TY  - JOUR
A1  - Vos, E. K.
A1  - Lagemaat, M. W.
A1  - Barentsz, J. O.
A1  - Fütterer, J. J.
A1  - Zamecnik, P.
A1  - Roozen, H.
A1  - Orzada, S.
A1  - Bitz, Andreas
A1  - Maas, M. C.
A1  - Scheenen, T. W. J.
T1  - Image quality and cancer visibility of T2-weighted Magnetic Resonance Imaging of the prostate at 7 Tesla
JF  - European Radiology
N2  - Objectives
To assess the image quality of T2-weighted (T2w) magnetic resonance imaging of the prostate and the visibility of prostate cancer at 7 Tesla (T).

Materials & methods
Seventeen prostate cancer patients underwent T2w imaging at 7T with only an external transmit/receive array coil. Three radiologists independently scored images for image quality, visibility of anatomical structures, and presence of artefacts. Krippendorff’s alpha and weighted kappa statistics were used to assess inter-observer agreement. Visibility of prostate cancer lesions was assessed by directly linking the T2w images to the confirmed location of prostate cancer on histopathology.

Results
T2w imaging at 7T was achievable with ‘satisfactory’ (3/5) to ‘good’ (4/5) quality. Visibility of anatomical structures was predominantly scored as ‘satisfactory’ (3/5) and ‘good’ (4/5). If artefacts were present, they were mostly motion artefacts and, to a lesser extent, aliasing artefacts and noise. Krippendorff’s analysis revealed an α = 0.44 between three readers for the overall image quality scores. Clinically significant cancer lesions in both peripheral zone and transition zone were visible at 7T.

Conclusion
T2w imaging with satisfactory to good quality can be routinely acquired, and cancer lesions were visible in patients with prostate cancer at 7T using only an external transmit/receive body array coil.
Y1  - 2014
U6  - https://doi.org/10.1007/s00330-014-3234-6
SN  - 1432-1084
VL  - 24
IS  - 8
SP  - 1950
EP  - 1958
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Hillen, Walter
A1  - Schiebel, U.
A1  - Zaengel, T.
T1  - Image quality in selenium-based digital radiography. Schiebel, U.; Hillen, W.; Zaengel, T.
JF  - Medical Imaging
Y1  - 1986
N1  - Proceedings of SPIE ;  626
SP  - 176
ER  - 
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  - https://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  - JOUR
A1  - Kurz, Melanie
T1  - Images of Sweden in Germany: from Sundborn and Bullerby to Ikea
JF  - nomad: the magazine for new design culture, business affairs and contemporary lifestyle
Y1  - 2019
SN  - 2513-0714
IS  - 8
SP  - 136
EP  - 147
ER  - 
TY  - JOUR
A1  - Hillen, Walter
A1  - Schiebel, U.
A1  - Zaengel, T.
T1  - Imaging performance of a digital storage phosphor system
JF  - Medical Physics. 14 (1987), H. 5
Y1  - 1987
SN  - 0094-2405
SP  - 744
EP  - 751
ER  - 
TY  - JOUR
A1  - Hillen, Walter
A1  - Rupp, S.
A1  - Schiebel, U.
A1  - Zaengel, Thomas T.
T1  - Imaging performance of a selenium-based detector for high-resolution radiography
JF  - Medical Imaging III: Image Formation
Y1  - 1989
SN  - 0-8194-0125-0
N1  - Proceedings of SPIE ; 1090
SP  - 296
ER  - 
TY  - THES
A1  - Bung, Daniel Bernhard
T1  - Imaging techniques for investigation of free-surface flows in hydraulic laboratories
N2  - This thesis aims at the presentation and discussion of well-accepted and new
imaging techniques applied to different types of flow in common hydraulic
engineering environments. All studies are conducted in laboratory conditions and
focus on flow depth and velocity measurements. Investigated flows cover a wide
range of complexity, e.g. propagation of waves, dam-break flows, slightly and fully
aerated spillway flows as well as highly turbulent hydraulic jumps.
Newimagingmethods are compared to different types of sensorswhich are frequently
employed in contemporary laboratory studies. This classical instrumentation as well
as the general concept of hydraulic modeling is introduced to give an overview on
experimental methods.
Flow depths are commonly measured by means of ultrasonic sensors, also known as
acoustic displacement sensors. These sensors may provide accurate data with high
sample rates in case of simple flow conditions, e.g. low-turbulent clear water flows.
However, with increasing turbulence, higher uncertainty must be considered.
Moreover, ultrasonic sensors can provide point data only, while the relatively large
acoustic beam footprint may lead to another source of uncertainty in case of
relatively short, highly turbulent surface fluctuations (ripples) or free-surface
air-water flows. Analysis of turbulent length and time scales of surface fluctuations
from point measurements is also difficult. Imaging techniques with different
dimensionality, however, may close this gap. It is shown in this thesis that edge
detection methods (known from computer vision) may be used for two-dimensional
free-surface extraction (i.e. from images taken through transparant sidewalls in
laboratory flumes). Another opportunity in hydraulic laboratory studies comes with
the application of stereo vision. Low-cost RGB-D sensors can be used to gather
instantaneous, three-dimensional free-surface elevations, even in flows with very
high complexity (e.g. aerated hydraulic jumps). It will be shown that the uncertainty
of these methods is of similar order as for classical instruments.
Particle Image Velocimetry (PIV) is a well-accepted and widespread imaging
technique for velocity determination in laboratory conditions. In combination with
high-speed cameras, PIV can give time-resolved velocity fields in 2D/3D or even as
volumetric flow fields. PIV is based on a cross-correlation technique applied to small
subimages of seeded flows. The minimum size of these subimages defines the
maximum spatial resolution of resulting velocity fields. A derivative of PIV for
aerated flows is also available, i.e. the so-called Bubble Image Velocimetry (BIV). This
thesis emphasizes the capacities and limitations of both methods, using relatively
simple setups with halogen and LED illuminations. It will be demonstrated that
PIV/BIV images may also be processed by means of Optical Flow (OF) techniques.
OF is another method originating from the computer vision discipline, based on the
assumption of image brightness conservation within a sequence of images. The
Horn-Schunck approach, which has been first employed to hydraulic engineering
problems in the studies presented herein, yields dense velocity fields, i.e. pixelwise
velocity data. As discussed hereinafter, the accuracy of OF competes well with PIV
for clear-water flows and even improves results (compared to BIV) for aerated flow
conditions. In order to independently benchmark the OF approach, synthetic images
with defined turbulence intensitiy are used.
Computer vision offers new opportunities that may help to improve the
understanding of fluid mechanics and fluid-structure interactions in laboratory
investigations. In prototype environments, it can be employed for obstacle detection
(e.g. identification of potential fish migration corridors) and recognition (e.g. fish
species for monitoring in a fishway) or surface reconstruction (e.g. inspection of
hydraulic structures). It can thus be expected that applications to hydraulic
engineering problems will develop rapidly in near future. Current methods have not
been developed for fluids in motion. Systematic future developments are needed to
improve the results in such difficult conditions.
Y1  - 2023
U6  - https://doi.org/10.25926/BUW/0-172
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Schmidt, T.
A1  - Haug, R. J.
T1  - Imaging the local density of states in a disordered semiconductor / T. Schmidt ; R. J. Haug ; V. I. Fal'ko ... A. Förster ...
JF  - 23rd International Conference on the Physics of Semiconductors : Berlin, Germany, July 21 - 26, 1996 / ed.: Matthias Scheffler ... - Vol. 3
Y1  - 1996
SN  - 981-02-2947-X
N1  - International Conference on the Physics of Semiconductors <23, 1996, Berlin>
SP  - 2251
EP  - ff.
PB  - World Scientific
CY  - Singapore [u.a.]
ER  - 
TY  - JOUR
A1  - Biselli, Manfred
A1  - Lüllau, E.
A1  - Dreisbach, C.
A1  - Grogg, A.
T1  - Immobilization of animal cells on chemically modified siran carrier / Lüllau, E. ; Dreisbach, C. ; Grogg, A. ; Biselli, M. ; Wandrey, C.
JF  - Animal cell technology : developments, processes, and products ; ESACT, European Society for Animal Cell Technology, the 11th meeting / Ed. R. E. Spier
Y1  - 1992
SN  - 0750604212
SP  - 469
EP  - 475
PB  - Butterworth-Heinemann
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Mourzina, I.G.
A1  - Yoshinobu, T.
A1  - Ermolenko, Y.E.
A1  - Vlasov, Y. G.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Immobilization of urease and cholinesterase on the surface of semiconductor transducer for the development of light-addressable potentiometric sensors
JF  - Technical digest of the 10th International Meeting on Chemical Sensors, July 11 - 14, 2004, Tsukuba, Japan / Japan Association of Chemical Sensors
Y1  - 2004
N1  - Chemical sensors ; 20.2004 Suppl. B. IMCS ; (10, 2004, Tsukuba) ; International Meeting on Chemical Sensors ; (10 : ; 2004.07.11-14 : ; Tsukuba)
SP  - 788
EP  - 789
PB  - Japan Association of Chemical Sensors
CY  - Fukuoka
ER  -