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A Studen,
E Chesi,
V Cindro,
N H Clinthorne,
E Cochran,
B Grošičar,
M Grkovski,
K Honscheid,
H Kagan,
C Lacasta,
G Llosa,
M Mikuž,
V Stankova, P Weilhammer,
D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Silicon based devices can extend PET-MR and SPECT-MR imaging to applications, where their advantages in performance outweigh benefits of high statistical counts.Silicon is in many ways an excellent detector material with numerous advantages, among others: excellent energy and spatial resolution, mature processing technology, large signal to noise ratio, relatively low price, availability, versatility and malleability. The signal in silicon is also immune to effects of magnetic field at the level normally used in MR devices. Tests in fields up to 7 T were performed in a study to determine effects of magnetic field on positron range in a silicon PET device. The curvature of positron tracks in direction perpendicular to the field's orientation shortens the distance between emission and annihilation point of the positron. The effect can be fully appreciated for a rotation of the sample for a fixed field direction, compressing range in all dimensions. A popular Ga-68 source was used showing a factor of 2 improvement in image noise compared to zero field operation. There was also a little increase in noise as the reconstructed resolution varied between 2.5 and 1.5 mm.A speculative applications can be recognized in both emission modalities, SPECT and PET.Compton camera is a subspecies of SPECT, where a silicon based scatter as a MR compatible part could inserted into the MR bore and the secondary detector could operate in less constrained environment away from the magnet. Introducing a Compton camera also relaxes requirements of the radiotracers used, extending the range of conceivable photon energies beyond 140.5 keV of the Tc-99m.In PET, one could exploit the compressed sub-millimeter range of positrons in the magnetic field. To exploit the advantage, detectors with spatial resolution commensurate to the effect must be used with silicon being an excellent candidate. Measurements performed outside of the MR achieving spatial resolution below 1 mm are reported.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 02/2013; 702:88-90. · 1.21 Impact Factor
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N H Clinthorne,
K Brzezinski,
E Chesi,
E Cochran,
M Grkovski,
B Grošičar,
K Honscheid,
S Huh,
H Kagan,
C Lacasta,
V Linhart,
M Mikuž,
S Smith,
V Stankova,
A Studen, P Weilhammer,
D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been a successful in achieving ~5mm FWHM spatial resolution in human studies and ~1mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches. Foremost is its high spatial resolution in 3D: our past studies show that there is little diffculty in localizing 511 keV photon interactions to ~0.3mm. Since spatial resolution and reconstructed image noise trade off in a highly non-linear manner that depends on the PET instrument response, if high spatial resolution is the goal, silicon may outperform standard PET detectors even though it has lower sensitivity to 511 keV photons. To evaluate silicon in a variety of PET "magnifying glass" configurations, an instrument has been constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors can be inserted to emulate dual-ring or imaging probe geometries. Recent results have demonstrated 0.7 mm FWHM resolution using pad detectors having 16×32 arrays of 1.4mm square pads and setups have shown promising results in both small animal and PET imaging probe configurations. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration.
Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2013; 699(21):216-220. · 1.21 Impact Factor
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V Linhart,
D Burdette,
E Chessi,
V Cindro,
N H Clinthorne,
E Cochran,
B Grošicar,
K Honscheid,
H Kagan,
C Lacasta,
G Llosá,
M Mikuž,
V Stankova,
A Studen, P Weilhammer,
D Žontar
[show abstract]
[hide abstract]
ABSTRACT: Spectroscopic and timing response studies have been conducted on a detector module consisting of a silicon Pixel Array Detector bonded on two VATAGP7 read-out chips manufactured by Gamma-Medica Ideas using laboratory gamma sources and the internal calibration facilities (the calibration system of the read-out chips). The performed tests have proven that the chips have (i) non-linear calibration curves which can be approximated by power functions, (ii) capability to measure the energy of photons with energy resolution better than 2 keV (exact range and resolution depend on experimental setup), (iii) the internal calibration facility which provides 6 out of 16 available internal calibration charges within our region of interest (spanning the Compton edge of 511 keV photons). The peaks induced by the internal calibration facility are suitable for a fit of the calibration curves. However, they are not suitable for measurements of equivalent noise charge because their full width at half maximum varies with their amplitude. These facts indicate that the VATAGP7 chips are useful and precise tools for a wide variety of spectroscopic devices. We have also explored time walk of the module and peaking time of the spectroscopy signals provided by the chips. We have observed that (iv) the time walk is caused partly by the peaking time of the signals provided by the fast shaper of the chips and partly by the timing uncertainty related to the varying position of the photon interaction, (v) the peaking time of the spectroscopy signals provided by the chips increases with increasing pulse height.
Journal of Instrumentation 01/2011; 6(01):C01092. · 1.87 Impact Factor
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A. Studen,
E. Chesi,
V. Cindro,
N.H. Clinthorne,
E. Cochran,
B. Grosicar,
K. Honscheid,
S.S. Huh,
H. Kagan,
C. Lacasta,
G. Llosa,
V. Linhart,
M. Mikuz,
V. Stankova, P. Weilhammer,
D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: PET probes are showing a lot of promise in extending performance of the conventional PET ring. The underlying idea is to supplement basic PET data with information collected in the finely segmented probe placed close to the region of interest. The benefit is two fold: a) data collected near the object are less prone to errors related to scattering and acolinearity and b) the object itself is magnified in the proximity focus. The principle would be beneficial to clinical applications where spatial resolution below the current limit is required in a narrow field of view. The probe should therefore have excellent spatial resolution, should be compact and robust and should be able to handle large count rates of the clinical environments. Based on those we decided to explore devices with high-resistivity silicon as the sensitive material. They provide high spatial resolution, are compact and robust, and can handle the foreseen rates. We constructed a prototype, based on 1 mm thick silicon wafers, cut into 40 by 26 mm<sup>2</sup> detectors further segmented into 1 × 1 mm<sup>2</sup> square pads, effectively providing 1 mm<sup>3</sup> sensitive voxels. For a module, two such detectors were placed in a back-to-back arrangement, providing filling factor in excess of 70 %. Stacking multiple modules is foreseen to compensate for low stopping power of silicon. The sensors are read out by 128 channel VATAGP7, GM-Ideas sourced application sensitive integrated circuit. Each module requires 16 chips, placed on 4 custom made PCB boards (hybrids) which are read independently. The modules were characterized and will be placed in a test PET ring. A simple point sources and phantoms will be imaged to confirm the predicted benefits.
Nuclear Science Symposium Conference Record (NSS/MIC), 2010 IEEE; 12/2010
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A Studen,
D Burdette,
E Chesi,
V Cindro,
N H Clinthorne,
E Cochran,
B Grosicar,
H Kagan,
C Lacasta,
V Linhart,
M Mikuz,
V Stankova, P Weilhammer,
D Zontar
[show abstract]
[hide abstract]
ABSTRACT: Simulation indicates that PET image could be improved by upgrading a conventional ring with a probe placed close to the imaged object. In this paper, timing issues related to a PET probe using high-resistivity silicon as a detector material are addressed. The final probe will consist of several (four to eight) 1-mm thick layers of silicon detectors, segmented into 1 x 1 mm(2) pads, each pad equivalent to an independent p + nn+ diode. A proper matching of events in silicon with events of the external ring can be achieved with a good timing resolution. To estimate the timing performance, measurements were performed on a simplified model probe, consisting of a single 1-mm thick detector with 256 square pads (1.4 mm side), coupled with two VATAGP7s, application-specific integrated circuits. The detector material and electronics are the same that will be used for the final probe. The model was exposed to 511 keV annihilation photons from an (22)Na source, and a scintillator (LYSO)-PMT assembly was used as a timing reference. Results were compared with the simulation, consisting of four parts: (i) GEANT4 implemented realistic tracking of electrons excited by annihilation photon interactions in silicon, (ii) calculation of propagation of secondary ionisation (electron-hole pairs) in the sensor, (iii) estimation of the shape of the current pulse induced on surface electrodes and (iv) simulation of the first electronics stage. A very good agreement between the simulation and the measurements were found. Both indicate reliable performance of the final probe at timing windows down to 20 ns.
Radiation Protection Dosimetry 03/2010; 139(1-3):199-203. · 0.82 Impact Factor
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P. Beltrame,
E. Bolle,
A. Braem,
C. Casella,
E. Chesi,
N. Clinthorne,
R. De Leo,
G. Dissertori,
L. Djambazov,
V. Fanti, [......],
F. Pauss,
M. Rafecas,
D. Renker,
A. Rudge,
D. Schinzel,
T. Schneider,
J. Seguinot,
P. Solevi,
S. Stapnes, P. Weilhammer
[show abstract]
[hide abstract]
ABSTRACT: The AX-PET demonstrator is based on a new concept in PET detectors, with LYSO crystals aligned along the z coordinate (patient's axis) and WLS (Wave-length shifter) strips placed orthogonal to them. This kind of structure permits to avoid parallax errors due to different depths of interaction of the photons in the crystals, to register the three coordinates of the impinging photon and to reconstruct Compton events. In this way both the spatial resolution and the sensitivity can be highly improved. Moreover, as both the LYSO crystals and the strips are readout via Geiger-mode Avalanche Photo Diodes (G-APDs) the detector is insensitive to magnetic fields and is then suitable to be used in a combined PET/MRI apparatus. A complete Monte Carlo simulation and dedicated reconstruction software, suited to the particular geometry arrangement, have been developed. The two final modules, each composed by 48 crystals and 156 WLS strips have been built and fully characterized in a dedicated test set-up. The results on the performances of the system obtained with a <sup>22</sup>Na point source (0.25 mm diameter) are reported.
Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE; 12/2009
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V. Linhart,
V. Borshchov,
D. Burdette,
E. Chesi,
V. Cindro,
N.H. Clinthorne,
E. Cochran,
B. Grosicar,
K. Honscheid,
H. Kagan,
C. Lacasta,
O. Listratenko,
G. Llosa,
M. Mikuz,
M. Protsenko,
V. Stankova,
A. Studen,
I. Tymchuk, P. Weilhammer,
D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: Detection and spectroscopy tests of the first functional unit of a self-dependent silicon detection module constructed on the base of micro-cable and TAB technology are presented. The tests were performed using pulse-height analysis of the signals induced by gamma rays in the silicon sensor. Good shapes of the spectra and satisfactory spectroscopy resolution (given by FWHM which is less than 2 keV) correspond with results on wire bonded modules. This fact demonstrates that the micro-cable technology does not degrade performance of the detection modules and the TAB is a prospective technology for construction of small stack of self-triggered spectroscopy system suitable for medical applications where very dense packaging of sensors and front-end electronics into small volumes is necessary.
Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE; 12/2009
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D. Burdette,
D. Albani,
E. Chesi,
N. H. Clinthorne,
E. Cochran,
K. Honscheid,
S.S. Huh,
H. Kagan,
M. Knopp,
C. Lacasta,
M. Mikuz,
P. Schmalbrock,
A. Studen, P. Weilhammer
2009 IEEE Nuclear Science Symposium Conference Record; 01/2009
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V. Stankova,
J. Bernabeu,
V. Borshchov,
D. Burdette,
E. Chesi,
N. H. Clinthorne,
Y. K. Dewaraja,
K. Honscheid,
H. Kagan,
C. Lacasta, [......],
V. Linhart,
M. Mikuz,
M. Protsenko,
W. L. Rogers,
V. Starkov,
A. Studen, P. Weilhammer,
L. Zhang,
G. Zinovjev,
D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: Recent progress in the development of micro-cables for very densely packed silicon pad detector modules to be used in a Compton Prostate Probe is reported. The purpose of this development is to optimize the packaging and interconnection of 1mm thick silicon sensors with their readout electronics in such a way that the assembly thickness is dominated by the sensor thickness. The sensor-chip interconnections are based on aluminum polyimide micro-cables. Development of micro-cables demonstrate that TAB technology can replace wire bonding technology, which does not allow optimally dense packaging, with TAB bonded modules which have electronically equally good performance. That gives us a motivation for the development of a detector-cable and chipcable assembly TABed to a very thin PCB module by a two layer detector cable achieving a total height of only 1.2mm.
Nuclear Science Symposium Conference Record, 2008. NSS '08. IEEE; 11/2008
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G. Llosa,
J. Bernabeu,
D. Burdette,
E. Chesi,
N.H. Clinthorne,
K. Honscheid,
H. Kagan,
C. Lacasta,
M. Mikuz,
P. Modesto,
W.L. Rogers,
A. Studen, P. Weilhammer
[show abstract]
[hide abstract]
ABSTRACT: A first prostate probe prototype based on the Compton imaging technique has been developed, with a scatter detector composed of a stack of five thick silicon pad detectors, and a scintillator as absorption detector. The silicon sensors are 4 cm times 1 cm, 1 mm thick, with 1.4 mm times 1.4 mm pad dimensions. The scatter detector performance has been optimized, and an energy resolution about 1.4 keV FWHM is obtained. The absorption detector consists of three Nal(Tl) scintillators that are placed around the scatter detector. A spatial resolution of 5 mm FWHM has been measured reconstructing an image of a point-like 133 Ba source placed at 11 cm distance from the scatter detector. Additional studies show the improvement of the detector resolution with increasing incident photon energy and relative distance from the scatter to the absorption detector. Simulations have also been performed for a complete understanding of the data, and to predict the expected resolution at near field operation of the device. The prototype construction is the first step in the development of a Compton probe for prostate imaging.
IEEE Transactions on Nuclear Science 07/2008; · 1.45 Impact Factor
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A Braem,
E Chesi,
C Joram,
S Mathot,
J Seuinot, P Weilhammer,
F Ciocia,
R De Leo,
E Nappi,
I Vilardi,
A Argentieri,
F Corsi,
A Dragone,
D Pasqua
[show abstract]
[hide abstract]
ABSTRACT: A u t h o r ' s p e r s o n a l c o p y Abstract We describe the design, fabrication and test results of a segmented Hybrid Photon Detector with integrated auto-triggering front-end electronics. Both the photodetector and its VLSI readout electronics are custom designed and have been tailored to the requirements of a recently proposed novel geometrical concept of a Positron Emission Tomograph. Emphasis is laid on the PET specific features of the device. The detector has been fabricated in the photocathode facility at CERN.
Nuclear Instruments and Methods in Physics Research A. 01/2007; 57160(85).
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D. Burdette,
E. Chesi,
N.H. Clinthorne,
E. Cochran,
K. Honscheid,
S.S. Huh,
H. Kagan,
M. Knopp,
C. Lacasta,
M. Mikuz,
W.L. Rogers,
P. Schmalbrock,
A. Studen, P. Weilhammer
[show abstract]
[hide abstract]
ABSTRACT: Very high resolution images can be achieved in small animal PET systems utilizing solid state silicon detectors (Compton PET). In such systems with sub-millimeter intrinsic resolutions, the range of the positron is the largest contribution to image blur. The size of the positron range effect depends on the initial positron energy and hence the radioactive tracer used. For higher energy positron emitters, such as <sup>124</sup>I and <sup>94m</sup>Tc which are gaining importance in small animal studies, the variation of the annihilation point dominates the spatial resolution. It has been suggested that this positron range effect can be reduced by embedding the PET field of view in a strong magnetic field. Conventional PET systems using scintillators and photomultiplier tubes require extensive modifications to operate in magnet fields; however, our silicon detector based system can operate in magnetic fields with minimal modifications. In this paper we present a progress report of embedding our small animal PET test-bench in magnetic fields up to 7 Tesla.
Nuclear Science Symposium Conference Record, 2006. IEEE; 12/2006
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[show abstract]
[hide abstract]
ABSTRACT: CdTe and CdZnTe deliver good energy resolution and stopping power in a room temperature solid state detector. Currently, these materials are becoming more available and larger detectors are being constructed by tiling many single crystal modules together. However, CdTe and CdZnTe remain expensive and it is therefore desirable to make use of as much of the crystal as possible and to tile the individual crystals closely with little or no dead space. Reducing surface current on these crystals without the use of guard rings could allow pixel maps to be extended to the edge of the crystal, thus making more effective use of the material and allowing tiling with less dead space. We have therefore developed a method of passivating the surface current in single crystal CdTe and CdZnTe detectors. Using this passivation method we have constructed a CdTe detector with 256 pixels which extend all the way to the edge of the crystal. To validate our results, we have also constructed a testing device, based on spring loaded gold plated pins, which can non-destructively test the current in each pixel of such a detector. Using this testing device, we have compared the dark current of edge pixels before and after our passivation process and see a significant reduction in surface current after passivation. The elimination of guard rings along with our implementation of a backplane readout solution allows this detector module to be tiled with dead space close that of the pixel septa.
Nuclear Science Symposium Conference Record, 2006. IEEE; 12/2006
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A. Studen,
D. Burdette,
E. Chesi,
N.H. Clinthorne,
S.S. Huh,
K. Honscheid,
H. Kagan,
C. Lacasta,
G. Llosa,
M. Mikuz,
W.L. Rogers, P. Weilhammer
[show abstract]
[hide abstract]
ABSTRACT: Our group is developing a Compton camera [Clinthorne, N, 2006] for medical imaging. Most camera incarnations envision the scatterer as a set of thick silicon pad detectors, and the absorber as a conventional NaI scintillator camera. High single detector countrates are expected in both sub-detectors, requiring good timing resolution in both detectors. For this paper the timing properties of currently used pad detectors associated with readout electronics were tested. The silicon pad detectors used were 1 mm thick, with a pad size of 1.4 by 1.4 mm<sup>2</sup>. The depletion voltage was 140 V, and the range of biases set were up to 300 V. The detectors are coupled to VATAGP3 ASIC; each channel consists of a charge-sensitive amplifier coupled to a pair of CR-RC shapers (200 ns, 2-5 mus). Trigger is given by a leading edge discriminator on the fast shaped pulse. The results were encouraging, showing 15-19 ns FWHM timing resolution with no time-walk correction for interaction electron energies above 10-times the threshold set on the triggering circuit. The present simulation studies predicted even a slightly worse resolution and the discrepancy will be resolved in further studies.
Nuclear Science Symposium Conference Record, 2006. IEEE; 12/2006
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[show abstract]
[hide abstract]
ABSTRACT: We have developed an automated system for the characterization and testing of CdZnTe/CdTe pixel detectors for X-ray and gamma-ray imaging. A set of custom made pogo-pin arrays and corresponding detector holders have been designed for a precise, non-damaging loading and unloading of detectors to a "measurement habitat" within the system. The architecture of the system is flexible, allowing measurements of current, spectral responses and pulse shapes from individual detector pixels. A multi-channel read-out (up to 256 channels) based on CMOS switches make possible the monitoring of leakage and/or X-ray induced photo- currents sequentially for all individual pixels, for groups of pixels, or for the full detector with different voltage ramping scenario. A measurement of spectral pixel responses can be done with a single-photon-counting ASIC for up to 256 pixels simultaneously, or from individual pixel(s) with discrete read-out electronics. The test system can satisfy many experimental needs including measurements of a detector's: 1) temporal response under X-ray or gamma ray irradiation; 2) photon count rate performance; 3) bulk/contact charge transport properties; 4) guard ring or/and passivation effectiveness, and 5) long term stability. Control and data acquisition can be conducted with a local computer, or via the Internet. The system has been successfully operated for about 2 years. Examples of the results obtained with detectors fabricated from different material vendors are presented.
Nuclear Science Symposium Conference Record, 2006. IEEE; 12/2006
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A. Dragone,
F. Corsi,
C. Marzocca,
P. Losito,
D. Pasqua,
E. Nappi,
R. De Leo,
J. Seguinot,
A. Braem,
E. Chesi,
C. Joram, P. Weilhammer,
F. Garibaldi,
H. Zaidi
[show abstract]
[hide abstract]
ABSTRACT: The design of a data acquisition system (DAQ) for a novel positron emission tomography (PET) scanner is reported. The PET system, based on long axially oriented scintillation crystals, readout by hybrid photon detectors (HPD), allows 3-D parallax-error free Compton enhanced gamma reconstruction. The DAQ system is composed of several readout cards, each one associated with a module of the PET scanner, and of a main card that controls the whole system. Using fast triggering signals from the silicon sensor back-planes, the main card performs the coincidence analysis and, in case of coincidence, it enables the readout of the two modules involved. The other modules are left free to perform new acquisitions. This concept based on several independent, event-driven and parallel readout chains, drastically reduces the acquisition dead time. Each enabled readout card digitizes, encodes and stores data from the associated module. Data are stored in a local FIFO and then are transferred through a network into a single computer. The system is designed according to the specifications of the IDEAS VaTaGP5 chip. Each readout card is able to accommodate all the chip readout modes and the test procedures and can be used as a standalone readout system that allows reading out up to 16 daisy chained chips per channel. The DAQ system here reported, designed for a two module demonstrator setup, was developed to study and optimize the essential design parameters.
IEEE Transactions on Nuclear Science 07/2006; · 1.45 Impact Factor
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Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 01/2006; 565(1):227-233. · 1.21 Impact Factor
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S.S. Huh,
D. Burdette,
E. Chesi,
K. Honscheid,
H. Kagan,
C. Lacasta,
G. Llosa,
M. Mikuz,
S.-J. Park,
W.L. Rogers,
A. Studen, P. Weilhammer,
N.H. Clinthorne
[show abstract]
[hide abstract]
ABSTRACT: A pixelated silicon positron sensitive imaging probe is under development to precisely localize superficially located tumors accumulating <sup>18</sup>F-FDG. <sup>18</sup>F-FDG has been a radioisotope of interest mainly because of the high uptake in tumors and the relatively short positron range. Silicon detectors have generally low detection efficiency for high energy photons and can be used for positron detection. We present a pixelated silicon positron sensitive imaging probe that has the 1.4-by-1.4-by-1.0 mm pixel size with equivalent electronic noise of ~1.2 keV FWHM. The small pixel size leads to the high spatial resolution. Probe movement in conjunction with appropriate reconstruction will allow sub-pixel resolution to be achieved. In addition the high energy resolution makes it possible to get depth information from the spectrum of deposited beta energies. We discuss data from Monte Carlo simulations, which will be useful for predicting performance of various configurations of completed devices. Also we report preliminary data from a simple experimental setup
Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005
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C. Lacasta,
J. Bernabeu,
V. Borshchov,
D. Burdette,
E. Chesi,
N.H. Clinthorne,
Y.K. Dewaraja,
K. Honscheid,
H. Kagan,
A. Listratenko, [......],
M. Mikuz,
P. Modesto,
M. Protsenko,
W.L. Rogers,
V. Starkov,
A. Studen, P. Weilhammer,
L. Zhang,
G. Zinovjev,
D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: This contribution describes the work made towards packaging optimization in the frame of the development of an endorectal probe for imaging the prostate. This application is based on the concept of electronic collimation for single gamma detection taking advantage of the Compton scattering of the photons in a stack of 1 mm thick silicon pad detectors and their later absorption in an external detector. This concept allows to remove the mechanical collimators used in the usual gamma cameras and, therefore, provides the possibility of improving both sensitivity and resolution. Packaging of the silicon sensors and their associated electronics is of paramount importance in this application. To address this important aspect of the device we have explored the tape automated bonding (TAB) technique for the connection of the silicon sensors to the readout electronics and for routing the signals to the outside. TAB offers an elegant solution not only for a flexible and compact interconnection between the readout ASICs and the sensors but also for ASIC selection and testing prior to the assembly of the detector and their associated readout electronics
Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005
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C. Lacasta,
J. Bernabeu,
D. Burdette,
E. Chesi,
N.H. Clinthorne,
Y.K. Dewaraja,
K. Honscheid,
H. Kagan,
G. Llosa,
M. Mikuz,
P. Modesto,
W.L. Rogers,
A. Studen, P. Weilhammer,
L. Zhang,
D. Zontar
[show abstract]
[hide abstract]
ABSTRACT: A first prototype of a Compton prostate probe has been built using a stack of five 4times1 cm<sup>2</sup>, 1 mm thick silicon pad detectors as a scatter detector, surrounded by three scintillation detectors in which the absorption of the scattered photons takes place. The silicon pad dimensions are 1.4times1.4 mm which provide the required spatial resolution. The energy resolution in the silicon sensors is about 1.4 keV FWHM as determined from several gamma sources. The results obtained validate the simulation predictions that foresee an improvement over current SPECT techniques by a factor 16-40 in sensitivity and 4-5 in spatial resolution simultaneously for an intra-rectal probe built employing this concept and placed at 2 cm from the prostate
Nuclear Science Symposium Conference Record, 2005 IEEE; 11/2005
