A5026551304- Medical Imaging Techniques and Applications
- Radiation Detection and Scintillator Technologies
- MRI in cancer diagnosis
- Advanced MRI Techniques and Applications
- Atomic and Subatomic Physics Research
- Radiomics and Machine Learning in Medical Imaging
- Prostate Cancer Diagnosis and Treatment
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Prostate Cancer Treatment and Research
- Advanced NMR Techniques and Applications
- Pancreatic and Hepatic Oncology Research
- Neurological Disease Mechanisms and Treatments
- Esophageal Cancer Research and Treatment
- Advanced Neuroimaging Techniques and Applications
- Colorectal Cancer Surgical Treatments
- Acute Ischemic Stroke Management
- Advanced X-ray and CT Imaging
- Cerebrovascular and Carotid Artery Diseases
- Radiation Therapy and Dosimetry
- NMR spectroscopy and applications
- Lanthanide and Transition Metal Complexes
- CCD and CMOS Imaging Sensors
- Cardiac Imaging and Diagnostics
- Stellar, planetary, and galactic studies
Radboud University Nijmegen
2015-2024
Radboud University Medical Center
2015-2024
University Medical Center
2017-2024
Itasca Consultants (France)
2023
Engineering Service Center und Handel (Germany)
2022
Elisabeth-TweeSteden Ziekenhuis
2022
New York University
2017
Siemens Healthcare (Germany)
2017
Norwegian University of Science and Technology
2017
Erwin L. Hahn Institute for Magnetic Resonance Imaging
2016
Monte Carlo simulation is an essential tool in emission tomography that can assist the design of new medical imaging devices, optimization acquisition protocols and development or assessment image reconstruction algorithms correction techniques. GATE, Geant4 Application for Tomographic Emission, encapsulates libraries to achieve a modular, versatile, scripted toolkit adapted field nuclear medicine. In particular, GATE allows description time-dependent phenomena such as source detector...
We developed positron emission tomography (PET) detectors based on monolithic scintillation crystals and position-sensitive light sensors. Intrinsic depth-of-interaction (DOI) correction is achieved by deriving the entry points of annihilation photons front surface crystal from sensor signals. Here we characterize next generation these detectors, consisting a 20 mm thick rectangular or trapezoidal LYSO:Ce read out back (double-sided readout, DSR) Hamamatsu S8550SPL avalanche photodiode (APD)...
Much research is being conducted on position-sensitive scintillation detectors for medical imaging, particularly emission tomography. Monte Carlo simulations play an essential role in many of these activities. As the process, transport photons through crystal(s), and conversion into electronic signals each have a major influence detector performance; all processes may need to be incorporated model obtain accurate results. In this work optical models GEANT4 simulation toolkit are validated by...
Computed diffusion-weighted magnetic resonance imaging (cDWI) refers to the synthesizing of arbitrary b value images (DWI) from a set measured by voxelwise fitting. The objectives this study were quantitatively analyze noise and contrast-to-noise ratio (CNR) in cDWI as function numerical simulations measurements patients with prostate cancer compare directly DWI at 1400 s/mm2.Numerical performed assess image CNR both regular DWI. Forty-two (age, 51-73 years; specific antigen level, 0.5-30...
The purpose of this work was to harmonize data acquisition and post‐processing single voxel proton MRS ( 1 H‐MRS) at 7 T, determine metabolite concentrations the accuracy reproducibility levels in adult human brain. This study performed compliance with local institutional ethics committees. same seven subjects were each examined twice using four different T MR systems from two vendors an identical semi‐localization by adiabatic selective refocusing spectroscopy sequence. Neurochemical...
Objective The aim of this study was to determine and validate the optimal combination parameters derived from 3-T diffusion-weighted imaging, dynamic contrast-enhanced magnetic resonance (MR) spectroscopic imaging for discriminating low-grade high-grade prostate cancer (PCa). Materials Methods approved by institutional review board, need informed consent waived. Ninety-four patients with PCa who had undergone multiparametric MR (MRI) before prostatectomy were included. Cancer indicated on...
Ultrafast dynamic contrast-enhanced magnetic resonance imaging of the breast enables assessment contrast inflow dynamics while providing images with diagnostic spatial resolution. However, slice thickness common ultrafast techniques still prevents multiplanar reconstruction. In addition, some temporal blurring enhancement characteristics occurs in case view-sharing is used. We evaluate a prototype compressed-sensing volume-interpolated breath-hold examination (CS-VIBE) sequence for MRI that...
Objectives Accurate lymph node (LN) staging is crucial for managing upper abdominal cancers. Ultrasmall superparamagnetic iron oxide (USPIO)–enhanced magnetic resonance imaging effectively distinguishes healthy and metastatic LNs through fat/water -weighted imaging. However, respiratory motion artifacts complicate detection of LNs. This study evaluates if a free-breathing radial stack-of-stars acquisition can match or outperform Cartesian reference scans to visualize depict uptake USPIO...
Minimizing dead space is one way to increase the detection efficiency of small-animal PET scanners. By using monolithic scintillator crystals (e.g., 20 mm/spl times/10 mm LSO), loss due inter-crystal reflective material minimized. Readout such can be performed by means or more avalanche photo-diode (APD) arrays optically coupled crystal. The entry point a gamma photon on crystal surface estimated from measured distribution scintillation light over APD array(s). estimating point, correction...
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Neural Networks trained with error back propagation Levenberg-Marquardt training (LM), an algebraic method and Support Vector Machines (SVM) were evaluated to extract the position information from measured light distributions generated by interactions of 511 keV photons in monolithic scintillator blocks. All three algorithms can achieve a similar average resolution (<formula...
Purpose To demonstrate that high quality T2-weighted (T2w) turbo spin-echo (TSE) imaging of the complete prostate can be achieved routinely and within safety limits at 7 T, using an external transceive body array coil only. Methods Nine healthy volunteers 12 cancer patients were scanned on a T whole-body system. Preparation consisted B0 radiofrequency shimming localized flip angle calibration. T1 T2 relaxation times measured used to define T2w-TSE protocol. T2w was performed TSE sequence...
Purpose To determine associations of metabolite levels derived from magnetic resonance (MR) spectroscopic imaging (ie, hydrogen 1 [1H] MR imaging) and apparent diffusion coefficients (ADCs) diffusion-weighted with prostate tissue composition assessed by digital image analysis histologic sections. Materials Methods Institutional ethical review board approved this retrospective study waived informed consent. Fifty-seven cancer patients underwent an examination followed prostatectomy. One...
Objectives The aims of this study were to assess the discriminative performance quantitative multiparametric magnetic resonance imaging (mpMRI) between prostate cancer and noncancer tissues tumor grade groups (GGs) in a multicenter, single-vendor study, investigate what extent site-specific differences affect variations mpMRI parameters. Materials Methods Fifty patients with biopsy-proven from 5 institutions underwent standardized preoperative protocol. Based on evaluation whole-mount...
T2-weighted (T2W) MRI provides high spatial resolution and tissue-specific contrast, but it is predominantly used for qualitative evaluation of prostate anatomy anomalies. This retrospective multicenter study evaluated the potential T2W image-derived textural features quantitative assessment peripheral zone cancer (PCa) aggressiveness. A standardized preoperative multiparametric was performed on 87 PCa patients across 6 institutions. intensity apparent diffusion coefficient (ADC) histogram,...
We are investigating the possibility of using monolithic scintillator blocks as detectors for small animal positron emission tomography (PET). These consist several cm/sup 3/ scintillating material, read out by one or more avalanche photo-diode (APD) arrays. The entry point an incoming gamma photon is estimated from distribution scintillation light over APD pixels. To optimize detector design, influence different design parameters investigated Geant4 simulations. make it possible to study...
Purpose Optimization of phosphorus (31P) MR spectroscopic imaging (MRSI) the human prostate at 7 T by evaluation T1 relaxation times and Nuclear Overhauser Effect (NOE) phosphorus-containing metabolites. Methods Twelve patients with cancer one healthy volunteer were scanned on a whole-body system using 31P endorectal coil combined an eight-channel 1H body array coil. measured progressive saturation in two-dimensional localization sequence. MRSI was performed twice: once without NOE low-power...
To evaluate the technical feasibility of high-resolution USPIO-enhanced magnetic resonance imaging pelvic lymph nodes (LNs) at ultrahigh field strength. The ethics review board approved this study and written informed consent was obtained from all patients. Three patients with rectal cancer three selected (recurrent) prostate were examined 7-T 24–36 h after intravenous ferumoxtran-10 administration; also received a 3-T MRI. Pelvic LN performed using TIAMO technique in combination...
Abstract Objectives To assess 3-Tesla (3-T) ultra-small superparamagnetic iron oxide (USPIO)-enhanced MRI in detecting lymph node (LN) metastases for resectable adenocarcinomas of the pancreas, duodenum, or periampullary region a node-to-node validation against histopathology. Methods Twenty-seven consecutive patients with pancreatic, duodenal, adenocarcinoma were enrolled this prospective single expert centre study. Ferumoxtran-10-enhanced 3-T was performed pre-surgery. LNs found on scored...
Purpose Volume selection in 1 H MR spectroscopic imaging (MRSI) of the prostate is commonly performed with low‐bandwidth refocusing pulses. However, their large chemical shift displacement error (CSDE) causes lipid signal contamination spectral range interest. Application high‐bandwidth adiabatic pulses limited by radiofrequency (RF) power deposition. In this study, we aimed to provide an MRSI sequence that overcomes these limitations. Methods Measurements were at 3 T endorectal receive...
Abstract Background Current intraoperative methods of visual inspection and tissue palpation by the surgeon, frozen section analysis cannot reliably prevent inadequate surgical margins in patients treated for oral squamous‐cell carcinoma (OSCC). This study assessed feasibility MRI assessment resection fresh OSCC specimens. Methods Ten consecutive tongue specimens containing were scanned using 3 T clinical whole‐body MRI. Two radiologists independently annotated location minimal tumor‐free...
The aim of this study was to identify characteristics phosphorus (P) spectra the human prostate and investigate changes individual phospholipid metabolites in cancer through vivo P magnetic resonance spectroscopic imaging (MRSI) at 7 T.In institutional review board-approved study, 15 patients with biopsy-proven underwent T2-weighted 3-dimensional MRSI T. Voxels were selected tumor location, normal-appearing peripheral zone tissue, transition base close seminal vesicles. Phosphorus metabolite...
An often‐employed strategy to enhance signals in 31 P MRS is the generation of nuclear Overhauser effect (NOE) by saturation water resonance. However, NOE allegedly increases variability data, because variation reported enhancements. This would negate signal‐to‐noise (SNR) gain it generates. We hypothesized that enhancement values not caused itself, but attributable measurement uncertainties used calculate enhancement. If true, expected increase SNR with improve repeatability measurements....