack height,...
Purpose: To establish the reliability of electron density (ED) mapping and tissue segmentation techniques using CT images for brachytherapy, considering stochastic systematic Hounsfield unit (HU) variations. Methods: Most common artifacts are simulated within a Monte Carlo theoretical framework. A set data is first generated with EGSnrc suite followed by their reconstruction performed an iterative algorithm. statistical analysis HU values from reconstructed to determine uncertainties effects...
Abstract Introduction The purpose of this study is quantify intrafraction motion ( IFM ) during lung volumetric‐modulated arc therapy VMAT and evaluate the impact mid‐treatment cone beam computed tomography CBCT )‐guided patient repositioning on target coverage. Method This analysis included tumours treated with to 50–60 Gy in 3–5 fractions. Treatment planning was based four‐dimensional CT scans from which internal tumour volumes ITV were derived. An isotropic 5 mm margin added obtain final...
Purpose: To improve Monte Carlo dose calculation accuracy through a new tissue segmentation technique with dual energy CT (DECT). Methods: Electron density (ED) and effective atomic number (EAN) can be extracted directly from DECT data stoichiometric calibration method. Images are acquired projections using the user code egs_cbct reconstructed an FDK backprojection algorithm. Calibration is performed of numerical RMI phantom. A weighted parameter algorithm then uses both EAN ED to assign...