TY  - JOUR
A1  - Philipp, Mohr
A1  - Efthimiou, Nikos
A1  - Pagano, Fiammetta
A1  - Kratochwil, Nicolaus
A1  - Pizzichemi, Marco
A1  - Tsoumpas, Charalampos
A1  - Auffray, Etiennette
A1  - Ziemons, Karl
T1  - Image reconstruction analysis for positron emission tomography with heterostructured scintillators
JF  - IEEE Transactions on Radiation and Plasma Medical Sciences
N2  - The concept of structure engineering has been proposed for exploring the next generation of radiation detectors with improved performance. A TOF-PET geometry with heterostructured scintillators with a pixel size of 3.0×3.1×15 mm3 was simulated using Monte Carlo. The heterostructures consisted of alternating layers of BGO as a dense material with high stopping power and plastic (EJ232) as a fast light emitter. The detector time resolution was calculated as a function of the deposited and shared energy in both materials on an event-by-event basis. While sensitivity was reduced to 32% for 100 μm thick plastic layers and 52% for 50 μm, the CTR distribution improved to 204±49 ps and 220±41 ps respectively, compared to 276 ps that we considered for bulk BGO. The complex distribution of timing resolutions was accounted for in the reconstruction. We divided the events into three groups based on their CTR and modeled them with different Gaussian TOF kernels. On a NEMA IQ phantom, the heterostructures had better contrast recovery in early iterations. On the other hand, BGO achieved a better contrast to noise ratio (CNR) after the 15th iteration due to the higher sensitivity. The developed simulation and reconstruction methods constitute new tools for evaluating different detector designs with complex time responses.
KW  - TOF PET
KW  - Heterostructure
KW  - Metascintillator
KW  - Multiple TOF kernels
KW  - Image Reconstruction
Y1  - 2022
U6  - http://dx.doi.org/10.1109/TRPMS.2022.3208615
SN  - 2469-7311
SN  - 2469-7303
VL  - 7
IS  - 1
SP  - 41
EP  - 51
PB  - IEEE
CY  - New York, NY
ER  - 
TY  - CHAP
A1  - Streun, M.
A1  - Al-Kaddoum, R.
A1  - Parl, C.
A1  - Pietrzyk, U.
A1  - Ziemons, Karl
A1  - Waasen, S. van
T1  - Simulation studies of optical photons in monolithic block scintillators
T2  - 2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)
N2  - The interest in PET detectors with monolithic block scintillators is growing. In order to obtain high spatial resolutions dedicated positioning algorithms are required. But even an ideal algorithm can only deliver information which is provided by the detector. In this simulation study we investigated the light distribution on one surface of cuboid LSO scintillators of different size. Scintillators with a large aspect ratio (small footprint and large height) showed significant position information only for a minimum interaction depth of the gamma particle. The results allow a quantitative estimate for a useful aspect ratio.
Y1  - 2012
SN  - 978-1-4673-0120-6 (electronic ISBN)
SN  - 978-1-4673-0118-3 (print ISBN)
U6  - http://dx.doi.org/10.1109/NSSMIC.2011.6154621
SP  - 1380
EP  - 1382
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Parl, C.
A1  - Larue, H.
A1  - Streun, M.
A1  - Ziemons, Karl
T1  - Double-side-readout technique for SiPM-matrices
JF  - 2010 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)
N2  - In our case the double-side-method is used to minimize the complexity of a matrix-readout. Here the number of channels is reduced to 2√N̅. It is also possible to benefit from the method in a single pixel readout system. One signal can be used to measure position and energy of the event, the other one can be applied to a fast trigger-circuit at the same time. In a next step we will investigate timing behavior and electrical crosstalk of the circuit.
Y1  - 2011
SN  - 1095-7863
SP  - 1486
EP  - 1487
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Streun, M.
A1  - Larue, H.
A1  - Parl, C.
A1  - Ziemons, Karl
T1  - A compact PET detector readout using charge-to-time conversion
JF  - 2009 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)
N2  - The readout of gamma detectors is considerably simplified when the event intensity is encoded as a pulse width (Pulse Width Modulation, PWM). Time-to-Digital-Converters (TDC) replace the conventional ADCs and multiple TDCs can be realized easily in one PLD chip (Programmable Logic Device). The output of a PWM stage is only one digital signal per channel which is well suited for transport so that further processing can be performed apart from the detector. This is particularly interesting for large systems with high channel density (e.g. high resolution scanners). In this work we present a circuit with a linear transfer function that requires a minimum of components by performing the PWM already in the preamp stage. This allows a very compact and also cost-efficient implementation of the front-end electronics.
Y1  - 2009
SN  - 1082-3654
SP  - 1868
EP  - 1870
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Ziemons, Karl
A1  - Achten, R.
A1  - Auffray, E.
A1  - Müller-Veggian, Mattea
T1  - The ClearPET™ neuro scanner: a dedicated LSO/LuYAP phoswich small animal PET scanner
JF  - 2004 IEEE Nuclear Science Symposium conference record : Nuclear Science Symposium, Medical Imaging Conference ; 16 - 22 October 2004, Rome, Italy ; [including the Symposium on Nuclear Power System (SNPS), 14th Room Temperature Semiconductor X- and Gamma-Ray Detectors Workshop and special focus workshops] / NPSS, Nuclear & Plasma Sciences Society. Guest ed.: J. Anthony Seibert
Y1  - 2004
SN  - 1082-3654
N1  - Nuclear Science Symposium Conference Record, 2004 IEEE
SP  - 2430
EP  - 2433
PB  - IEEE Operations Center
CY  - Piscataway, NJ
ER  -