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Protecting quantum entanglement from leakage and qubit errors via repetitive parity measurements

Bultink, C.C. (author), O'Brien, T. E. (author), Vollmer, R. (author), Muthusubramanian, N. (author), Beekman, M. W. (author), Rol, M.A. (author), Fu, X. (author), Tarasinski, B.M. (author), Ostroukh, V.P. (author), Varbanov, B.M. (author), Bruno, A. (author), DiCarlo, L. (author)

Protecting quantum information from errors is essential for large-scale quantum computation. Quantum error correction (QEC) encodes information in entangled states of many qubits and performs parity measurements to identify errors without destroying the encoded information. However, traditional QEC cannot handle leakage from the qubit...

journal article 2020

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uPAR-targeted multimodal tracer for pre- and intraoperative imaging in cancer surgery

Boonstra, M.C. (author), Van Driel, P.B.A.A. (author), Van Willigen, D.M. (author), Stammes, M.A. (author), Prevoo, H.A.J.M. (author), Tummers, Q.R.J.G. (author), Mazar, A.P. (author), Beekman, F.J. (author), Kuppen, P.J.K. (author), Van de Velde, C.J.H. (author), Löwik, C.W.G.M. (author), Frangioni, J.V. (author), Van Leeuwen, F.W.B. (author), Sier, C.F.M. (author), Vahrmeijer, A.L. (author)

Pre- and intraoperative diagnostic techniques facilitating tumor staging are of paramount importance in colorectal cancer surgery. The urokinase receptor (uPAR) plays an important role in the development of cancer, tumor invasion, angiogenesis, and metastasis and over-expression is found in the majority of carcinomas. This study aims to develop...

journal article 2015

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U-SPECT-BioFluo: An integrated radionuclide, bioluminescence, and fluorescence imaging platform

Van Oosterom, M.N. (author), Kreuger, R. (author), Buckle, T. (author), Mahn, W.A. (author), Bunschoten, A. (author), Josephson, L. (author), Van Leeuwen, F.W.B. (author), Beekman, F.J. (author)

Background: In vivo bioluminescence, fluorescence, and single-photon emission computed tomography (SPECT) imaging provide complementary information about biological processes. However, to date these signatures are evaluated separately on individual preclinical systems. In this paper, we introduce a fully integrated bioluminescence-fluorescence...

journal article 2014

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A Hadron Radiation Installation and Verification Method

Beekman, F.J. (author), Bom, V.R. (author)

A hadron radiation installation adapted to subject a target to irradiation by a hadron radiation beam, said installation comprising: - a target support configured to support, preferably immobilize, a target: - a hadron radiation apparatus adapted to emit a hadron radiation beam along a beam axis to irradiate the target supported by the target...

patent 2013

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Effects of attenuation map accuracy on attenuation-corrected micro-SPECT images

Wu, C. (author), Gratama van Andel, H.A. (author), Laverman, P. (author), Boerman, O.C. (author), Beekman, F.J. (author)

Background In single-photon emission computed tomography (SPECT), attenuation of photon flux in tissue affects quantitative accuracy of reconstructed images. Attenuation maps derived from X-ray computed tomography (CT) can be employed for attenuation correction. The attenuation coefficients as well as registration accuracy between SPECT and CT...

journal article 2013

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Intratumoral administration of Holmium-166 Acetylacetonate Microspheres: Antitumor efficacy and feasibility of multimodality imaging in renal cancer

Bult, W. (author), Kroeze, S.G.C. (author), Elschot, M. (author), Seevinck, P.R. (author), Beekman, F.J. (author), De Jong, H.W.A.M. (author), Uges, D.R.A. (author), Kosterink, J.G.W. (author), Luijten, P.R. (author), Hennink, W.E. (author)

The increasing incidence of small renal tumors in an aging population with comorbidities has stimulated the development of minimally invasive treatments. This study aimed to assess the efficacy and demonstrate feasibility of multimodality imaging of intratumoral administration of holmium-166 microspheres (166HoAcAcMS). This new technique locally...

journal article 2013

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Targeted multi-pinhole SPECT

Branderhorst, W. (author), Vastenhouw, B. (author), Van der Have, F. (author), Blezer, E.L.A. (author), Bleeker, W.K. (author), Beekman, F.J. (author)

Purpose: 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 of interest. Here we present new tools that improve targeted imaging of specific organs and tumours, and validate the effects of...

journal article 2010

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An enhanced high-resolution EMCCD-based gamma camera using SiPM side detection

Heemskerk, J.W.T. (author), Korevaar, M.A.N. (author), Huizenga, J. (author), Kreuger, R. (author), Schaart, D.R. (author), Goorden, M.C. (author), Beekman, F.J. (author)

To improve multi-pinhole single photon emission computed tomography (SPECT) devices we are developing a high-resolution gamma detector consisting of a 3-mm-thick scintillation crystal that converts gamma photons to light, on top of an optically coupled high-resolution, high-sensitivity light sensor (EMCCD). This gamma camera can detect...

journal article 2010

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A Comprehensive Model of the Response of Silicon Photomultipliers

Van Dam, H.T. (author), Seifert, S. (author), Vinke, R. (author), Dendooven, P. (author), Löhner, H. (author), Beekman, F.J. (author), Schaart, D.R. (author)

The response of a silicon photomultiplier (SiPM) to optical signals is inherently nonproportional due to saturation, afterpulsing, and crosstalk. Existing models of the SiPM response do not account for all of these effects, and therefore, these models are not sufficiently accurate for many applications. In this work, a comprehensive model of the...

journal article 2010

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Accurate Coregistration between Ultra-High-Resolution Micro-SPECT and Circular Cone-BeamMicro-CT Scanners

Ji, C. (author), Van der Have, F. (author), Gratama van Andel, H. (author), Ramakers, R. (author), Beekman, F.J. (author)

Spatially registering SPECT with CT makes it possible to anatomically localize SPECT tracers. In this study, an accurate method for the coregistration of ultra-high-resolution SPECT volumes andmultiple cone-beam CT volumes is developed and validated, which does not require markers during animal scanning. Methods. Transferable animal beds were...

journal article 2010

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Absolute quantitative total-body small-animal SPECT with focusing pinholes

Wu, C. (author), Van der Have, F. (author), Vastenhouw, B. (author), Dierckx, R.A.J.O. (author), Paans, A.M.J. (author), Beekman, F.J. (author)

Purpose: In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity and scatter for multi-pinhole SPECT. The aim of...

journal article 2010

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LaBr3:Ce and SiPMs for time-of-flight PET: Achieving 100 ps coincidence resolving time

Schaart, D.R. (author), Seifert, S. (author), Vinke, R. (author), Van Dam, H.T. (author), Dendooven, P. (author), Löhner, H. (author), Beekman, F.J. (author)

The use of time-of-flight (TOF) information in positron emission tomography (PET) enables significant improvement in image noise properties and, therefore, lesion detection. Silicon photomultipliers (SiPMs) are solid-state photosensors that have several advantages over photomultiplier tubes (PMTs). SiPMs are small, essentially transparent to 511...

journal article 2010

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Pixel-based subsets for rapid multi-pinhole SPECT reconstruction

Branderhorst, W. (author), Vastenhouw, B. (author), Beekman, F.J. (author)

Single photon emission computed tomography (SPECT) and positron emission tomography (PET) visualize distributions of radioactive tracer molecules in vivo. These distributions can be calculated from projection images with iterative image reconstruction algorithms. In each iteration an update of the image is calculated after comparing a set of...

journal article 2010

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Optical simulation of monolithic scintillator detectors using GATE/GEANT4

Van der Laan, D.J. (author), Schaart, D.R. (author), Maas, M.C. (author), Beekman, F.J. (author), Bruyndonckx, P. (author), Van Eijk, C.W.E. (author)

Much research is being conducted on position-sensitive scintillation detectors for medical imaging, particularly for emission tomography. Monte Carlo simulations play an essential role in many of these research activities. As the scintillation process, the transport of scintillation photons through the crystal(s), and the conversion of these...

journal article 2010

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High-resolution tomography of positron emitters with clustered pinhole SPECT

Goorden, M.C. (author), Beekman, F.J. (author)

State-of-the-art small-animal single photon emission computed tomography (SPECT) enables sub-half-mm resolution imaging of radio-labelled molecules. Due to severe photon penetration through pinhole edges, current multi-pinhole SPECT is not suitable for high-resolution imaging of photons with high energies, such as the annihilation photons...

journal article 2010

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Small-animal SPECT and SPECT/CT: Application in cardiovascular research

Golestani, R. (author), Wu, C. (author), Tio, R.A. (author), Zeebregts, C.J. (author), Petrov, A.D. (author), Beekman, F.J. (author), Dierckx, R.A.J.O. (author), Boersma, H.H. (author), Slart, R.H.J.A. (author)

Preclinical cardiovascular research using noninvasive radionuclide and hybrid imaging systems has been extensively developed in recent years. Single photon emission computed tomography (SPECT) is based on the molecular tracer principle and is an established tool in noninvasive imaging. SPECT uses gamma cameras and collimators to form projection...

journal article 2010

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Theoretical analysis of full-ring multi-pinhole brain SPECT

Goorden, M.C. (author), Rentmeester, M.C.M. (author), Beekman, F.J. (author)

Presently used clinical brain SPECT suffers from limited spatio-temporal resolution. Here we investigate the feasibility of high-resolution and high-sensitivity full-ring multi-pinhole brain SPECT (MP-SPECT). Using an analytical model we optimized pinhole-detector geometries of MP-SPECT for different detector intrinsic resolutions Ri. System...

journal article 2009

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On-Chip Pixel Binning in Photon-Counting EMCCD-Based Gamma Camera: A Powerful Tool for Noise Reduction

Westra, A.H. (author), Heemskerk, J.W.T. (author), Korevaar, M.A.N. (author), Theuwissen, A.J.P. (author), Kreuger, R. (author), Ligtvoet, K.M. (author), Beekman, F.J. (author)

Charge Coupled Devices (CCDs) optically coupled to scintillation crystals can be used to construct high resolution gamma cameras. Previously, several groups have reported intrinsic detector spatial resolutions below 100 microns. When the CCD images can be read out fast enough, the energy and interaction position of individual gamma quanta can be...

journal article 2009

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3-D Rat Brain Phantom for High-Resolution Molecular Imaging: Experimental studies aimed at advancing understanding of human brain disease and malfunction, and of behavior problems, may be aided by computer models of small laboratory animals

Beekman, F.J. (author), Vastenhouw, B. (author), Van der Wilt, G. (author), Vervloet, M. (author), Visscher, R. (author), Booij, J. (author), Gerrits, M. (author), Ji, C. (author), Ramakers, R. (author), Van der Have, F. (author)

With the steadily improving resolution of novel small-animal single photon emission computed tomography (SPECT) and positron emission tomography devices, highly detailed phantoms are required for testing and optimizing these systems. We present a three-dimensional (3-D) digital and physical phantom pair to represent, e.g., cerebral blood flow,...

journal article 2009

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Small field-of-view dedicated cardiac SPECT systems: Impact of projection truncation

Xiao, J. (author), Verzijlbergen, F.J. (author), Viergever, M.A. (author), Beekman, F.J. (author)

journal article 2009