A5070473983- Medical Imaging Techniques and Applications
- Digital Radiography and Breast Imaging
- Advanced MRI Techniques and Applications
- Advanced X-ray and CT Imaging
- Breast Cancer Treatment Studies
- Advanced Radiotherapy Techniques
- AI in cancer detection
- Infrared Thermography in Medicine
- Radiomics and Machine Learning in Medical Imaging
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Ultrasound Imaging and Elastography
- Cell Image Analysis Techniques
- Cardiac Imaging and Diagnostics
- Advanced Image and Video Retrieval Techniques
- Advanced Vision and Imaging
- Breast Lesions and Carcinomas
- Radiopharmaceutical Chemistry and Applications
- Global Cancer Incidence and Screening
- Advanced NMR Techniques and Applications
- Cardiovascular Health and Disease Prevention
- Generative Adversarial Networks and Image Synthesis
- Explainable Artificial Intelligence (XAI)
- Medical Image Segmentation Techniques
- Monoclonal and Polyclonal Antibodies Research
University Medical Center Utrecht
2007-2023
Utrecht University
2019
Amsterdam UMC Location University of Amsterdam
2014-2017
University of Amsterdam
2013-2014
Eindhoven University of Technology
2006
We present a new rodent SPECT system (U-SPECT-II) that enables molecular imaging of murine organs down to resolutions less than half millimeter and high-resolution total-body imaging. <b>Methods:</b> The U-SPECT-II is based on triangular stationary detector set-up, an <i>XYZ</i> stage moves the animal during scanning, interchangeable cylindric collimators (each containing 75 pinhole apertures) for both mouse rat A novel graphical user interface incorporating preselection field view with aid...
Block-iterative image reconstruction methods, such as ordered subset expectation maximization (OSEM), are commonly used to accelerate reconstruction. In OSEM, the speed-up factor over maximum likelihood (MLEM) is approximately equal number of subsets in which projection data divided. Traditionally, each consists a couple views, and more used, solution deviates from MLEM solutions. We found for multi-pinhole single photon emission computed tomography (SPECT) that even moderate acceleration...
In x-ray mammography, flattening of the breast improves image quality and reduces absorbed dose. Current mammographic compression guidelines are based on applying a standardized force to each breast. Because size is not taken into consideration, this approach leads large variations in applied pressure (force per unit contact area). It authors' hypothesis that pressure-controlled protocol, which takes area account, (1) standardization across population terms physiological conditions...
Small-animal single photon emission computed tomography (SPECT) with focused multi-pinhole collimation geometries allows scanning modes in which large amounts of photons can be collected from specific volumes interest. Here we present new tools that improve targeted imaging organs and tumours, validate the effects improved targeting pinhole focus.A SPECT system 75 pinholes stationary detectors was used (U-SPECT-II). An XYZ stage automatically translates animal bed a sequence order to scan...
Monte Carlo-based iterative reconstruction to correct for photon scatter and collimator effects has been proven be superior over analytical correction schemes in single-photon emission computed tomography (SPECT/CT), but it is currently not commonly used daily clinical practice due the long associated times. We propose use a convolutional neural network (CNN) upgrade fast filtered back projection (FBP) image quality so that reconstructions comparable can obtained within seconds. A total of...
In this work we aimed to study the possibility of using supervised classifiers quantify main components carotid atherosclerotic plaque in vivo on basis multisequence MRI data. data consisting five MR weightings were obtained from 25 symptomatic subjects. Histological micrographs endarterectomy specimens carotids used as a standard reference for training and evaluation. The set subjects was divided (12 subjects) an evaluation (13 subjects). Four different two human readers determined...
Purpose: X‐ray mammography is the primary tool for early detection of breast cancer and follow‐up after conserving therapy (BCT). BCT‐treated breasts are smaller, less elastic, more sensitive to pain. Instead current force‐controlled approach applying same force each breast, pressure‐controlled protocols aim improve standardization in terms physiology by taking contact area inelasticity into account. The purpose this study estimate potential pressure reduce discomfort pain, particularly...
To assess the accuracy of two methods determining contact area between compression paddle and breast in mammography. An accurate method to determine is essential accurately calculate average pressure applied by paddle.For a set 300 compressions, we measured areas paddle, both capacitively using transparent foil with indium-tin-oxide (ITO) coating attached retrospectively from obtained mammograms image processing software (Volpara Enterprise, algorithm version 1.5.2). A gold standard was...
In mammography, the height of image receptor is adjusted to patient before compressing breast. An inadequate setting can result in an imbalance between forces applied by and paddle, causing clamped breast be pushed up or down relative body during compression. This leads unnecessary stretching skin other tissues around breast, which make imaging procedure more painful for patient. The goal this study was implement a method measure minimize force imbalance, assess its feasibility as objective...
Highly focused Micro-SPECT scanners enable the acquisition of functional small animal data with very high-resolution. To acquire a maximum emitted photons from specific structure interest and at same time minimize required time, typically only subvolume is scanned that contains organs interest. This Volume Interest (VOI) can be defined manually based on photographs taken prior to SPECT scanning, for example two lateral views top view. In these however, surface visible therefore visual...
Ultra-high-resolution SPECT images can be obtained with focused multipinhole collimators. Here we investigate the influence of unwanted high tracer uptake outside scan volume on reconstructed distributions inside volume, for (99m)Tc-tetrofosmin myocardial perfusion scanning in mice. Simulated projections a digital mouse phantom (MOBY) focusing system (U-SPECT-II, MILabs, The Netherlands) were generated. With this differently sized user-defined volumes selected, by translating animal 3D...
Longitudinal imaging of intratumoral distributions antibodies in vivo mouse cancer models is great importance for developing therapies. In this study, multipinhole SPECT with sub–half-millimeter resolution was tested exploring radiolabeled directed toward the epidermal growth factor receptor (EGFr) and compared full 3-dimensional target expression assessed by immunohistochemistry. <b>Methods:</b><sup>111</sup>In-labeled zalutumumab, a human monoclonal EGFr-targeting antibody, administered at...
The restricted bore diameter of current simultaneous positron emission tomography/magnetic resonance imaging (PET/MRI) systems can be an impediment to achieving similar patient positioning during PET/MRI planning and radiotherapy. Our goal was evaluate the B1 transmit (B1+) uniformity, B1+ efficiency, specific absorption rate (SAR) a novel radiofrequency (RF) body coil design, in which RF shielded PET detectors were integrated with aim enabling wide-bore system.We designed constructed...
The simultaneous use of positron emission tomography (PET) and magnetic resonance imaging (MRI) requires attenuation correction (AC) photon-attenuating objects, such as MRI receive arrays. However, AC flexible, on-body arrays is complex therefore often omitted. This can lead to significant, spatially varying PET signal losses when conventional are used. Only few dedicated, photon transparent PET/MRI exist, none which compatible with our new, wide-bore 1.5 T system dedicated radiotherapy...
Motivation: Prospective gating potentially reduces respiratory motion-induced degradation in 31P liver MRSI at the cost of increased acquisition time. This presents a difficult trade-off, since protocols are already time-consuming while effects motion yet unknown. Goal(s): To characterize spectral quality degrading typical on human data. Approach: We analyzed spectra obtained from free breathing scans to determine differences between uncorrected and prospectively gated acquisitions using...
The Unity 1.5T MR-linac has clinically been introduced to provide stereotactic precision for moving targets. We are now developing an integrated MRI/PET system with identical MRI performance planning of treatments. offers 70 cm bore size and includes PET detectors mounted in the gap a split gradient coil. Recently, first ring was installed. performed extensive interference tests acquired simultaneous images using brain phantom. Our vision is that combination will allow use information...
The feasibility of simultaneous 1H/31P PET/MR imaging added-on to an existing 7T MRI system was assessed. Space constraints preclude using whole-body birdcages. Instead, 8-channel 1H dipole array stacked with additional 8-31P channels is set up. By positioning PET detectors between the RF-shield and gradient coil, further shielding PET-crystals electronics can be omitted. 31P scans had a higher SNR compared birdcage setup. setup gives ~5% degradation sensitivity. Similarly, impact new...