A novel fully integrated handheld gamma camera

Energy Technology Data Exchange (ETDEWEB)

Massari, R.; Ucci, A.; Campisi, C. [Biostructure and Bioimaging Institute (IBB), National Research Council of Italy (CNR), Rome (Italy); Scopinaro, F. [University of Rome “La Sapienza”, S. Andrea Hospital, Rome (Italy); Soluri, A., E-mail: alessandro.soluri@ibb.cnr.it [Biostructure and Bioimaging Institute (IBB), National Research Council of Italy (CNR), Rome (Italy)

2016-10-01

In this paper, we present an innovative, fully integrated handheld gamma camera, namely designed to gather in the same device the gamma ray detector with the display and the embedded computing system. The low power consumption allows the prototype to be battery operated. To be useful in radioguided surgery, an intraoperative gamma camera must be very easy to handle since it must be moved to find a suitable view. Consequently, we have developed the first prototype of a fully integrated, compact and lightweight gamma camera for radiopharmaceuticals fast imaging. The device can operate without cables across the sterile field, so it may be easily used in the operating theater for radioguided surgery. The prototype proposed consists of a Silicon Photomultiplier (SiPM) array coupled with a proprietary scintillation structure based on CsI(Tl) crystals. To read the SiPM output signals, we have developed a very low power readout electronics and a dedicated analog to digital conversion system. One of the most critical aspects we faced designing the prototype was the low power consumption, which is mandatory to develop a battery operated device. We have applied this detection device in the lymphoscintigraphy technique (sentinel lymph node mapping) comparing the results obtained with those of a commercial gamma camera (Philips SKYLight). The results obtained confirm a rapid response of the device and an adequate spatial resolution for the use in the scintigraphic imaging. This work confirms the feasibility of a small gamma camera with an integrated display. This device is designed for radioguided surgery and small organ imaging, but it could be easily combined into surgical navigation systems.

Gamma camera

International Nuclear Information System (INIS)

Schlosser, P.A.; Steidley, J.W.

1980-01-01

The design of a collimation system for a gamma camera for use in nuclear medicine is described. When used with a 2-dimensional position sensitive radiation detector, the novel system can produce superior images than conventional cameras. The optimal thickness and positions of the collimators are derived mathematically. (U.K.)

Decision about buying a gamma camera

International Nuclear Information System (INIS)

Ganatra, R.D.

1992-01-01

A large part of the referral to a nuclear medicine department is usually for imaging studies. Sooner or later, the nuclear medicine specialist will be called upon to make a decision about when and what type of gamma camera to buy. There is no longer an option of choosing between a rectilinear scanner and a gamma camera as the former is virtually out of the market. The decision that one has to make is when to invest in a gamma camera, and then on what basis to select the gamma camera

Decision about buying a gamma camera

Energy Technology Data Exchange (ETDEWEB)

Ganatra, R D

1993-12-31

A large part of the referral to a nuclear medicine department is usually for imaging studies. Sooner or later, the nuclear medicine specialist will be called upon to make a decision about when and what type of gamma camera to buy. There is no longer an option of choosing between a rectilinear scanner and a gamma camera as the former is virtually out of the market. The decision that one has to make is when to invest in a gamma camera, and then on what basis to select the gamma camera 1 tab., 1 fig

Computer assisted collimation gamma camera: A new approach to imaging contaminated tissues

International Nuclear Information System (INIS)

Quartuccio, M.; Franck, D.; Pihet, P.; Begot, S.; Jeanguillaume, C.

2000-01-01

Measurement systems with the capability of imaging tissues contaminated with radioactive materials would find relevant applications in medical physics research and possibly in health physics. The latter in particular depends critically on the performance achieved for sensitivity and spatial resolution. An original approach of computer assisted collimation gamma camera (French acronym CACAO) which could meet suitable characteristics has been proposed elsewhere. CACAO requires detectors with high spatial resolution. The present work was aimed at investigating the application of the CACAO principle on a laboratory testing bench using silicon detectors made of small pixels. (author)

Computer assisted collimation gamma camera: A new approach to imaging contaminated tissues

Energy Technology Data Exchange (ETDEWEB)

Quartuccio, M.; Franck, D.; Pihet, P.; Begot, S.; Jeanguillaume, C

2000-07-01

Measurement systems with the capability of imaging tissues contaminated with radioactive materials would find relevant applications in medical physics research and possibly in health physics. The latter in particular depends critically on the performance achieved for sensitivity and spatial resolution. An original approach of computer assisted collimation gamma camera (French acronym CACAO) which could meet suitable characteristics has been proposed elsewhere. CACAO requires detectors with high spatial resolution. The present work was aimed at investigating the application of the CACAO principle on a laboratory testing bench using silicon detectors made of small pixels. (author)

Miniature gamma-ray camera for tumor localization

International Nuclear Information System (INIS)

Lund, J.C.; Olsen, R.W.; James, R.B.; Cross, E.

1997-08-01

The overall goal of this LDRD project was to develop technology for a miniature gamma-ray camera for use in nuclear medicine. The camera will meet a need of the medical community for an improved means to image radio-pharmaceuticals in the body. In addition, this technology-with only slight modifications-should prove useful in applications requiring the monitoring and verification of special nuclear materials (SNMs). Utilization of the good energy resolution of mercuric iodide and cadmium zinc telluride detectors provides a means for rejecting scattered gamma-rays and improving the isotopic selectivity in gamma-ray images. The first year of this project involved fabrication and testing of a monolithic mercuric iodide and cadmium zinc telluride detector arrays and appropriate collimators/apertures. The second year of the program involved integration of the front-end detector module, pulse processing electronics, computer, software, and display

Fully integrated digital GAMMA camera-computer system

International Nuclear Information System (INIS)

Berger, H.J.; Eisner, R.L.; Gober, A.; Plankey, M.; Fajman, W.

1985-01-01

Although most of the new non-nuclear imaging techniques are fully digital, there has been a reluctance in nuclear medicine to abandon traditional analog planar imaging in favor of digital acquisition and display. The authors evaluated a prototype digital camera system (GE STARCAM) in which all of the analog acquisition components are replaced by microprocessor controls and digital circuitry. To compare the relative effects of acquisition matrix size on image quality and to ascertain whether digital techniques could be used in place of analog imaging, Tc-99m bone scans were obtained on this digital system and on a comparable analog camera in 10 patients. The dedicated computer is used for camera setup including definition of the energy window, spatial energy correction, and spatial distortion correction. The display monitor, which is used for patient positioning and image analysis, is 512/sup 2/ non-interlaced, allowing high resolution imaging. Data acquisition and processing can be performed simultaneously. Thus, the development of a fully integrated digital camera-computer system with optimized display should allow routine utilization of non-analog studies in nuclear medicine and the ultimate establishment of fully digital nuclear imaging laboratories

Optimization of gamma-ray cameras of Anger type

International Nuclear Information System (INIS)

Jatteau, Michel; Lelong, Pierre; Normand, Gerard; Ott, Jean; Pauvert, Joseph; Pergrale, Jean

1979-01-01

Most of the radionuclide imaging equipments used for the diagnosis in nuclear medicine include a scintillation camera of the Anger type. Following a period of camera improvements connected to pure technological advances, perfecting the camera can only result nowadays from more thorough studies based on numerical approaches and computer simulations. Two important contributions to an optimization study of Anger gamma-ray cameras are presented, the first one being related to the light collection by the photomultiplier tubes, i.e. one of the processes which determine for a large part the performance parameters; the second one being connected to the computation of the intrinsic geometrical and spectral resolutions, which are two of the main characteristics acting on the image quality. The validity of computer simulation is shown by comparison between theoretical and experimental results before the simulation programmes to study the influence of various parameters are used [fr

The use of a portable gamma camera for preoperative lymphatic mapping: a comparison with a conventional gamma camera

Energy Technology Data Exchange (ETDEWEB)

Vidal-Sicart, Sergi; Paredes, Pilar [Hospital Clinic Barcelona, Nuclear Medicine Department (CDIC), Barcelona (Spain); Institut d' Investigacio Biomedica Agusti Pi Sunyer (IDIBAPS), Barcelona (Spain); Vermeeren, Lenka; Valdes-Olmos, Renato A. [Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital (NKI-AVL), Nuclear Medicine Department, Amsterdam (Netherlands); Sola, Oriol [Hospital Clinic Barcelona, Nuclear Medicine Department (CDIC), Barcelona (Spain)

2011-04-15

Planar lymphoscintigraphy is routinely used for preoperative sentinel node visualization, but large gamma cameras are not always available. We evaluated the reproducibility of lymphatic mapping with a smaller and portable gamma camera. In two centres, 52 patients with breast cancer received preoperative lymphoscintigraphy with a conventional gamma camera with a field of view of 40 x 40 cm. Static anterior and lateral images were performed at 15 min, 2 h and 4 h after injection of the radiotracer ({sup 99m}Tc-nanocolloid). At 2 h after injection, anterior and oblique images were also performed with a portable gamma camera (Sentinella, Oncovision) positioned to obtain a field of view of 20 x 20 cm. Visualization of lymphatic drainage on conventional images and images with the portable device were compared for number of nodes depicted, their intensity and localization of sentinel nodes. The images performed with the conventional gamma camera depicted sentinel nodes in 94%, while the portable gamma camera showed drainage in 73%. There was however no significant difference in visualization between the two devices when a lead shield was used to mask the injection area in 43 patients (95 vs 88%, p = 0.25). Second-echelon nodes were visualized in 62% of the patients with the conventional gamma camera and in 29% of the cases with the portable gamma camera. Preoperative imaging with a portable gamma camera fitted with a pinhole collimator to obtain a field of view of 20 x 20 cm is able to depict sentinel nodes in 88% of the cases, if a lead shield is used to mask the injection site. This device may be useful in centres without the possibility to perform a preoperative image. (orig.)

The use of a portable gamma camera for preoperative lymphatic mapping: a comparison with a conventional gamma camera

International Nuclear Information System (INIS)

Vidal-Sicart, Sergi; Paredes, Pilar; Vermeeren, Lenka; Valdes-Olmos, Renato A.; Sola, Oriol

2011-01-01

Planar lymphoscintigraphy is routinely used for preoperative sentinel node visualization, but large gamma cameras are not always available. We evaluated the reproducibility of lymphatic mapping with a smaller and portable gamma camera. In two centres, 52 patients with breast cancer received preoperative lymphoscintigraphy with a conventional gamma camera with a field of view of 40 x 40 cm. Static anterior and lateral images were performed at 15 min, 2 h and 4 h after injection of the radiotracer ( 99m Tc-nanocolloid). At 2 h after injection, anterior and oblique images were also performed with a portable gamma camera (Sentinella, Oncovision) positioned to obtain a field of view of 20 x 20 cm. Visualization of lymphatic drainage on conventional images and images with the portable device were compared for number of nodes depicted, their intensity and localization of sentinel nodes. The images performed with the conventional gamma camera depicted sentinel nodes in 94%, while the portable gamma camera showed drainage in 73%. There was however no significant difference in visualization between the two devices when a lead shield was used to mask the injection area in 43 patients (95 vs 88%, p = 0.25). Second-echelon nodes were visualized in 62% of the patients with the conventional gamma camera and in 29% of the cases with the portable gamma camera. Preoperative imaging with a portable gamma camera fitted with a pinhole collimator to obtain a field of view of 20 x 20 cm is able to depict sentinel nodes in 88% of the cases, if a lead shield is used to mask the injection site. This device may be useful in centres without the possibility to perform a preoperative image. (orig.)

ISPA - a high accuracy X-ray and gamma camera Exhibition LEPFest 2000

CERN Multimedia

2000-01-01

ISPA offers ... Ten times better resolution than Anger cameras High efficiency single gamma counting Noise reduction by sensitivity to gamma energy ...for Single Photon Emission Computed Tomography (SPECT)

Comparison of uteroplacental blood flow in normal and pre-eclamptic patients measurement with technetium-99m and a computer-linked gamma camera

International Nuclear Information System (INIS)

Cho, S.H.; Moon, H.; Kim, D.S.; Cho, S.S.

1985-01-01

Uteroplacental blood flow studies in preeclampsia are of special interest since the vascular changes reported in this disease might constitute a structural basis for a reduction of blood flow. Evidence has also been given for a decreased uteroplacental blood flow in preeclampsia. Among the various methods to estimate the maternal placental blood flow, the one most frequently reported in the literature during the last years has been the time activity analysis of short lived radiotracer such as technetium-99m or indium-113m injected intravenously. Only few studies with the above mentioned technique comparing normal and preeclampsia cases have been undertaken. In clinical practice we frequently experience difficuly in finding the optimal time to get the delivery in preeclampsia patients. The aim of this study was first to measure uteroplacental blood flow in preeclamptic pregnancies using a computer-linked gamma camera method for the time-activity analysis of technetium-99m and second to discuss the possibility of clinical application of these measurements for determination of fetal well-being and the timing of the delivery in these patients. Uteroplacental blood flow was measured from 13 preeclamptic patients and 19 pregnancies without any complication after 35 completed weeks of gestation from Jan. 1983 to Sep. 1983 at Obstetrics department of Hanyang University Hospital. (Author)

Comparison of uteroplacental blood flow in normal and pre-eclamptic patients measurement with technetium-99m and a computer-linked gamma camera

Energy Technology Data Exchange (ETDEWEB)

Cho, S.H.; Moon, H.; Kim, D.S.; Cho, S.S.

1985-05-01

Uteroplacental blood flow studies in preeclampsia are of special interest since the vascular changes reported in this disease might constitute a structural basis for a reduction of blood flow. Evidence has also been given for a decreased uteroplacental blood flow in preeclampsia. Among the various methods to estimate the maternal placental blood flow, the one most frequently reported in the literature during the last years has been the time activity analysis of short lived radiotracer such as technetium-99m or indium-113m injected intravenously. Only few studies with the above mentioned technique comparing normal and preeclampsia cases have been undertaken. In clinical practice we frequently experience difficuly in finding the optimal time to get the delivery in preeclampsia patients. The aim of this study was first to measure uteroplacental blood flow in preeclamptic pregnancies using a computer-linked gamma camera method for the time-activity analysis of technetium-99m and second to discuss the possibility of clinical application of these measurements for determination of fetal well-being and the timing of the delivery in these patients. Uteroplacental blood flow was measured from 13 preeclamptic patients and 19 pregnancies without any complication after 35 completed weeks of gestation from Jan. 1983 to Sep. 1983 at Obstetrics department of Hanyang University Hospital. (Author).

Design and tests of a portable mini gamma camera

International Nuclear Information System (INIS)

Sanchez, F.; Benlloch, J.M.; Escat, B.; Pavon, N.; Porras, E.; Kadi-Hanifi, D.; Ruiz, J.A.; Mora, F.J.; Sebastia, A.

2004-01-01

Design optimization, manufacturing, and tests, both laboratory and clinical, of a portable gamma camera for medical applications are presented. This camera, based on a continuous scintillation crystal and a position-sensitive photomultiplier tube, has an intrinsic spatial resolution of ≅2 mm, an energy resolution of 13% at 140 keV, and linearities of 0.28 mm (absolute) and 0.15 mm (differential), with a useful field of view of 4.6 cm diameter. Our camera can image small organs with high efficiency and so it can address the demand for devices of specific clinical applications like thyroid and sentinel node scintigraphy as well as scintimammography and radio-guided surgery. The main advantages of the gamma camera with respect to those previously reported in the literature are high portability, low cost, and weight (2 kg), with no significant loss of sensitivity and spatial resolution. All the electronic components are packed inside the minigamma camera, and no external electronic devices are required. The camera is only connected through the universal serial bus port to a portable personal computer (PC), where a specific software allows to control both the camera parameters and the measuring process, by displaying on the PC the acquired image on 'real time'. In this article, we present the camera and describe the procedures that have led us to choose its configuration. Laboratory and clinical tests are presented together with diagnostic capabilities of the gamma camera

Gamma camera

International Nuclear Information System (INIS)

Tschunt, E.; Platz, W.; Baer, U.; Heinz, L.

1978-01-01

A gamma camera has a plurality of exchangeable collimators, one of which is mounted in the ray inlet opening of the camera, while the others are placed on separate supports. The supports are swingably mounted upon a column one above the other through about 90 0 to a collimator exchange position. Each of the separate supports is swingable to a vertically aligned position, with limiting of the swinging movement and positioning of the support at the desired exchange position. The collimators are carried on the supports by means of a series of vertically disposed coil springs. Projections on the camera are movable from above into grooves of the collimator at the exchange position, whereupon the collimator is turned so that it is securely prevented from falling out of the camera head

Development of gamma camera and application to decontamination

International Nuclear Information System (INIS)

Yoshida, Akira; Moro, Eiji; Takahashi, Isao

2013-01-01

A gamma camera has been developed to support recovering from the contamination caused by the accident of Fukushima Dai-ichi Nuclear Power Plant of Tokyo Electric Power Company. The gamma camera enables recognition of the contamination by visualizing radioactivity. The gamma camera has been utilized for risk communication (explanation to community resident) at local governments in Fukushima. From now on, the gamma camera will be applied to solve decontaminations issues; improving efficiency of decontamination, visualizing the effect of decontamination work and reducing radioactive waste. (author)

Gamma ray camera

International Nuclear Information System (INIS)

Wang, S.-H.; Robbins, C.D.

1979-01-01

An Anger gamma ray camera is improved by the substitution of a gamma ray sensitive, proximity type image intensifier tube for the scintillator screen in the Anger camera. The image intensifier tube has a negatively charged flat scintillator screen, a flat photocathode layer, and a grounded, flat output phosphor display screen, all of which have the same dimension to maintain unit image magnification; all components are contained within a grounded metallic tube, with a metallic, inwardly curved input window between the scintillator screen and a collimator. The display screen can be viewed by an array of photomultipliers or solid state detectors. There are two photocathodes and two phosphor screens to give a two stage intensification, the two stages being optically coupled by a light guide. (author)

Digital quality control of the camera computer interface

International Nuclear Information System (INIS)

Todd-Pokropek, A.

1983-01-01

A brief description is given of how the gamma camera-computer interface works and what kind of errors can occur. Quality control tests of the interface are then described which include 1) tests of static performance e.g. uniformity, linearity, 2) tests of dynamic performance e.g. basic timing, interface count-rate, system count-rate, 3) tests of special functions e.g. gated acquisition, 4) tests of the gamma camera head, and 5) tests of the computer software. The tests described are mainly acceptance and routine tests. Many of the tests discussed are those recommended by an IAEA Advisory Group for inclusion in the IAEA control schedules for nuclear medicine instrumentation. (U.K.)

Evaluation of tomographic ISOCAM Park II gamma camera parameters using Monte Carlo method

International Nuclear Information System (INIS)

Oramas Polo, Ivón

2015-01-01

In this paper the evaluation of tomographic ISOCAM Park II gamma camera parameters was performed using the Monte Carlo code SIMIND. The parameters uniformity, resolution and contrast were evaluated by Jaszczak phantom simulation. In addition the qualitative assessment of the center of rotation was performed. The results of the simulation are compared and evaluated against the specifications of the manufacturer of the gamma camera and taking into account the National Protocol for Quality Control of Nuclear Medicine Instruments of the Cuban Medical Equipment Control Center. A computational Jaszczak phantom model with three different distributions of activity was obtained. They can be used to perform studies with gamma cameras. (author)

Gamma camera system

International Nuclear Information System (INIS)

Miller, D.W.; Gerber, M.S.; Schlosser, P.A.; Steidley, J.W.

1980-01-01

A detailed description is given of a novel gamma camera which is designed to produce superior images than conventional cameras used in nuclear medicine. The detector consists of a solid state detector (e.g. germanium) which is formed to have a plurality of discrete components to enable 2-dimensional position identification. Details of the electronic processing circuits are given and the problems and limitations introduced by noise are discussed in full. (U.K.)

Gamma camera

International Nuclear Information System (INIS)

Berninger, W.H.

1975-01-01

The light pulse output of a scintillator, on which incident collimated gamma rays impinge, is detected by an array of photoelectric tubes each having a convexly curved photocathode disposed in close proximity to the scintillator. Electronic circuitry connected to outputs of the phototubes develops the scintillation event position coordinate electrical signals with good linearity and with substantial independence of the spacing between the scintillator and photocathodes so that the phototubes can be positioned as close to the scintillator as is possible to obtain less distortion in the field of view and improved spatial resolution as compared to conventional planar photocathode gamma cameras

Advanced system for Gamma Cameras modernization

International Nuclear Information System (INIS)

Osorio Deliz, J. F.; Diaz Garcia, A.; Arista Romeu, E. J.

2015-01-01

Analog and digital gamma cameras still largely used in developing countries. Many of them rely in old hardware electronics, which in many cases limits their use in actual nuclear medicine diagnostic studies. Consequently, there are different worldwide companies that produce medical equipment engaged into a partial or total Gamma Cameras modernization. Present work has demonstrated the possibility of substitution of almost entire signal processing electronics placed at inside a Gamma Camera detector head by a digitizer PCI card. this card includes four 12 Bits Analog-to-Digital-Converters of 50 MHz speed. It has been installed in a PC and controlled through software developed in Lab View. Besides, there were done some changes to the hardware inside the detector head including redesign of the Orientation Display Block (ODA card). Also a new electronic design was added to the Microprocessor Control Block (MPA card) which comprised a PIC micro controller acting as a tuning system for individual Photomultiplier Tubes. The images, obtained by measurement of 99m Tc point radioactive source, using modernized camera head demonstrate its overall performance. The system was developed and tested in an old Gamma Camera ORBITER II SIEMENS GAMMASONIC at National Institute of Oncology and Radiobiology (INOR) under CAMELUD project supported by National Program PNOULU and IAEA . (Author)

Gamma cameras - a method of evaluation

International Nuclear Information System (INIS)

Oates, L.; Bibbo, G.

2000-01-01

Full text: With the sophistication and longevity of the modern gamma camera it is not often that the need arises to evaluate a gamma camera for purchase. We have recently been placed in the position of retiring our two single headed cameras of some vintage and replacing them with a state of the art dual head variable angle gamma camera. The process used for the evaluation consisted of five parts: (1) Evaluation of the technical specification as expressed in the tender document; (2) A questionnaire adapted from the British Society of Nuclear Medicine; (3) Site visits to assess gantry configuration, movement, patient access and occupational health, welfare and safety considerations; (4) Evaluation of the processing systems offered; (5) Whole of life costing based on equally configured systems. The results of each part of the evaluation were expressed using a weighted matrix analysis with each of the criteria assessed being weighted in accordance with their importance to the provision of an effective nuclear medicine service for our centre and the particular importance to paediatric nuclear medicine. This analysis provided an objective assessment of each gamma camera system from which a purchase recommendation was made. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

PC-AT to gamma camera interface ANUGAMI-S

International Nuclear Information System (INIS)

Bhattacharya, Sadhana; Gopalakrishnan, K.R.

1997-01-01

PC-AT to gamma camera interface is an image acquisition system used in nuclear medicine centres and hospitals. The interface hardware and acquisition software have been designed and developed to meet most of the routine clinical applications using gamma camera. The state of the art design of the interface provides quality improvement in addition to image acquisition, by applying on-line uniformity correction which is very essential for gamma camera applications in nuclear medicine. The improvement in the quality of the image has been achieved by image acquisition in positionally varying and sliding energy window. It supports all acquisition modes viz. static, dynamic and gated acquisition modes with and without uniformity correction. The user interface provides the acquisition in various user selectable frame sizes, orientation and colour palettes. A complete emulation of camera console has been provided along with persistence scope and acquisition parameter display. It is a universal system which provides a modern, cost effective and easily maintainable solution for interfacing any gamma camera to PC or upgradation of analog gamma camera. (author). 4 refs., 3 figs

Comparison of myocardial perfusion imaging between the new high-speed gamma camera and the standard anger camera

International Nuclear Information System (INIS)

Tanaka, Hirokazu; Chikamori, Taishiro; Hida, Satoshi

2013-01-01

Cadmium-zinc-telluride (CZT) solid-state detectors have been recently introduced into the field of myocardial perfusion imaging. The aim of this study was to prospectively compare the diagnostic performance of the CZT high-speed gamma camera (Discovery NM 530c) with that of the standard 3-head gamma camera in the same group of patients. The study group consisted of 150 consecutive patients who underwent a 1-day stress-rest 99m Tc-sestamibi or tetrofosmin imaging protocol. Image acquisition was performed first on a standard gamma camera with a 15-min scan time each for stress and for rest. All scans were immediately repeated on a CZT camera with a 5-min scan time for stress and a 3-min scan time for rest, using list mode. The correlations between the CZT camera and the standard camera for perfusion and function analyses were strong within narrow Bland-Altman limits of agreement. Using list mode analysis, image quality for stress was rated as good or excellent in 97% of the 3-min scans, and in 100% of the ≥4-min scans. For CZT scans at rest, similarly, image quality was rated as good or excellent in 94% of the 1-min scans, and in 100% of the ≥2-min scans. The novel CZT camera provides excellent image quality, which is equivalent to standard myocardial single-photon emission computed tomography, despite a short scan time of less than half of the standard time. (author)

Performance characteristics of ZLC 37 Siemens gamma camera

Energy Technology Data Exchange (ETDEWEB)

Abdelgadir, Wafaa Abdelrahman [Department of Physics, Faculty of Science, University of Khartoum, Khartoum (Sudan)

1994-04-01

The relationships between the ZLC 37 Siemens {gamma} camera parameters (energy resolution, plane sensitivity, intrinsic uniformity, intrinsic resolution, system uniformity and system resolution) and diagnostic imaging performance was investigated. These parameters when computers when compared with internationally published data showed that the ZLC 37 Siemens {gamma} cameras is in good operative conditions. The effect of the scattering media and WW on the spatial resolution, when the distance is kept fixed were investigated. Comparison of resolution for the media (air, water, water + radioactivity) when using WW (10, 15,20%) showed that the resolution is best for air, better for water and worse for water + radioactivity up to a concentration of 8% for a 10% WW. (Author) 28 refs. , 10 tabs. , 22 figs. Also available from the Department of Physics, Faculty of Science, University of Khartoum, Khartoum (SD)

A technique for the absolute measurement of activity using a gamma camera and computer

International Nuclear Information System (INIS)

Fleming, J.S.

1979-01-01

The quantity of activity of an isotope in an organ is of interest in gamma camera studies. There are problems in correcting the regional gamma camera counts for varying absorption in body tissue, particularly for thick organs. A description is given of a general method, based on anterior, posterior and lateral views. The method has been applied to liver 99 Tcsup(m) sulphur colloid imaging. Phantom measurements showed that the smallest error to be expected was 3.2%. In practice errors would be 5 to 10%, although lower errors would be associated with estimates of liver/spleen ratios. (U.K.)

The role of the gamma camera in the study of gastric function

International Nuclear Information System (INIS)

Esser, J.D.; Mannell, A.; Hinder, R.A.

1984-01-01

With the gamma camera food labelled with radioactive tracers can be visualized as it enters and leaves the stomach. Radiopharmaceuticals such as technetium-99m di-isopropyl iminodiacetic acid simulate the bile pathway and can be used to demonstrate duodenogastric reflux. Duodenogastric reflux and gastric emptying of solid or liquid meals can be quantitated when the gamma camera is linked to a microprocessor. The test meal used at the Johannesburg and Hillbrow Hospitals consists of a 99 (sup m)Tc-labelled chicken liver weighing 30 g mixed with 70 g cooked ground beef. These studies are valuable for investigating symptomatic postgastrectomy patients and patients who have neurogenic or metabolic diseases which result in abnormal gastric function. The efficacy of drugs given to relieve these symptoms can also be assessed. In this paper we discuss the nuclear medicine techniques used to study gastric function. Examples are given of abnormalities which may not be diagnosed on gastroscopy or barium meal examination but which can be clearly identified by gamma camera techniques

What about getting physiological information into dynamic gamma camera studies

International Nuclear Information System (INIS)

Kiuru, A.; Nickles, R. J.; Holden, J. E.; Polcyn, R. E.

1976-01-01

A general technique has been developed for the multiplexing of time dependent analog signals into the individual frames of a gamma camera dynamic function study. A pulse train, frequency-modulated by the physiological signal, is capacitively coupled to the preamplifier servicing anyone of the outer phototubes of the camera head. These negative tail pulses imitate photoevents occuring at a point outside of the camera field of view, chosen to occupy a data cell in an unused corner of the computer-stored square image. By defining a region of interest around this cell, the resulting time-activity curve displays the physiological variable in temporal synchrony with the radiotracer distribution. (author)

PC-AT to gamma camera interface Anugami-S

International Nuclear Information System (INIS)

Bhattacharya, Sadhana; Sonalkar, S.Y.; Kataria, S.K.

2000-01-01

The gamma camera interface ANUGAMI-S is an image acquisition system used in nuclear medicine centres and hospitals. The state of the art design of the interface provides quality improvement in addition to image acquisition, by applying on-line uniformity correction which is very essential for gamma camera applications in nuclear medicine. The improvement in the quality of the image has been achieved by image acquisition in positionally varying and sliding energy window. It supports all acquisition modes viz. static, dynamic and gated acquisition modes with and without uniformity correction. The user interface provides the acquisition in various user selectable parameters with image display and related acquisition parameter display. It is a universal system which provides a modern, cost effective and easily maintainable solution for interfacing any gamma camera to PC or upgradation of analog gamma camera. The paper describes the system details and gated acquisition achieved on the present system. (author)

Upgrade of the JET gamma-ray cameras

International Nuclear Information System (INIS)

Soare, S.; Curuia, M.; Anghel, M.; Constantin, M.; David, E.; Craciunescu, T.; Falie, D.; Pantea, A.; Tiseanu, I.; Kiptily, V.; Prior, P.; Edlington, T.; Griph, S.; Krivchenkov, Y.; Loughlin, M.; Popovichev, S.; Riccardo, V; Syme, B.; Thompson, V.; Lengar, I.; Murari, A.; Bonheure, G.; Le Guern, F.

2007-01-01

Full text: The JET gamma-ray camera diagnostics have already provided valuable information on the gamma-ray imaging of fast ion in JET plasmas. The applicability of gamma-ray imaging to high performance deuterium and deuterium-tritium JET discharges is strongly dependent on the fulfilment of rather strict requirements for the characterisation of the neutron and gamma-ray radiation fields. These requirements have to be satisfied within very stringent boundary conditions for the design, such as the requirement of minimum impact on the co-existing neutron camera diagnostics. The JET Gamma-Ray Cameras (GRC) upgrade project deals with these issues with particular emphasis on the design of appropriate neutron/gamma-ray filters ('neutron attenuators'). Several design versions have been developed and evaluated for the JET GRC neutron attenuators at the conceptual design level. The main design parameter was the neutron attenuation factor. The two design solutions, that have been finally chosen and developed at the level of scheme design, consist of: a) one quasi-crescent shaped neutron attenuator (for the horizontal camera) and b) two quasi-trapezoid shaped neutron attenuators (for the vertical one). The second design solution has different attenuation lengths: a short version, to be used together with the horizontal attenuator for deuterium discharges, and a long version to be used for high performance deuterium and DT discharges. Various neutron-attenuating materials have been considered (lithium hydride with natural isotopic composition and 6 Li enriched, light and heavy water, polyethylene). Pure light water was finally chosen as the attenuating material for the JET gamma-ray cameras. The neutron attenuators will be steered in and out of the detector line-of-sight by means of an electro-pneumatic steering and control system. The MCNP code was used for neutron and gamma ray transport in order to evaluate the effect of the neutron attenuators on the neutron field of the

Gamma camera

International Nuclear Information System (INIS)

Reiss, K.H.; Kotschak, O.; Conrad, B.

1976-01-01

A gamma camera with a simplified setup as compared with the state of engineering is described permitting, apart from good localization, also energy discrimination. Behind the usual vacuum image amplifier a multiwire proportional chamber filled with trifluorine bromium methane is connected in series. Localizing of the signals is achieved by a delay line, energy determination by means of a pulse height discriminator. With the aid of drawings and circuit diagrams, the setup and mode of operation are explained. (ORU) [de

Dual photon absorptiometry for bone mineral measurements using a gamma camera

International Nuclear Information System (INIS)

Valkema, R.; Prpic, H.; Blokland, J.A.K.; Camps, J.A.J.; Papapoulos, S.E.; Bijvoet, O.L.M.; Pauwels, E.K.J.

1994-01-01

A gamma camera was equipped with a special collimator and arm assembly for bone mineral measurements with dual photon absorptiometry (DPA). The system was evaluated in vitro and in vivo and compared both with a rectilinear DPA and a dual energy X-ray (DEXA) system. All 3 systems showed a linear response in measurements of 4 vials, containing different amounts of hydroxyapatite. Phantom measurements with the gamma camera system showed a precision of 1.6% to 2.8%. Results obtained in 8 healthy volunteers with rectilinear and gamma camera systems were well correlated (R 2 = 0.78). With the photon beam directed from posterior to anterior, the separation of vertebrae was easy with the gamma camera system. We conclude that bone mineral measurements can be made with a gamma camera for assessment of fracture risk and in the decision process whether a patient needs treatment or not. For follow-up, the precision of DPA with a gamma camera is inadequate. (orig.)

Scanning gamma camera

International Nuclear Information System (INIS)

Engdahl, L.W.; Batter, J.F. Jr.; Stout, K.J.

1977-01-01

A scanning system for a gamma camera providing for the overlapping of adjacent scan paths is described. A collimator mask having tapered edges provides for a graduated reduction in intensity of radiation received by a detector thereof, the reduction in intensity being graduated in a direction normal to the scanning path to provide a blending of images of adjacent scan paths. 31 claims, 15 figures

Computer vision camera with embedded FPGA processing

Science.gov (United States)

Lecerf, Antoine; Ouellet, Denis; Arias-Estrada, Miguel

2000-03-01

Traditional computer vision is based on a camera-computer system in which the image understanding algorithms are embedded in the computer. To circumvent the computational load of vision algorithms, low-level processing and imaging hardware can be integrated in a single compact module where a dedicated architecture is implemented. This paper presents a Computer Vision Camera based on an open architecture implemented in an FPGA. The system is targeted to real-time computer vision tasks where low level processing and feature extraction tasks can be implemented in the FPGA device. The camera integrates a CMOS image sensor, an FPGA device, two memory banks, and an embedded PC for communication and control tasks. The FPGA device is a medium size one equivalent to 25,000 logic gates. The device is connected to two high speed memory banks, an IS interface, and an imager interface. The camera can be accessed for architecture programming, data transfer, and control through an Ethernet link from a remote computer. A hardware architecture can be defined in a Hardware Description Language (like VHDL), simulated and synthesized into digital structures that can be programmed into the FPGA and tested on the camera. The architecture of a classical multi-scale edge detection algorithm based on a Laplacian of Gaussian convolution has been developed to show the capabilities of the system.

Toward standardising gamma camera quality control procedures

International Nuclear Information System (INIS)

Alkhorayef, M.A.; Alnaaimi, M.A.; Alduaij, M.A.; Mohamed, M.O.; Ibahim, S.Y.; Alkandari, F.A.; Bradley, D.A.

2015-01-01

Attaining high standards of efficiency and reliability in the practice of nuclear medicine requires appropriate quality control (QC) programs. For instance, the regular evaluation and comparison of extrinsic and intrinsic flood-field uniformity enables the quick correction of many gamma camera problems. Whereas QC tests for uniformity are usually performed by exposing the gamma camera crystal to a uniform flux of gamma radiation from a source of known activity, such protocols can vary significantly. Thus, there is a need for optimization and standardization, in part to allow direct comparison between gamma cameras from different vendors. In the present study, intrinsic uniformity was examined as a function of source distance, source activity, source volume and number of counts. The extrinsic uniformity and spatial resolution were also examined. Proper standard QC procedures need to be implemented because of the continual development of nuclear medicine imaging technology and the rapid expansion and increasing complexity of hybrid imaging system data. The present work seeks to promote a set of standard testing procedures to contribute to the delivery of safe and effective nuclear medicine services. - Highlights: • Optimal parameters for quality control of the gamma camera are proposed. • For extrinsic and intrinsic uniformity a minimum of 15,000 counts is recommended. • For intrinsic flood uniformity the activity should not exceed 100 µCi (3.7 MBq). • For intrinsic uniformity the source to detector distance should be at least 60 cm. • The bar phantom measurement must be performed with at least 15 million counts.

Initial clinical experience with dedicated ultra fast solid state cardiac gamma camera

International Nuclear Information System (INIS)

Aland, Nusrat; Lele, V.

2010-01-01

Full text: To analyze the imaging and diagnostic performance of new dedicated ultra fast solid state detector gamma camera and compare it with standard dual detector gamma camera in myocardial perfusion imaging. Material and Methods: In total 900 patients underwent myocardial perfusion imaging between 1st February 2010 and 29th August 2010 either stress/rest or rest/stress protocol. There was no age or gender bias (there were 630 males and 270 females). 5 and 15 mCi of 99m Tc - Tetrofosmin/MIBI was injected for 1st and 2nd part of the study respectively. Waiting period after injection was 20 min for regular stress and 40 min for pharmacological stress and 40 min after rest injection. Acquisition was performed on solid state detector gamma camera for a duration of 5 min and 3 min for 1st and 2nd part respectively. Interpretation of myocardial perfusion was done and QGS/QPS protocol was used for EF analysis. Out of these, 20 random patients underwent back to back myocardial perfusion SPECT imaging on standard dual detector gamma camera on same day. There was no age or gender bias (there were 9 males, 11 females). Acquisition time was 20 min for each part of the study. Interpretation was done using Autocard and EF analyses with 4 DM SPECT. Images obtained were then compared with those of solid state detector gamma camera. Result: Good quality and high count myocardial perfusion images were obtained with lesser amount of tracer activity on solid state detector gamma camera. Obese patients also showed good quality images with less tracer activity. As compared to conventional dual detector gamma camera images were brighter and showed better contrast with solid state gamma camera. Right ventricular imaging was better seen. Analyses of diastolic dysfunction was possible with 16 frame gated studies with solid state gamma camera. Shorter acquisition time with comfortable position reduced possibility of patient motion. All cardiac views were obtained with no movement of the

A SPECT demonstrator—revival of a gamma camera

Science.gov (United States)

Valastyán, I.; Kerek, A.; Molnár, J.; Novák, D.; Végh, J.; Emri, M.; Trón, L.

2006-07-01

A gamma camera has been updated and converted to serve as a demonstrator for educational purposes. The gantry and the camera head were the only part of the system that remained untouched. The main reason for this modernization was to increase the transparency of the gamma camera by partitioning the different logical building blocks of the system and thus providing access for inspection and improvements throughout the chain. New data acquisition and reconstruction software has been installed. By taking these measures, the camera is now used in education and also serves as a platform for tests of new hardware and software solutions. The camera is also used to demonstrate 3D (SPECT) imaging by collecting 2D projections from a rotatable cylindrical phantom. Since the camera head is not attached mechanically to the phantom, the effect of misalignment between the head and the rotation axis of the phantom can be studied.

A SPECT demonstrator-revival of a gamma camera

International Nuclear Information System (INIS)

Valastyan, I.; Kerek, A.; Molnar, J.; Novak, D.; Vegh, J.; Emri, M.; Tron, L.

2006-01-01

A gamma camera has been updated and converted to serve as a demonstrator for educational purposes. The gantry and the camera head were the only part of the system that remained untouched. The main reason for this modernization was to increase the transparency of the gamma camera by partitioning the different logical building blocks of the system and thus providing access for inspection and improvements throughout the chain. New data acquisition and reconstruction software has been installed. By taking these measures, the camera is now used in education and also serves as a platform for tests of new hardware and software solutions. The camera is also used to demonstrate 3D (SPECT) imaging by collecting 2D projections from a rotatable cylindrical phantom. Since the camera head is not attached mechanically to the phantom, the effect of misalignment between the head and the rotation axis of the phantom can be studied

Development of the neutron filters for JET gamma-ray cameras

International Nuclear Information System (INIS)

Soare, S.; Curuia, M.; Anghel, M.; Constantin, M.; David, E.; Kiptily, V.; Prior, P.; Edlington, T.; Griph, S.; Krivchenkov, Y.; Popovichev, S.; Riccardo, V.; Syme, B; Thompson, V.; Murari, A.; Zoita, V.; Bonheure, G.; Le Guern

2007-01-01

The JET gamma-ray camera diagnostics have already provided valuable information on the gamma-ray imaging of fast ion evaluation in JET plasmas. The JET Gamma-Ray Cameras (GRC) upgrade project deals with the design of appropriate neutron/gamma-ray filters ('neutron attenuaters').The main design parameter was the neutron attenuation factor. The two design solutions, that have been finally chosen and developed at the level of scheme design, consist of: a) one quasi-crescent shaped neutron attenuator (for the horizontal camera) and b) two quasi-trapezoid shaped neutron attenuators (for the vertical one). Various neutron-attenuating materials have been considered (lithium hydride with natural isotopic composition and 6 Li enriched, light and heavy water, polyethylene). Pure light water was finally chosen as the attenuating material for the JET gamma-ray cameras. FEA methods used to evaluate the behaviour of the filter casings under the loadings (internal hydrostatic pressure, torques) have proven the stability of the structure. (authors)

Control system for gamma camera

International Nuclear Information System (INIS)

Miller, D.W.

1977-01-01

An improved gamma camera arrangement is described which utilizing a solid state detector, formed of high purity germanium. the central arrangement of the camera operates to effect the carrying out of a trapezoidal filtering operation over antisymmetrically summed spatial signals through gated integration procedures utilizing idealized integrating intervals. By simultaneously carrying out peak energy evaluation of the input signals, a desirable control over pulse pile-up phenomena is achieved. Additionally, through the use of the time derivative of incoming pulse or signal energy information to initially enable the control system, a low level information evaluation is provided serving to enhance the signal processing efficiency of the camera

Performance assessment of gamma cameras. Part 1

International Nuclear Information System (INIS)

Elliot, A.T.; Short, M.D.; Potter, D.C.; Barnes, K.J.

1980-11-01

The Dept. of Health and Social Security and the Scottish Home and Health Dept. has sponsored a programme of measurements of the important performance characteristics of 15 leading types of gamma cameras providing a routine radionuclide imaging service in hospitals throughout the UK. Measurements have been made of intrinsic resolution, system resolution, non-uniformity, spatial distortion, count rate performance, sensitivity, energy resolution and shield leakage. The main aim of this performance assessment was to provide sound information to the NHS to ease the task of those responsible for the purchase of gamma cameras. (U.K.)

Monte Carlo simulation for dual head gamma camera

International Nuclear Information System (INIS)

Osman, Yousif Bashir Soliman

2015-12-01

Monte Carlo (MC) simulation technique was used widely in medical physics applications. In nuclear medicine MC was used to design new medical imaging devices such as positron emission tomography (PET), gamma camera and single photon emission computed tomography (SPECT). Also it can be used to study the factors affecting image quality and internal dosimetry, Gate is on of monte Carlo code that has a number of advantages for simulation of SPECT and PET. There is a limit accessibilities in machines which are used in clinics because of the work load of machines. This makes it hard to evaluate some factors effecting machine performance which must be evaluated routinely. Also because of difficulties of carrying out scientific research and training of students, MC model can be optimum solution for the problem. The aim of this study was to use gate monte Carlo code to model Nucline spirit, medico dual head gamma camera hosted in radiation and isotopes center of Khartoum which is equipped with low energy general purpose LEGP collimators. This was used model to evaluate spatial resolution and sensitivity which is important factor affecting image quality and to demonstrate the validity of gate by comparing experimental results with simulation results on spatial resolution. The gate model of Nuclide spirit, medico dual head gamma camera was developed by applying manufacturer specifications. Then simulation was run. In evaluation of spatial resolution the FWHM was calculated from image profile of line source of Tc 99m gammas emitter of energy 140 KeV at different distances from modeled camera head at 5,10,15,20,22,27,32,37 cm and for these distances the spatial resolution was founded to be 5.76, 7.73, 10.7, 13.8, 14.01,16.91, 19.75 and 21.9 mm, respectively. These results showed a decrement of spatial resolution with increase of the distance between object (line source) and collimator in linear manner. FWHM calculated at 10 cm was compared with experimental results. The

The value of gamma camera and computed tomography data set coregistration to assess Lewis Y antigen targeting in small cell lung cancer by 111Indium-labeled humanized monoclonal antibody 3S193

International Nuclear Information System (INIS)

Quaia, Emilio; Krug, Lee M.; Pandit-Taskar, Neeta; Nagel, Andrew; Reuter, Victor E.; Humm, John; Divgi, Chaitanya

2008-01-01

Aim: To assess the value of data set coregistration of gamma camera and computed tomography (CT) in the assessment of targeting of humanized monoclonal antibody 3S193 labeled with indium-111 ( 111 In-hu3S193) to small cell lung cancer (SCLC). Methods and materials: Ten patients (6 male and 4 female; mean age ± S.D., 60 ± 4 years), from an overall population of 20 patients with SCLCs expressing Lewis Y antigen at immunohistochemical analysis, completed a four weekly injections of 111 In-hu3S193 and underwent gamma camera imaging. All had had, as part of their baseline evaluation, Fluorine18 fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Two readers in consensus retrospectively coregistered the gamma camera images with the CT component of the FDG PET/CT by automatic or manual alignment. The resulting image sets were visually examined and SCLC lesions targeting at coregistered gamma camera and CT was correlated side-by-side with the 18 F-FDG uptake. Results: A total number of 31 lesions from SCLC with a thoracic (n = 13) or extrathoracic location (n = 18) were all positive on FDG PET/CT. Coregistration of the gamma camera to the CT demonstrated targeting of antibody to all lesions >2 cm (n = 20) and in a few lesions ≤2 cm (n = 2), with no visualization of most lesions ≤2 cm (n = 9). No 111 In-hu3S193 uptake in normal tissues was observed. Conclusion: Coregistration of antibody gamma camera imaging to FDG PET/CT is feasible and allows valuable assessment of 111 In-hu3S193 antibody targeting to SCLC lesions >2 cm, while lesions ≤2 cm reveal a limited targeting

Spectroscopic gamma camera for use in high dose environments

Energy Technology Data Exchange (ETDEWEB)

Ueno, Yuichiro, E-mail: yuichiro.ueno.bv@hitachi.com [Research and Development Group, Hitachi, Ltd., Hitachi-shi, Ibaraki-ken 319-1221 (Japan); Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi [Research and Development Group, Hitachi, Ltd., Hitachi-shi, Ibaraki-ken 319-1221 (Japan); Fujishima, Yasutake; Kometani, Yutaka [Hitachi Works, Hitachi-GE Nuclear Energy, Ltd., Hitachi-shi, Ibaraki-ken (Japan); Suzuki, Yasuhiko [Measuring Systems Engineering Dept., Hitachi Aloka Medical, Ltd., Ome-shi, Tokyo (Japan); Umegaki, Kikuo [Faculty of Engineering, Hokkaido University, Sapporo-shi, Hokkaido (Japan)

2016-06-21

We developed a pinhole gamma camera to measure distributions of radioactive material contaminants and to identify radionuclides in extraordinarily high dose regions (1000 mSv/h). The developed gamma camera is characterized by: (1) tolerance for high dose rate environments; (2) high spatial and spectral resolution for identifying unknown contaminating sources; and (3) good usability for being carried on a robot and remotely controlled. These are achieved by using a compact pixelated detector module with CdTe semiconductors, efficient shielding, and a fine resolution pinhole collimator. The gamma camera weighs less than 100 kg, and its field of view is an 8 m square in the case of a distance of 10 m and its image is divided into 256 (16×16) pixels. From the laboratory test, we found the energy resolution at the 662 keV photopeak was 2.3% FWHM, which is enough to identify the radionuclides. We found that the count rate per background dose rate was 220 cps h/mSv and the maximum count rate was 300 kcps, so the maximum dose rate of the environment where the gamma camera can be operated was calculated as 1400 mSv/h. We investigated the reactor building of Unit 1 at the Fukushima Dai-ichi Nuclear Power Plant using the gamma camera and could identify the unknown contaminating source in the dose rate environment that was as high as 659 mSv/h.

A versatile calibration procedure for portable coded aperture gamma cameras and RGB-D sensors

Science.gov (United States)

Paradiso, V.; Crivellaro, A.; Amgarou, K.; de Lanaute, N. Blanc; Fua, P.; Liénard, E.

2018-04-01

The present paper proposes a versatile procedure for the geometrical calibration of coded aperture gamma cameras and RGB-D depth sensors, using only one radioactive point source and a simple experimental set-up. Calibration data is then used for accurately aligning radiation images retrieved by means of the γ-camera with the respective depth images computed with the RGB-D sensor. The system resulting from such a combination is thus able to retrieve, automatically, the distance of radioactive hotspots by means of pixel-wise mapping between gamma and depth images. This procedure is of great interest for a wide number of applications, ranging from precise automatic estimation of the shape and distance of radioactive objects to Augmented Reality systems. Incidentally, the corresponding results validated the choice of a perspective design model for a coded aperture γ-camera.

Regional cerebral blood flow measurement using N-isopropyl-p-[123I] iodoamphetamine and rotating gamma camera emission computed tomography

International Nuclear Information System (INIS)

Matsuda, Hiroshi; Seki, Hiroyasu; Ishida, Hiroko

1985-01-01

Thirty-one regional cerebral blood flow (rCBF) measurements were performed on 26 patients with cerebrovascular accidents using N-Isopropyl-p-[ 123 I] Iodoamphetamine ( 123 I-IMP) and rotating gamma camera emission computed tomography (ECT). The equation for determining rCBF is as follows: F=100.R.Cb/(N.A), where F is rCBF in ml/100 g/min., R is the constant withdrawal rate of arterial blood in ml/min., Cb is the brain activity concentration in μCi/g, A is the total activity (5 min.) in the withdrawal arterial whole blood in μCi and N is the fraction of A that is true tracer activity (0.75). In determining Cb at 5 min. after injection, reconstructed counts from 35 min. to 59 min. were corrected to represent those from 4 min. to 5 min. with the use of time activity curve for the entire brain immediately after injection to 30 min. Reconstructed counts of central region in tomographic image were corrected 118% of the obtained values from the result of the countingrate ratio between peripheral and central regions of interests obtained from phantom study. Brain mean blood flow values were distributed from 11 to 39 ml/100 g/min. In 119 cortical regions obtained from 11 measurements in 9 patients, there was a significant correlation (r=0.41, p 123 I-IMP and rotating gamma camera ECT and those from 133 Xe inhalation method. rCBF measurement using 123 I-IMP and rotating gamma camera ECT is not only relatively noninvasive measurement for the entire brain but also three-dimensional evaluation. Besides, it is superior in spatial resolution and accuracy to conventional 133 Xe clearance method. (author)

Programmable electronic system for analog and digital gamma cameras modernization

International Nuclear Information System (INIS)

Osorio Deliz, J. F.; Diaz Garcia, A.; Arista Omeu, E. J.

2013-01-01

At present the use of analog and digital gamma cameras is continuously increasing in developing countries. Many of them still largely rely in old hardware electronics, which in many cases limits their use in actual nuclear medicine diagnostic studies. For this reason worldwide there are different medical equipment manufacturing companies engaged into partial or total Gamma Cameras modernization. Nevertheless in several occasions acquisition prices are not affordable for developing countries. This work describes the basic features of a programmable electronic system that allows improving acquisitions functions and processing of analog and digital gamma cameras. This system is based on an electronic board for the acquisition and digitization of nuclear pulses which have been generated by gamma camera detector. It comprises a hardware interface with PC and the associated software to fully signal processing. Signal shaping and image processing are included. The extensive use of reference tables in the processing and signal imaging software allowed the optimization of the processing speed. Time design and system cost were also decreased. (Author)

Development and evaluation of a Gamma Camera tuning system

International Nuclear Information System (INIS)

Arista Romeu, E. J.; Diaz Garcia, A.; Osorio Deliz, J. F.

2015-01-01

Correct operation of conventional analogue Gamma Cameras implies a good conformation of the position signals that correspond to a specific photo-peak of the radionuclide of interest. In order to achieve this goal the energy spectrum from each photo multiplier tube (PMT) has to be set within the same energy window. For this reason a reliable tuning system is an important part of all gamma cameras processing systems. In this work is being tested and evaluated a new prototype of tuning card that was developed and setting up for this purpose. The hardware and software of the circuit allow the regulation if each PMT high voltage. By this means a proper gain control for each of them is accomplished. The Tuning Card prototype was simulated in a virtual model and its satisfactory operation was proven in a Siemens Orbiter Gamma Camera. (Author)

An alternate way for image documentation in gamma camera processing units

International Nuclear Information System (INIS)

Schneider, P.

1980-01-01

For documentation of images and curves generated by a gamma camera processing system a film exposure tool from a CT system was linked to the video monitor by use of a resistance bridge. The machine has a stock capacity of 100 plane films. For advantage there is no need for an interface, the complete information on the monitor is transferred to the plane film and compared to software controlled data output on printer or plotter the device is tremendously time saving. (orig.) [de

Gamma camera display system

International Nuclear Information System (INIS)

Stout, K.J.

1976-01-01

A gamma camera having an array of photomultipliers coupled via pulse shaping circuitry and a resistor weighting circuit to a display for forming an image of a radioactive subject is described. A linearizing circuit is coupled to the weighting circuit, the linearizing circuit including a nonlinear feedback circuit with diode coupling to the weighting circuit for linearizing the correspondence between points of the display and points of the subject. 4 Claims, 5 Drawing Figures

Regional cerebral blood flow measurement using N-isopropyl-p-(/sup 123/I) iodoamphetamine and rotating gamma camera emission computed tomography

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroshi; Seki, Hiroyasu; Ishida, Hiroko (Kanazawa Univ. (Japan). School of Medicine)

1985-01-01

Thirty-one regional cerebral blood flow (rCBF) measurements were performed on 26 patients with cerebrovascular accidents using N-Isopropyl-p-(/sup 123/I) Iodoamphetamine (/sup 123/I-IMP) and rotating gamma camera emission computed tomography (ECT). The equation for determining rCBF is as follows: F=100.R.Cb/(N.A), where F is rCBF in ml/100 g/min., R is the constant withdrawal rate of arterial blood in ml/min., Cb is the brain activity concentration in ..mu..Ci/g, A is the total activity (5 min.) in the withdrawal arterial whole blood in ..mu..Ci and N is the fraction of A that is true tracer activity (0.75). In determining Cb at 5 min. after injection, reconstructed counts from 35 min. to 59 min. were corrected to represent those from 4 min. to 5 min. with the use of time activity curve for the entire brain immediately after injection to 30 min. Reconstructed counts of central region in tomographic image were corrected 118% of the obtained values from the result of the counting rate ratio between peripheral and central regions of interest obtained from phantom study. Brain mean blood flow values were distributed from 11 to 39 ml/100 g/min. In 119 cortical regions obtained from 11 measurements in 9 patients, there was a significant correlation (r=0.41, p < 0.001) between rCBF values obtained from /sup 123/I-IMP and rotating gamma camera ECT and those from /sup 133/Xe inhalation method. rCBF measurement using /sup 123/I-IMP and rotating gamma camera ECT is not only relatively noninvasive measurement for the entire brain but also three-dimensional evaluation. Besides, it is superior in spatial resolution and accuracy to conventional /sup 133/Xe clearance method.

Bullet scintigraphy: can gamma camera be used for depleted uranium accident measurements?

International Nuclear Information System (INIS)

Spaic, R.; Markovic, S.; Pavlovic, S.; Radic, Z.; Pavlovic, R.; Ajdinovic, B.; Baskot, B.; Djurovic, B.

2002-01-01

The aim of this study was to see could gamma cameras be used for measurement of internal contamination with depleted uranium. Radioactive waste depleted uranium, which is by-product from the production of enriched fuel for nuclear rectors and weapons now, is used for manufacture bullets, which are used in Iraq, Republic of Srpska and Yugoslavia. In this paper is measured minimum detectable activity (MDA) of gamma cameras for depleted uranium, iodine and technetium. For detection of the depleted uranium are used low energy X-rays, energy of 100 keV with 20% windows width. About 40% of gamma emissions of the depleted uranium are in these limits. Measured MDA activities 50-100 Bq for depleted uranium, iodine and technetium are about then times more then same for WBC (5 Bq). Gamma cameras can be used for relatively measurement of depleted uranium activity, what can be used for absorbed dose estimation. Detection of low level internal contamination with depleted uranium can be done with gamma cameras. (authors)

PC based simulation of gamma camera for training of operating and maintenance staff

International Nuclear Information System (INIS)

Singh, B.; Kataria, S.K.; Samuel, A.M.

2000-01-01

Gamma camera- a sophisticated imaging system is used for functional assessment of biological subsystems/organs in nuclear medicine. The radioactive tracer attached to the native substance is injected into the patient. The distribution of radioactivity in the patient is imaged by the gamma camera. This report describes a PC based package for simulation of gamma cameras and effect of malfunctioning of its subsystems on images of different phantoms

Characteristics of a single photon emission tomography system with a wide field gamma camera

International Nuclear Information System (INIS)

Mathonnat, F.; Soussaline, F.; Todd-Pokropek, A.E.; Kellershohn, C.

1979-01-01

This text summarizes a work study describing the imagery possibilities of a single photon emission tomography system composed of a conventional wide field gamma camera, connected to a computer. The encouraging results achieved on the various phantoms studied suggest a significant development of this technique in clinical work in Nuclear Medicine Departments [fr

Realisation of a gamma emission tomograph by a servo-controlled camera and bed

International Nuclear Information System (INIS)

Guzman-Torres, D.R.

1980-07-01

We took part in the building of a transverse axial emission tomograph intended for nuclear medicine. The following three points were dealt with: mathematical, choice of processing algorithm; electronic, development of equipment; experimental, testing of the system built. On the mathematical side, following a survey of reconstruction methods, we studied the use of a reconstruction algorithm after filtering of the projections by convolution which gives a good spatial resolution. We also proposed a means to solve the computing time/quality of image problem, leading to a satisfactory result within a shorter total investigation time. In this way the computing time has been reduced by a factor three. In the electronics field we built an interface between the bed, the gamma camera and the computer already in the laboratory. The present instrument corresponds to version no. 2. The system control the bed and gamma camera which are operated from the computer. Experimentally we were able on checking the calculations with a phantom made up of small emitting sources, to prove by finding the exact spot our ability to locate active foci on the patient. While the results obtained are encouraging from the image restitution viewpoint, the study of problems related to self-absorption inside the organ and those of statistical noise have still to be continued [fr

An imaging system for a gamma camera

International Nuclear Information System (INIS)

Miller, D.W.; Gerber, M.S.

1980-01-01

A detailed description is given of a novel gamma camera which is designed to produce superior images than conventional cameras used in nuclear medicine. The detector consists of a solid state detector (e.g. germanium) which is formed to have a plurality of discrete components to enable 2-dimensional position identification. Details of the electronic processing circuits are given and the problems and limitations introduced by noise are discussed in full. (U.K.)

Dynamic gamma camera scintigraphy in primary hypoovarism

International Nuclear Information System (INIS)

Peshev, N.; Mladenov, B.; Topalov, I.; Tsanev, Ts.

1988-01-01

Twenty-seven patients with primary hypoovarism and 10 controls were examined. After intravenous injection of 111 to 175 MBq 99m Tc pertechnetate, dynamic gamma camera scintigraphy for 15 minutes was carried out. In the patients with primary amenorrhea no functioning ovarial tissue was visualized or the ovaries were diminished in size, strongly reduced and non-homogenous accumulation of the radionuclide with unclear and uneven delineation were observed. In the patients with primary infertility, the gamma camera investigation gave information not only about the presence of ovarial parenchyma, but about the extent of the inflammatory process, too. In the patients after surgical intervention, the dynamic radioisotope investigation gave information about the volume and the site of the surgical intervention, as well as about the conditions of the residual parenchyma

The implementation of quality controls of gamma camera functioning and simulation of tomography techniques by Gate and GEANT4

International Nuclear Information System (INIS)

Ben Ameur, Narjes

2011-01-01

The reliability of medical devices is directly linked to the services quality offered to the patient. For this reason, quality control tests should be regularly conducted in every nuclear medicine service according to international norms. Our approach consists on realizing different quality control tests recommended by the Nema norm on a gamma-camera in order to evaluate its performance. The obtained data allowed us to study the different physical phenomena happening during a SPECT exam. It also allowed us to identify those affecting the image quality based on the simulation programmes: GEANT 4 and Gate. The obtained results of the quality control showed that the Gamma-camera has a high performance in terms of spatial resolution, linearity, uniformity and rotational center. The establishment of a model for a gamma-camera Symbia E (Siemens) using a Gate platform confirms the reliability of this platform in the conception and the optimization of the detectors.

Integration of gamma cameras and PET devices of multiple vendors in several locations

International Nuclear Information System (INIS)

Dresel, S.; Vollmar, C.; Sengupta, S.; Hahn, K.

2002-01-01

Full text: The Department of Nuclear Medicine of the University of Munich consists of four independently operated locations with a total of 18 gamma cameras (of three vendors), one PET scanner and one coincidence gamma camera. Recent hardware improvements, the installation and development of fast networks and new technologies for storage of large data volumes all contribute to the propagation of digital reading and reporting of nuclear medicine studies. Thus, the vision of a fully digitized nuclear medicine department becomes reality. In 1997 the department started with a strategy to fully integrate the entire number of imaging devices into one network for filmless reading, archiving and distributing nuclear medicine studies throughout the hospitals. The decision was made to use HERMES workstations (Nuclear Diagnostics, Sweden) to connect all primary imaging modalities. The purpose of the workstations located in the Nuclear Medicine departments is threefold: postprocessing, reading and archiving of all data. The workstations are networked throughout the different hospitals and are able to read the proprietary or DICOM data of the vendors of the gamma camera and PET equipment. The HERMES system is connected via DICOM interface to a long term storage device (AGFA, Germany). Additionally a JAVA (SUN Microsystems, USA) based software (JARVIS, Nuclear Diagnostics) is available to view all data from any computer using a web browser. Furthermore all data is linked to the hospital information system and selected imaging data are distributed throughout the hospitals. After commencement of full service of the network in 2000 the department is over 95 % filmfree. The high costs of purchasing hardware- and software-components are compensated for by saving costs of films and by the improvement of the work flow. Independently from these issues, filmless reporting proves to be advantageous over conventional film reading in many facts that justify to switch to a digital department

Portable mini gamma camera for medical applications

CERN Document Server

Porras, E; Benlloch, J M; El-Djalil-Kadi-Hanifi, M; López, S; Pavon, N; Ruiz, J A; Sánchez, F; Sebastiá, A

2002-01-01

A small, portable and low-cost gamma camera for medical applications has been developed and clinically tested. This camera, based on a scintillator crystal and a Position Sensitive Photo-Multiplier Tube, has a useful field of view of 4.6 cm diameter and provides 2.2 mm of intrinsic spatial resolution. Its mobility and light weight allow to reach the patient from any desired direction. This camera images small organs with high efficiency and so addresses the demand for devices of specific clinical applications. In this paper, we present the camera and briefly describe the procedures that have led us to choose its configuration and the image reconstruction method. The clinical tests and diagnostic capability are also presented and discussed.

Realization of a gamma emission tomography by a servo-controlled camera and bed

International Nuclear Information System (INIS)

Parmentier, M.; Gunzman, D.; Bidet, R.

1979-01-01

A gamma-camera and a whole-body bed were connected to a minicomputer which controlled automatically their movements. By combining horizontal displacement of the bed with vertical displacement and rotation of the camera we were able to obtain the equivalent of camera rotation around the bed. This method provides an inexpensive way of realizing gamma emission tomography [fr

Single photon emission computed tomography of the brain with a rotating gamma camera

Energy Technology Data Exchange (ETDEWEB)

Biersack, H J; Knopp, R; Winkler, C; Wappenschmidt, J

1981-08-01

In 471 patients SPECT of the brain was performed in addition to conventional serial brain scintigraphy using a rotating gamma camera (GAMMATOME T 9000). 23 patients had tumorous lesions, 26 had vascular lesions, and 422 patients revealed normal brain findings. 5 of the 23 patients with tumorous lesion and 5 of the 12 patients with vascular lesion (anamnesis shorter than 4 weeks) showed positive SPECT results but false negative conventional brain scans. Specificity could be improved up to 98% (412 out of 422 patients) using SPECT and conventional scintigraphy.

Fabrication of a phantom and its application for checking gamma camera performance

International Nuclear Information System (INIS)

Yesmin, S; Ahmad, G. U.; Afroz, S.; Hossain, S.; Rashid, H.

2004-01-01

The primary aim of the present work is to fabricate a total performance phantom, which could be used for checking the performance characteristics of gamma camera. The phantom was locally fabricated at machine shop of Bangladesh University of Engineering and Technology (BUET) and used for checking the performance characteristics of gamma camera LF-61 of Centre for Nuclear Medicine and Ultrasound, Dhaka. With 10 mCi of Tc-99m, imaging of the phantom acquired with a reasonable counts. The image was inspected physically for evaluation of the camera performances. The visual inspection of the phantom image revealed that the performance characteristics like: spatial resolution, linearity, uniformity and lesion detection capability of the gamma camera could clearly be evaluated with reasonable acceptance level. This phantom is expected to be useful for checking performance characteristics of SPECT system as well. (author)

From whole-body counting to imaging: The computer aided collimation gamma camera project (CACAO)

Energy Technology Data Exchange (ETDEWEB)

Jeanguillaume, C.; Begot, S.; Quartuccio, M.; Douiri, A.; Ballongue, P

2000-07-01

Whole-body counting is the method of choice for in vivo detection of contamination. To extend this well established method, the possible advantages of imaging radiocontaminants are examined. The use of the CACAO project is then studied. A comparison of simulated reconstructed images obtained by the CACAO project and by a conventional gamma camera used in nuclear medicine follows. Imaging a radionuclide contaminant with a geometrical sensitivity of 10{sup -2} seems possible in the near future. (author)

From whole-body counting to imaging: The computer aided collimation gamma camera project (CACAO)

International Nuclear Information System (INIS)

Jeanguillaume, C.; Begot, S.; Quartuccio, M.; Douiri, A.; Ballongue, P.

2000-01-01

Whole-body counting is the method of choice for in vivo detection of contamination. To extend this well established method, the possible advantages of imaging radiocontaminants are examined. The use of the CACAO project is then studied. A comparison of simulated reconstructed images obtained by the CACAO project and by a conventional gamma camera used in nuclear medicine follows. Imaging a radionuclide contaminant with a geometrical sensitivity of 10 -2 seems possible in the near future. (author)

Standardization of test conditions for gamma camera performance measurement

International Nuclear Information System (INIS)

Jordan, K.

1982-02-01

The way of measuring gamma camera performance is to use point sources or flood sources in air, often in combination with bar phantoms. This method has nothing in common with the use of a camera in clinical practice. Particularly in the case of low energy emitters, like Tc-99m, the influence of scattered radiation over the performance of cameras is very high. The IEC document 'Characteristics and test conditions of radionuclide imaging devices' is discussed

Gastric emptying of liquid meals: validation of the gamma camera technique

Energy Technology Data Exchange (ETDEWEB)

Lawaetz, Otto; Dige-Petersen, Harriet

1989-05-01

To assess the extent of errors and to provide correction factors for gamma camera gastric emptying studies of liquid meals labelled with radionuclides (/sup 99/Tc/sup m/ or /sup 113/In/sup m/), phantom studies were performed with different gastric emptying procedures, gamma cameras and data handling systems. To validate the overall accuracy of the method, 24 combined aspiration and gamma camera gastric emptying studies were carried out in three normal volunteers. Gastric meal volume was underestimated due to scattered radiation from the stomach. The underestimation was 7-20% varying with the size of the gastric region of interest (ROI), the energy of the nuclide and the fraction of meal in the stomach. The overestimation, due to scattered radiation from the gut, was negligible (1-3%) for any of the procedures. The gamma camera technique eliminated much of the error due to variations of stomach geometry and produced accurate quantitative gastric emptying data comparable to those obtained by evacuation (P > 0.10), when the entire field maximum 1-min count achieved within the first 20 min of a study was taken as representing the original volume of the meal ingested, and when corrections for area related errors due to scattered radiation from the stomach were performed. (author).

Camera Concepts for the Advanced Gamma-Ray Imaging System (AGIS)

Science.gov (United States)

Nepomuk Otte, Adam

2009-05-01

The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. Design goals are ten times better sensitivity, higher angular resolution, and a lower energy threshold than existing Cherenkov telescopes. Each telescope is equipped with a camera that detects and records the Cherenkov-light flashes from air showers. The camera is comprised of a pixelated focal plane of blue sensitive and fast (nanosecond) photon detectors that detect the photon signal and convert it into an electrical one. The incorporation of trigger electronics and signal digitization into the camera are under study. Given the size of AGIS, the camera must be reliable, robust, and cost effective. We are investigating several directions that include innovative technologies such as Geiger-mode avalanche-photodiodes as a possible detector and switched capacitor arrays for the digitization.

On-Line High Dose-Rate Gamma Ray Irradiation Test of the CCD/CMOS Cameras

Energy Technology Data Exchange (ETDEWEB)

Cho, Jai Wan; Jeong, Kyung Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

In this paper, test results of gamma ray irradiation to CCD/CMOS cameras are described. From the CAMS (containment atmospheric monitoring system) data of Fukushima Dai-ichi nuclear power plant station, we found out that the gamma ray dose-rate when the hydrogen explosion occurred in nuclear reactors 1{approx}3 is about 160 Gy/h. If assumed that the emergency response robot for the management of severe accident of the nuclear power plant has been sent into the reactor area to grasp the inside situation of reactor building and to take precautionary measures against releasing radioactive materials, the CCD/CMOS cameras, which are loaded with the robot, serve as eye of the emergency response robot. In the case of the Japanese Quince robot system, which was sent to carry out investigating the unit 2 reactor building refueling floor situation, 7 CCD/CMOS cameras are used. 2 CCD cameras of Quince robot are used for the forward and backward monitoring of the surroundings during navigation. And 2 CCD (or CMOS) cameras are used for monitoring the status of front-end and back-end motion mechanics such as flippers and crawlers. A CCD camera with wide field of view optics is used for monitoring the status of the communication (VDSL) cable reel. And another 2 CCD cameras are assigned for reading the indication value of the radiation dosimeter and the instrument. In the preceding assumptions, a major problem which arises when dealing with CCD/CMOS cameras in the severe accident situations of the nuclear power plant is the presence of high dose-rate gamma irradiation fields. In the case of the DBA (design basis accident) situations of the nuclear power plant, in order to use a CCD/CMOS camera as an ad-hoc monitoring unit in the vicinity of high radioactivity structures and components of the nuclear reactor area, a robust survivability of this camera in such intense gamma-radiation fields therefore should be verified. The CCD/CMOS cameras of various types were gamma irradiated at a

Multiaxial tomography of heart chambers by gated blood-pool emission computed tomography using a rotating gamma camera

International Nuclear Information System (INIS)

Tamaki, N.; Mukai, T.; Ishii, Y.; Yonekura, Y.; Yamamoto, K.; Kadota, K.; Kambara, H.; Kawai, C.; Torizuka, K.

1983-01-01

Fifteen patients and three volunteers underwent radionuclide blood-pool cardiac studies with electrocardiographic gating. Following conventional planar-gated imaging (anterior and left anterior oblique projections), emission computed tomography (ECT), using a rotating gamma camera, was performed.A series of transaxial tomograms of the cardiac chambers was obtained. The left ventricular short-axis plane, long-axis plane, and four-chamber-view plane were then reorganized; each chamber was visualized separately. Compared to gated planar imaging, this technique showed regional asynergy more clearly in patients with myocardial infarction and demonstrated dilatation of the atria and ventricles more accurately in patients with an atrial septal defect and valvular heart diseases. In addition, when a section of the heart is otained at any angle with gated blood pool ECT, three-dimensional assessment of cardiac chambers in motion is more precise; mutual superimposition becomes unnecessary

Gamma camera image processing and graphical analysis mutual software system

International Nuclear Information System (INIS)

Wang Zhiqian; Chen Yongming; Ding Ailian; Ling Zhiye; Jin Yongjie

1992-01-01

GCCS gamma camera image processing and graphical analysis system is a special mutual software system. It is mainly used to analyse various patient data acquired from gamma camera. This system is used on IBM PC, PC/XT or PC/AT. It consists of several parts: system management, data management, device management, program package and user programs. The system provides two kinds of user interfaces: command menu and command characters. It is easy to change and enlarge this system because it is best modularized. The user programs include almost all the clinical protocols used now

Gamma camera system

International Nuclear Information System (INIS)

Miller, D.W.; Gerber, M.S.

1977-01-01

A gamma camera system having control components operating in conjunction with a solid state detector is described. The detector is formed of a plurality of discrete components which are associated in geometrical or coordinate arrangement defining a detector matrix to derive coordinate signal outputs. These outputs are selectively filtered and summed to form coordinate channel signals and corresponding energy channel signals. A control feature of the invention regulates the noted summing and filtering performance to derive data acceptance signals which are addressed to further treating components. The latter components include coordinate and enery channel multiplexers as well as energy-responsive selective networks. A sequential control is provided for regulating the signal processing functions of the system to derive an overall imaging cycle

A study on the performance evaluation of small gamma camera collimators using detective quantun efficiency

International Nuclear Information System (INIS)

Jeon, Ho Sang

2008-02-01

The anger-type gamma camera and novel marker compound using Tc-99m were firstly introduced in 1963. The gamma camera systems have being improved and applied to various fields, for example, medical, industrial, and environmental fields. Gamma camera is mainly composed of collimator, detector, and signal processor. And the radiative source is namely the imaging object. The collimator is essential component of gamma camera system because the imaging performance of system is mainly dependent on the collimator. The performance evaluation of collimators can be done by using evaluating factors. In this study, the novel factors for gamma camera evaluation are suggested. The established evaluating factors by NEMA are FWHM, sensitivity, and uniformity. They have some limitations in spite of their usefulness. Firstly, performance evaluation by those factors give insensitive and indirect results only. Secondly, the evaluation of noise property is ambiguous. Thirdly, there is no synthetic evaluation of system performance. Simulation with Monte Carlo code and experiment with a small camera camera were simultaenuously performed to verify novel evaluating factors. For the evaluation of spatial resolution, MTF was applied instead of FWHM. The MTF values presents excellent linear relationship with FWHM values. The NNPS was applied instead of uniformity and sensitivity for the evaluation of noise fluctuation. The NNPS values also presents linear relationship with sensitivity and unifomity. Moreover, these novel factors give quantities as the function of spatial frequencies. Finally, the DQE values were given by calculations with MTF, NNPS, and input SNR. DQE effectively presents the synthetic evaluation of gamma camera performance. It is the conclusion that MTF, NNPS, and DQE can be novel evaluating factors for gamma camera systems and the new factor for synthetic evaluation is derived

Geant4 simulation of a 3D high resolution gamma camera

International Nuclear Information System (INIS)

Akhdar, H.; Kezzar, K.; Aksouh, F.; Assemi, N.; AlGhamdi, S.; AlGarawi, M.; Gerl, J.

2015-01-01

The aim of this work is to develop a 3D gamma camera with high position resolution and sensitivity relying on both distance/absorption and Compton scattering techniques and without using any passive collimation. The proposed gamma camera is simulated in order to predict its performance using the full benefit of Geant4 features that allow the construction of the needed geometry of the detectors, have full control of the incident gamma particles and study the response of the detector in order to test the suggested geometries. Three different geometries are simulated and each configuration is tested with three different scintillation materials (LaBr3, LYSO and CeBr3)

Performance tests of two portable mini gamma cameras for medical applications

International Nuclear Information System (INIS)

Sanchez, F.; Fernandez, M. M.; Gimenez, M.; Benlloch, J. M.; Rodriguez-Alvarez, M. J.; Garcia de Quiros, F.; Lerche, Ch. W.; Pavon, N.; Palazon, J. A.; Martinez, J.; Sebastia, A.

2006-01-01

We have developed two prototypes of portable gamma cameras for medical applications based on a previous prototype designed and tested by our group. These cameras use a CsI(Na) continuous scintillation crystal coupled to the new flat-panel-type multianode position-sensitive photomultiplier tube, H8500 from Hamamatsu Photonics. One of the prototypes, mainly intended for intrasurgical use, has a field of view of 44x44 mm 2 , and weighs 1.2 kg. Its intrinsic resolution is better than 1.5 mm and its energy resolution is about 13% at 140 keV. The second prototype, mainly intended for osteological, renal, mammary, and endocrine (thyroid, parathyroid, and suprarenal) scintigraphies, weighs a total of 2 kg. Its average spatial resolution is 2 mm; it has a field of view of 95x95 mm 2 , with an energy resolution of about 15% at 140 keV. The main advantages of these gamma camera prototypes with respect to those previously reported in the literature are high portability and low weight, with no significant loss of sensitivity and spatial resolution. All the electronic components are packed inside the mini gamma cameras, and no external electronic devices are required. The cameras are only connected through the universal serial bus port to a portable PC. In this paper, we present the design of the cameras and describe the procedures that have led us to choose their configuration together with the most important performance features of the cameras. For one of the prototypes, clinical tests on melanoma patients are presented and images are compared with those obtained with a conventional camera

Gamma camera with an original system of scintigraphic image printing incorporated

International Nuclear Information System (INIS)

Roux, G.

A new gamma camera has been developed, using Anger's Principle to localise the scintillations and incorporating the latest improvements which give a standard of efficiency at present competitive for this kind of apparatus. In the general design of the system special care was devoted to its ease of employment and above all to the production of high-quality scintigraphic images, the recording of images obtained from the gamma camera posing a problem to which a solution is proposed. This consists in storing all the constituent data of an image in a cell matrix of format similar to the scope of the object, the superficial information density of the image being represented by the cell contents. When the examination is finished a special printer supplies a 35x43 cm 2 document in colour on paper, or in black and white on radiological film, at 2:1 or 1:1 magnifications. The laws of contrast representation by the colours or shades of grey are chosen a posteriori according to the organ examined. Documents of the same quality as those so far supplied by a rectilinear scintigraph are then obtained with the gamma camera, which offers its own advantages in addition. The first images acquired in vivo with the whole system, gamma camera plus printer, are presented [fr

A clinical gamma camera-based pinhole collimated system for high resolution small animal SPECT imaging

Energy Technology Data Exchange (ETDEWEB)

Mejia, J.; Galvis-Alonso, O.Y., E-mail: mejia_famerp@yahoo.com.b [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Biologia Molecular; Castro, A.A. de; Simoes, M.V. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Clinica Medica; Leite, J.P. [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Medicina. Dept. de Neurociencias e Ciencias do Comportamento; Braga, J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Astrofisica

2010-11-15

The main objective of the present study was to upgrade a clinical gamma camera to obtain high resolution tomographic images of small animal organs. The system is based on a clinical gamma camera to which we have adapted a special-purpose pinhole collimator and a device for positioning and rotating the target based on a computer-controlled step motor. We developed a software tool to reconstruct the target's three-dimensional distribution of emission from a set of planar projections, based on the maximum likelihood algorithm. We present details on the hardware and software implementation. We imaged phantoms and heart and kidneys of rats. When using pinhole collimators, the spatial resolution and sensitivity of the imaging system depend on parameters such as the detector-to-collimator and detector-to-target distances and pinhole diameter. In this study, we reached an object voxel size of 0.6 mm and spatial resolution better than 2.4 and 1.7 mm full width at half maximum when 1.5- and 1.0-mm diameter pinholes were used, respectively. Appropriate sensitivity to study the target of interest was attained in both cases. Additionally, we show that as few as 12 projections are sufficient to attain good quality reconstructions, a result that implies a significant reduction of acquisition time and opens the possibility for radiotracer dynamic studies. In conclusion, a high resolution single photon emission computed tomography (SPECT) system was developed using a commercial clinical gamma camera, allowing the acquisition of detailed volumetric images of small animal organs. This type of system has important implications for research areas such as Cardiology, Neurology or Oncology. (author)

Gamma camera scatter suppression unit WAM

International Nuclear Information System (INIS)

Kishi, Haruo; Shibahara, Noriyuki; Hirose, Yoshiharu; Shimonishi, Yoshihiro; Oumura, Masahiro; Ikeda, Hozumi; Hamada, Kunio; Ochi, Hironobu; Itagane, Hiroshi.

1990-01-01

In gamma camera imaging, scattered radiation is one of big factors to decrease image contrast. Simply, scatter suppression makes signal to noise ratio larger, but it makes statistics error because of radionuclide injection limit to the human body. EWA is a new method that suppresses scattered radiation and improves image contrast. In this article, WAM which is commercialized EWA method by Siemens Gammasonics Inc. is presented. (author)

A triple GEM gamma camera for medical application

Energy Technology Data Exchange (ETDEWEB)

Anulli, F. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Balla, A. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Bencivenni, G. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Corradi, G. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); D' Ambrosio, C. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Domenici, D. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Felici, G. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Gatta, M. [Laboratori Nazionali di Frascati INFN, Frascati (Italy); Morone, M.C. [Dipartimento di Biopatologia e Diagnostica per immagini, Universita di Roma Tor Vergata (Italy); INFN - Sezione di Roma Tor Vergata (Italy); Murtas, F. [Laboratori Nazionali di Frascati INFN, Frascati (Italy)]. E-mail: fabrizio.murtas@lnf.infn.it; Schillaci, O. [Dipartimento di Biopatologia e Diagnostica per immagini, Universita di Roma Tor Vergata (Italy)

2007-03-01

A Gamma Camera for medical applications 10x10cm{sup 2} has been built using a triple GEM chamber prototype. The photon converters placed in front of the three GEM foils, has been realized with different technologies. The chamber, High Voltage supplied with a new active divider made in Frascati, is readout through 64 pads, 1mm{sup 2} wide, organized in a row of 8cm long, with LHCb ASDQ chip. This Gamma Camera can be used both for X-ray movie and PET-SPECT imaging; this chamber prototype is placed in a scanner system, creating images of 8x8cm{sup 2}. Several measurements have been performed using phantom and radioactive sources of Tc99m(140keV) and Na22(511keV). Results on spatial resolution and image reconstruction are presented.

Performance evaluation of a hand-held, semiconductor (CdZnTe)-based gamma camera

CERN Document Server

Abe, A; Lee, J; Oka, T; Shizukuishi, K; Kikuchi, T; Inoue, T; Jimbo, M; Ryuo, H; Bickel, C

2003-01-01

We have designed and developed a small field of view gamma camera, the eZ SCOPE, based on use of a CdZnTe semiconductor. This device utilises proprietary signal processing technology and an interface to a computer-based imaging system. The purpose of this study was to evaluate the performance of the eZ scope in comparison with currently employed gamma camera technology. The detector is a single wafer of 5-mm-thick CdZnTe that is divided into a 16 x 16 array (256 pixels). The sensitive area of the detector is a square of dimension 3.2 cm. Two parallel-hole collimators are provided with the system and have a matching (256 hole) pattern to the CdZnTe detector array: a low-energy, high-resolution parallel-hole (LEHR) collimator fabricated of lead and a low-energy, high-sensitivity parallel-hole (LEHS) collimator fabricated of tungsten. Performance measurements and the data analysis were done according to the procedures of the NEMA standard. We also studied the long-term stability of the system with continuous use...

Quality control of plane and tomographic gamma cameras

International Nuclear Information System (INIS)

Moretti, J.L.; Roussi, A.

1993-01-01

In this article, the authors present different methods of gamma camera quality control in matters of uniformity, spatial resolution, spatial linearity, sensitivity, energy resolution, counting rate performance, SPECT parameters. The authors refer mainly to NEMA standards. 14 figs., 8 tabs

Quality assessment of gamma camera systems

International Nuclear Information System (INIS)

Kindler, M.

1985-01-01

There are methods and equipment in nuclear medical diagnostics that allow selective visualisation of the functioning of organs or organ systems, using radioactive substances for labelling and demonstration of metabolic processes. Following a previous contribution on fundamentals and systems components of a gamma camera system, the article in hand deals with the quality characteristics of such a system and with practical quality control and its significance for clinical applications. [de

NEMA NU-1 2007 based and independent quality control software for gamma cameras and SPECT

International Nuclear Information System (INIS)

Vickery, A; Joergensen, T; De Nijs, R

2011-01-01

A thorough quality assurance of gamma and SPECT cameras requires a careful handling of the measured quality control (QC) data. Most gamma camera manufacturers provide the users with camera specific QC Software. This QC software is indeed a useful tool for the following of day-to-day performance of a single camera. However, when it comes to objective performance comparison of different gamma cameras and a deeper understanding of the calculated numbers, the use of camera specific QC software without access to the source code is rather avoided. Calculations and definitions might differ, and manufacturer independent standardized results are preferred. Based upon the NEMA Standards Publication NU 1-2007, we have developed a suite of easy-to-use data handling software for processing acquired QC data providing the user with instructive images and text files with the results.

Annihilation gamma ray background characterization and rejection for a positron camera

International Nuclear Information System (INIS)

Levin, C.S.; Tornai, M.P.; MacDonald, L.R.

1996-01-01

We have developed a miniature (1.2 cm 2 ) beta-ray camera prototype to assist a surgeon in locating and removing the margins of a resected tumor. When imaging positron emitting radiopharmaceuticals, annihilation gamma ray interactions in the detector can mimic those of the betas. The extent of the background contamination depends on the detector, geometry and tumor specificity of the radiopharmaceutical. We have characterized the effects that annihilation gamma rays have on positron imaging with the camera. We studied beta and gamma ray detection rates and imaging using small positron or electron sources directly exposed to the detector to simulate hot tumor remnants and a cylinder filled with 18 F to simulate annihilation background from the brain. For various ratios of phantom brain/tumor activity, a annihilation gamma rate of 1.8 cts/sec/gCi was measured in the CaF 2 (Eu) detector. We present two gamma-ray background rejection schemes that use a β-γ coincidence. Results show that the coincidence methods works with ∼99% gamma ray rejection efficiency

Gamma camera

International Nuclear Information System (INIS)

Conrad, B.; Heinzelmann, K.G.

1975-01-01

A gamma camera is described which obviates the distortion of locating signals generally caused by the varied light conductive capacities of the light conductors in that the flow of light through each light conductor may be varied by means of a shutter. A balancing of the flow of light through each of the individual light conductors, in effect, collective light conductors may be balanced on the basis of their light conductive capacities or properties, so as to preclude a distortion of the locating signals caused by the varied light conductive properties of the light conductors. Each light conductor has associated therewith two, relative to each other, independently adjustable shutters, of which one forms a closure member and the other an adjusting shutter. In this embodiment of the invention it is thus possible to block all of the light conductors leading to a photoelectric transducer, with the exception of those light conductors which are to be balanced. The balancing of the individual light conductors may then be obtained on the basis of the output signals of the photoelectric transducer. (auth)

Two dimensional spatial distortion correction algorithm for scintillation GAMMA cameras

International Nuclear Information System (INIS)

Chaney, R.; Gray, E.; Jih, F.; King, S.E.; Lim, C.B.

1985-01-01

Spatial distortion in an Anger gamma camera originates fundamentally from the discrete nature of scintillation light sampling with an array of PMT's. Historically digital distortion correction started with the method based on the distortion measurement by using 1-D slit pattern and the subsequent on-line bi-linear approximation with 64 x 64 look-up tables for X and Y. However, the X, Y distortions are inherently two-dimensional in nature, and thus the validity of this 1-D calibration method becomes questionable with the increasing distortion amplitude in association with the effort to get better spatial and energy resolutions. The authors have developed a new accurate 2-D correction algorithm. This method involves the steps of; data collection from 2-D orthogonal hole pattern, 2-D distortion vector measurement, 2-D Lagrangian polynomial interpolation, and transformation to X, Y ADC frame. The impact of numerical precision used in correction and the accuracy of bilinear approximation with varying look-up table size have been carefully examined through computer simulation by using measured single PMT light response function together with Anger positioning logic. Also the accuracy level of different order Lagrangian polynomial interpolations for correction table expansion from hole centroids were investigated. Detailed algorithm and computer simulation are presented along with camera test results

A flexible geometry Compton camera for industrial gamma ray imaging

International Nuclear Information System (INIS)

Royle, G.J.; Speller, R.D.

1996-01-01

A design for a Compton scatter camera is proposed which is applicable to gamma ray imaging within limited access industrial sites. The camera consists of a number of single element detectors arranged in a small cluster. Coincidence circuitry enables the detectors to act as a scatter camera. Positioning the detector cluster at various locations within the site, and subsequent reconstruction of the recorded data, allows an image to be obtained. The camera design allows flexibility to cater for limited space or access simply by positioning the detectors in the optimum geometric arrangement within the space allowed. The quality of the image will be limited but imaging could still be achieved in regions which are otherwise inaccessible. Computer simulation algorithms have been written to optimize the various parameters involved, such as geometrical arrangement of the detector cluster and the positioning of the cluster within the site, and to estimate the performance of such a device. Both scintillator and semiconductor detectors have been studied. A prototype camera has been constructed which operates three small single element detectors in coincidence. It has been tested in a laboratory simulation of an industrial site. This consisted of a small room (2 m wide x 1 m deep x 2 m high) into which the only access points were two 6 cm diameter holes in a side wall. Simple images of Cs-137 sources have been produced. The work described has been done on behalf of BNFL for applications at their Sellafield reprocessing plant in the UK

Experience with dedicated ultra fast solid state cardiac gamma camera: technologist perspective

International Nuclear Information System (INIS)

Parab, Anil; Gaikar, Anil; Patil, Kashinath; Lele, V.

2010-01-01

Full text: To describe technologist perspective of working with ultra fast solid state gamma camera and comparison with conventional dual head gamma camera. Material and Methods: 900 Myocardial Perfusion scan were carried out on dedicated solid state detector cardiac camera between 1st February 2010 till 29th August 2010. 27 studies were done back to back on a conventional dual head gamma camera. In 2 cases dual head isotope imaging was done (Thallium+ 99m Tc-tetrofosmin). Rest stress protocol was used in 600 patients and stress - rest protocol was used in 300. 1:3 ratio of injected activity was maintained for both protocols (5 mCi for 1st study and 15 mCi for second study). For Rest - Stress protocol, 5 mCi of 99m Tc - Tetrofosmin was injected at rest, 40 minutes later, 5 min image was acquired on the solid state detector. Patient was then stressed. 15 mCi 99m Tc - Tetrofosmin was injected at peak stress. Images were acquired 20 minutes later for 3 minutes (total duration of study 90-100 min). For stress rest protocol, 5 mCi 99m Tc - Tetrofosmin was injected at peak stress. 5 mCi images were acquired 20 minutes later. Rest injection of 15 mCi was given 1 hour post stress injection. Rest images were acquired 40 minutes after rest injection (total duration of study 110-120 min). Results: We observed even with lesser amount activity and acquisition time of 5 min/cardiac scan it showed high sensitivity count rate over 2.2-4.7 kcps (10 times more counts than standard gamma camera). System gives better energy resolution < 7%. Better image contrast. Dual isotope imaging can be possible. Spatial resolution 4.3-4.9 mm. Excellent quality images were obtained using low activities (5 mCi/15 mCi) using 1/3rd the acquisition time compared to conventional dual head gamma camera Even in obese patients 7 mCi/21 mCi activity yielded excellent images at 1/3 rd acquisition time Quick acquisition resulted in greater patient comfort and no motion artifact also due to non rotation of

Preliminary Experience with Small Animal SPECT Imaging on Clinical Gamma Cameras

Directory of Open Access Journals (Sweden)

P. Aguiar

2014-01-01

Full Text Available The traditional lack of techniques suitable for in vivo imaging has induced a great interest in molecular imaging for preclinical research. Nevertheless, its use spreads slowly due to the difficulties in justifying the high cost of the current dedicated preclinical scanners. An alternative for lowering the costs is to repurpose old clinical gamma cameras to be used for preclinical imaging. In this paper we assess the performance of a portable device, that is, working coupled to a single-head clinical gamma camera, and we present our preliminary experience in several small animal applications. Our findings, based on phantom experiments and animal studies, provided an image quality, in terms of contrast-noise trade-off, comparable to dedicated preclinical pinhole-based scanners. We feel that our portable device offers an opportunity for recycling the widespread availability of clinical gamma cameras in nuclear medicine departments to be used in small animal SPECT imaging and we hope that it can contribute to spreading the use of preclinical imaging within institutions on tight budgets.

Kernel integration scatter model for parallel beam gamma camera and SPECT point source response

International Nuclear Information System (INIS)

Marinkovic, P.M.

2001-01-01

Scatter correction is a prerequisite for quantitative single photon emission computed tomography (SPECT). In this paper a kernel integration scatter Scatter correction is a prerequisite for quantitative SPECT. In this paper a kernel integration scatter model for parallel beam gamma camera and SPECT point source response based on Klein-Nishina formula is proposed. This method models primary photon distribution as well as first Compton scattering. It also includes a correction for multiple scattering by applying a point isotropic single medium buildup factor for the path segment between the point of scatter an the point of detection. Gamma ray attenuation in the object of imaging, based on known μ-map distribution, is considered too. Intrinsic spatial resolution of the camera is approximated by a simple Gaussian function. Collimator is modeled simply using acceptance angles derived from the physical dimensions of the collimator. Any gamma rays satisfying this angle were passed through the collimator to the crystal. Septal penetration and scatter in the collimator were not included in the model. The method was validated by comparison with Monte Carlo MCNP-4a numerical phantom simulation and excellent results were obtained. The physical phantom experiments, to confirm this method, are planed to be done. (author)

Development of a high sensitivity pinhole type gamma camera using semiconductors for low dose rate fields

Science.gov (United States)

Ueno, Yuichiro; Takahashi, Isao; Ishitsu, Takafumi; Tadokoro, Takahiro; Okada, Koichi; Nagumo, Yasushi; Fujishima, Yasutake; Yoshida, Akira; Umegaki, Kikuo

2018-06-01

We developed a pinhole type gamma camera, using a compact detector module of a pixelated CdTe semiconductor, which has suitable sensitivity and quantitative accuracy for low dose rate fields. In order to improve the sensitivity of the pinhole type semiconductor gamma camera, we adopted three methods: a signal processing method to set the discriminating level lower, a high sensitivity pinhole collimator and a smoothing image filter that improves the efficiency of the source identification. We tested basic performances of the developed gamma camera and carefully examined effects of the three methods. From the sensitivity test, we found that the effective sensitivity was about 21 times higher than that of the gamma camera for high dose rate fields which we had previously developed. We confirmed that the gamma camera had sufficient sensitivity and high quantitative accuracy; for example, a weak hot spot (0.9 μSv/h) around a tree root could be detected within 45 min in a low dose rate field test, and errors of measured dose rates with point sources were less than 7% in a dose rate accuracy test.

Analysis of dark current images of a CMOS camera during gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

Náfrádi, Gábor, E-mail: nafradi@reak.bme.hu [INT, BME, EURATOM Association, H-1111 Budapest (Hungary); Czifrus, Szabolcs, E-mail: czifrus@reak.bme.hu [INT, BME, EURATOM Association, H-1111 Budapest (Hungary); Kocsis, Gábor, E-mail: kocsis.gabor@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary); Pór, Gábor, E-mail: por@reak.bme.hu [INT, BME, EURATOM Association, H-1111 Budapest (Hungary); Szepesi, Tamás, E-mail: szepesi.tamas@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary); Zoletnik, Sándor, E-mail: zoletnik.sandor@wigner.mta.hu [Wigner RCP, RMI, EURATOM Association, POB 49, 1525 Budapest (Hungary)

2013-12-15

Highlights: • Radiation tolerance of a fast framing CMOS camera EDICAM examined. • We estimate the expected gamma dose and spectrum of EDICAM with MCNP. • We irradiate EDICAM by 23.5 Gy in 70 min in a fission rector. • Dose rate normalised average brightness of frames grows linearly with the dose. • Dose normalised average brightness of frames follows the dose rate time evolution. -- Abstract: We report on the behaviour of the dark current images of the Event Detection Intelligent Camera (EDICAM) when placed into an irradiation field of gamma rays. EDICAM is an intelligent fast framing CMOS camera operating in the visible spectral range, which is designed for the video diagnostic system of the Wendelstein 7-X (W7-X) stellarator. Monte Carlo calculations were carried out in order to estimate the expected gamma spectrum and dose for an entire year of operation in W7-X. EDICAM was irradiated in a pure gamma field in the Training Reactor of BME with a dose of approximately 23.5 Gy in 1.16 h. During the irradiation, numerous frame series were taken with the camera with exposure times 20 μs, 50 μs, 100 μs, 1 ms, 10 ms, 100 ms. EDICAM withstood the irradiation, but suffered some dynamic range degradation. The behaviour of the dark current images during irradiation is described in detail. We found that the average brightness of dark current images depends on the total ionising dose that the camera is exposed to and the dose rate as well as on the applied exposure times.

Evaluation of efficiency of a semiconductor gamma camera

CERN Document Server

Otake, H; Takeuchi, Y

2002-01-01

We evaluation basic characteristics of a compact type semiconductor gamma camera (eZ-SCOPE AN) of Cadmium Zinc Telluride (CdZnTe). This new compact gamma camera has 256 semiconductors representing the same number of pixels. Each semiconductor is 2 mm square and is located in 16 lines and rows on the surface of the detector. The specific performance characteristics were evaluated in the study referring to National Electrical Manufactures Association (NEMA) standards; intrinsic energy resolution, intrinsic count rate performance, integral uniformity, system planar sensitivity, system spatial resolution, and noise to the neighboring pixels. The intrinsic energy resolution measured 5.7% as full width half maximum (FWHM). The intrinsic count rate performance ranging from 17 kcps to 1,285 kcps was evaluated, but the highest intrinsic count rate was not observed. Twenty percents count loss was recognized at 1,021 kcps. The integral uniformity was 1.3% with high sensitivity collimator. The system planar sensitivity w...

A study on the optimization of optical guide of gamma camera detector

International Nuclear Information System (INIS)

Chung, Yong Hyun; Cho, Gyu Seong; Kim, Ho Kyung; Lee, Wan No; Kim, Young Soo

2000-01-01

An optical guide, which is a light guide located between NaI(Tl) scintillation-crystal and array of photo-multiplier tubes (PMTs) in the gamma camera detector system, is an essential component to deliver the spatial information recorded in scintillator to the PMTs. Without the optical guide, the spatial information within the range of a single PMT could not be obtained. For the design of the optimal optical guide, it is necessary to characterize its properties, especially sensitivity and spatial resolution of detector. In this study, the thickness and the refractive index of optical guide, which affect not only on the sensitivity but also on the spatial resolution of gamma-camera detector, were investigated by using Monte Carlo simulation. A 12'x12'x3/8' NaI(Tl) and 23 PMTs with each 5' diameter were considered as a gamma-camera detector components. Interactions of optical photons in the scintillator and the optical guide were simulated using a commercial code DETECT97, and the spatial resolution, mainly interfered by the intrinsic inward distortion within the PMT, was investigated using our own ANGER program, which was developed to calculate positions of incident photons in the gamma camera. From the simulation results, it was found that an optical guide with 1.6 of refractive index and 10 mm of thickness give maximum sensitivity and minimum spatial distortion, respectively

Study of a new architecture of gamma cameras with Cd/ZnTe/CdTe semiconductors; Etude d'une nouvelle architecture de gamma camera a base de semi-conducteurs CdZnTe /CdTe

Energy Technology Data Exchange (ETDEWEB)

Guerin, L

2007-11-15

This thesis studies new semi conductors for gammas cameras in order to improve the quality of image in nuclear medicine. The chapter 1 reminds the general principle of the imaging gamma, by describing the radiotracers, the channel of detection and the types of Anger gamma cameras acquisition. The physiological, physical and technological limits of the camera are then highlighted, to better identify the needs of future gamma cameras. The chapter 2 is dedicated to a bibliographical study. At first, semi-conductors used in imaging gamma are presented, and more particularly semi-conductors CDTE and CdZnTe, by distinguishing planar detectors and monolithic pixelated detectors. Secondly, the classic collimators of the gamma cameras, used in clinical routine for the most part of between them, are described. Their geometry is presented, as well as their characteristics, their advantages and their inconveniences. The chapter 3 is dedicated to a state of art of the simulation codes dedicated to the medical imaging and the methods of reconstruction in imaging gamma. These states of art allow to introduce the software of simulation and the methods of reconstruction used within the framework of this thesis. The chapter 4 presents the new architecture of gamma camera proposed during this work of thesis. It is structured in three parts. The first part justifies the use of semiconducting detectors CdZnTe, in particular the monolithic pixelated detectors, by bringing to light their advantages with regard to the detection modules based on scintillator. The second part presents gamma cameras to base of detectors CdZnTe (prototypes or commercial products) and their associated collimators, as well as the interest of an association of detectors CdZnTe in the classic collimators. Finally, the third part presents in detail the HiSens architecture. The chapter 5 describes both software of simulation used within the framework of this thesis to estimate the performances of the Hi

Heart imaging by cadmium telluride gamma camera European Program 'BIOMED' consortium

CERN Document Server

Scheiber, C; Chambron, J; Prat, V; Kazandjan, A; Jahnke, A; Matz, R; Thomas, S; Warren, S; Hage-Hali, M; Regal, R; Siffert, P; Karman, M

1999-01-01

Cadmium telluride semiconductor detectors (CdTe) operating at room temperature are attractive for medical imaging because of their good energy resolution providing excellent spatial and contrast resolution. The compactness of the detection system allows the building of small light camera heads which can be used for bedside imaging. A mobile pixellated gamma camera based on 2304 CdTe (pixel size: 3x3 mm, field of view: 15 cmx15 cm) has been designed for cardiac imaging. A dedicated 16-channel integrated circuit has also been designed. The acquisition hardware is fully programmable (DSP card, personal computer-based system). Analytical calculations have shown that a commercial parallel hole collimator will fit the efficiency/resolution requirements for cardiac applications. Monte-Carlo simulations predict that the Moire effect can be reduced by a 15 deg. tilt of the collimator with respect to the detector grid. A 16x16 CdTe module has been built for the preliminary physical tests. The energy resolution was 6.16...

SU-E-E-06: Teaching About the Gamma Camera and Ultrasound Imaging

International Nuclear Information System (INIS)

Lowe, M; Spiro, A; Vogel, R; Donaldson, N; Gosselin, C

2015-01-01

Purpose: Instructional modules on applications of physics in medicine are being developed. The target audience consists of students who have had an introductory undergraduate physics course. This presentation will concentrate on an active learning approach to teach the principles of the gamma camera. There will also be a description of an apparatus to teach ultrasound imaging. Methods: Since a real gamma camera is not feasible in the undergraduate classroom, we have developed two types of optical apparatus that teach the main principles. To understand the collimator, LEDS mimic gamma emitters in the body, and the photons pass through an array of tubes. The distance, spacing, diameter, and length of the tubes can be varied to understand the effect upon the resolution of the image. To determine the positions of the gamma emitters, a second apparatus uses a movable green laser, fluorescent plastic in lieu of the scintillation crystal, acrylic rods that mimic the PMTs, and a photodetector to measure the intensity. The position of the laser is calculated with a centroid algorithm.To teach the principles of ultrasound imaging, we are using the sound head and pulser box of an educational product, variable gain amplifier, rotation table, digital oscilloscope, Matlab software, and phantoms. Results: Gamma camera curriculum materials have been implemented in the classroom at Loyola in 2014 and 2015. Written work shows good knowledge retention and a more complete understanding of the material. Preliminary ultrasound imaging materials were run in 2015. Conclusion: Active learning methods add another dimension to descriptions in textbooks and are effective in keeping the students engaged during class time. The teaching apparatus for the gamma camera and ultrasound imaging can be expanded to include more cases, and could potentially improve students’ understanding of artifacts and distortions in the images

SU-E-E-06: Teaching About the Gamma Camera and Ultrasound Imaging

Energy Technology Data Exchange (ETDEWEB)

Lowe, M; Spiro, A [Loyola University Maryland, Baltimore, Maryland (United States); Vogel, R [Iowa Doppler Products, Iowa City, Iowa (United States); Donaldson, N; Gosselin, C [Rockhurst University, Kansas City, MO (United States)

2015-06-15

Purpose: Instructional modules on applications of physics in medicine are being developed. The target audience consists of students who have had an introductory undergraduate physics course. This presentation will concentrate on an active learning approach to teach the principles of the gamma camera. There will also be a description of an apparatus to teach ultrasound imaging. Methods: Since a real gamma camera is not feasible in the undergraduate classroom, we have developed two types of optical apparatus that teach the main principles. To understand the collimator, LEDS mimic gamma emitters in the body, and the photons pass through an array of tubes. The distance, spacing, diameter, and length of the tubes can be varied to understand the effect upon the resolution of the image. To determine the positions of the gamma emitters, a second apparatus uses a movable green laser, fluorescent plastic in lieu of the scintillation crystal, acrylic rods that mimic the PMTs, and a photodetector to measure the intensity. The position of the laser is calculated with a centroid algorithm.To teach the principles of ultrasound imaging, we are using the sound head and pulser box of an educational product, variable gain amplifier, rotation table, digital oscilloscope, Matlab software, and phantoms. Results: Gamma camera curriculum materials have been implemented in the classroom at Loyola in 2014 and 2015. Written work shows good knowledge retention and a more complete understanding of the material. Preliminary ultrasound imaging materials were run in 2015. Conclusion: Active learning methods add another dimension to descriptions in textbooks and are effective in keeping the students engaged during class time. The teaching apparatus for the gamma camera and ultrasound imaging can be expanded to include more cases, and could potentially improve students’ understanding of artifacts and distortions in the images.

First demonstration of real-time gamma imaging by using a handheld Compton camera for particle therapy

Energy Technology Data Exchange (ETDEWEB)

Taya, T., E-mail: taka48138@ruri.waseda.jp [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kataoka, J.; Kishimoto, A.; Iwamoto, Y.; Koide, A. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Nishio, T. [Graduate School of Biomedical and Health Science, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima-shi, Hiroshima (Japan); Kabuki, S. [School of Medicine, Tokai University, 143 Shimokasuya, Isehara-shi, Kanagawa (Japan); Inaniwa, T. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba (Japan)

2016-09-21

The use of real-time gamma imaging for cancer treatment in particle therapy is expected to improve the accuracy of the treatment beam delivery. In this study, we demonstrated the imaging of gamma rays generated by the nuclear interactions during proton irradiation, using a handheld Compton camera (14 cm×15 cm×16 cm, 2.5 kg) based on scintillation detectors. The angular resolution of this Compton camera is ∼8° at full width at half maximum (FWHM) for a {sup 137}Cs source. We measured the energy spectra of the gamma rays using a LaBr{sub 3}(Ce) scintillator and photomultiplier tube, and using the handheld Compton camera, performed image reconstruction when using a 70 MeV proton beam to irradiate a water, Ca(OH){sub 2}, and polymethyl methacrylate (PMMA) phantom. In the energy spectra of all three phantoms, we found an obvious peak at 511 keV, which was derived from annihilation gamma rays, and in the energy spectrum of the PMMA phantom, we found another peak at 718 keV, which contains some of the prompt gamma rays produced from {sup 10}B. Therefore, we evaluated the peak positions of the projection from the reconstructed images of the PMMA phantom. The differences between the peak positions and the Bragg peak position calculated using simulation are 7 mm±2 mm and 3 mm±8 mm, respectively. Although we could quickly acquire online gamma imaging of both of the energy ranges during proton irradiation, we cannot arrive at a clear conclusion that prompt gamma rays sufficiently trace the Bragg peak from these results because of the uncertainty given by the spatial resolution of the Compton camera. We will develop a high-resolution Compton camera in the near future for further study. - Highlights: • Gamma imaging during proton irradiation by a handheld Compton camera is demonstrated. • We were able to acquire the online gamma-ray images quickly. • We are developing a high resolution Compton camera for range verification.

Rapid objective measurement of gamma camera resolution using statistical moments.

Science.gov (United States)

Hander, T A; Lancaster, J L; Kopp, D T; Lasher, J C; Blumhardt, R; Fox, P T

1997-02-01

An easy and rapid method for the measurement of the intrinsic spatial resolution of a gamma camera was developed. The measurement is based on the first and second statistical moments of regions of interest (ROIs) applied to bar phantom images. This leads to an estimate of the modulation transfer function (MTF) and the full-width-at-half-maximum (FWHM) of a line spread function (LSF). Bar phantom images were acquired using four large field-of-view (LFOV) gamma cameras (Scintronix, Picker, Searle, Siemens). The following factors important for routine measurements of gamma camera resolution with this method were tested: ROI placement and shape, phantom orientation, spatial sampling, and procedural consistency. A 0.2% coefficient of variation (CV) between repeat measurements of MTF was observed for a circular ROI. The CVs of less than 2% were observed for measured MTF values for bar orientations ranging from -10 degrees to +10 degrees with respect to the x and y axes of the camera acquisition matrix. A 256 x 256 matrix (1.6 mm pixel spacing) was judged sufficient for routine measurements, giving an estimate of the FWHM to within 0.1 mm of manufacturer-specified values (3% difference). Under simulated clinical conditions, the variation in measurements attributable to procedural effects yielded a CV of less than 2% in newer generation cameras. The moments method for determining MTF correlated well with a peak-valley method, with an average difference of 0.03 across the range of spatial frequencies tested (0.11-0.17 line pairs/mm, corresponding to 4.5-3.0 mm bars). When compared with the NEMA method for measuring intrinsic spatial resolution, the moments method was found to be within 4% of the expected FWHM.

Computer aided collimation gamma (Cacao): a new approach in measuring and visualizing the distribution of X and gamma ray emitters in contaminate wounds; Cacao (camera a collimation assistee par ordinateur): une nouvelle approche pour reconstruire et visualiser des contaminations d'emetteurs X et gamma dans les blessures

Energy Technology Data Exchange (ETDEWEB)

Douiri, A. [Hopital Pitie-Salpetriere (LENA), 75 - Paris (France); Jeanguillaume, C. [Centre Hospitalier Universitaire de Larrey, Service de Medecine Nucleaire, 49 - Angers (France); Franck, D.; Carlan, L. de [Institut de Radioprotection et de Surete Nucleaire, IRSN, Dept. de Protection de la Sante de l' Homme et de Dosimetrie, 92 - Fontenay aux Roses (France); Quartuccio, M.; Begot, S. [Faculte des Sciences d' Orsay (LPS), 91 - Orsay (France)

2003-07-01

The treatment of contaminated wounds can be greatly improved by visualizing the distribution of the radioactivity that is present. The low sensitivity of the conventional Anger camera means that it can only be used where there is a high level of activity. Moreover, these gamma cameras cannot make full use of the recent progress made in high spatial resolution semi-conductor detectors. In order to increase sensitivity while at the same time maintaining a sufficient resolution of the reconstructed image, the principle of the Computer aided collimation gamma camera (CACAO in French) was proposed as a possible means of using gamma cameras in intern dosimetry. This principle is based on the combined use of collimators with holes that are wider- than the intrinsic resolution of the detector, circular and linear scanning movements, a detector sensitive to the source depth and a specific reconstruction algorithm. This article presents the recent developments of the CACAO system and illustrates by a theoretical and experimental study, its performances compared with the classic tomography system. We start with a general overview of the CACAO system and its reconstruction algorithm. First of all, the superiority of the CACAO system is demonstrated by a simulation ,study. Then, an experimental bench was developed using an implanted silicon pixel detector specifically designed to allow the visualization of a subject contaminated with low energy X and gamma emitters. The study presented here shows images obtained from a phantom composed of three sources of Americium {sup 341}Am. Although the comparison between the conventional and CACAO approaches were not carried out with optimal parameters, especially for CACAO, the initial results show that CACAO has an improved sensitivity and a superior resolution. Finally, the transposition of this system to the practical study of contaminated wounds is discussed. (authors)

Adaptation of the Camera Link Interface for Flight-Instrument Applications

Science.gov (United States)

Randall, David P.; Mahoney, John C.

2010-01-01

COTS (commercial-off-the-shelf) hard ware using an industry-standard Camera Link interface is proposed to accomplish the task of designing, building, assembling, and testing electronics for an airborne spectrometer that would be low-cost, but sustain the required data speed and volume. The focal plane electronics were designed to support that hardware standard. Analysis was done to determine how these COTS electronics could be interfaced with space-qualified camera electronics. Interfaces available for spaceflight application do not support the industry standard Camera Link interface, but with careful design, COTS EGSE (electronics ground support equipment), including camera interfaces and camera simulators, can still be used.

Slit-Slat Collimator Equipped Gamma Camera for Whole-Mouse SPECT-CT Imaging

Science.gov (United States)

Cao, Liji; Peter, Jörg

2012-06-01

A slit-slat collimator is developed for a gamma camera intended for small-animal imaging (mice). The tungsten housing of a roof-shaped collimator forms a slit opening, and the slats are made of lead foils separated by sparse polyurethane material. Alignment of the collimator with the camera's pixelated crystal is performed by adjusting a micrometer screw while monitoring a Co-57 point source for maximum signal intensity. For SPECT, the collimator forms a cylindrical field-of-view enabling whole mouse imaging with transaxial magnification and constant on-axis sensitivity over the entire axial direction. As the gamma camera is part of a multimodal imaging system incorporating also x-ray CT, five parameters corresponding to the geometric displacements of the collimator as well as to the mechanical co-alignment between the gamma camera and the CT subsystem are estimated by means of bimodal calibration sources. To illustrate the performance of the slit-slat collimator and to compare its performance to a single pinhole collimator, a Derenzo phantom study is performed. Transaxial resolution along the entire long axis is comparable to a pinhole collimator of same pinhole diameter. Axial resolution of the slit-slat collimator is comparable to that of a parallel beam collimator. Additionally, data from an in-vivo mouse study are presented.

Development and evaluation of a portable CZT coded aperture gamma-camera

Energy Technology Data Exchange (ETDEWEB)

Montemont, G.; Monnet, O.; Stanchina, S.; Maingault, L.; Verger, L. [CEA, LETI, Minatec Campus, Univ. Grenoble Alpes, 38054 Grenoble, (France); Carrel, F.; Lemaire, H.; Schoepff, V. [CEA, LIST, 91191 Gif-sur-Yvette, (France); Ferrand, G.; Lalleman, A.-S. [CEA, DAM, DIF, 91297 Arpajon, (France)

2015-07-01

We present the design and the evaluation of a CdZnTe (CZT) based gamma camera using a coded aperture mask. This camera, based on a 8 cm{sup 3} detection module, is small enough to be portable and battery-powered (4 kg weight and 4 W power dissipation). As the detector has spectral capabilities, the gamma camera allows isotope identification and colored imaging, by affecting one color channel to each identified isotope. As all data processing is done at real time, the user can directly observe the outcome of an acquisition and can immediately react to what he sees. We first present the architecture of the system, how the detector works, and its performances. After, we focus on the imaging technique used and its strengths and limitations. Finally, results concerning sensitivity, spatial resolution, field of view and multi-isotope imaging are shown and discussed. (authors)

Development and evaluation of a portable CZT coded aperture gamma-camera

International Nuclear Information System (INIS)

Montemont, G.; Monnet, O.; Stanchina, S.; Maingault, L.; Verger, L.; Carrel, F.; Lemaire, H.; Schoepff, V.; Ferrand, G.; Lalleman, A.-S.

2015-01-01

We present the design and the evaluation of a CdZnTe (CZT) based gamma camera using a coded aperture mask. This camera, based on a 8 cm 3 detection module, is small enough to be portable and battery-powered (4 kg weight and 4 W power dissipation). As the detector has spectral capabilities, the gamma camera allows isotope identification and colored imaging, by affecting one color channel to each identified isotope. As all data processing is done at real time, the user can directly observe the outcome of an acquisition and can immediately react to what he sees. We first present the architecture of the system, how the detector works, and its performances. After, we focus on the imaging technique used and its strengths and limitations. Finally, results concerning sensitivity, spatial resolution, field of view and multi-isotope imaging are shown and discussed. (authors)

Utilization of a gamma camera in research of the concentration in marine products

International Nuclear Information System (INIS)

Nakamura, Ryoichi

1981-01-01

A gamma camera was used for the study of the metabolism of micro elements in marine products. Hexagrammos otakii (rock trout) was put under anesthesia with MS-222. By cutting partly the abdomen, the internal organs were exposed. 1 - 2 mCi of technetium-99m was injected into the bulbus arteriosus. From immediately after the injection, photographs were taken consecutively, one picture every 0.5 second for 30 seconds, to a total of 60 pictures. Since the gamma camera has been developed solely for human beings, there is some inconvenience when it is applied to marine products. The advantages of using a gamma camera are the observation on the behavior of substances in a body while a marine product is alive, and the grasping of the variation in substance behavior at extremely brief intervals. The disadvantages are the low resolution of about 5 mm - 7 mm, and the difficulty in differentiating overlapping organs. (J.P.N.)

Value of coincidence gamma camera PET for diagnosing head and neck tumors: functional imaging and image coregistration

International Nuclear Information System (INIS)

Dresel, S.; Brinkbaeumer, K.; Schmid, R.; Hahn, K.

2001-01-01

54 patients suffering from head and neck tumors (30 m, 24 f, age: 32-67 years) were examined using dedicated PET and coincidence gamma camera PET after injection of 185-350 MBq [ 18 F]FDG. Examinations were carried out on the dedicated PET first (Siemens ECAT Exact HR+) followed by a scan on the coincidence gamma camera PET (Picker Prism 2000 XP-PCD, Marconi Axis g-PET 2 AZ). Dedicated PET was acquired in 3D mode, coincidence gamma camera PET was performed in list mode using an axial filter. Reconstruction of data was performed iteratively on both, dedicated PET and coincidence gamma camera PET. All patients received a CT scan in multislice technique (Siemens Somatom Plus 4, Marconi MX 8000). Image coregistration was performed on an Odyssey workstation (Marconi). All findings have been verified by the gold standard histology or in case of negative histology by follow-up. Results: Using dedicated PET the primary or recurrent lesion was correctly diagnosed in 47/48 patients, using coincidence gamma camera PET in 46/48 patients and using CT in 25/48 patients. Metastatic disease in cervical lymph nodes was diagnosed in 17/18 patients with dedicated PET, in 16/18 patients with coincidence gamma camera PET and in 15/18 with CT. False-positive results with regard to lymph node metastasis were seen with one patient for dedicated PET and hybrid PET, respectively, and with 18 patients for CT. In a total of 11 patients unknown metastatic lesions were seen with dedicated PET and with coincidence gamma camera PET elsewhere in the body (lung: n = 7, bone: n = 3, liver: n = 1). Additional malignant disease other than the head and neck tumor was found in 4 patients. (orig.) [de

Use of gamma camera for measurement of the internal contamination with depleted uranium

International Nuclear Information System (INIS)

Spaic, R.; Markovic, S.; Pavlovic, S.; Pavlovic, R.; Ajdinovic, B.; Baskot, B.; Djurovic, B.

2000-01-01

Depleted uranium from radioactive wastes is used for manufacturing bullets used in Iraq, Republic of Serbia and Yugoslavia. These bullets are extremely dense and capable of penetrating heavily armored vehicles. Their medical importance lies in the fact that the bullets contain seventy percent depleted uranium which creates aerosolized particles less than five microns in diameter, small enough to be inhaled, after spontaneous bullet burn at impact. Nuclear medicine scientists must be aware of this and be prepared to measure internal contamination of persons exposed to this radioactive material. Whole body counters (WBC) represent appropriate equipment for this purpose but their availability in developing countries is not sufficient. Gamma camera is an alternative. The minimum detectable activity (MDA) of depleted uranium, iodine and technetium for gamma cameras was measured in this paper. Low energy X-ray 100 KeV with 20% windows are used for the depleted uranium detection. About 40% gamma emissions from depleted uranium fall within these limits. The activities measured (50-100 Bq) are about ten times higher then on WBC (5 Bq). This does not limit the use of gamma cameras for measurement of lung or whole body internal contamination with depleted uranium. (author)

Feasibility study of a lens-coupled charge-coupled device gamma camera

International Nuclear Information System (INIS)

Lee, Hakjae; Jung, Youngjun; Kim, Jungmin; Bae, Seungbin; Lee, Kisung; Kang, Jungwon

2011-01-01

A charge-coupled device (CCD) is generally used in a digital camera as a light-collecting device such as a photomultiplier tube (PMT). Because of its low sensitivity and very high dark current, CCD have not been popularly used for gamma imaging systems. However, a recent CCD technological breakthrough has improved CCD sensitivity, and the use of a Peltier cooling system can significantly minimize the dark current. In this study, we investigated the feasibility of a prototype CCD gamma camera consisting of a CsI scintillator, optical lenses, and a CCD module. Despite electron-multiplying (EM) CCDs having higher performance, in this study, we built a cost-effective system consisted of low-cost components compared to EMCCDs. Our prototype detector consists of a CsI scintillator, two optical lenses, and a conventional Peltier-cooled CCD. The performance of this detector was evaluated by acquiring the sensitivity, resolution, and the modulation transfer function (MTF). The sensitivity of the prototype detector showed excellent linearity. With a 1 mm-diameter pinhole collimator, the full width at half-maximum (FWHM) of a 1.1 mm Tc-99m line source image was 2.85 mm. These results show that the developed prototype camera is feasible for small animal gamma imaging.

Standardization of test conditions for gamma camera performance measurement

International Nuclear Information System (INIS)

Jordan, K.

1980-01-01

The actual way of measuring gamma camera performance is to use point sources or flood sources in air, often in combination with bar phantoms. This method mostly brings best performance parameters for cameras but it has nothing in common with the use of a camera in clinical practice. Particular in the case of low energy emitters, like Tc-99m, the influence of scattered radiation over the performance of cameras is very high. Therefore it is important to have test conditions of radionuclide imaging devices, that will approach as best as practicable the measuring conditions in clinical applications. It is therefore a good news that the International Electrochemical Commission IEC has prepared a draft 'Characteristics and test conditions of radionuclide imaging devices' which is now submitted to the national committees for formal approval under the Six Months' Rule. Some essential points of this document are discussed in the paper. (orig.) [de

Performance and quality control of scintillation cameras

International Nuclear Information System (INIS)

Moretti, J.L.; Iachetti, D.

1983-01-01

Acceptance testing, quality and control assurance of gamma-cameras are a part of diagnostic quality in clinical practice. Several parameters are required to achieve a good diagnostic reliability: intrinsic spatial resolution, spatial linearity, uniformities, energy resolution, count-rate characteristics, multiple window spatial analysis. Each parameter was measured and also estimated by a test easy to implement in routine practice. Material required was a 4028 multichannel analyzer linked to a microcomputeur, mini-computers and a set of phantoms (parallel slits, diffusing phantom, orthogonal hole transmission pattern). Gamma-cameras on study were:CGR 3400, CGR 3420, G.E.4000. Siemens ZLC 75 and large field Philips. Several tests proposed by N.E.M.A. and W.H.O. have to be improved concerning too punctual spatial determinations during distortion measurements with multiple window. Contrast control of image need to be monitored with high counting rate. This study shows the need to avoid punctual determinations and the interest to give sets of values of the same parameter on the whole field and to report mean values with their standard variation [fr

Advantages of computer cameras over video cameras/frame grabbers for high-speed vision applications

Science.gov (United States)

Olson, Gaylord G.; Walker, Jo N.

1997-09-01

Cameras designed to work specifically with computers can have certain advantages in comparison to the use of cameras loosely defined as 'video' cameras. In recent years the camera type distinctions have become somewhat blurred, with a great presence of 'digital cameras' aimed more at the home markets. This latter category is not considered here. The term 'computer camera' herein is intended to mean one which has low level computer (and software) control of the CCD clocking. These can often be used to satisfy some of the more demanding machine vision tasks, and in some cases with a higher rate of measurements than video cameras. Several of these specific applications are described here, including some which use recently designed CCDs which offer good combinations of parameters such as noise, speed, and resolution. Among the considerations for the choice of camera type in any given application would be such effects as 'pixel jitter,' and 'anti-aliasing.' Some of these effects may only be relevant if there is a mismatch between the number of pixels per line in the camera CCD and the number of analog to digital (A/D) sampling points along a video scan line. For the computer camera case these numbers are guaranteed to match, which alleviates some measurement inaccuracies and leads to higher effective resolution.

New detection modules for gamma, beta and X-ray cameras

International Nuclear Information System (INIS)

Azman, S.; Bolle, E.; Dang, K.Q.; Dang, W.; Dietzel, K.I.; Froberg, T.; Gaarder, P.E.; Gjaerum, J.A.; Haugen, S.H.; Hellum, G.; Henriksen, J.R.; Johanson, T.M.; Kobbevik, A.; Maehlum, G.; Meier, D.; Mikkelsen, S.; Ninive, I.; Oya, P.; Pavlov, N.; Pettersen, D.M.; Sundal, B.M.; Talebi, J.; Yoshioka, K.

2003-01-01

Full text: Ideas ASA is developing new detection modules for gamma, beta and X-ray cameras. Recent developments focus on modules using various semi-conductor materials (CZT, HgI, Si). The development includes ASIC design, detector module development, and implementation in camera heads. In this presentation we describe the characteristics of important ASICs and its properties in terms of electronic noise, and the modes for measuring signals (switched current modes, sparsified modes, self triggered modes). The ASICs are specific for detectors and applications. We describe recent developments using various semi - conductor materials. We describe important design aspects for medical applications and in life science (SPECT, beta, X-ray cameras)

Europe's space camera unmasks a cosmic gamma-ray machine

Science.gov (United States)

1996-11-01

The new-found neutron star is the visible counterpart of a pulsating radio source, Pulsar 1055-52. It is a mere 20 kilometres wide. Although the neutron star is very hot, at about a million degrees C, very little of its radiant energy takes the form of visible light. It emits mainly gamma-rays, an extremely energetic form of radiation. By examining it at visible wavelengths, astronomers hope to figure out why Pulsar 1055-52 is the most efficient generator of gamma-rays known so far, anywhere the Universe. The Faint Object Camera found Pulsar 1055-52 in near ultraviolet light at 3400 angstroms, a little shorter in wavelength than the violet light at the extremity of the human visual range. Roberto Mignani, Patrizia Caraveo and Giovanni Bignami of the Istituto di Fisica Cosmica in Milan, Italy, report its optical identification in a forthcoming issue of Astrophysical Journal Letters (1 January 1997). The formal name of the object is PSR 1055-52. Evading the glare of an adjacent star The Italian team had tried since 1988 to spot Pulsar 1055-52 with two of the most powerful ground-based optical telescopes in the Southern Hemisphere. These were the 3.6-metre Telescope and the 3.5-metre New Technology Telescope of the European Southern Observatory at La Silla, Chile. Unfortunately an ordinary star 100,000 times brighter lay in almost the same direction in the sky, separated from the neutron star by only a thousandth of a degree. The Earth's atmosphere defocused the star's light sufficiently to mask the glimmer from Pulsar 1055-52. The astronomers therefore needed an instrument in space. The Faint Object Camera offered the best precision and sensitivity to continue the hunt. Devised by European astronomers to complement the American wide field camera in the Hubble Space Telescope, the Faint Object Camera has a relatively narrow field of view. It intensifies the image of a faint object by repeatedly accelerating electrons from photo-electric films, so as to produce

Gamma camera system

International Nuclear Information System (INIS)

Miller, D.W.; Gerber, M.S.

1982-01-01

The invention provides a composite solid state detector for use in deriving a display, by spatial coordinate information, of the distribution or radiation emanating from a source within a region of interest, comprising several solid state detector components, each having a given surface arranged for exposure to impinging radiation and exhibiting discrete interactions therewith at given spatially definable locations. The surface of each component and the surface disposed opposite and substantially parallel thereto are associated with impedence means configured to provide for each opposed surface outputs for signals relating the given location of the interactions with one spatial coordinate parameter of one select directional sense. The detector components are arranged to provide groupings of adjacently disposed surfaces mutually linearly oriented to exhibit a common directional sense of the spatial coordinate parameter. Means interconnect at least two of the outputs associated with each of the surfaces within a given grouping for collecting the signals deriving therefrom. The invention also provides a camera system for imaging the distribution of a source of gamma radiation situated within a region of interest

Development of a tomographic system adapted to 3D measurement of contaminated wounds based on the Cacao concept (Computer aided collimation Gamma Camera)

International Nuclear Information System (INIS)

Douiri, A.

2002-03-01

The computer aided collimation gamma camera (CACAO in French) is a gamma camera using a collimator with large holes, a supplementary linear scanning motion during the acquisition and a dedicated reconstruction program taking full account of the source depth. The CACAO system was introduced to improve both the sensitivity and the resolution in nuclear medicine. This thesis focuses on the design of a fast and robust reconstruction algorithm in the CACAO project. We start by an overview of tomographic imaging techniques in nuclear medicine. After modelling the physical CACAO system, we present the complete reconstruction program which involves three steps: 1) shift and sum 2) deconvolution and filtering 3) rotation and sum. The deconvolution is the critical step that decreases the signal to noise ratio of the reconstructed images. We propose a regularized multi-channel algorithm to solve the deconvolution problem. We also present a fast algorithm based on Splines functions and preserving the high quality of the reconstructed images for the shift and the rotation steps. Comparisons of simulated reconstructed images in 2D and 3D for the conventional system (CPHC) and CACAO demonstrate the ability of CACAO system to increase the quality of the SPECT images. Finally, this study concludes with an experimental approach with a pixellated detector conceived for a 3D measurement of contaminated wounds. This experimentation proves the possible advantages of coupling the CACAO project with pixellated detectors. Moreover, a variety of applications could fully benefit from the CACAO system, such as low activity imaging, the use of high-energy gamma isotopes and the visualization of deep organs. Moreover the combination of the CACAO system with a pixels detector may open up further possibilities for the future of nuclear medicine. (author)

Computing camera heading: A study

Science.gov (United States)

Zhang, John Jiaxiang

2000-08-01

An accurate estimate of the motion of a camera is a crucial first step for the 3D reconstruction of sites, objects, and buildings from video. Solutions to the camera heading problem can be readily applied to many areas, such as robotic navigation, surgical operation, video special effects, multimedia, and lately even in internet commerce. From image sequences of a real world scene, the problem is to calculate the directions of the camera translations. The presence of rotations makes this problem very hard. This is because rotations and translations can have similar effects on the images, and are thus hard to tell apart. However, the visual angles between the projection rays of point pairs are unaffected by rotations, and their changes over time contain sufficient information to determine the direction of camera translation. We developed a new formulation of the visual angle disparity approach, first introduced by Tomasi, to the camera heading problem. Our new derivation makes theoretical analysis possible. Most notably, a theorem is obtained that locates all possible singularities of the residual function for the underlying optimization problem. This allows identifying all computation trouble spots beforehand, and to design reliable and accurate computational optimization methods. A bootstrap-jackknife resampling method simultaneously reduces complexity and tolerates outliers well. Experiments with image sequences show accurate results when compared with the true camera motion as measured with mechanical devices.

Small Field of View Scintimammography Gamma Camera Integrated to a Stereotactic Core Biopsy Digital X-ray System

Energy Technology Data Exchange (ETDEWEB)

Andrew Weisenberger; Fernando Barbosa; T. D. Green; R. Hoefer; Cynthia Keppel; Brian Kross; Stanislaw Majewski; Vladimir Popov; Randolph Wojcik

2002-10-01

A small field of view gamma camera has been developed for integration with a commercial stereotactic core biopsy system. The goal is to develop and implement a dual-modality imaging system utilizing scintimammography and digital radiography to evaluate the reliability of scintimammography in predicting the malignancy of suspected breast lesions from conventional X-ray mammography. The scintimammography gamma camera is a custom-built mini gamma camera with an active area of 5.3 cm /spl times/ 5.3 cm and is based on a 2 /spl times/ 2 array of Hamamatsu R7600-C8 position-sensitive photomultiplier tubes. The spatial resolution of the gamma camera at the collimator surface is < 4 mm full-width at half-maximum and a sensitivity of /spl sim/ 4000 Hz/mCi. The system is also capable of acquiring dynamic scintimammographic data to allow for dynamic uptake studies. Sample images of preliminary clinical results are presented to demonstrate the performance of the system.

Compact CdZnTe-Based Gamma Camera For Prostate Cancer Imaging

International Nuclear Information System (INIS)

Cui, Y.; Lall, T.; Tsui, B.; Yu, J.; Mahler, G.; Bolotnikov, A.; Vaska, P.; DeGeronimo, G.; O'Connor, P.; Meinken, G.; Joyal, J.; Barrett, J.; Camarda, G.; Hossain, A.; Kim, K.H.; Yang, G.; Pomper, M.; Cho, S.; Weisman, K.; Seo, Y.; Babich, J.; LaFrance, N.; James, R.B.

2011-01-01

In this paper, we discuss the design of a compact gamma camera for high-resolution prostate cancer imaging using Cadmium Zinc Telluride (CdZnTe or CZT) radiation detectors. Prostate cancer is a common disease in men. Nowadays, a blood test measuring the level of prostate specific antigen (PSA) is widely used for screening for the disease in males over 50, followed by (ultrasound) imaging-guided biopsy. However, PSA tests have a high false-positive rate and ultrasound-guided biopsy has a high likelihood of missing small cancerous tissues. Commercial methods of nuclear medical imaging, e.g. PET and SPECT, can functionally image the organs, and potentially find cancer tissues at early stages, but their applications in diagnosing prostate cancer has been limited by the smallness of the prostate gland and the long working distance between the organ and the detectors comprising these imaging systems. CZT is a semiconductor material with wide band-gap and relatively high electron mobility, and thus can operate at room temperature without additional cooling. CZT detectors are photon-electron direct-conversion devices, thus offering high energy-resolution in detecting gamma rays, enabling energy-resolved imaging, and reducing the background of Compton-scattering events. In addition, CZT material has high stopping power for gamma rays; for medical imaging, a few-mm-thick CZT material provides adequate detection efficiency for many SPECT radiotracers. Because of these advantages, CZT detectors are becoming popular for several SPECT medical-imaging applications. Most recently, we designed a compact gamma camera using CZT detectors coupled to an application-specific-integrated-circuit (ASIC). This camera functions as a trans-rectal probe to image the prostate gland from a distance of only 1-5 cm, thus offering higher detection efficiency and higher spatial resolution. Hence, it potentially can detect prostate cancers at their early stages. The performance tests of this camera

A protocol for the calibration of gamma cameras to estimate internal contamination in emergency situations

Energy Technology Data Exchange (ETDEWEB)

Dantas, B.M.; Lucena, E.A.; Dantas, A.L.A.; Araujo, F.; Melo, D. [Instituto de Radioprotecao e Dosimetria, CNEN, Av. Salvador Allende s/n, Rio de Janeiro (Brazil); Rebelo, A.M.O. [University Hospital, Nuclear Medicine Center, Rio de Janeiro (Brazil); Teran, M.; Paolino, A. [Facultad de Quimica, Montevideo (Uruguay); Hermida, J.C. [Hospital de Clinicas, Facultad de Medicina, Montevideo (Uruguay); Rojo, A.M. [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina); Puerta, J.A.; Morales, J. [Universidad Nacional de Colombia, Medellin (Colombia); Bejerano, G.M.L. [Centro de Proteccion e Higiene de las Radiaciones, Ciudad de la Habana (Cuba); Alfaro, M.; Ruiz, M.A. [Instituto Nacional de Investigaciones Nucleares, Ocoyoacac (Mexico); Videla, R.; Pinones, O. [Comision Chilena de Energia Nuclear, Santiago (Chile); Gonzalez, S. [Instituto Peruano de Energia Nuclear, Lima (Peru); Navarro, T. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain); Cruz-Suarez, R. [International Atomic Energy Agency, Vienna (Austria)

2007-07-01

The concern about accidents involving radioactive materials has led to the search of alternative methods to quickly identify and quantify radionuclides in workers and in the population. One of the options to face up an eventual demand for mass monitoring of internal contamination is the use of a nuclear medicine diagnostic equipment known as gamma camera, a device used to scan patients who have been administered specific amounts of radioactive materials for medical purposes. Although the gamma camera is used for image diagnosis, it can be calibrated with anthropomorphic phantoms or point sources for the quantification of radionuclide activities in the human body. This work presents a protocol for the calibration of gamma cameras for such application. In order to evaluate the suitability of this type of equipment, a gamma camera available in a public hospital located in Rio de Janeiro was calibrated for the in vivo measurement of {sup 131}I. The calibration includes the determination of detection efficiencies and minimum detectable activities for each radionuclide. The results show that the gamma camera presents enough sensitivity to detect activity levels corresponding to effective doses below 1 mSv. The protocol is the basis to establish a network of Nuclear Medicine Centres, located in public hospitals in eight countries of Latin America (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru and Uruguay) and in Spain that could be requested to collaborate in remediation actions in the event of an accident involving incorporation of radioactive materials. This protocol is one of the most significant outputs of the IAEA-ARCAL Project (RLA/9/049-LXXVIII) aimed to the Harmonization of Internal Dosimetry Procedures. (authors)

A protocol for the calibration of gamma cameras to estimate internal contamination in emergency situations

International Nuclear Information System (INIS)

Dantas, B.M.; Lucena, E.A.; Dantas, A.L.A.; Araujo, F.; Melo, D.; Rebelo, A.M.O.; Teran, M.; Paolino, A.; Hermida, J.C.; Rojo, A.M.; Puerta, J.A.; Morales, J.; Bejerano, G.M.L.; Alfaro, M.; Ruiz, M.A.; Videla, R.; Pinones, O.; Gonzalez, S.; Navarro, T.; Cruz-Suarez, R.

2007-01-01

The concern about accidents involving radioactive materials has led to the search of alternative methods to quickly identify and quantify radionuclides in workers and in the population. One of the options to face up an eventual demand for mass monitoring of internal contamination is the use of a nuclear medicine diagnostic equipment known as gamma camera, a device used to scan patients who have been administered specific amounts of radioactive materials for medical purposes. Although the gamma camera is used for image diagnosis, it can be calibrated with anthropomorphic phantoms or point sources for the quantification of radionuclide activities in the human body. This work presents a protocol for the calibration of gamma cameras for such application. In order to evaluate the suitability of this type of equipment, a gamma camera available in a public hospital located in Rio de Janeiro was calibrated for the in vivo measurement of 131 I. The calibration includes the determination of detection efficiencies and minimum detectable activities for each radionuclide. The results show that the gamma camera presents enough sensitivity to detect activity levels corresponding to effective doses below 1 mSv. The protocol is the basis to establish a network of Nuclear Medicine Centres, located in public hospitals in eight countries of Latin America (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru and Uruguay) and in Spain that could be requested to collaborate in remediation actions in the event of an accident involving incorporation of radioactive materials. This protocol is one of the most significant outputs of the IAEA-ARCAL Project (RLA/9/049-LXXVIII) aimed to the Harmonization of Internal Dosimetry Procedures. (authors)

A specially designed cut-off gamma camera for high resolution SPECT of the brain

International Nuclear Information System (INIS)

Larsson, S.A.; Bergstrand, G.; Bergstedt, H.; Berg, J.; Flygare, O.; Schnell, P.O.; Anderson, N.; Lagergren, C.

1984-01-01

A modern gamma camera system for Single Photon Emission Computed Tomography (SPECT) has been modified in order to optimize examinations of the head. By cutting off a part of the detector housing at one edge, it has been possible to rotate the camera close to the skull, still covering the entire brain and the skull base. The minimum radius of rotation used was thereby reduced, in the mean, from 21.2 cm to 13.0 cm in examination of 18 patients. In combination with an adjustment of the 64 x 64 acquisition matrix to a field of view of 26x26 cm/sup 2/, the spatial resolution improved from 18.6 mm (FWHM) to 12.6 +- 0.3 mm (FWHM) using the conventional LEGP-collimator and to 10.4 +- 0.3 mm (FWHM) using the LEHR-collimator. No other modification than a slight cut of the light guide was made in the internal construction of the camera. Thus, the physical properties of the detector head are not essentially changed from those of a non-modified unit. The improved spatial resolution of the cut-off camera SPECT-system implies certain clinical advantages in studies of the brain, the cerebrospinal fluid (CSF)-space and the skull base

Performances evaluation of the coincidence detection on a gamma-camera

International Nuclear Information System (INIS)

Dreuille, O. de; Gaillard, J.F.; Brasse, D.; Bendriem, B.; Groiselle, C.; Rocchisani, J.M.; Moretti, J.L.

2000-01-01

The performance of the VERTEX gamma-camera (ADAC) working in coincidence mode are investigated using a protocol derived from the NEMA and IEC recommendations. With a field of view determined by two rectangular detectors (50.8 cm x 40 cm) composed of NaI crystal, this camera allows a 3-D acquisition with different energy window configurations: photopeak-photopeak only (PP) and photopeak-photopeak + photopeak-Compton (PC). An energy resolution of 11% and a scatter fraction of 27% and 33% for the 3D-PP and 3D-PC mode respectively are the main significant results of our study. The spatial resolution equals 5.9 mm and the limit of the detectability ranges from 16 mm to 13 mm for a contrast of 2.5: as a function of the random estimation, the maximum of the Noise Equivalent Count rate varies from 3 kcps to 4.5 kcps for the PP mode and from 3.85 kcps to 6.1 kcps for the PC mode. These maxima are reached for a concentration of 8 kBq/ml for the PP mode and 5 kBq/ml for the PC mode. These values are compared with the results obtained by other groups for the VERTEX gamma camera and several dedicated PET systems. (authors)

Patient restraining device for the pinhole collimator and gamma scintillation camera

International Nuclear Information System (INIS)

Kay, T.D.

1977-01-01

A patient restraining device for use with the pinhole collimator of a conventional Gamma Scintillation Camera, the restraining device being made of an adapter ring and a patient holder. The adapter ring is secured directly to the pinhole collimator while the holder is adjustably mounted on the adapter. The adapter ring is so designed to accommodate a variety of holders so as to enable the scanning of many different areas of a patient's anatomy by the scintillation camera

Optimisation of a dual head semiconductor Compton camera using Geant4

Energy Technology Data Exchange (ETDEWEB)

Harkness, L.J. [Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L697ZE (United Kingdom)], E-mail: ljh@ns.ph.liv.ac.uk; Boston, A.J.; Boston, H.C.; Cooper, R.J.; Cresswell, J.R.; Grint, A.N.; Nolan, P.J.; Oxley, D.C.; Scraggs, D.P. [Department of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L697ZE (United Kingdom); Beveridge, T.; Gillam, J. [School of Physics and Materials Engineering, Monash University, Melbourne (Australia); Lazarus, I. [STFC Daresbury Laboratory, Warrington, Cheshire (United Kingdom)

2009-06-01

Conventional medical gamma-ray camera systems utilise mechanical collimation to provide information on the position of an incident gamma-ray photon. Systems that use electronic collimation utilising Compton image reconstruction techniques have the potential to offer huge improvements in sensitivity. Position sensitive high purity germanium (HPGe) detector systems are being evaluated as part of a single photon emission computed tomography (SPECT) Compton camera system. Data have been acquired from the orthogonally segmented planar SmartPET detectors, operated in Compton camera mode. The minimum gamma-ray energy which can be imaged by the current system in Compton camera configuration is 244 keV due to the 20 mm thickness of the first scatter detector which causes large gamma-ray absorption. A simulation package for the optimisation of a new semiconductor Compton camera has been developed using the Geant4 toolkit. This paper will show results of preliminary analysis of the validated Geant4 simulation for gamma-ray energies of SPECT, 141 keV.

CBF tomographic measurement with the scintillation camera

International Nuclear Information System (INIS)

Kayayan, R.; Philippon, B.; Pehlivanian, E.

1989-01-01

Single photon emission tomography (SPECT) allows calculation of regional cerebral blood flow (CBF) in multiple cross-sections of the human brain. The methods of Kanno and Lassen is utilized and a study of reproductibility in terms of integration numbers and period of integrations is performed by computer simulation and experimental study with a Gamma-camera. Finally, the possibility of calculating the regional cerabral blood flow with a double headed rotating Gamma-camera by inert gas inhalation, like the Xenon-133 is discussed [fr

Biomedical image acquisition system using a gamma camera

International Nuclear Information System (INIS)

Jara B, A.T.; Sevillano, J.; Del Carpio S, J.A.

2003-01-01

A gamma camera images PC acquisition board has been developed. The digital system has been described using VHDL and has been synthesized and implemented in a Altera Max7128S CPLD and two PALs 16L8. The use of programmable-logic technologies has afforded a higher scale integration and a reduction of the digital delays and also has allowed us to modify and bring up to date the entire digital design easily. (orig.)

Evaluation of different physical parameters that affect the clinical image quality for gamma camera by using different radionuclides

International Nuclear Information System (INIS)

Salah, F.A.; Ziada, G.; Hejazy, M.A.; Khalil, W.A.

2008-01-01

Some scintillation camera manufactures adhere to standard code of performance specification established by National Electric Manufactures Association (NEMA). Items such as differential and integral uniformity, spatial resolution energy resolution, etc. are all calculated with reproducible methodology that allows the user reliable technique for creation of these standards to avoid any lack of clinical service that may violate the ethics of patient care. Because 99m Tc is the most frequently used radionuclide in nuclear medicine, many clinics perform the daily uniformity and weekly resolution checks using this radionuclide. But when other commonly used radionuclide such as Tl-201,Ga-67 and I-131 are used, no standardized quality control is performed. So in these study we perform to evaluate the response of ADAC(digital) gamma camera and SELO(analogue) gamma camera to four radionuclide (Tl-201,Ga-67, I-131, and 99m Tc) flood image acquired using different non-uniformity correction tables. In the planer study uniformity and resolution images were obtained using ADAC and SELO cameras, linearity was obtained only by ADAC camera, while in the SPECT study uniformity and contrast images were obtained using ADAC camera only. The response for using different non-uniformity correction tables acquired using different isotopes was different from gamma camera model to another. We can conclude that the most of the gamma camera quality control parameters (uniformity, resolution and contrast) are influenced by variation in the correction tables, while other parameters not affected by this variation like linearity. (author)

Intraoperative radioguidance with a portable gamma camera: a novel technique for laparoscopic sentinel node localisation in urological malignancies

International Nuclear Information System (INIS)

Vermeeren, L.; Valdes Olmos, R.A.; Vogel, W.V.; Sivro, F.; Hoefnagel, C.A.; Meinhardt, W.; Bex, A.; Poel, H.G. van der; Horenblas, S.

2009-01-01

Our aim was to assess the feasibility of intraoperative radioguidance with a portable gamma camera during laparoscopic sentinel node (SN) procedures in urological malignancies. We evaluated the use of the intraoperative portable gamma camera in 20 patients: 16 patients with prostate carcinoma (PCC), 2 patients with renal cell carcinoma (RC) and 2 patients with testicular cancer (TC). Intra/peritumoural injection of 99m Tc-nanocolloid ( 99m Tc) was followed by planar lymphoscintigraphy, SPECT/CT and marking of SN levels. Before laparoscopy a 125 I seed was fixed on the laparoscopic gamma probe as a pointer of SN seeking. The portable gamma camera was set to display the 99m Tc signal for SN localisation and the 125 I signal for SN seeking. Matching of these signals on screen indicated exact SN localisation, and consequently this SN was removed. The mean injected dose was 218 MBq in PCC, 228 MBq in RC and 88 MBq in TC. Pelvic SN were visualised in all PCC patients, with uncommonly located SN in seven patients. SN metastases were found in seven patients (one in a uncommonly located SN). Both RC patients and TC patients had para-aortic SN, which were all tumour free. A total of 59 SN were removed. The portable gamma camera enabled real-time SN display/identification in 18 patients (90%). The use of a portable gamma camera in combination with a laparoscopic gamma probe incorporates intraoperative real-time imaging with improved SN identification in urological malignancies. This procedure might also be useful for SN identification of other deep draining malignancies. (orig.)

Multiwire proportional gamma camera for imaging /sup 99/Tcsup(m) radionuclide distributions

Energy Technology Data Exchange (ETDEWEB)

Bateman, J E; Connolly, J F [Science Research Council, Chilton (UK). Rutherford Lab.

1978-05-01

A gamma camera made of multiple multiwire proportional chambers with thin converter foils has been evaluated for clinical application. Results are presented from a small prototype (10 cm x 10 cm) showing good imaging of /sup 99/Tcsup(m) radionuclide distributions and confirming the predictions of the theory regarding quantum efficiency and spatial resolution. The technique is especially aimed at creating a gamma camera with an active area > approximately 3 1m/sup 2/, a quantum efficiency of 15% and a spatial resolution approximately 3 mm, whole body scanning and tomographic applications. The results generated by the current prototype indicate that the above requirements can be met using relatively cheap mass production techniques from the electronics industry. This apparatus is covered by patent application number 26595/77.

A multiwire proportional gamma camera for imaging 99Tcsup(m) radionuclide distributions

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.

1978-01-01

A gamma camera made of multiple multiwire proportional chambers with thin converter foils has been evaluated for clinical application. Results are presented from a small prototype (10 cm x 10 cm) showing good imaging of 99 Tcsup(m) radionuclide distributions and confirming the predictions of the theory regarding quantum efficiency and spatial resolution. The technique is especially aimed at creating a gamma camera with an active area > approximately 3 1m 2 , a quantum efficiency of 15% and a spatial resolution approximately 3 mm, whole body scanning and tomographic applications. The results generated by the current prototype indicate that the above requirements can be met using relatively cheap mass production techniques from the electronics industry. This apparatus is covered by patent application number 26595/77. (author)

Three-layer GSO depth-of-interaction detector for high-energy gamma camera

International Nuclear Information System (INIS)

Yamamoto, S.; Watabe, H.; Kawachi, N.; Fujimaki, S.; Kato, K.; Hatazawa, J.

2014-01-01

Using Ce-doped Gd 2 SiO 5 (GSO) of different Ce concentrations, three-layer DOI block detectors were developed to reduce the parallax error at the edges of a pinhole gamma camera for high-energy gamma photons. GSOs with Ce concentrations of 1.5 mol% (decay time ∼40 ns), 0.5 mol% crystal (∼60 ns), 0.4 mol% (∼80 ns) were selected for the depth of interaction (DOI) detectors. These three types of GSOs were optically coupled in the depth direction, arranged in a 22×22 matrix and coupled to a flat panel photomultiplier tube (FP-PMT, Hamamatsu H8500). Sizes of these GSO cells were 1.9 mm×1.9 mm×4 mm, 1.9 mm×1.9 mm×5 mm, and 1.9 mm×1.9 mm×6 mm for 1.5 mol%, 0.5 mol%, and 0.4 mol%, respectively. With these combinations of GSOs, all spots corresponding to GSO cells were clearly resolved in the position histogram. Pulse shape spectra showed three peaks for these three decay times of GSOs. The block detector was contained in a 2-cm-thick tungsten shield, and a pinhole collimator with a 0.5-mm aperture was mounted. With pulse shape discrimination, we separated the point source images of the Cs-137 for each DOI layer. The point source image of the lower layer was detected at the most central part of the field-of-view, and the distribution was the smallest. The point source image of the higher layer was detected at the most peripheral part of the field-of-view, and the distribution was widest. With this information, the spatial resolution of the pinhole gamma camera can be improved. We conclude that DOI detection is effective for pinhole gamma cameras for high energy gamma photons

Securing Embedded Smart Cameras with Trusted Computing

Directory of Open Access Journals (Sweden)

Winkler Thomas

2011-01-01

Full Text Available Camera systems are used in many applications including video surveillance for crime prevention and investigation, traffic monitoring on highways or building monitoring and automation. With the shift from analog towards digital systems, the capabilities of cameras are constantly increasing. Today's smart camera systems come with considerable computing power, large memory, and wired or wireless communication interfaces. With onboard image processing and analysis capabilities, cameras not only open new possibilities but also raise new challenges. Often overlooked are potential security issues of the camera system. The increasing amount of software running on the cameras turns them into attractive targets for attackers. Therefore, the protection of camera devices and delivered data is of critical importance. In this work we present an embedded camera prototype that uses Trusted Computing to provide security guarantees for streamed videos. With a hardware-based security solution, we ensure integrity, authenticity, and confidentiality of videos. Furthermore, we incorporate image timestamping, detection of platform reboots, and reporting of the system status. This work is not limited to theoretical considerations but also describes the implementation of a prototype system. Extensive evaluation results illustrate the practical feasibility of the approach.

Design of gamma camera data acquisition system based on PCI9810

International Nuclear Information System (INIS)

Zhao Yuanyuan; Zhao Shujun; Liu Yang

2004-01-01

This paper describe the design of gamma camera's data acquisition system, which is based on PCI9810 data acquisition card of ADLink Technology Inc. The main function of PCI9810 and the program of data acquisition system are described. (authors)

Improving the spatial resolution of the multiple multiwire proportional chamber gamma camera

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.

1978-03-01

Results are presented showing how the spatial resolution of the multiple multiwire proportional chamber (MMPC) gamma camera may be improved. Under the best conditions 1.6 mm bars can be resolved. (author)

Intraoperative radioguidance with a portable gamma camera: a novel technique for laparoscopic sentinel node localisation in urological malignancies

Energy Technology Data Exchange (ETDEWEB)

Vermeeren, L.; Valdes Olmos, R.A.; Vogel, W.V.; Sivro, F.; Hoefnagel, C.A. [Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands); Meinhardt, W.; Bex, A.; Poel, H.G. van der; Horenblas, S. [Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Urology, Amsterdam (Netherlands)

2009-07-15

Our aim was to assess the feasibility of intraoperative radioguidance with a portable gamma camera during laparoscopic sentinel node (SN) procedures in urological malignancies. We evaluated the use of the intraoperative portable gamma camera in 20 patients: 16 patients with prostate carcinoma (PCC), 2 patients with renal cell carcinoma (RC) and 2 patients with testicular cancer (TC). Intra/peritumoural injection of {sup 99m}Tc-nanocolloid ({sup 99m}Tc) was followed by planar lymphoscintigraphy, SPECT/CT and marking of SN levels. Before laparoscopy a {sup 125}I seed was fixed on the laparoscopic gamma probe as a pointer of SN seeking. The portable gamma camera was set to display the {sup 99m}Tc signal for SN localisation and the {sup 125}I signal for SN seeking. Matching of these signals on screen indicated exact SN localisation, and consequently this SN was removed. The mean injected dose was 218 MBq in PCC, 228 MBq in RC and 88 MBq in TC. Pelvic SN were visualised in all PCC patients, with uncommonly located SN in seven patients. SN metastases were found in seven patients (one in a uncommonly located SN). Both RC patients and TC patients had para-aortic SN, which were all tumour free. A total of 59 SN were removed. The portable gamma camera enabled real-time SN display/identification in 18 patients (90%). The use of a portable gamma camera in combination with a laparoscopic gamma probe incorporates intraoperative real-time imaging with improved SN identification in urological malignancies. This procedure might also be useful for SN identification of other deep draining malignancies. (orig.)

Gamma camera based FDG PET in oncology

International Nuclear Information System (INIS)

Park, C. H.

2002-01-01

Positron Emission Tomography(PET) was introduced as a research tool in the 1970s and it took about 20 years before PET became an useful clinical imaging modality. In the USA, insurance coverage for PET procedures in the 1990s was the turning point, I believe, for this progress. Initially PET was used in neurology but recently more than 80% of PET procedures are in oncological applications. I firmly believe, in the 21st century, one can not manage cancer patients properly without PET and PET is very important medical imaging modality in basic and clinical sciences. PET is grouped into 2 categories; conventional (c) and gamma camera based ( CB ) PET. CB PET is more readily available utilizing dual-head gamma cameras and commercially available FDG to many medical centers at low cost to patients. In fact there are more CB PET in operation than cPET in the USA. CB PET is inferior to cPET in its performance but clinical studies in oncology is feasible without expensive infrastructures such as staffing, rooms and equipments. At Ajou university Hospital, CBPET was installed in late 1997 for the first time in Korea as well as in Asia and the system has been used successfully and effectively in oncological applications. Our was the fourth PET operation in Korea and I believe this may have been instrumental for other institutions got interested in clinical PET. The following is a brief description of our clinical experience of FDG CBPET in oncology

Development of gamma camera display phantom for quality control in developing countries

International Nuclear Information System (INIS)

Todd-Pokropek, A.

1981-08-01

A special phantom suitable for the routine evaluation of ''end-to-end'' gamma camera system performance, that is, system performance from input to output, is described. The design finally adopted, called the ''strip-wedge phantom'' and consisting of an array of copper or aluminium wedges of various thicknesses, permits the evaluation of contrast along one axis and resolution along the other. It is proposed that on acceptance testing of a gamma camera system a series of progressively degraded images should be obtained from the best possible with the system to very poor. An ''action threshold'' should then be defined such that image quality below this threshold would warrant such action as calling in the service engineer. Daily routine images should then be examined with reference to this threshold. Experience with the phantom is summarized

Ectomography - a tomographic method for gamma camera imaging

International Nuclear Information System (INIS)

Dale, S.; Edholm, P.E.; Hellstroem, L.G.; Larsson, S.

1985-01-01

In computerised gamma camera imaging the projections are readily obtained in digital form, and the number of picture elements may be relatively few. This condition makes emission techniques suitable for ectomography - a tomographic technique for directly visualising arbitrary sections of the human body. The camera rotates around the patient to acquire different projections in a way similar to SPECT. This method differs from SPECT, however, in that the camera is placed at an angle to the rotational axis, and receives two-dimensional, rather than one-dimensional, projections. Images of body sections are reconstructed by digital filtration and combination of the acquired projections. The main advantages of ectomography - a high and uniform resolution, a low and uniform attenuation and a high signal-to-noise ratio - are obtained when imaging sections close and parallel to a body surface. The filtration eliminates signals representing details outside the section and gives the section a certain thickness. Ectomographic transverse images of a line source and of a human brain have been reconstructed. Details within the sections are correctly visualised and details outside are effectively eliminated. For comparison, the same sections have been imaged with SPECT. (author)

A pixellated gamma-camera based on CdTe detectors clinical interests and performances

CERN Document Server

Chambron, J; Eclancher, B; Scheiber, C; Siffert, P; Hage-Ali, M; Regal, R; Kazandjian, A; Prat, V; Thomas, S; Warren, S; Matz, R; Jahnke, A; Karman, M; Pszota, A; Németh, L

2000-01-01

A mobile gamma camera dedicated to nuclear cardiology, based on a 15 cmx15 cm detection matrix of 2304 CdTe detector elements, 2.83 mmx2.83 mmx2 mm, has been developed with a European Community support to academic and industrial research centres. The intrinsic properties of the semiconductor crystals - low-ionisation energy, high-energy resolution, high attenuation coefficient - are potentially attractive to improve the gamma-camera performances. But their use as gamma detectors for medical imaging at high resolution requires production of high-grade materials and large quantities of sophisticated read-out electronics. The decision was taken to use CdTe rather than CdZnTe, because the manufacturer (Eurorad, France) has a large experience for producing high-grade materials, with a good homogeneity and stability and whose transport properties, characterised by the mobility-lifetime product, are at least 5 times greater than that of CdZnTe. The detector matrix is divided in 9 square units, each unit is composed ...

Recent developments in gamma camera technology for myocardial perfusion scintigraphy

International Nuclear Information System (INIS)

Bengel, Frank M.

2010-01-01

Economic pressure, competition from alternative modalities and an increasing awareness of patient radiation exposure have triggered a rapid development of novel technology for cardiac single-photon emission computed tomography (SPECT) in recent years. The trend clearly goes towards systems with higher sensitivity and resolution, and towards faster acquisition protocols. Those goals are achieved by various measures: On the one hand, several manufacturers have integrated novel semiconductor detector materials together with innovative collimators into dedicated cardiac scanners. On the other hand, new collimators and reconstruction algorithms have lead to increased speed and accuracy of conventional gamma cameras. Imaging times now can be reduced to as much as 10% of that of previous standard protocols, and/or injected activity can be reduced. This is achieved without loss of diagnostic accuracy. These novel developments are still in early phases of clinical implementation. Their potential for a profound change of the clinical practice of myocardial perfusion scintigraphy, however, becomes increasingly obvious. (orig.)

Design of a Compton camera for 3D prompt-{gamma} imaging during ion beam therapy

Energy Technology Data Exchange (ETDEWEB)

Roellinghoff, F., E-mail: roelling@ipnl.in2p3.fr [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Richard, M.-H., E-mail: mrichard@ipnl.in2p3.fr [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Chevallier, M.; Constanzo, J.; Dauvergne, D. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Freud, N. [INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Henriquet, P.; Le Foulher, F. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Letang, J.M. [INSA-Lyon Laboratory of Nondestructive Testing using Ionizing Radiation (CNDRI), F-69621 Villeurbanne Cedex (France); Montarou, G. [LPC, CNRS/IN2P3, Clermont-F. University (France); Ray, C.; Testa, E.; Testa, M. [Universite de Lyon, F-69622 Lyon (France); Universite Lyon 1 and CNRS/IN2P3, UMR 5822, IPNL, F-69622 Villeurbanne (France); Walenta, A.H. [Uni-Siegen, FB Physik, Emmy-Noether Campus, D-57068 Siegen (Germany)

2011-08-21

We investigate, by means of Geant4 simulations, a real-time method to control the position of the Bragg peak during ion therapy, based on a Compton camera in combination with a beam tagging device (hodoscope) in order to detect the prompt gamma emitted during nuclear fragmentation. The proposed set-up consists of a stack of 2 mm thick silicon strip detectors and a LYSO absorber detector. The {gamma} emission points are reconstructed analytically by intersecting the ion trajectories given by the beam hodoscope and the Compton cones given by the camera. The camera response to a polychromatic point source in air is analyzed with regard to both spatial resolution and detection efficiency. Various geometrical configurations of the camera have been tested. In the proposed configuration, for a typical polychromatic photon point source, the spatial resolution of the camera is about 8.3 mm FWHM and the detection efficiency 2.5x10{sup -4} (reconstructable photons/emitted photons in 4{pi}). Finally, the clinical applicability of our system is considered and possible starting points for further developments of a prototype are discussed.

The Advanced Gamma-ray Imaging System (AGIS) - Camera Electronics Development

Science.gov (United States)

Tajima, Hiroyasu; Bechtol, K.; Buehler, R.; Buckley, J.; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Hanna, D.; Horan, D.; Humensky, B.; Karlsson, N.; Kieda, D.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Mukherjee, R.; Ong, R.; Otte, N.; Quinn, J.; Schroedter, M.; Swordy, S.; Wagner, R.; Wakely, S.; Weinstein, A.; Williams, D.; Camera Working Group; AGIS Collaboration

2010-03-01

AGIS, a next-generation imaging atmospheric Cherenkov telescope (IACT) array, aims to achieve a sensitivity level of about one milliCrab for gamma-ray observations in the energy band of 50 GeV to 100 TeV. Achieving this level of performance will require on the order of 50 telescopes with perhaps as many as 1M total electronics channels. The larger scale of AGIS requires a very different approach from the currently operating IACTs, with lower-cost and lower-power electronics incorporated into camera modules designed for high reliability and easy maintenance. Here we present the concept and development status of the AGIS camera electronics.

The use of a Micromegas as a detector for gamma camera

International Nuclear Information System (INIS)

Barbouchi, Asma; Trabelsi, Adel

2008-01-01

The micromegas (Micro Mesh Gaseaous) is a gas detector; it was developed by I.Giomattaris and G.Charpak for application in the field of experimental particle physics. But the polyvalence of this detector makes it to be used in several areas such as medical imaging. This detector has an X-Y readout capability of resolution less than 100μm, an energy resolution down to 14% for energy range 1-10 keV and an overall efficiency of 70%. Monte carlo simulation is widely used in nuclear medicine. It allows predicting the behaviour of system. Gate (Geant4 for Application Tomography Emission) is a platform for monte carlo simulation. It is dedicated to PET/SPECT (Position Emission Tomography / single Photon Emission Tomography) applications. Our goal is to model a gamma camera that use a Micromegas as a detector and to compare their performances (energy resolution, point spread function...) with those of a scintillated gamma camera by using Gate

Two-dimensional diced scintillator array for innovative, fine-resolution gamma camera

International Nuclear Information System (INIS)

Fujita, T.; Kataoka, J.; Nishiyama, T.; Ohsuka, S.; Nakamura, S.; Yamamoto, S.

2014-01-01

We are developing a technique to fabricate fine spatial resolution (FWHM<0.5mm) and cost-effective photon counting detectors, by using silicon photomultipliers (SiPMs) coupled with a finely pixelated scintillator plate. Unlike traditional X-ray imagers that use a micro-columnar CsI(Tl) plate, we can pixelate various scintillation crystal plates more than 1 mm thick, and easily develop large-area, fine-pitch scintillator arrays with high precision. Coupling a fine pitch scintillator array with a SiPM array results in a compact, fast-response detector that is ideal for X-ray, gamma-ray, and charged particle detection as used in autoradiography, gamma cameras, and photon counting CTs. As the first step, we fabricated a 2-D, cerium-doped Gd 3 Al 2 Ga 3 O 12 (Ce:GAGG) scintillator array of 0.25 mm pitch, by using a dicing saw to cut micro-grooves 50μm wide into a 1.0 mm thick Ce:GAGG plate. The scintillator plate is optically coupled with a 3.0×3.0mm pixel 4×4 SiPM array and read-out via the resistive charge-division network. Even when using this simple system as a gamma camera, we obtained excellent spatial resolution of 0.48 mm (FWHM) for 122 keV gamma-rays. We will present our plans to further improve the signal-to-noise ratio in the image, and also discuss a variety of possible applications in the near future

Implementation of an image acquisition and processing system based on FlexRIO, CameraLink and areaDetector

Energy Technology Data Exchange (ETDEWEB)

Esquembri, S.; Ruiz, M. [Instrumentation and Applied Acoustic Research Group, Technical University of Madrid (UPM), Madrid (Spain); Barrera, E., E-mail: eduardo.barrera@upm.es [Instrumentation and Applied Acoustic Research Group, Technical University of Madrid (UPM), Madrid (Spain); Sanz, D.; Bustos, A. [Instrumentation and Applied Acoustic Research Group, Technical University of Madrid (UPM), Madrid (Spain); Castro, R.; Vega, J. [National Fusion Laboratory, CIEMAT, Madrid (Spain)

2016-11-15

Highlights: • The system presented acquires and process images from any CameraLink compliant camera. • The frame grabber implanted with FlexRIO technology have image time stamping and preprocessing capabilities. • The system is integrated into EPICS using areaDetector for a flexible configuration of image the acquisition and processing chain. • Is fully compatible with the architecture of the ITER Fast Controllers. - Abstract: Image processing systems are commonly used in current physics experiments, such as nuclear fusion experiments. These experiments usually require multiple cameras with different resolutions, framerates and, frequently, different software drivers. The integration of heterogeneous types of cameras without a unified hardware and software interface increases the complexity of the acquisition system. This paper presents the implementation of a distributed image acquisition and processing system for CameraLink cameras. This system implements a camera frame grabber using Field Programmable Gate Arrays (FPGAs), a reconfigurable hardware platform that allows for image acquisition and real-time preprocessing. The frame grabber is integrated into Experimental Physics and Industrial Control System (EPICS) using the areaDetector EPICS software module, which offers a common interface shared among tens of cameras to configure the image acquisition and process these images in a distributed control system. The use of areaDetector also allows the image processing to be parallelized and concatenated using: multiple computers; areaDetector plugins; and the areaDetector standard type for data, NDArrays. The architecture developed is fully compatible with ITER Fast Controllers and the entire system has been validated using a camera hardware simulator that stream videos from fusion experiment databases.

SiPM-MAROC gamma-camera prototype with monolithic NaI(Tl) scintillator

Energy Technology Data Exchange (ETDEWEB)

Philippov, Dmitry; Ilyin, Andrey; Belyaev, Vladimir; Popova, Elan [National Research Nuclear University, Moscow Engineering Physics Institute (Russian Federation); Buzhan, Pavel; Stifutkin, Alexei [Moscow Engineering Physics Institute (Russian Federation)

2015-05-18

A full-body gamma-camera based on SiPM readout is currently under development as a part of MEPHI R activity supported in the framework of Russian Megagrants program. A goal of this development is a fast upgrade of existing medical equipment with minor changes in a system design and construction in order to combine SPECT and MR instruments. A monolithic NaI(Tl) scintillator commonly used for conventional PMT-based gamma cameras has been chosen for this study. SiPMs will be coupled with the scintillator via an optical guide. To cover scintillator surface thousands of SiPMs are required, together with multichannel front-end electronics. That means that readout electronics have to be very compact, with low power consumption and low cost. 64 – channel ASIC MAROC from Weeroc provides individual readout of each SiPM and has been considered as the best choice among electronics solutions available on the market. As the photodetector parameters are the key issues here, KETEK SiPMs with high detection efficiency, low crosstalk and low noise have been chosen for this study. In order to study the proposed detection system in detail and obtain detector module parameters, required for MC simulation, a 64-channel small prototype with 6x6mm{sup 2} SiPMs has been constructed and tested. SiPMs in SMD packages have been assembled as a matrix of 8x8 elements and readout by MAROC-based board. Prototype has been tested with different shape NaI(Tl) scintillators and gammas with different energy. Dedicated algorithms for extraction of gamma-event’s energy and position are under development. They are based on fitting a matrix of individual SiPMs responses by an analytical function F(x,y). They will be tested with GEANT-simulated events and experimental data. Development of the next (engineering) prototype of SiPM’s module for gamma-camera will be started soon.

SiPM-MAROC gamma-camera prototype with monolithic NaI(Tl) scintillator

International Nuclear Information System (INIS)

Philippov, Dmitry; Ilyin, Andrey; Belyaev, Vladimir; Popova, Elan; Buzhan, Pavel; Stifutkin, Alexei

2015-01-01

A full-body gamma-camera based on SiPM readout is currently under development as a part of MEPHI R activity supported in the framework of Russian Megagrants program. A goal of this development is a fast upgrade of existing medical equipment with minor changes in a system design and construction in order to combine SPECT and MR instruments. A monolithic NaI(Tl) scintillator commonly used for conventional PMT-based gamma cameras has been chosen for this study. SiPMs will be coupled with the scintillator via an optical guide. To cover scintillator surface thousands of SiPMs are required, together with multichannel front-end electronics. That means that readout electronics have to be very compact, with low power consumption and low cost. 64 – channel ASIC MAROC from Weeroc provides individual readout of each SiPM and has been considered as the best choice among electronics solutions available on the market. As the photodetector parameters are the key issues here, KETEK SiPMs with high detection efficiency, low crosstalk and low noise have been chosen for this study. In order to study the proposed detection system in detail and obtain detector module parameters, required for MC simulation, a 64-channel small prototype with 6x6mm 2 SiPMs has been constructed and tested. SiPMs in SMD packages have been assembled as a matrix of 8x8 elements and readout by MAROC-based board. Prototype has been tested with different shape NaI(Tl) scintillators and gammas with different energy. Dedicated algorithms for extraction of gamma-event’s energy and position are under development. They are based on fitting a matrix of individual SiPMs responses by an analytical function F(x,y). They will be tested with GEANT-simulated events and experimental data. Development of the next (engineering) prototype of SiPM’s module for gamma-camera will be started soon.

A micro-machined retro-reflector for improving light yield in ultra-high-resolution gamma cameras

NARCIS (Netherlands)

Heemskerk, J.W.T.; Korevaar, M.A.N.; Kreuger, R.; Ligtvoet, C.M.; Schotanus, P.; Beekman, F.J.

2009-01-01

High-resolution imaging of x-ray and gamma-ray distributions can be achieved with cameras that use charge coupled devices (CCDs) for detecting scintillation light flashes. The energy and interaction position of individual gamma photons can be determined by rapid processing of CCD images of

Values of tumor markers (AFP, β-HCG and CEA) and gamma-camera scintigraphy in patients with testicular tumors

International Nuclear Information System (INIS)

Milkov, V.; Sultanov, S.; Tsvetkov, D.

1989-01-01

Complex gamma-camera and radioimmunologic study of the tumor markers AFP, β-HCG and CEA was performed in 7 patients with testicular tumors. In all tested patients gamma-camera scintigraphy of the testes clearly delineated the zone of the pathological process. Gamma-camera examination very well differentiates malignant from nonmalignant processes in the testes. The serum levels of the tumor markers AFP and β-HCG proved elevated in 3 of the tested patients during the preoperative period. The histological types of the tumors in these patients were: teratocarcinoma in one and embryonal carcinoma in the other two. It is believed that investigation of the three tumor markers may gain acceptance as additonal method in the complex diagnosis of these diseases

An operative gamma camera for sentinel lymph node procedure in case of breast cancer

CERN Document Server

Salvador, S; Mathelin, C; Guyonne, J; Huss, D

2007-01-01

Large field of view gamma cameras are widely used to perform lymphoscintigraphy in the sentinel lymph nodes (SLN) procedure in case of breast cancer. However, they are not specified for this application and their sizes do not enable their use in the operative room to control the excision of the all SLN. We present the results obtained with a prototype of a new mini gamma camera developed especially for the operative lymphoscintigraphy of the axillary area in case of breast cancer. This prototype is composed of 10 mm thick parallel lead collimator, a 2 mm thick GSO:Ce inorganic scintillating crystal from Hitachi and a Hamamatsu H8500 flat panel multianode (64 channels) photomultiplier tube (MAPMT) equipped with a dedicated electronics. Its actual field of view is 50 × 50mm2. The gamma interaction position in the GSO scintillating plate is obtained by calculating the center of gravity of the fired MAPMT channels. The measurements performed with this prototype demonstrate the usefulness of this mini gamma camer...

Computer aided collimation gamma (Cacao): a new approach in measuring and visualizing the distribution of X and gamma ray emitters in contaminate wounds

International Nuclear Information System (INIS)

Douiri, A.; Jeanguillaume, C.; Franck, D.; Carlan, L. de; Quartuccio, M.; Begot, S.

2003-01-01

The treatment of contaminated wounds can be greatly improved by visualizing the distribution of the radioactivity that is present. The low sensitivity of the conventional Anger camera means that it can only be used where there is a high level of activity. Moreover, these gamma cameras cannot make full use of the recent progress made in high spatial resolution semi-conductor detectors. In order to increase sensitivity while at the same time maintaining a sufficient resolution of the reconstructed image, the principle of the Computer aided collimation gamma camera (CACAO in French) was proposed as a possible means of using gamma cameras in intern dosimetry. This principle is based on the combined use of collimators with holes that are wider- than the intrinsic resolution of the detector, circular and linear scanning movements, a detector sensitive to the source depth and a specific reconstruction algorithm. This article presents the recent developments of the CACAO system and illustrates by a theoretical and experimental study, its performances compared with the classic tomography system. We start with a general overview of the CACAO system and its reconstruction algorithm. First of all, the superiority of the CACAO system is demonstrated by a simulation ,study. Then, an experimental bench was developed using an implanted silicon pixel detector specifically designed to allow the visualization of a subject contaminated with low energy X and gamma emitters. The study presented here shows images obtained from a phantom composed of three sources of Americium 341 Am. Although the comparison between the conventional and CACAO approaches were not carried out with optimal parameters, especially for CACAO, the initial results show that CACAO has an improved sensitivity and a superior resolution. Finally, the transposition of this system to the practical study of contaminated wounds is discussed. (authors)

A didactic experiment showing the Compton scattering by means of a clinical gamma camera.

Science.gov (United States)

Amato, Ernesto; Auditore, Lucrezia; Campennì, Alfredo; Minutoli, Fabio; Cucinotta, Mariapaola; Sindoni, Alessandro; Baldari, Sergio

2017-06-01

We describe a didactic approach aimed to explain the effect of Compton scattering in nuclear medicine imaging, exploiting the comparison of a didactic experiment with a gamma camera with the outcomes from a Monte Carlo simulation of the same experimental apparatus. We employed a 99m Tc source emitting 140.5keV photons, collimated in the upper direction through two pinholes, shielded by 6mm of lead. An aluminium cylinder was placed on the source at 50mm of distance. The energy of the scattered photons was measured on the spectra acquired by the gamma camera. We observed that the gamma ray energy measured at each step of rotation gradually decreased from the characteristic energy of 140.5keV at 0° to 102.5keV at 120°. A comparison between the obtained data and the expected results from the Compton formula and from the Monte Carlo simulation revealed a full agreement within the experimental error (relative errors between -0.56% and 1.19%), given by the energy resolution of the gamma camera. Also the electron rest mass has been evaluated satisfactorily. The experiment was found useful in explaining nuclear medicine residents the phenomenology of the Compton scattering and its importance in the nuclear medicine imaging, and it can be profitably proposed during the training of medical physics residents as well. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

MO-AB-206-02: Testing Gamma Cameras Based On TG177 WG Report

Energy Technology Data Exchange (ETDEWEB)

Halama, J. [Loyola Univ. Medical Center (United States)

2016-06-15

This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described. Learning Objectives: Be able to describe basic physics principles of PET and operation of PET scanners. Learn about recent advances in PET scanner hardware technology. Be able to describe advances in reconstruction techniques and improvements Be able to list relevant performance tests. The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions. Learning Objectives: At the end of the presentation members of the audience will: Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems. Be familiar with the tests of a SPECT/CT system that include the CT images

MO-AB-206-02: Testing Gamma Cameras Based On TG177 WG Report

International Nuclear Information System (INIS)

Halama, J.

2016-01-01

This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described. Learning Objectives: Be able to describe basic physics principles of PET and operation of PET scanners. Learn about recent advances in PET scanner hardware technology. Be able to describe advances in reconstruction techniques and improvements Be able to list relevant performance tests. The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions. Learning Objectives: At the end of the presentation members of the audience will: Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems. Be familiar with the tests of a SPECT/CT system that include the CT images

An innovative silicon photomultiplier digitizing camera for gamma-ray astronomy

Czech Academy of Sciences Publication Activity Database

Heller, M.; Schioppa, E.jr.; Porcelli, A.; Pujadas, I.T.; Zietara, K.; della Volpe, D.; Montaruli, T.; Cadoux, F.; Favre, Y.; Aguilar, J.A.; Christov, A.; Prandini, E.; Rajda, P.; Rameez, M.; Bilnik, W.; Blocki, J.; Bogacz, L.; Borkowski, J.; Bulik, T.; Frankowski, A.; Grudzinska, M.; Idzkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandát, Dušan; Marszalek, A.; Medina Miranda, L. D.; Michałowski, J.; Moderski, R.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Pasko, P.; Pech, Miroslav; Schovánek, Petr; Seweryn, K.; Sliusar, V.; Skowron, K.; Stawarz, L.; Stodulska, M.; Stodulski, M.; Walter, R.; Wiecek, M.; Zagdanski, A.

2017-01-01

Roč. 77, č. 1 (2017), s. 1-31, č. článku 47. ISSN 1434-6044 R&D Projects: GA MŠk LE13012; GA MŠk LG14019 Institutional support: RVO:68378271 Keywords : silicon photomultiplier * digitizing camera * gamma-ray astronomy Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 5.331, year: 2016

Detection of mixed-range proton pencil beams with a prompt gamma slit camera

International Nuclear Information System (INIS)

Priegnitz, M; Helmbrecht, S; Fiedler, F; Janssens, G; Smeets, J; Vander Stappen, F; Perali, I; Sterpin, E

2016-01-01

With increasing availability of proton and particle therapy centers for tumor treatment, the need for in vivo range verification methods comes more into the focus. Imaging of prompt gamma rays emitted during the treatment is one of the possibilities currently under investigation. A knife-edge shaped slit camera was recently proposed for this task and measurements proved the feasibility of range deviation detection in homogeneous and inhomogeneous targets. In the present paper, we concentrate on laterally inhomogeneous materials, which lead to range mixing situations when crossed by one pencil beam: different sections of the beam have different ranges. We chose exemplative cases from clinical irradiation and assembled idealized tissue equivalent targets. One-dimensional emission profiles were obtained by measuring the prompt gamma emission with the slit camera. It could be shown that the resulting range deviations can be detected by evaluation of the measured data with a previously developed range deviation detection algorithm. The retrieved value, however, strongly depends on the target composition, and is not necessarily in direct relation to the ranges of both parts of the beam. By combining the range deviation detection with an analysis of the slope of the distal edge of the measured prompt gamma profile, the origin of the detected range deviation, i.e. the mixed range of the beam, is also identified. It could be demonstrated that range mixed prompt gamma profiles exhibit less steep distal slopes than profiles from beams traversing laterally homogeneous material. For future application of the slit camera to patient irradiation with double scattered proton beams, situations similar to the range mixing cases are present and results could possibly apply. (paper)

SiPM arrays and miniaturized readout electronics for compact gamma camera

Energy Technology Data Exchange (ETDEWEB)

Dinu, N., E-mail: dinu@lal.in2p3.fr [Laboratory of Linear Accelerator, IN2P3, CNRS, Orsay (France); Imando, T. Ait; Nagai, A. [Laboratory of Linear Accelerator, IN2P3, CNRS, Orsay (France); Pinot, L. [Laboratory of Imaging and Modelisation in Neurobiology and Cancerology, IN2P3, CNRS, Orsay (France); Puill, V. [Laboratory of Linear Accelerator, IN2P3, CNRS, Orsay (France); Callier, S. [Omega Microelectronics Group, CNRS, Palaiseau (France); Janvier, B.; Esnault, C.; Verdier, M.-A. [Laboratory of Imaging and Modelisation in Neurobiology and Cancerology, IN2P3, CNRS, Orsay (France); Raux, L. [Omega Microelectronics Group, CNRS, Palaiseau (France); Vandenbussche, V.; Charon, Y.; Menard, L. [Laboratory of Imaging and Modelisation in Neurobiology and Cancerology, IN2P3, CNRS, Orsay (France)

2015-07-01

This article reports on the design and features of a very compact and light gamma camera based on SiPM arrays and miniaturized readout electronics dedicated to tumor localization during radio-guided cancer surgery. This gamma camera, called MAGICS, is composed of four (2×2) photo-detection elementary modules coupled to an inorganic scintillator. The 256 channels photo-detection system covers a sensitive area of 54×53 m{sup 2}. Each elementary module is based on four (2×2) SiPM monolithic arrays, each array consisting of 16 SiPM photo-sensors (4×4) with 3×3 mm{sup 2} sensitive area, coupled to a miniaturized readout electronics and a dedicated ASIC. The overall dimensions of the electronics fit the size of the detector, enabling to assemble side-by-side several elementary modules in a close-packed arrangement. The preliminary performances of the system are very encouraging, showing an energy resolution of 9.8% and a spatial resolution of less than 1 mm at 122 keV.

Development of an omnidirectional gamma-ray imaging Compton camera for low-radiation-level environmental monitoring

Science.gov (United States)

Watanabe, Takara; Enomoto, Ryoji; Muraishi, Hiroshi; Katagiri, Hideaki; Kagaya, Mika; Fukushi, Masahiro; Kano, Daisuke; Satoh, Wataru; Takeda, Tohoru; Tanaka, Manobu M.; Tanaka, Souichi; Uchida, Tomohisa; Wada, Kiyoto; Wakamatsu, Ryo

2018-02-01

We have developed an omnidirectional gamma-ray imaging Compton camera for environmental monitoring at low levels of radiation. The camera consisted of only six CsI(Tl) scintillator cubes of 3.5 cm, each of which was readout by super-bialkali photo-multiplier tubes (PMTs). Our camera enables the visualization of the position of gamma-ray sources in all directions (∼4π sr) over a wide energy range between 300 and 1400 keV. The angular resolution (σ) was found to be ∼11°, which was realized using an image-sharpening technique. A high detection efficiency of 18 cps/(µSv/h) for 511 keV (1.6 cps/MBq at 1 m) was achieved, indicating the capability of this camera to visualize hotspots in areas with low-radiation-level contamination from the order of µSv/h to natural background levels. Our proposed technique can be easily used as a low-radiation-level imaging monitor in radiation control areas, such as medical and accelerator facilities.

Scintillation camera-computer systems: General principles of quality control

International Nuclear Information System (INIS)

Ganatra, R.D.

1992-01-01

Scintillation camera-computer systems are designed to allow the collection, digital analysis and display of the image data from a scintillation camera. The components of the computer in such a system are essentially the same as those of a computer used in any other application, i.e. a central processing unit (CPU), memory and magnetic storage. Additional hardware items necessary for nuclear medicine applications are an analogue-to-digital converter (ADC), which converts the analogue signals from the camera to digital numbers, and an image display. It is possible that the transfer of data from camera to computer degrades the information to some extent. The computer can generate the image for display, but it also provides the capability of manipulating the primary data to improve the display of the image. The first function of conversion from analogue to digital mode is not within the control of the operator, but the second type of manipulation is in the control of the operator. These type of manipulations should be done carefully without sacrificing the integrity of the incoming information

Progress towards a semiconductor Compton camera for prompt gamma imaging during proton beam therapy for range and dose verification

Science.gov (United States)

Gutierrez, A.; Baker, C.; Boston, H.; Chung, S.; Judson, D. S.; Kacperek, A.; Le Crom, B.; Moss, R.; Royle, G.; Speller, R.; Boston, A. J.

2018-01-01

The main objective of this work is to test a new semiconductor Compton camera for prompt gamma imaging. Our device is composed of three active layers: a Si(Li) detector as a scatterer and two high purity Germanium detectors as absorbers of high-energy gamma rays. We performed Monte Carlo simulations using the Geant4 toolkit to characterise the expected gamma field during proton beam therapy and have made experimental measurements of the gamma spectrum with a 60 MeV passive scattering beam irradiating a phantom. In this proceeding, we describe the status of the Compton camera and present the first preliminary measurements with radioactive sources and their corresponding reconstructed images.

Calibration of gamma cameras for the evaluation of accidental intakes of high-energy photon emitting radionuclides by humans based on urine samples

Energy Technology Data Exchange (ETDEWEB)

Degenhardt, A.L.; Lucena, E.A.; Reis, A.A. dos; Souza, W.O.; Dantas, A.L.A.; Dantas, B.M., E-mail: bmdantas@ird.gov.br [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Div. de Dosimetria

2017-07-01

The prompt response to emergency situations involving suspicion of intakes of radionuclides requires the use of simple and rapid methods of internal monitoring of the exposed individuals. The use of gamma cameras to estimate intakes and committed doses was investigated by the Centers for Disease Control and Preventions (CDC) of the USA in 2010.The present study aims to develop a calibration protocol for gamma cameras to be applied on internal monitoring based on urine samples to evaluate the incorporation of high-energy photon emitting radionuclides in emergency situations. A gamma camera available in a public hospital located in the city of Rio de Janeiro was calibrated using a standard liquid source of {sup 152}Eu supplied by the LNMRI of the IRD.'Efficiency vs Energy' curves at 10 and 30 cm were obtained. Calibration factors, Minimum Detectable Activities and Minimum Detectable Effective Doses of the gamma camera were calculated for {sup 137}Cs and {sup 60}Co. The gamma camera evaluated in this work presents enough sensitivity to detect activities of such radionuclides at dose levels suitable to assess suspected accidental intakes. (author)

Gamma camera system with composite solid state detector

International Nuclear Information System (INIS)

Gerber, M.S.; Miller, D.W.

1977-01-01

A composite solid-state detector is described for utilization within gamma cameras. The detector's formed of an array of detector crystals, the opposed surfaces of each of which are formed incorporating an impedance-derived configuration for determining one coordinate of the location of discrete impinging photons upon the detector. A combined read-out for all detectors within the composite array is achieved through a row and column interconnection of the impedance configurations. Utilizing the read-outs for respective sides of the discrete crystals, a resultant time-constant characteristic for the composite detector crystal array remains essentially that of individual crystal detectors

Estimated GFR (eGFR by prediction equation in staging of chronic kidney disease compared to gamma camera GFR

Directory of Open Access Journals (Sweden)

Mohammad Masum Alam

2016-07-01

Full Text Available Background: Glomerular filtration rate is an effective tool for diagnosis and staging of chronic kidney disease. The effect ofrenal insufficiency by different method of this tool among patients with CKD is controversial.Objective: The objec­tive of this study was to evaluate the performance of eGFR in staging of CKD compared to gamma camera based GFR.Methods: This cross sectional analytical study was conducted in the Department of Biochemistry Bangabandhu Sheikh Mujib Medical University (BSMMU with the collaboration with National Institute of Nuclear Medicine and Allied Sciences, BSMMU during the period of January 2011 to December 2012. Gama camera based GFR was estimated from DTP A reno gram and eGFR was estimated by three prediction equations. Comparison was done by Bland Altman agree­ment test to see the agreement on the measurement of GFR between three equation based eGFR method and gama camera based GFR method. Staging comparison was done by Kappa analysis to see the agreement between the stages identified by those different methods.Results: Bland-Altman agreement analysis between GFR measured by gamma camera, CG equation ,CG equation corrected by BSA and MDRD equation shows statistically significant. CKD stages determined by CG GFR, CG GFR corrected by BSA , MDRD GFR and gamma camera based GFR was compared by Kappa statistical analysis .The kappa value was 0.66, 0.77 and 0.79 respectively.Conclusions: This study findings suggest that GFR estimation by MDRD equation in CKD patients shows good agreement with gamma camera based GFR and for staging of CKD patients, eGFR by MDRD formula may be used as very effective tool in Bangladeshi population.

Simulation-based evaluation and optimization of a new CdZnTe gamma-camera architecture (HiSens)

International Nuclear Information System (INIS)

Robert, Charlotte; Montemont, Guillaume; Rebuffel, Veronique; Guerin, Lucie; Verger, Loick; Buvat, Irene

2010-01-01

A new gamma-camera architecture named HiSens is presented and evaluated. It consists of a parallel hole collimator, a pixelated CdZnTe (CZT) detector associated with specific electronics for 3D localization and dedicated reconstruction algorithms. To gain in efficiency, a high aperture collimator is used. The spatial resolution is preserved thanks to accurate 3D localization of the interactions inside the detector based on a fine sampling of the CZT detector and on the depth of interaction information. The performance of this architecture is characterized using Monte Carlo simulations in both planar and tomographic modes. Detective quantum efficiency (DQE) computations are then used to optimize the collimator aperture. In planar mode, the simulations show that the fine CZT detector pixelization increases the system sensitivity by 2 compared to a standard Anger camera without loss in spatial resolution. These results are then validated against experimental data. In SPECT, Monte Carlo simulations confirm the merits of the HiSens architecture observed in planar imaging.

An Imaging Camera for Biomedical Application Based on Compton Scattering of Gamma Rays

OpenAIRE

Fontana, Cristiano Lino

2013-01-01

In this thesis we present the R&D of a Compton Camera (CC) for small object imaging. The CC concept requires two detectors to obtain the incoming direction of the gamma ray. This approach, sometimes named ``Electronic Collimation,'' differs from the usual technique that employs collimators for physically selecting gamma-rays of a given direction. This solution offers the advantage of much greater sensitivity and hence smaller doses. We propose a novel design, which uses two simila...

Applications of multi-pinhole gamma camera collimation to tomography and image enhancement

Science.gov (United States)

Simpson, D. R.

1981-06-01

Multi-pinhole gamma camera collimation was introduced in the field of emission tomography. This collimation process simultaneously produces several images covering a limited angular range, which may then be recombined to obtain tomographic slices of the object imaged. A possible method for improving the images obtained by this technique by combining two multi-pinhole views taken 90 deg apart was investigated. Collimators were designed and built both for tomography and imaging tablet disintegration, and computer programs were written to reconstruct the images by simple backprojection and by filtered backprojection. The use of multi-pinhole collimators to image the disintegration of tablets in vivo was clearly demonstrated. Phantom tests done in vitro were capable of imaging defects as small as 5 sq mm, while images made with real tablets both in vitro and in vivo readily showed the onset and progress of the tablet disintegration.

Is it practical to use the gamma camera dead time

International Nuclear Information System (INIS)

Morin, P.P.; Morin, J.F.; Caroff, J.; Lahellec, M.; Savina, A.

1975-01-01

The linearity of gamma camera counting is an essential feature for users engaged in quantitative dynamic studies. Instead of defining this quality by the usual dead time, the disadvantages of which are reported, it is proposed to use the experimental count rate giving 10% loss. It is shown that by proceeding in this way all ambiguity would be abolished, where both the counting linearity itself and its relation to sensitivity are concerned [fr

Correction of dynamic time-activity curves for gamma-camera dead time, radiotracer delivery, and radioactive decay: special considerations with ultrashort-lived radioisotopes

International Nuclear Information System (INIS)

Kuruc, A.; Zimmerman, R.E.; Treves, S.

1985-01-01

Time-vs.-activity curves obtained by using ultrashort-lived radioisotopes often need to be corrected for the effects of gamma-camera dead time and physical decay. Count loss due to gamma-camera dead time can be monitored by using an electronic oscillator incorporated into the gamma camera. Two algorithms that use this information to correct time-activity curves are discussed. It is also shown that the effect of physical decay on a time-activity curve is dependent on the time course of delivery of the radioisotope to the organ of interest. A mathematical technique that corrects physical decay is described

Calibration of a Stereo Radiation Detection Camera Using Planar Homography

Directory of Open Access Journals (Sweden)

Seung-Hae Baek

2016-01-01

Full Text Available This paper proposes a calibration technique of a stereo gamma detection camera. Calibration of the internal and external parameters of a stereo vision camera is a well-known research problem in the computer vision society. However, few or no stereo calibration has been investigated in the radiation measurement research. Since no visual information can be obtained from a stereo radiation camera, it is impossible to use a general stereo calibration algorithm directly. In this paper, we develop a hybrid-type stereo system which is equipped with both radiation and vision cameras. To calibrate the stereo radiation cameras, stereo images of a calibration pattern captured from the vision cameras are transformed in the view of the radiation cameras. The homography transformation is calibrated based on the geometric relationship between visual and radiation camera coordinates. The accuracy of the stereo parameters of the radiation camera is analyzed by distance measurements to both visual light and gamma sources. The experimental results show that the measurement error is about 3%.

Defining the lung outline from a gamma camera transmission attenuation map

International Nuclear Information System (INIS)

Fleming, John S; Pitcairn, Gary; Newman, Stephen

2006-01-01

Segmentation of the lung outline from gamma camera transmission images of the thorax is useful in attenuation correction and quantitative image analysis. This paper describes and compares two threshold-based methods of segmentation. Simulated gamma camera transmission images of test objects were used to produce a knowledge base of the variation of threshold defining the lung outline with image resolution and chest wall thickness. Two segmentation techniques based on global (GT) and context-sensitive (CST) thresholds were developed and evaluated in simulated transmission images of realistic thoraces. The segmented lung volumes were compared to the true values used in the simulation. The mean distances between segmented and true lung surface were calculated. The techniques were also applied to three real human subject transmission images. The lung volumes were estimated and the segmentations were compared visually. The CST segmentation produced significantly superior segmentations than the GT technique in the simulated data. In human subjects, the GT technique underestimated volumes by 13% compared to the CST technique. It missed areas that clearly belonged to the lungs. In conclusion, both techniques segmented the lungs with reasonable accuracy and precision. The CST approach was superior, particularly in real human subject images

Energy independent uniformity improvement for gamma camera systems

International Nuclear Information System (INIS)

Lange, K.

1979-01-01

In a gamma camera system having an array of photomultiplier tubes for detecting scintillation events and preamplifiers connecting each tube to a weighting resistor matrix for determining the position coordinates of the events, means are provided for summing the signals from all photomultipliers to obtain the total energy of each event. In one embodiment, at least two different percentages of the summed voltage are developed and used to change the gain of the preamplifiers as a function of total energy when energies exceed specific levels to thereby obtain more accurate correspondence between the true coordinates of the event and its coordinates in a display

Gabor zone-plate apertures for imaging with the mercuric iodide gamma-ray camera

Energy Technology Data Exchange (ETDEWEB)

Patt, B E [EG and G Energy Measurements, Inc., Goleta, CA (USA); Meyyappan, A; Cai, A; Wade, G [California Univ., Santa Barbara (USA). Dept. of Electrical and Computer Engineering

1990-12-20

Gabor zone-plate (GZP) apertures have been developed for use in EG and G EM's mercuric iodide (HgI{sub 2}) gamma-ray camera. The purpose of such an aperture is to increase efficiency, while maintaining good resolution. The GZP is similar to the Fresnel zone plate (FZP) but it has continuous transitions between opaque and transparent regions. Because there are no sharp transitions in the transmission, the inherent interference noise in GZP imaging is lower than that in FZP imaging. GZP parameters were chosen by considering the effects of constraints such as detector pixel size, number of pixels, minimum field of view required, maximum angle of incidence tolerated, and the Nyquist criterion for the minimum sampling rate. As a result an aperture was designed and fabricated with eight zones and a diameter of 3 cm. Lead was chosen as the aperture medium due to its high attenuation coefficient. Experimental data were obtained from the camera with the above GZP aperture. The point-spread function was determined and compared to the calculated response. Excellent agreement was obtained. The reconstruction process involves simulating, by computer, planar-wave illumination of a scaled transparency of the image and recording the intensity pattern at the focal plane. (orig.).

Performance of the prototype LaBr{sub 3} spectrometer developed for the JET gamma-ray camera upgrade

Energy Technology Data Exchange (ETDEWEB)

Rigamonti, D., E-mail: davide.rigamonti@mib.infn.it; Nocente, M.; Gorini, G. [Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola,” CNR, Milano (Italy); Muraro, A.; Giacomelli, L.; Cippo, E. P.; Tardocchi, M. [Istituto di Fisica del Plasma “P. Caldirola,” CNR, Milano (Italy); Perseo, V. [Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Boltruczyk, G.; Gosk, M.; Korolczuk, S.; Mianowski, S.; Zychor, I. [Narodowe Centrum Badań Jądrowych (NCBJ), 05-400 Otwock-Swierk (Poland); Fernandes, A.; Pereira, R. C. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Figueiredo, J. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); EUROfusion Programme Management Unit, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Kiptily, V. [Culham Science Centre for Fusion Energy, Culham (United Kingdom); Murari, A. [EUROfusion Programme Management Unit, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Consorzio RFX (CNR, ENEA, INFN, Universita’ di Padova, Acciaierie Venete SpA), Padova (Italy); Collaboration: EUROfusion Consortium, JET, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)

2016-11-15

In this work, we describe the solution developed by the gamma ray camera upgrade enhancement project to improve the spectroscopic properties of the existing JET γ-ray camera. Aim of the project is to enable gamma-ray spectroscopy in JET deuterium-tritium plasmas. A dedicated pilot spectrometer based on a LaBr{sub 3} crystal coupled to a silicon photo-multiplier has been developed. A proper pole zero cancellation network able to shorten the output signal to a length of 120 ns has been implemented allowing for spectroscopy at MHz count rates. The system has been characterized in the laboratory and shows an energy resolution of 5.5% at E{sub γ} = 0.662 MeV, which extrapolates favorably in the energy range of interest for gamma-ray emission from fast ions in fusion plasmas.

Emission computerized axial tomography from multiple gamma-camera views using frequency filtering.

Science.gov (United States)

Pelletier, J L; Milan, C; Touzery, C; Coitoux, P; Gailliard, P; Budinger, T F

1980-01-01

Emission computerized axial tomography is achievable in any nuclear medicine department from multiple gamma camera views. Data are collected by rotating the patient in front of the camera. A simple fast algorithm is implemented, known as the convolution technique: first the projection data are Fourier transformed and then an original filter designed for optimizing resolution and noise suppression is applied; finally the inverse transform of the latter operation is back-projected. This program, which can also take into account the attenuation for single photon events, was executed with good results on phantoms and patients. We think that it can be easily implemented for specific diagnostic problems.

Breast-specific gamma-imaging: molecular imaging of the breast using 99mTc-sestamibi and a small-field-of-view gamma-camera.

Science.gov (United States)

Jones, Elizabeth A; Phan, Trinh D; Blanchard, Deborah A; Miley, Abbe

2009-12-01

Breast-specific gamma-imaging (BSGI), also known as molecular breast imaging, is breast scintigraphy using a small-field-of-view gamma-camera and (99m)Tc-sestamibi. There are many different types of breast cancer, and many have characteristics making them challenging to detect by mammography and ultrasound. BSGI is a cost-effective, highly sensitive and specific technique that complements other imaging modalities currently being used to identify malignant lesions in the breast. Using the current Society of Nuclear Medicine guidelines for breast scintigraphy, Legacy Good Samaritan Hospital began conducting BSGI, breast scintigraphy with a breast-optimized gamma-camera. In our experience, optimal imaging has been conducted in the Breast Center by a nuclear medicine technologist. In addition, the breast radiologists read the BSGI images in correlation with the mammograms, ultrasounds, and other imaging studies performed. By modifying the current Society of Nuclear Medicine protocol to adapt it to the practice of breast scintigraphy with these new systems and by providing image interpretation in conjunction with the other breast imaging studies, our center has found BSGI to be a valuable adjunctive procedure in the diagnosis of breast cancer. The development of a small-field-of-view gamma-camera, designed to optimize breast imaging, has resulted in improved detection capabilities, particularly for lesions less than 1 cm. Our experience with this procedure has proven to aid in the clinical work-up of many of our breast patients. After reading this article, the reader should understand the history of breast scintigraphy, the pharmaceutical used, patient preparation and positioning, imaging protocol guidelines, clinical indications, and the role of breast scintigraphy in breast cancer diagnosis.

Evaluation of a high-resolution, breast-specific, small-field-of-view gamma camera for the detection of breast cancer

International Nuclear Information System (INIS)

Brem, R.F.; Kieper, D.A.; Rapelyea, J.A.; Majewski, S.

2003-01-01

Purpose: The purpose of our study is to review the state of the art in nuclear medicine imaging of the breast (scintimammography) and to evaluate a novel, high-resolution, breast-specific gamma camera (HRBGC) for the detection of suspicious breast lesions. Materials and Methods: Fifty patients with 58 breast lesions in whom a scintimammogram was clinically indicated were prospectively evaluated with a general-purpose gamma camera and a HRBGC prototype. Nuclear studies were prospectively classified as negative (normal/benign) or positive (suspicious/malignant) by two radiologists, blinded to mammographic and histologic results with both the conventional and high-resolution. All lesions were confirmed by pathology. Results: Included in this study were 30 benign and 28 malignant lesions. The sensitivity for detection of breast cancer was 64.3% (18/28) with the conventional camera and 78.6% (22/28) with the HRBGC. Specificity of both systems was 93.3% (28/30). In the 18 nonpalpable cancers, sensitivity was 55.5% (10/18) and 72.2% (13/18) with the general-purpose camera and HRBGC, respectively. In cancers ≤ 1cm, 7 of 15 were detected with the general-purpose camera and 10 of 15 with the HRBGC. Four of the cancers (median size, 8.5 mm) detected with the HRBGC were missed by the conventional camera Conclusion: Evaluation of indeterminate breasts lesions with a high resolution, breast-specific gamma camera results in improved sensitivity for the detection of cancer with greater improvement demonstrated in nonpalpable and ≤1 cm cancers

Hydra phantom applicability for carrying out tests of field uniformity in gamma cameras

International Nuclear Information System (INIS)

Aragao Filho, Geraldo L.; Oliveira, Alex C.H.

2014-01-01

Nuclear Medicine is a medical modality that makes use of radioactive material 'in vivo' in humans, making them a temporary radioactive source. The radiation emitted by the patient's body is detected by a specific equipment, called a gamma camera, creates an image showing the spatial and temporal biodistribution of radioactive material administered to the patient. Therefore, it's of fundamental importance a number of specific measures to make sure that procedure be satisfactory, called quality control. To Nuclear Medicine, quality control of gamma camera has the purpose of ensuring accurate scintillographic imaging, truthful and reliable for the diagnosis, guaranteeing visibility and clarity of details of structures, and also to determine the frequency and the need for preventive maintenance of equipment. To ensure the quality control of the gamma camera it's necessary to use some simulators, called phantom, used in Nuclear Medicine to evaluate system performance, system calibration and simulation of injuries. The goal of this study was to validate a new simulator for nuclear medicine, the Hydra phantom. The phantom was initially built for construction of calibration curves used in radiotherapy planning and quality control in CT. It has similar characteristics to specific phantoms in nuclear medicine, containing inserts and water area. Those inserts are regionally sourced materials, many of them are already used in the literature and based on information about density and interaction of radiation with matter. To verify its efficiency in quality control in Nuclear Medicine, was performed a test for uniformity field, one of the main tests performed daily, so we can verify the ability of the gamma camera to reproduce a uniform distribution of the administered activity in the phantom, been analysed qualitatively, through the image, and quantitatively, through values established for Central Field Of View (CFOV) and Useful Field Of View (UFOV). Also, was evaluated their

A new method for elimination of artifacts produced by collimator septum effect in gamma-camera images

International Nuclear Information System (INIS)

Uchida, Isao; Onai, Yoshio; Tomaru, Teizo; Irifune, Toraji; Kakegawa, Makoto.

1978-01-01

Collimator artifacts may be present within the images produced by collimators whose septal width approaches the inherent resolution of the gamma-camera system. As the inherent resolution of the gamma-camera is improved, collimator artifacts become more prominent. The purpose of this study is to eliminate collimator artifacts from gamma-camera images. To eliminate the septum effect produced by high-energy parallel-hole collimators with thick septa, the following method was used: X and Y signals from the detector are made to ride on the triangular waves changing periodically, and resultant position signals obtained by this processing are applied to the corresponding deflection circuits in the CRT display. The oscillation amplitude of processed position signals can be regulated by the frequency and amplitude of the triangular waves. Regulation of the oscillation amplitude of position signals, which would produce maximum reduction of collimator artifacts, was to approach the spatial frequency responses of the overall processed line spread functions obtained experimentally to those of the Gaussian functions with FWHM equal to the geometric resolution calculated from the equation given by Gerber and Miller. In images of a pancreas phantom containing 131 I, collimator artifacts were clearly seen in the unprocessed case, but were eliminated in the processed case. (auth.)

Development of an LYSO based gamma camera for positron and scinti-mammography

Science.gov (United States)

Liang, H.-C.; Jan, M.-L.; Lin, W.-C.; Yu, S.-F.; Su, J.-L.; Shen, L.-H.

2009-08-01

In this research, characteristics of combination of PSPMTs (position sensitive photo-multiplier tube) to form a larger detection area is studied. A home-made linear divider circuit was built for merging signals and readout. Borosilicate glasses were chosen for the scintillation light sharing in the crossover region. Deterioration effect caused by the light guide was understood. The influences of light guide and crossover region on the separable crystal size were evaluated. According to the test results, a gamma camera with a crystal block of 90 × 90 mm2 covered area, composed of 2 mm LYSO crystal pixels, was designed and fabricated. Measured performances showed that this camera worked fine in both 511 keV and lower energy gammas. The light loss behaviour within the crossover region was analyzed and realized. Through count rate measurements, the 176Lu nature background didn't show severe influence on the single photon imaging and exhibited an amount of less than 1/3 of all the events acquired. These results show that with using light sharing techniques, combination of multiple PSPMTs in both X and Y directions to build a large area imaging detector is capable to be achieved. Also this camera design is feasible to keep both the abilities for positron and single photon breast imaging applications. Separable crystal size is 2 mm with 2 mm thick glass applied for the light sharing in current status.

Development of an LYSO based gamma camera for positron and scinti-mammography

International Nuclear Information System (INIS)

Liang, H-C; Jan, M-L; Lin, W-C; Yu, S-F; Shen, L-H; Su, J-L

2009-01-01

In this research, characteristics of combination of PSPMTs (position sensitive photo-multiplier tube) to form a larger detection area is studied. A home-made linear divider circuit was built for merging signals and readout. Borosilicate glasses were chosen for the scintillation light sharing in the crossover region. Deterioration effect caused by the light guide was understood. The influences of light guide and crossover region on the separable crystal size were evaluated. According to the test results, a gamma camera with a crystal block of 90 x 90 mm 2 covered area, composed of 2 mm LYSO crystal pixels, was designed and fabricated. Measured performances showed that this camera worked fine in both 511 keV and lower energy gammas. The light loss behaviour within the crossover region was analyzed and realized. Through count rate measurements, the 176 Lu nature background didn't show severe influence on the single photon imaging and exhibited an amount of less than 1/3 of all the events acquired. These results show that with using light sharing techniques, combination of multiple PSPMTs in both X and Y directions to build a large area imaging detector is capable to be achieved. Also this camera design is feasible to keep both the abilities for positron and single photon breast imaging applications. Separable crystal size is 2 mm with 2 mm thick glass applied for the light sharing in current status.

Impact of intense x-ray pulses on a NaI(Tl)-based gamma camera

Science.gov (United States)

Koppert, W. J. C.; van der Velden, S.; Steenbergen, J. H. L.; de Jong, H. W. A. M.

2018-03-01

In SPECT/CT systems x-ray and γ-ray imaging is performed sequentially. Simultaneous acquisition may have advantages, for instance in interventional settings. However, this may expose a gamma camera to relatively high x-ray doses and deteriorate its functioning. We studied the NaI(Tl) response to x-ray pulses with a photodiode, PMT and gamma camera, respectively. First, we exposed a NaI(Tl)-photodiode assembly to x-ray pulses to investigate potential crystal afterglow. Next, we exposed a NaI(Tl)-PMT assembly to 10 ms LED pulses (mimicking x-ray pulses) and measured the response to flashing LED probe-pulses (mimicking γ-pulses). We then exposed the assembly to x-ray pulses, with detector entrance doses of up to 9 nGy/pulse, and analysed the response for γ-pulse variations. Finally, we studied the response of a Siemens Diacam gamma camera to γ-rays while exposed to x-ray pulses. X-ray exposure of the crystal, read out with a photodiode, revealed 15% afterglow fraction after 3 ms. The NaI(Tl)-PMT assembly showed disturbances up to 10 ms after 10 ms LED exposure. After x-ray exposure however, responses showed elevated baselines, with 60 ms decay-time. Both for x-ray and LED exposure and after baseline subtraction, probe-pulse analysis revealed disturbed pulse height measurements shortly after exposure. X-ray exposure of the Diacam corroborated the elementary experiments. Up to 50 ms after an x-ray pulse, no events are registered, followed by apparent energy elevations up to 100 ms after exposure. Limiting the dose to 0.02 nGy/pulse prevents detrimental effects. Conventional gamma cameras exhibit substantial dead-time and mis-registration of photon energies up to 100 ms after intense x-ray pulses. This is due PMT limitations and due to afterglow in the crystal. Using PMTs with modified circuitry, we show that deteriorative afterglow effects can be reduced without noticeable effects on the PMT performance, up to x-ray pulse doses of 1 nGy.

Iterative reconstruction of SiPM light response functions in a square-shaped compact gamma camera

Science.gov (United States)

Morozov, A.; Alves, F.; Marcos, J.; Martins, R.; Pereira, L.; Solovov, V.; Chepel, V.

2017-05-01

Compact gamma cameras with a square-shaped monolithic scintillator crystal and an array of silicon photomultipliers (SiPMs) are actively being developed for applications in areas such as small animal imaging, cancer diagnostics and radiotracer guided surgery. Statistical methods of position reconstruction, which are potentially superior to the traditional centroid method, require accurate knowledge of the spatial response of each photomultiplier. Using both Monte Carlo simulations and experimental data obtained with a camera prototype, we show that the spatial response of all photomultipliers (light response functions) can be parameterized with axially symmetric functions obtained iteratively from flood field irradiation data. The study was performed with a camera prototype equipped with a 30  ×  30  ×  2 mm3 LYSO crystal and an 8  ×  8 array of SiPMs for 140 keV gamma rays. The simulations demonstrate that the images, reconstructed with the maximum likelihood method using the response obtained with the iterative approach, exhibit only minor distortions: the average difference between the reconstructed and the true positions in X and Y directions does not exceed 0.2 mm in the central area of 22  ×  22 mm2 and 0.4 mm at the periphery of the camera. A similar level of image distortions is shown experimentally with the camera prototype.

Imaging of radiocesium uptake dynamics in a plant body using a newly developed high-resolution gamma camera for radiocesium

Energy Technology Data Exchange (ETDEWEB)

Kawachi, Naoki; Yin, Yong-Gen; Suzui, Nobuo; Ishii, Satomi; Fujimaki, Shu [Radiotracer Imaging Gr., Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Yoshihara, Toshihiro [Plant Molecular Biology, Laboratory of Environmental Science, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Chiba 270-1194 (Japan); Watabe, Hiroshi [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578 (Japan); Yamamoto, Seiichi [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya 461-8673 (Japan)

2014-07-01

Vast agricultural and forest areas around the Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station in Japan were contaminated with radiocesium (Cs-134 and Cs-137) after the accident following the earthquake and tsunami in March 2011. A variety of agricultural studies, such as fertilizer management and plant breeding, have been undertaken intensively for reduction of radiocesium uptake in crops, or, enhancement of uptake in phyto-remediation. In this study, we newly developed a gamma camera specific for plant nutritional research, and performed quantitative analyses on uptake and partitioning of radiocesium in intact plant bodies. In general, gamma camera is a common technology in medical imaging, but it is not applicable to high-energy gamma rays such as emissions from Cs-137 (662 keV). Therefore, we designed our new gamma camera to prevent the penetration and scattering of the high-energy gamma rays. A single-crystal scintillator, Ce-doped Gd{sub 3}Al{sub 2}Ga{sub 3}O{sub 12} (Ce:GAGG), was employed, which has a relatively high density, a large light output, no natural radioactivity and no hygroscopicity. A 44 x 44 matrix of the Ce:GAGG pixels, with dimensions of 0.85 mm x 0.85 mm x 10 mm for each pixel, was coupled to a high-quantum efficiency position sensitive photomultiplier tube. This gamma detector unit was encased in a 20-mm-thick tungsten container with a tungsten pinhole collimator on the front. By using this gamma camera, soybean plants (Glycine max), grown in hydroponic solutions and fed with 1-2 MBq of Cs-137, were imaged for 6.5 days in maximum to investigate and visualize the uptake dynamics into/within the areal part. As a result, radiocesium gradually appeared in the shoot several hours after feeding of Cs-137, and then accumulated intensively in the maturing pods and seeds in a characteristic pattern. Our results also demonstrated that this gamma-camera method enables quantitative evaluation of plant ability to absorb, transport

Upgrading of analogue cameras using modern PC based computer

International Nuclear Information System (INIS)

Pardom, M.F.; Matos, L.

2002-01-01

Aim: The use of computers along with analogue cameras enables them to perform tasks involving time-activity parameters. The INFORMENU system converts a modern PC computer into a dedicated nuclear medicine computer system with a total cost affordable to emerging economic countries, and easily adaptable to all existing cameras. Materials and Methods: In collaboration with nuclear medicine physicians, an application including hardware and software was developed by a private firm. The system runs smoothly on Windows 98 and its operation is very easy. The main features are comparable to the brand commercial computer systems; such as image resolution until 1024 x 1024, low count loss at high count rate, uniformity correction, integrated graphical and text reporting, and user defined clinical protocols. Results: The system is used in more than 20 private and public institutions. The count loss is less than 1% in all the routine work, improvement of uniformity correction of 3-5 times, improved utility of the analogue cameras. Conclusion: The INFORMENU system improves the utility of analogue cameras permitting the inclusion of dynamic clinical protocols and quantifications, helping the development of the nuclear medicine practice. The operation and maintenance costs were lowered. The end users improve their knowledge of modern nuclear medicine

Performance characteristics of ZLC 37 Siemens gamma camera

International Nuclear Information System (INIS)

Abdelgadir, Wafaa Abdelrahman

1994-04-01

The relationships between the ZLC 37 Siemens γ camera parameters (energy resolution, plane sensitivity, intrinsic uniformity, intrinsic resolution, system uniformity and system resolution) and diagnostic imaging performance was investigated. These parameters when computers when compared with internationally published data showed that the ZLC 37 Siemens γ cameras is in good operative conditions. The effect of the scattering media and WW on the spatial resolution, when the distance is kept fixed were investigated. Comparison of resolution for the media (air, water, water + radioactivity when using WW (10, 15,20%) showed that the resolution is best for air, better for water and worse for water + radioactivity up to a concentration of 8% for a 10% WW. (Author)

Gamma camera imaging of bilateral adrenocartical hyperplasia and adrenal tumors in the dog

International Nuclear Information System (INIS)

Mulnix, J.A.; Van den Brom, W.E.; Lubberink, A.A.; de Bruijne, J.J.; Rijnberk, A.

1976-01-01

Gamma camera imaging of the adrenal glands was done in 8 dogs with hyperadrenocorticism and 4 normal dogs given intravenous injections of 131I-19-iodocholesterol. In normal dogs, both adrenal glands could be visualized separately, and there was no difficulty in distinguishing among the images of normal glands, hyperplastic glands, and functional adrenal tumors. In addition, gamma camera imaging enabled the correct surgical site to be selected for removal of adrenal tumors. Hyperadrenocorticism was diagnosed in 8 dogs by evaluation of urinary 17-hydroxycorticosteroid (OHCS) excretion rates, urinary 17-OHCS and plasma 11 beta-OHCS responses to dexamethasone suppression of endogenous adrenocorticotropin (ACTH) secretion, and plasma 11 beta-OHCS response to intravenous administration of ACTH. Base line 17-OHCS excretion increased in 5 of the 8 dogs. Plasma 11 beta-OHCS concentrations were not decreased by dexamethasone administration in the 4 dogs subsequently found to have adrenal tumors; however, there was an exaggerated increase in plasma 11 beta-OHCS concentration after administration of ACTH in 3 of the 4 dogs which had bilateral adrenocortical hyperplasia

Impact of intense x-ray pulses on a NaI(Tl)-based gamma camera

NARCIS (Netherlands)

Koppert, Wilco J C; van der Velden, Sandra; Steenbergen, J H Leo; de Jong, Hugo W A M

2018-01-01

INTRODUCTION: In SPECT/CT systems X-ray and -ray imaging is performed sequentially. Simultaneous acquisition may have advantages, for instance in interventional settings. However, this may expose a gamma camera to relatively high X-ray doses and deteriorate its functioning. We studied the NaI(Tl)

Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

International Nuclear Information System (INIS)

Agostini, Denis; Marie, Pierre-Yves; Ben-Haim, Simona; Rouzet, Francois; Songy, Bernard; Giordano, Alessandro; Gimelli, Alessia; Hyafil, Fabien; Sciagra, Roberto; Bucerius, Jan; Verberne, Hein J.; Slart, Riemer H.J.A.; Lindner, Oliver

2016-01-01

The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims (1) to identify the main acquisitions protocols; (2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally (3) to determine the impact of CZT on radiation exposure. (orig.)

Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

Energy Technology Data Exchange (ETDEWEB)

Agostini, Denis [CHU Caen and Normandy University, Department of Nuclear Medicine, Caen (France); Normandy University, Caen (France); Marie, Pierre-Yves [University of Lorraine, Faculty of Medicine, Nancyclotep Experimental Imaging Platform, Nancy (France); University of Lorraine, Faculty of Medicine, CHU Nancy, Department of Nuclear Medicine, Nancy (France); University of Lorraine, Faculty of Medicine, Nancy (France); Ben-Haim, Simona [University College London, University College Hospital, Institute of Nuclear Medicine, London (United Kingdom); Chaim Sheba Medical Center, Department of Nuclear Medicine, Ramat Gan (Israel); Rouzet, Francois [University Hospital of Paris-Bichat, UMR 1148, Inserm et Paris Diderot-Paris 7 University Paris, Department of Nuclear Medicine, Paris (France); UMR 1148, Inserm and Paris Diderot-Paris 7 University Paris, Paris (France); Songy, Bernard [Centre Cardiologique du Nord, Saint-Denis (France); Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of Sacred Heart, Largo A. Gemelli, Department of Bioimages and Radiological Sciences, Rome (Italy); Gimelli, Alessia [Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Hyafil, Fabien [Bichat University Hospital, Assistance Publique - Hopitaux de Paris, UMR 1148, Inserm and Paris Diderot-Paris 7 University, Department of Nuclear Medicine, Paris (France); Sciagra, Roberto [University of Florence, Nuclear Medicine Unit, Department of Experimental and Clinical Biomedical Sciences, Florence (Italy); Bucerius, Jan [Maastricht University Medical Center, Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Verberne, Hein J. [Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Slart, Riemer H.J.A. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University of Twente, Faculty of Science and Technology, Department of Biomedical Photonic Imaging, Enschede (Netherlands); Lindner, Oliver [Institute of Radiology, Nuclear Medicine and Molecular Imaging, Heart and Diabetes Center NRW, Bad Oeynhausen (Germany); Collaboration: Cardiovascular Committee of the European Association of Nuclear Medicine (EANM)

2016-12-15

The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims (1) to identify the main acquisitions protocols; (2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally (3) to determine the impact of CZT on radiation exposure. (orig.)

The review of myocardial positron emission computed tomography and positron imaging by gamma camera

Energy Technology Data Exchange (ETDEWEB)

Ohtake, Tohru [Tokyo Univ. (Japan). Faculty of Medicine

1998-04-01

To measure myocardial blood flow, Nitrogen-13 ammonia, Oxygen-15 water, Rubidium-82 and et al. are used. Each has merit and demerit. By measuring myocardial coronary flow reserve, the decrease of flow reserve during dipyridamole in patients with hypercholesterolemia or diabetes mellitus without significant coronary stenosis was observed. The possibility of early detection of atherosclerosis was showed. As to myocardial metabolism, glucose metabolism is measured by Fluorine-18 fluorodeoxyglucose (FDG), and it is considered as useful for the evaluation of myocardial viability. We are using FDG to evaluate insulin resistance during insulin clamp in patients with diabetes mellitus by measuring glucose utilization rate of myocardium and skeletal muscle. FFA metabolism has been measured by {sup 11}C-palmitate, but absolute quantification has not been performed. Recently the method for absolute quantification was reported, and new radiopharmaceutical {sup 18}F-FTHA was reported. Oxygen metabolism has been estimated by {sup 11}C-acetate. Myocardial viability, cardiac efficiency was evaluated by oxygen metabolism. As to receptor or sympathetic nerve end, cardiac insufficiency or cardiac transplantation was evaluated. Imaging of positron emitting radiopharmaceutical by gamma camera has been performed. Collimator method is clinically useful for cardiac imaging of viability study. (author). 54 refs.

A USB 2.0 computer interface for the UCO/Lick CCD cameras

Science.gov (United States)

Wei, Mingzhi; Stover, Richard J.

2004-09-01

The new UCO/Lick Observatory CCD camera uses a 200 MHz fiber optic cable to transmit image data and an RS232 serial line for low speed bidirectional command and control. Increasingly RS232 is a legacy interface supported on fewer computers. The fiber optic cable requires either a custom interface board that is plugged into the mainboard of the image acquisition computer to accept the fiber directly or an interface converter that translates the fiber data onto a widely used standard interface. We present here a simple USB 2.0 interface for the UCO/Lick camera. A single USB cable connects to the image acquisition computer and the camera's RS232 serial and fiber optic cables plug into the USB interface. Since most computers now support USB 2.0 the Lick interface makes it possible to use the camera on essentially any modern computer that has the supporting software. No hardware modifications or additions to the computer are needed. The necessary device driver software has been written for the Linux operating system which is now widely used at Lick Observatory. The complete data acquisition software for the Lick CCD camera is running on a variety of PC style computers as well as an HP laptop.

NUKAB system use with the PICKER DYNA CAMERA II

International Nuclear Information System (INIS)

Collet, H.; Faurous, P.; Lehn, A.; Suquet, P.

Present-day data processing units connected to scintillation gamma cameras can make use of cabled programme or recorded programme systems. The NUKAB system calls on the latter technique. The central element of the data processing unit, connected to the PICKER DYNA CAMERA II output, consists of a DIGITAL PDP 8E computer with 12-bit technological words. The use of a 12-bit technological format restricts the possibilities of digitalisation, 64x64 images representing the practical limit. However the NUKAB system appears well suited to the processing of data from gamma cameras at present in service. The addition of output terminals of the tracing panel type should widen the possibilities of the system. It seems that the 64x64 format is not a handicap in view of the resolution power of the detectors [fr

Feasibility of the gamma camera acceptance testing procedure introduced by the Swiss Federal Office of public health

International Nuclear Information System (INIS)

Baechler, S.; Bochud, F.; Verdun, F.R.; Corminboeuf, F.; Linder, R.; Trueb, Ph.; Malterre, J.; Bischof Delaloye, A.

2006-01-01

Like in the field of radiology, digital systems are also becoming the standard in the field of nuclear medicine. This offers not only the possibility to process, transmit and archive data from patients more easily but also to introduce quantitative measurements for quality controls. In this framework, standards concerning the qualification of gamma camera systems have been updated and appeared to be useful to set legal requirements, in spite of the fact, that this is not their goals. The aim of this study was first to choose a set of tests described in standards to define measurements to be performed at the acceptance of the systems and after the regular maintenance (at least once every six months). Reference values are then established to control the stability of the system. To verify the feasibility, from a technical and a time requirements points of view, the tests proposed for the quality assurance programme have been applied on three gamma camera systems. The results of this study show that new requirements concerning the quality assurance of gamma camera of the Swiss Federal Office of Public Health based on international standards required to slightly modify some procedures to reduce the time necessary for the acceptance and status tests. (authors)

Characteristics of Multihole Collimator Gamma Camera Simulation Modeled Using MCNP5

International Nuclear Information System (INIS)

Saripan, M. I.; Mashohor, S.; Adnan, W. A. Wan; Marhaban, M. H.; Hashim, S.

2008-01-01

This paper describes the characteristics of the multihole collimator gamma camera that is simulated using the combination of the Monte Carlo N-Particles Code (MCNP) version 5 and in-house software. The model is constructed based on the GCA-7100A Toshiba Gamma Camera at the Royal Surrey County Hospital, Guildford, Surrey, UK. The characteristics are analyzed based on the spatial resolution of the images detected by the Sodium Iodide (NaI) detector. The result is recorded in a list-mode file referred to as a PTRAC file within MCNP5. All pertinent nuclear reaction mechanisms, such as Compton and Rayleigh scattering and photoelectric absorption are undertaken by MCNP5 for all materials encountered by each photon. The experiments were conducted on Tl-201, Co-57, Tc-99 m and Cr-51 radio nuclides. The comparison of full width half maximum value of each datasets obtained from experimental work, simulation and literature are also reported in this paper. The relationship of the simulated data is in agreement with the experimental results and data obtained in the literature. A careful inspection at each of the data points of the spatial resolution of Tc-99 m shows a slight discrepancy between these sets. However, the difference is very insignificant, i.e. less than 3 mm only, which corresponds to a size of less than 1 pixel only (of the segmented detector)

PET with a dual-head coincidence gamma camera in head and neck cancer: A comparison with computed tomography and dedicated PET

International Nuclear Information System (INIS)

Zimny, M.

2001-01-01

Positron emission tomography with 18 F-fluoro-deoxyglucose (FDG PET) is a promising imaging tool for detecting and staging of primary or recurrent head and neck cancer. The aim of this study was to evaluate a dual-head gamma camera modified for coincidence detection (KGK-PET) in comparison to computed tomography (CT) and dedicated PET (dPET). 50 patients with known or suspected primary or recurrent head and neck cancer were enrolled. 32 patients underwent KGK-PET and dPET using a one-day protocol. The sensitivity for the detection of primary/ recurrent head and neck cancer for KGK-PET and CT was 80% and 54%, respectively, specificity was 73% and 82%, respectively. The sensitivity and specificity for the detection of lymph node metastases based on neck sides with KGK-PET was 71% (CT: 65%) and 88% (CT: 89%) respectively. In comparison to dPET, KGK-PET revealed concordant results in 32/32 patients with respect to primary tumor/recurrent disease and in 55/60 evaluated neck sides. All involved neck sides that were missed by KGK-PET were also negative with dPET. These results indicate that in patients with head and neck cancer KGK-PET reveals information, that are similar to dPET and complementary to CT. (orig.) [de

Defective organification of iodine in an infant demonstrated with 123J and gamma camera

International Nuclear Information System (INIS)

Goebel, R.; Leb, G.; Sulzer, M.; Graz Univ.

1979-01-01

A defective organification of iodine is demonstrated in a two year old male infant. The availability and a relatively simple radiation detector and storage system (gamma camera and 1600 word memory) gives a reasonable low radiation dose, allows correction for extrathyroid neck activity and obviates problems of collimation. (orig.) [de

An introduction to emission computed tomography

International Nuclear Information System (INIS)

Williams, E.D.

1985-01-01

This report includes salient features of the theory and an examination of practical considerations for someone who is using or introducing tomography, selecting equipment for it or wishing to develop a clinical application. Emphasis is on gamma camera tomography. The subject is dealt with under the following headings: emission computed and gamma camera tomography and the relationship to other medical imaging techniques, the tomographic reconstruction technique theory, rotating gamma camera tomography, attenuation correction and quantitative reconstruction, other single photon tomographic techniques, positron tomography, image display, clinical application of single photon and positron tomography, and commercial systems for SPECT. Substantial bibliography. (U.K.)

Clinical significance of gamma camera renography in chronic renal insufficiency

International Nuclear Information System (INIS)

Dudczak, R.; Frischauf, H.; Kletter, K.

1980-01-01

Gamma camera renography allows, together with renal imaging, an evaluation of individual renal function. For these examinations, I 123 orthoiodohippurate is preferred and most widely used. The results on patients with chronic renal insufficiency, including urologic and posttransplantation patients, are reported. Whereas the method is of clinical significance in evaluating posttransplantation complications and in assessing individual kidney function preoperatively in urology, as well as in monitoring therapeutic effects in the early period of renal disease, it is of limited diagnostic value in chronic renal insufficiency. In this latter regard, clinical and laboratory examinations are of primary importance. (author)

Performance assessment of a slat gamma camera collimator for 511 keV imaging. Corrigendum. Phys. Med. Biol., v. 44, p. 1735-1741

International Nuclear Information System (INIS)

Britten, A.J.; Klie, R.

1999-01-01

Further to the recent work on slat gamma camera collimators by Britten and Klie (see above), the authors would like to add some references on the early work in gamma camera slat collimators, which should have been included for completeness. These papers are the original publication by Keyes (1975), and the work carried out by Webb et al (1992, 1993) deriving equations for geometric sensitivity and showing Monte Carlo modelling of performance. (author)

TU-H-206-01: An Automated Approach for Identifying Geometric Distortions in Gamma Cameras

Energy Technology Data Exchange (ETDEWEB)

Mann, S; Nelson, J [Clinical Imaging Physics Group and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Samei, E [Clinical Imaging Physics Group and Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Departments of Physics, Electrical and Computer Engineering, and Biomedical Engineering, and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States)

2016-06-15

Purpose: To develop a clinically-deployable, automated process for detecting artifacts in routine nuclear medicine (NM) quality assurance (QA) bar phantom images. Methods: An artifact detection algorithm was created to analyze bar phantom images as part of an ongoing QA program. A low noise, high resolution reference image was acquired from an x-ray of the bar phantom with a Philips Digital Diagnost system utilizing image stitching. NM bar images, acquired for 5 million counts over a 512×512 matrix, were registered to the template image by maximizing mutual information (MI). The MI index was used as an initial test for artifacts; low values indicate an overall presence of distortions regardless of their spatial location. Images with low MI scores were further analyzed for bar linearity, periodicity, alignment, and compression to locate differences with respect to the template. Findings from each test were spatially correlated and locations failing multiple tests were flagged as potential artifacts requiring additional visual analysis. The algorithm was initially deployed for GE Discovery 670 and Infinia Hawkeye gamma cameras. Results: The algorithm successfully identified clinically relevant artifacts from both systems previously unnoticed by technologists performing the QA. Average MI indices for artifact-free images are 0.55. Images with MI indices < 0.50 have shown 100% sensitivity and specificity for artifact detection when compared with a thorough visual analysis. Correlation of geometric tests confirms the ability to spatially locate the most likely image regions containing an artifact regardless of initial phantom orientation. Conclusion: The algorithm shows the potential to detect gamma camera artifacts that may be missed by routine technologist inspections. Detection and subsequent correction of artifacts ensures maximum image quality and may help to identify failing hardware before it impacts clinical workflow. Going forward, the algorithm is being

High-performance dual-speed CCD camera system for scientific imaging

Science.gov (United States)

Simpson, Raymond W.

1996-03-01

Traditionally, scientific camera systems were partitioned with a `camera head' containing the CCD and its support circuitry and a camera controller, which provided analog to digital conversion, timing, control, computer interfacing, and power. A new, unitized high performance scientific CCD camera with dual speed readout at 1 X 106 or 5 X 106 pixels per second, 12 bit digital gray scale, high performance thermoelectric cooling, and built in composite video output is described. This camera provides all digital, analog, and cooling functions in a single compact unit. The new system incorporates the A/C converter, timing, control and computer interfacing in the camera, with the power supply remaining a separate remote unit. A 100 Mbyte/second serial link transfers data over copper or fiber media to a variety of host computers, including Sun, SGI, SCSI, PCI, EISA, and Apple Macintosh. Having all the digital and analog functions in the camera made it possible to modify this system for the Woods Hole Oceanographic Institution for use on a remote controlled submersible vehicle. The oceanographic version achieves 16 bit dynamic range at 1.5 X 105 pixels/second, can be operated at depths of 3 kilometers, and transfers data to the surface via a real time fiber optic link.

Radioimmunological determination of alphafetoprotein and gamma camera scintigraphy in patients with tumours of the testes

International Nuclear Information System (INIS)

Milkov, V.; Sultanov, S.

1989-01-01

By means of radioimmunological method the blood serum concentrations of alphafetoprotein (AFP) were investigated in 35 patients with histologically confirmed tumours of the testes prior to surgical intervention. Parallely in all patients gamma camera scintigraphy of the testes was performed. Seven of all investigated 15 patients with seminoma of the testes had increased concentrations of AFP in the blood serum. In 7 of the examinated 10 patients with diagnosis teratoma of the testes increased blood serum concentrations of AFP were established, while 6 of the examined patients with embryonic tumour of the testis had increased blood serum concentrations of AFP. In comparison with the results established in the control group of 30 healthy males, this increase of AFP was statistically reliable. All examined patients showed positive scintigraphic findings, which confirmed the diagnosis of tumour of the testes. It is concluded that the parallel determination of blood serum AFP and gamma camera investigation of the testes could be successfully apllied in the diagnosis of these malignant diseases

FACT-The first Cherenkov telescope using a G-APD camera for TeV gamma-ray astronomy

International Nuclear Information System (INIS)

Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, S.; Commichau, V.; Domke, M.; Dorner, D.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Koehne, J.-H.; Kraehenbuehl, T.; Kranich, D.; Krumm, B.; Lorenz, E.

2011-01-01

Geiger-mode Avalanche Photodiodes (G-APD) bear the potential to significantly improve the sensitivity of Imaging Air Cherenkov Telescopes (IACT). We are currently building the First G-APD Cherenkov Telescope (FACT) by refurbishing an old IACT with a mirror area of 9.5 square meters and are constructing a new, fine-pixelized camera using novel G-APDs. The main goal is to evaluate the performance of a complete system by observing very high energy gamma-rays from the Crab Nebula. This is an important field test to check the feasibility of G-APD-based cameras to replace at some time the PMT-based cameras of planned future IACTs like AGIS and CTA. In this article, we present the basic design of such a camera as well as some important details.

PET with a coincidence gamma camera: results in selected oncological questions

International Nuclear Information System (INIS)

Lauer, I.; Haase, A; Adam, S.; Prueter, I.; Richter, E.; Baehre, M.

2001-01-01

Since early 1997, about 1660 investigations with coincidence gamma camera PET (CGC-PET) have been performed in our department, mostly undertaken for oncological questions. Based on these data, several retrospective and prospective studies were performed. In the following, the results in CUP (cancer of unknown primary) syndrome, melanoma and malignant lymphoma are presented. Methods: CGC-PET was performed after application of 250-350 MBq [ 18 F]FDG using a coincidence double head gamma camera with 19 mm Nal cristal. CUP-Syndrome: After completing conventional diagnostic procedures, 32 patients have been examined in a prospective study, including 25 patients with recently detected CUP and 7 patients undergoing restaging after therapy. Localization of the primary tumor was successful in 12 (38%) cases. Melanoma: We evaluated 50 studies in 41 patients suffering from melanoma, retrospectively. CGC-PET showed a sensitivity of 76%, and a specificity of 94%. In comparison to conventional diagnostic methods, CGC-PET delineated important additional information in 16%. CGC-PET was superior to morphological diagnostic tools in the differentiation between residual scar tissue and active tumor following immunochemotherapy. Malignant lymphoma: 29 CGC-PET in 29 patients were performed for staging of malignant lymphoma, sensitivity was 86% versus 88% for CT. Overall CGC-PET showed additional information to conventional diagnostic methods, but revealed problems in detecting small infiltrations of organs. In restaging malignant melanoma (26 patients, 33 studies), specificity of CGC-PET was superior to conventional diagnostics (92% versus 35%). (orig.) [de

Novel computer-based endoscopic camera

Science.gov (United States)

Rabinovitz, R.; Hai, N.; Abraham, Martin D.; Adler, Doron; Nissani, M.; Fridental, Ron; Vitsnudel, Ilia

1995-05-01

We have introduced a computer-based endoscopic camera which includes (a) unique real-time digital image processing to optimize image visualization by reducing over exposed glared areas and brightening dark areas, and by accentuating sharpness and fine structures, and (b) patient data documentation and management. The image processing is based on i Sight's iSP1000TM digital video processor chip and Adaptive SensitivityTM patented scheme for capturing and displaying images with wide dynamic range of light, taking into account local neighborhood image conditions and global image statistics. It provides the medical user with the ability to view images under difficult lighting conditions, without losing details `in the dark' or in completely saturated areas. The patient data documentation and management allows storage of images (approximately 1 MB per image for a full 24 bit color image) to any storage device installed into the camera, or to an external host media via network. The patient data which is included with every image described essential information on the patient and procedure. The operator can assign custom data descriptors, and can search for the stored image/data by typing any image descriptor. The camera optics has extended zoom range of f equals 20 - 45 mm allowing control of the diameter of the field which is displayed on the monitor such that the complete field of view of the endoscope can be displayed on all the area of the screen. All these features provide versatile endoscopic camera with excellent image quality and documentation capabilities.

Breast Imaging Utilizing Dedicated Gamma Camera and (99m)Tc-MIBI: Experience at the Tel Aviv Medical Center and Review of the Literature Breast Imaging.

Science.gov (United States)

Even-Sapir, Einat; Golan, Orit; Menes, Tehillah; Weinstein, Yuliana; Lerman, Hedva

2016-07-01

The scope of the current article is the clinical role of gamma cameras dedicated for breast imaging and (99m)Tc-MIBI tumor-seeking tracer, as both a screening modality among a healthy population and as a diagnostic modality in patients with breast cancer. Such cameras are now commercially available. The technology utilizing a camera composed of a NaI (Tl) detector is termed breast-specific gamma imaging. The technology of dual-headed camera composed of semiconductor cadmium zinc telluride detectors that directly converts gamma-ray energy into electronic signals is termed molecular breast imaging. Molecular breast imaging system has been installed at the Department of Nuclear medicine at the Tel Aviv Sourasky Medical Center, Tel Aviv in 2009. The article reviews the literature well as our own experience. Copyright © 2016 Elsevier Inc. All rights reserved.

Applications of iQID cameras

Science.gov (United States)

Han, Ling; Miller, Brian W.; Barrett, Harrison H.; Barber, H. Bradford; Furenlid, Lars R.

2017-09-01

iQID is an intensified quantum imaging detector developed in the Center for Gamma-Ray Imaging (CGRI). Originally called BazookaSPECT, iQID was designed for high-resolution gamma-ray imaging and preclinical gamma-ray single-photon emission computed tomography (SPECT). With the use of a columnar scintillator, an image intensifier and modern CCD/CMOS sensors, iQID cameras features outstanding intrinsic spatial resolution. In recent years, many advances have been achieved that greatly boost the performance of iQID, broadening its applications to cover nuclear and particle imaging for preclinical, clinical and homeland security settings. This paper presents an overview of the recent advances of iQID technology and its applications in preclinical and clinical scintigraphy, preclinical SPECT, particle imaging (alpha, neutron, beta, and fission fragment), and digital autoradiography.

Dynamic imaging with coincidence gamma camera

International Nuclear Information System (INIS)

Elhmassi, Ahmed

2008-01-01

In this paper we develop a technique to calculate dynamic parameters from data acquired using gamma-camera PET (gc PET). Our method is based on an algorithm development for dynamic SPECT, which processes all decency projection data simultaneously instead of reconstructing a series of static images individually. The algorithm was modified to account for the extra data that is obtained with gc PET (compared with SPEC). The method was tested using simulated projection data for both a SPECT and a gc PET geometry. These studies showed the ability of the code to reconstruct simulated data with a varying range of half-lives. The accuracy of the algorithm was measured in terms of the reconstructed half-life and initial activity for the simulated object. The reconstruction of gc PET data showed improvement in half-life and activity compared to SPECT data of 23% and 20%, respectively (at 50 iterations). The gc PET algorithm was also tested using data from an experimental phantom and finally, applied to a clinical dataset, where the algorithm was further modified to deal with the situation where the activity in certain pixels decreases and then increases during the acquisition. (author)

Easy method to measure radioactive waste with a gamma-camera detector

International Nuclear Information System (INIS)

Murat, C.; Barrau, C.

2007-01-01

The aim of this technical note is to evaluate an easy method to measure 99m Tc samples with an activity of 1000, 100 and 10 Bq/L. This study is performed with a gamma camera detector in two departments of nuclear medicine in Avignon and in Nimes. We develop a procedure to measure 99m Tc radioactive waste at the two hospitals output in accordance with the D.G.S./D.H.O.S. no. 2001/323 circular requests of the Ministry for Employment and Solidarity. (authors)

Use of calibration methodology of gamma cameras for the workers surveillance using a thyroid simulator

International Nuclear Information System (INIS)

Alfaro, M.; Molina, G.; Vazquez, R.; Garcia, O.

2010-09-01

In Mexico there are a significant number of nuclear medicine centers in operation. For what the accidents risk related to the transport and manipulation of open sources used in nuclear medicine can exist. The National Institute of Nuclear Research (ININ) has as objective to establish a simple and feasible methodology for the workers surveillance related with the field of the nuclear medicine. This radiological surveillance can also be applied to the public in the event of a radiological accident. To achieve this it intends to use the available equipment s in the nuclear medicine centers, together with the neck-thyroid simulators elaborated by the ININ to calibrate the gamma cameras. The gamma cameras have among their component elements that conform spectrometric systems like the employees in the evaluation of the internal incorporation for direct measurements, reason why, besides their use for diagnostic for image, they can be calibrated with anthropomorphic simulators and also with punctual sources for the quantification of the radionuclides activity distributed homogeneously in the human body, or located in specific organs. Inside the project IAEA-ARCAL-RLA/9/049-LXXVIII -Procedures harmonization of internal dosimetry- where 9 countries intervened (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru, Uruguay and Spain). It was developed a protocol of cameras gamma calibration for the determination in vivo of radionuclides. The protocol is the base to establish and integrated network in Latin America to attend in response to emergencies, using nuclear medicine centers of public hospitals of the region. The objective is to achieve the appropriate radiological protection of the workers, essential for the sure and acceptable radiation use, the radioactive materials and the nuclear energy. (Author)

A new collimator for measurement of rCBF by means of gamma camera

International Nuclear Information System (INIS)

Zechmann, W.; Oberladstaetter, M.; Raccabona, G.; Vogl, G.; Gerstenbrand, F.

1982-01-01

Atraumatic measurement of rCBF by means of gamma camera and conventional collimators requires high doses of 133 Xenon to obtain high count rates over the cerebral ROI's. The input of time-activity curve of breathing air by means of a probe measurement is not possible on line without difficulties. A new collimator, developed by ours, which is comparable with standard rCBF-Multiprobe systems, which allows high countrates and low dose of 133 Xenon is presented. A special air bypass enables to get the breathing curve with simple ROI technique. The collimator can easily be adapted to the camera by means of an insert adapter ring. With this collimator the rCBF measurement with conventional equipment of a nuclear medicine department is possible. (Author)

A gamma camera method for quantitation of split renal function in children followed for vesicoureteric reflux

International Nuclear Information System (INIS)

Tamminen, T.E.; Riihimaeki, E.J.; Taehti, E.E.; Helsinki Univ. Central Hospital

1978-01-01

A method for quantitative estimation of split renal function using a computerized gamma camera system is described. 42 children and adolescents with existing or preexisting vesicouretric reflux and recurrent urinary tract infection were investigated. Total renal clearance of DTPA was calculated with a disapperarance curve derived from the largest extrarenal area in the field of view of a gamma camera with diverging collimator. Split renal function was estimated with the slopes of second phase renograms. The plasma disaapearance clearance of DTPA, calculated using one compartement model with two late blood samples, gave similar resusults with the clearance estimated from the body disappearance curves. The proportional planimetric renal parenchymal areas had good correlation with the split clearance estimated from renogram slopes. The method offers data on renal function and urinary tract dynamics which is very valuable in the follow-up of children with recurrent urinary tract infection and vesicoureteric reflux. (orig.) [de

Inter-laboratory comparison study of gamma cameras in Pakistan

International Nuclear Information System (INIS)

Shahid, M.A.; Mumtaz-ul-Haq

1988-01-01

The evaluation of the performance of both instrument and the physician are important in any quality assurance programme in nuclear medicine imaging. The IAEA launched a similar program in 1984 under its Regional Cooperation Agreement program in South Asian Countries. The first part of the study consisted of the evaluation of imaging equipment by imaging IAEA-WHO Simulated Anatomic Liver Phantom (SALP) and its interpretation by the physician. From Pakistan, 8 gamma cameras from 7 laboratories were used for the study and 16 physician interpreted in the SALP images. This paper reports the results of SALP images from Pakistan and shows the efficacy of 80 to 100% as regards the quality of image obtained and the interpretation done by the physicians. (author)

Gamma camera correction system and method for using the same

International Nuclear Information System (INIS)

Inbar, D.; Gafni, G.; Grimberg, E.; Bialick, K.; Koren, J.

1986-01-01

A gamma camera is described which consists of: (a) a detector head that includes photodetectors for producing output signals in response to radiation stimuli which are emitted by a radiation field and which interact with the detector head and produce an event; (b) signal processing circuitry responsive to the output signals of the photodetectors for producing a sum signal that is a measure of the total energy of the event; (c) an energy discriminator having a relatively wide window for comparison with the sum signal; (d) the signal processing circuitry including coordinate computation circuitry for operating on the output signals, and calculating an X,Y coordinate of an event when the sum signal lies within the window of the energy discriminator; (e) an energy correction table containing spatially dependent energy windows for producing a validation signal if the total energy of an event lies within the window associated with the X,Y coordinates of the event; (f) the signal processing circuitry including a dislocation correction table containing spatially dependent correction factors for converting the X,Y coordinates of an event to relocated coordinates in accordance with correction factors determined by the X,Y coordinates; (g) a digital memory for storing a map of the radiation field; and (h) means for recording an event at its relocated coordinates in the memory if the energy correction table produces a validation signal

Computational techniques in gamma-ray skyshine analysis

International Nuclear Information System (INIS)

George, D.L.

1988-12-01

Two computer codes were developed to analyze gamma-ray skyshine, the scattering of gamma photons by air molecules. A review of previous gamma-ray skyshine studies discusses several Monte Carlo codes, programs using a single-scatter model, and the MicroSkyshine program for microcomputers. A benchmark gamma-ray skyshine experiment performed at Kansas State University is also described. A single-scatter numerical model was presented which traces photons from the source to their first scatter, then applies a buildup factor along a direct path from the scattering point to a detector. The FORTRAN code SKY, developed with this model before the present study, was modified to use Gauss quadrature, recent photon attenuation data and a more accurate buildup approximation. The resulting code, SILOGP, computes response from a point photon source on the axis of a silo, with and without concrete shielding over the opening. Another program, WALLGP, was developed using the same model to compute response from a point gamma source behind a perfectly absorbing wall, with and without shielding overhead. 29 refs., 48 figs., 13 tabs

Realization and study of spectral properties of the ISGRI gamma-ray camera; Mise en oeuvre et etude des proprietes spectrales de la gamma-camera ISGRI

Energy Technology Data Exchange (ETDEWEB)

Limousin, O

2001-11-01

This work evaluates spectroscopic and physical properties of CdTe detectors in view of assembling a large number on a new generation spectro-imager for space gamma-ray astronomy. Study, optimization, realization and calibration of modular detection units of the ISGRI camera are described. After a description of the experimental context of the INTEGRAL program and a review of the physical processes involved in gamma-ray photon detectors, we present an analysis of the properties of CdTe detectors attempting to be so exhaustive as possible. We propose the base point of a global model, which relates charge transport properties, spectral response and possible instabilities in the detectors. We propose a new formulation of the Hecht relation that describes charge loss as a function of the detector charge transport properties. We discuss at length the method of charge loss correction and its consequences on the associated integrated electronics definition. Finally, we illustrate our instrument capabilities using as an example the observation of titanium 44 lines in historical supernovae. (author)

Localization of the placenta in the 3 trimester of gestation with the use of a gamma-camera and radioactive sup(113m)In indium isotope

Energy Technology Data Exchange (ETDEWEB)

Brudnik, A.; Chromy, G.; Ulfik, A.; Bielawski, J.; Wasylewski, A. (Slaska Akademia Medyczna, Katowice (Poland))

1980-01-01

In 56 women, treated because of uterine bleedings in the 3 trimester of gestation the localization of the placenta was looked for with use of a gamma camera (Toshiba Co.) and indium radioisotope 113-In. The methodic procedures were elaborated for the application of the gamma-camera and the utilization of radioactive marker /sup 125/Sb in the anatomic reference areas. Full conformity of results with findings at cesarean section was met. Isotope placentography with the application of gamma camera gives a high percentage of adequate diagnoses, least dose of exposition, uncomplicated procedures. The negative diagnosis in suspected cases of placenta previa permitted to decrease the time of hospital stay in a number of cases observed because of uterine bleedings in the 3 trimester of pregnancy.

Localization of the placenta in the 3 trimester of gestation with the use of a gamma-camera and radioactive sup(113m)In indium isotope

International Nuclear Information System (INIS)

Brudnik, A.; Chromy, G.; Ulfik, A.; Bielawski, J.; Wasylewski, A.

1980-01-01

In 56 women, treated because of uterine bleedings in the 3 trimester of gestation the localization of the placenta was looked for with use of a gamma camera (Toshiba Co.) and indium radioisotope 113-In. The methodic procedures were elaborated for the application of the gamma-camera and the utilization of radioactive marker 125 Sb in the anatomic reference areas. Full conformity of results with findings at cesarean section was met. Isotope placentography with the application of gamma camera gives a high percentage of adequate diagnoses, least dose of exposition, uncomplicated procedures. The negative diagnosis in suspected cases of placenta previa permitted to decrease the time of hospital stay in a number of cases observed because of uterine bleedings in the 3 trimester of pregnancy. (author)

Test bed for real-time image acquisition and processing systems based on FlexRIO, CameraLink, and EPICS

International Nuclear Information System (INIS)

Barrera, E.; Ruiz, M.; Sanz, D.; Vega, J.; Castro, R.; Juárez, E.; Salvador, R.

2014-01-01

Highlights: • The test bed allows for the validation of real-time image processing techniques. • Offers FPGA (FlexRIO) image processing that does not require CPU intervention. • Is fully compatible with the architecture of the ITER Fast Controllers. • Provides flexibility and easy integration in distributed experiments based on EPICS. - Abstract: Image diagnostics are becoming standard ones in nuclear fusion. At present, images are typically analyzed off-line. However, real-time processing is occasionally required (for instance, hot-spot detection or pattern recognition tasks), which will be the objective for the next generation of fusion devices. In this paper, a test bed for image generation, acquisition, and real-time processing is presented. The proposed solution is built using a Camera Link simulator, a Camera Link frame-grabber, a PXIe chassis, and offers software interface with EPICS. The Camera Link simulator (PCIe card PCIe8 DVa C-Link from Engineering Design Team) generates simulated image data (for example, from video-movies stored in fusion databases) using a Camera Link interface to mimic the frame sequences produced with diagnostic cameras. The Camera Link frame-grabber (FlexRIO Solution from National Instruments) includes a field programmable gate array (FPGA) for image acquisition using a Camera Link interface; the FPGA allows for the codification of ad-hoc image processing algorithms using LabVIEW/FPGA software. The frame grabber is integrated in a PXIe chassis with system architecture similar to that of the ITER Fast Controllers, and the frame grabber provides a software interface with EPICS to program all of its functionalities, capture the images, and perform the required image processing. The use of these four elements allows for the implementation of a test bed system that permits the development and validation of real-time image processing techniques in an architecture that is fully compatible with that of the ITER Fast Controllers

Investigation of high resolution compact gamma camera module based on a continuous scintillation crystal using a novel charge division readout method

International Nuclear Information System (INIS)

Dai Qiusheng; Zhao Cuilan; Qi Yujin; Zhang Hualin

2010-01-01

The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel subtractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99m Tc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image shrinkage problem associated with the conventional resistive readout can be effectively overcome by the novel subtractive resistive readout with an appropriate fraction subtraction factor. The response output area (ROA) of the camera shown in the flood image was improved up to 34%, and an intrinsic spatial resolution better than 2 mm of detector was achieved. In conclusion, the utilization of a continuous scintillation crystal and a flat-panel PSPMT equipped with a novel subtractive resistive readout is a feasible approach for developing a high performance and lower cost compact gamma camera. (authors)

Expedited, uniform processing of multi-vendor gamma test data

International Nuclear Information System (INIS)

Zimmerman, R.E.

2002-01-01

Aim: Acceptance testing of gamma camera performance is time consuming. When data is collected from different vendors image format and methodology differences can result in disjointed and difficult to compare results. Even when performing NEMA specified tests consistent processing of data from multi-vendor cameras results in methodological inconsistencies. A more uniform and consistent method to process data collected from gamma cameras would be a boon to those involved in acquiring and processing such test data. Methods and Materials: Image J is an image processing program freely available on the Web at http://rsb.info.nih.gov/ij/. It can be run using a normal Web browser or installed on any computer. Since it is written in Java it is platform and operating system independent. Image J is very extensible, object based and has a large international user community in many imaging disciplines. Extensions to Image J are written using the Java programming language and the internal macro recording facility. Image J handles multiple image formats useful in nuclear medicine including DICOM, RAW, BMP, JPG, Interfile, AVI and QT. Extensions have been written to process and determine gamma camera intrinsic and extrinsic uniformity, COR errors, planar extrinsic resolution and reconstructed spatial resolution. The testing and processing adhere closely to NEMA specified procedures and result in quantitative measures of performance traceable to NEMA and manufacturers specifications. Results and Conclusions: Extensions to Image J written specifically to process gamma camera acceptance test data have resulted in considerable decrease in time to complete the analysis and allows a consistent, vendor independent, method to measure performance of cameras from multiple vendors. Quality control images from multiple camera vendors are also easily processed in a consistent fashion. The availability of this or similar platform and vendor independent software should lead to more complete

Color reproduction software for a digital still camera

Science.gov (United States)

Lee, Bong S.; Park, Du-Sik; Nam, Byung D.

1998-04-01

We have developed a color reproduction software for a digital still camera. The image taken by the camera was colorimetrically reproduced on the monitor after characterizing the camera and the monitor, and color matching between two devices. The reproduction was performed at three levels; level processing, gamma correction, and color transformation. The image contrast was increased after the level processing adjusting the level of dark and bright portions of the image. The relationship between the level processed digital values and the measured luminance values of test gray samples was calculated, and the gamma of the camera was obtained. The method for getting the unknown monitor gamma was proposed. As a result, the level processed values were adjusted by the look-up table created by the camera and the monitor gamma correction. For a color transformation matrix for the camera, 3 by 3 or 3 by 4 matrix was used, which was calculated by the regression between the gamma corrected values and the measured tristimulus values of each test color samples the various reproduced images were displayed on the dialogue box implemented in our software, which were generated according to four illuminations for the camera and three color temperatures for the monitor. An user can easily choose he best reproduced image comparing each others.

Evaluation of intrinsic uniformity of gamma camera in the Servicio de Medicina Nuclear at the Hospital San Juan de Dios

International Nuclear Information System (INIS)

Mora Ramirez, Erick

2007-01-01

The quality assurance program in a nuclear medicine department aims to minimize errors and artifacts that cover all aspects of clinical practice. The quality control can be seen such as one particular procedure used to meet measurements that can be followed along the time. The intrinsic flood-field uniformity is one of the quality control procedures to evaluate the response of a gamma camera to a spatially uniform flux of an incident gamma radiation over the field of view. The gamma cameras, recording the integral and differential uniformity figures of the intrinsic uniformity during the 2007, were evaluated in order to establish how well the instruments were working. An evaluation of the acquisition protocol which implies the variation of the acquired counts, the energy window width and its placement was performed at the beginning. After that the recorded data were analyzed creating plots which were showing the performance of the systems. Using an energy window placed at 140 keV at 20 %, with matrix size of 512 x 512, acquiring 15 million counts and the source activity close to 700 μC; it was thought that good enough images and uniformities are obtained. Both are within the manufactures requirements; however, increasing the number of acquired counts, images are much better and an improvement in the evaluated parameters can be seen. The performance evaluation of the three gamma cameras was taking into account for approximately 240 days, showing an integral uniformity range of 1.04 - 3.5 % and the range for differential uniformity vary from 0.88 up to 2.7 %. It concludes that the gamma cameras were working quite well, no need to vary the acquisition protocol because it is good enough to perform this test. Also, factors affecting the quality of the images are radioactive waste material not very well shielded and temperature room variations, especially at the beginning of the workday. (author) [es

Users' guide to the positron camera DDP516 computer system

International Nuclear Information System (INIS)

Bracher, B.H.

1979-08-01

This publication is a guide to the operation, use and software for a DDP516 computer system provided by the Data Handling Group primarily for the development of a Positron Camera. The various sections of the publication fall roughly into three parts. (1) Sections forming the Operators Guide cover the basic operation of the machine, system utilities and back-up procedures. Copies of these sections are kept in a 'Nyrex' folder with the computer. (2) Sections referring to the software written particularly for Positron Camera Data Collection describe the system in outline and lead to details of file formats and program source files. (3) The remainder of the guide, describes General-Purpose Software. Much of this has been written over some years by various members of the Data Handling Group, and is available for use in other applications besides the positron camera. (UK)

Measurement of the iodine uptake by the thyroid: comparative analysis between the gamma camera system with 'pinhole' collimator and 13S002 system

International Nuclear Information System (INIS)

Silva, Carlos Borges da; Mello, Rossana Corbo R. de; Rebelo, Ana Maria O.

2002-01-01

The thyroid uptake measurements are common in medical uses and are considered a direct and precise form of diagnostic, however, different results have been observed as measurements of thyroid uptake are taken using distinct equipment. This study attempts to find the cause of the differences between a thyroid uptake probe and a gamma camera. These discrepancies can be associated to the different patients samples, equipment's problems or operator procedures errors. This work presents the results of comparative uptake measurements performed in a neck phantom and a 4-hour thyroid uptake study in 40 patients, using a Gamma Camera Ohio Nuclear model Sigma 410 with a pinhole collimator and Nuclear Medicine System model 13S002, developed by Instituto de Engenharia Nuclear. The results observed show that in spite of non satisfactory results commented in literature, both the System 13S002 and System Gamma Camera Ohio can be used in uptake thyroid diagnostic with statistical confidence degree of 99 %. (author)

Development of a tomographic system adapted to 3D measurement of contaminated wounds based on the Cacao concept (Computer aided collimation Gamma Camera); Developpement a partir du concept CACAO (Camera A Collimation Assistee par Ordinateur) d'un systeme tomographique adapte a la mesure 3D de plaies contaminees

Energy Technology Data Exchange (ETDEWEB)

Douiri, A

2002-03-01

The computer aided collimation gamma camera (CACAO in French) is a gamma camera using a collimator with large holes, a supplementary linear scanning motion during the acquisition and a dedicated reconstruction program taking full account of the source depth. The CACAO system was introduced to improve both the sensitivity and the resolution in nuclear medicine. This thesis focuses on the design of a fast and robust reconstruction algorithm in the CACAO project. We start by an overview of tomographic imaging techniques in nuclear medicine. After modelling the physical CACAO system, we present the complete reconstruction program which involves three steps: 1) shift and sum 2) deconvolution and filtering 3) rotation and sum. The deconvolution is the critical step that decreases the signal to noise ratio of the reconstructed images. We propose a regularized multi-channel algorithm to solve the deconvolution problem. We also present a fast algorithm based on Splines functions and preserving the high quality of the reconstructed images for the shift and the rotation steps. Comparisons of simulated reconstructed images in 2D and 3D for the conventional system (CPHC) and CACAO demonstrate the ability of CACAO system to increase the quality of the SPECT images. Finally, this study concludes with an experimental approach with a pixellated detector conceived for a 3D measurement of contaminated wounds. This experimentation proves the possible advantages of coupling the CACAO project with pixellated detectors. Moreover, a variety of applications could fully benefit from the CACAO system, such as low activity imaging, the use of high-energy gamma isotopes and the visualization of deep organs. Moreover the combination of the CACAO system with a pixels detector may open up further possibilities for the future of nuclear medicine. (author)

A new gamma camera for positron emission tomography

International Nuclear Information System (INIS)

Schotanus, P.

1988-01-01

This thesis describes the detection of annihiliation radiation employing a new principle: radiation is absorbed in a barium fluoride (BaF 2) crystal and the resulting scintillation light is detected in a multiwire proportional chamber filled with a photsensitive vapour. The application of such a detector for PET is new; the use of a high density fast scintillator in combination with a low pressure wire chamber offers a good detection efficiency and permits high count rates because of the small dead time. In this work, the physical background of the above detection mechanism is explored and the performance parameters of a gamma camera using this new principle, are determined. Furthermore, a comprehensive research on the scintillation mechanism and physical characteristics of the increasingly popular BaF 2 scintillator is presented. Also, a new class of ultraviolet (UV) scintillation materials, consisting of rare earth doped fluorides, is introduced. (author). 211 refs.; 30 figs.; 17 tabs

Testing of camera performance standards at steady and local overloading

International Nuclear Information System (INIS)

Keszthelyine Landori, S.; Adorjanne Farkas, M.; Csirik, J.

1983-01-01

Camera performance standards are usually given for low count rates and uniform irradiation. A conventional analog gamma camera system (Gamma MB 9100 manufactured under the know-how of Picker DC 4/12 in Hungary) was studied on the basis of the Picker test procedure and the NEMA standard system. Uniformity, linearity, spatial and energy resolution were measured at high count rates and uniform irradiation (steady overloading). Linearity was studied at local overloading. Linearity, spatial and energy resolution were measured by a 1024-channel analyzer-computer system of KFKI, Hungary. The data were evaluated on the basis of NEMA standards, while uniformity was measured by the Gamma data processing system and evaluated by special SEGAMS programs. Performance variations were studied between 7500 cps and 75.000 cps pulse rates. Spatial and energy resolution were influenced strongly, uniformity slightly by pulse rates, while linearity did not change at all. Linearity was not influenced even by local overloading. (author)

Assessment of right ventricular function with nonimaging first pass ventriculography and comparison of results with gamma camera studies.

Science.gov (United States)

Zhang, Z; Liu, X J; Liu, Y Z; Lu, P; Crawley, J C; Lahiri, A

1990-08-01

A new technique has been developed for measuring right ventricular function by nonimaging first pass ventriculography. The right ventricular ejection fraction (RVEF) obtained by non-imaging first pass ventriculography was compared with that obtained by gamma camera first pass and equilibrium ventriculography. The data has demonstrated that the correlation of RVEFs obtained by the nonimaging nuclear cardiac probe and by gamma camera first pass ventriculography in 15 subjects was comparable (r = 0.93). There was also a good correlation between RVEFs obtained by the nonimaging nuclear probe and by equilibrium gated blood pool studies in 33 subjects (r = 0.89). RVEF was significantly reduced in 15 patients with right ventricular and/or inferior myocardial infarction compared to normal subjects (28 +/- 9% v. 45 +/- 9%). The data suggests that nonimaging probes may be used for assessing right ventricular function accurately.

Gamma-camera 18F-FDG PET in diagnosis and staging of patients presenting with suspected lung cancer and comparison with dedicated PET

DEFF Research Database (Denmark)

Oturai, Peter S; Mortensen, Jann; Enevoldsen, Henriette

2004-01-01

It is not clear whether high-quality coincidence gamma-PET (gPET) cameras can provide clinical data comparable with data obtained with dedicated PET (dPET) cameras in the primary diagnostic work-up of patients with suspected lung cancer. This study focuses on 2 main issues: direct comparison...

Dual-head gamma camera system for intraoperative localization of radioactive seeds

International Nuclear Information System (INIS)

Arsenali, B; Viergever, M A; Gilhuijs, K G A; De Jong, H W A M; Beijst, C; Dickerscheid, D B M

2015-01-01

Breast-conserving surgery is a standard option for the treatment of patients with early-stage breast cancer. This form of surgery may result in incomplete excision of the tumor. Iodine-125 labeled titanium seeds are currently used in clinical practice to reduce the number of incomplete excisions. It seems likely that the number of incomplete excisions can be reduced even further if intraoperative information about the location of the radioactive seed is combined with preoperative information about the extent of the tumor. This can be combined if the location of the radioactive seed is established in a world coordinate system that can be linked to the (preoperative) image coordinate system. With this in mind, we propose a radioactive seed localization system which is composed of two static ceiling-suspended gamma camera heads and two parallel-hole collimators. Physical experiments and computer simulations which mimic realistic clinical situations were performed to estimate the localization accuracy (defined as trueness and precision) of the proposed system with respect to collimator-source distance (ranging between 50 cm and 100 cm) and imaging time (ranging between 1 s and 10 s). The goal of the study was to determine whether or not a trueness of 5 mm can be achieved if a collimator-source distance of 50 cm and imaging time of 5 s are used (these specifications were defined by a group of dedicated breast cancer surgeons). The results from the experiments indicate that the location of the radioactive seed can be established with an accuracy of 1.6 mm  ±  0.6 mm if a collimator-source distance of 50 cm and imaging time of 5 s are used (these experiments were performed with a 4.5 cm thick block phantom). Furthermore, the results from the simulations indicate that a trueness of 3.2 mm or less can be achieved if a collimator-source distance of 50 cm and imaging time of 5 s are used (this trueness was achieved for all 14 breast phantoms which

Survey of Current Status of Quality Control of Gamma Cameras in Republic of Korea

International Nuclear Information System (INIS)

Choe, Jae Gol; Joh, Cheol Woo

2008-01-01

It is widely recognized that good quality control (QC) program is essential for adequate imaging diagnosis using gamma camera. The purpose of this study is to survey the current status of QC of gamma cameras in Republic of Korea for implementing appropriate nationwide quality control guidelines and programs. A collection of data is done for personnel, equipment and appropriateness of each nuclear medicine imaging laboratory's' quality control practice. This survey is done by collection of formatted questionnaire by mails, e mails or interviews. We also reviewed the current recommendations concerning quality assurance by international societies. This survey revealed that practice of quality control is irregular and not satisfactory. The irregularity of the QC practice seems due partly to the lack of trained personnel, equipment, budget, time and hand-on guidelines. The implementation of QC program may cause additional burden to the hospitals, patients and nuclear medicine laboratories. However, the benefit of a good QC program is obvious that the hospitals can provide good quality nuclear medicine imaging studies to the patients. It is important to use least cumbersome QC protocol, to educate the nuclear medicine and hospital administrative personnel concerning QC, and to establish national QC guidelines to help each individual nuclear medicine laboratory

Performance of the gamma-ray camera based on GSO(Ce) scintillator array and PSPMT with the ASIC readout system

International Nuclear Information System (INIS)

Ueno, Kazuki; Hattori, Kaori; Ida, Chihiro; Iwaki, Satoru; Kabuki, Shigeto; Kubo, Hidetoshi; Kurosawa, Shunsuke; Miuchi, Kentaro; Nagayoshi, Tsutomu; Nishimura, Hironobu; Orito, Reiko; Takada, Atsushi; Tanimori, Toru

2008-01-01

We have studied the performance of a readout system with ASIC chips for a gamma-ray camera based on a 64-channel multi-anode PSPMT (Hamamatsu flat-panel H8500) coupled to a GSO(Ce) scintillator array. The GSO array consists of 8x8 pixels of 6x6x13 mm 3 with the same pixel pitch as the anode of the H8500. This camera is intended to serve as an absorber of an electron tracking Compton gamma-ray camera that measures gamma rays up to ∼1 MeV. Because we need a readout system with low power consumption for a balloon-borne experiment, we adopted a 32-channel ASIC chip, IDEAS VA32 H DR11, which has one of the widest dynamic range among commercial chips. However, in the case of using a GSO(Ce) crystal and the H8500, the dynamic range of VA32 H DR11 is narrow, and therefore the H8500 has to be operated with a low gain of about 10 5 . If the H8500 is operated with a low gain, the camera has a narrow incident-energy dynamic range from 100 to 700 keV, and a bad energy resolution of 13.0% (FWHM) at 662 keV. We have therefore developed an attenuator board in order to operate the H8500 with the typical gain of 10 6 , which can measure up to ∼1 MeV gamma ray. The board makes the variation of the anode gain uniform and widens the dynamic range of the H8500. The system using the new attenuator board has a good uniformity of min:max∼1:1.6, an incident-energy dynamic range from 30 to 900 keV, a position resolution of less than 6 mm, and a typical energy resolution of 10.6% (FWHM) at 662 keV with a low power consumption of about 1.7 W/64ch

Calibration of gamma camera systems for a multicentre European {sup 123}I-FP-CIT SPECT normal database

Energy Technology Data Exchange (ETDEWEB)

Tossici-Bolt, Livia [Southampton Univ. Hospitals NHS Trust, Dept. of Medical Physics and Bioengineering, Southampton (United Kingdom); Dickson, John C. [UCLH NHS Foundation Trust and Univ. College London, Institute of Nuclear Medicine, London (United Kingdom); Sera, Terez [Univ. of Szeged, Dept. of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Nijs, Robin de [Rigshospitalet and Univ. of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Bagnara, Maria Claudia [Az. Ospedaliera Universitaria S. Martino, Medical Physics Unit, Genoa (Italy); Jonsson, Cathrine [Karolinska Univ. Hospital, Dept. of Nuclear Medicine, Medical Physics, Stockholm (Sweden); Scheepers, Egon [Univ. of Amsterdam, Dept. of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Zito, Felicia [Fondazione IRCCS Granda, Ospedale Maggiore Policlinico, Dept. of Nuclear Medicine, Milan (Italy); Seese, Anita [Univ. of Leipzig, Dept. of Nuclear Medicine, Leipzig (Germany); Koulibaly, Pierre Malick [Univ. of Nice-Sophia Antipolis, Nuclear Medicine Dept., Centre Antoine Lacassagne, Nice (France); Kapucu, Ozlem L. [Gazi Univ., Faculty of Medicine, Dept. of Nuclear Medicine, Ankara (Turkey); Koole, Michel [Univ. Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Raith, Maria [Medical Univ. of Vienna, Dept. of Nuclear Medicine, Vienna (Austria); George, Jean [Univ. Catholique Louvain, Nuclear Medicine Division, Mont-Godinne Medical Center, Mont-Godinne (Belgium); Lonsdale, Markus Nowak [Bispebjerg Univ. Hospital, Dept. of Clinical Physiology and Nuclear Medicine, Copenhagen (Denmark); Muenzing, Wolfgang [Univ. of Munich, Dept. of Nuclear Medicine, Munich (Germany); Tatsch, Klaus [Univ. of Munich, Dept. of Nuclear Medicine, Munich (Germany); Municipal Hospital of Karlsruhe Inc., Dept. of Nuclear Medicine, Karlsruhe (Germany); Varrone, Andrea [Center for Psychiatric Research, Karolinska Inst., Dept. of Clinical Neuroscience, Stockholm (Sweden)

2011-08-15

A joint initiative of the European Association of Nuclear Medicine (EANM) Neuroimaging Committee and EANM Research Ltd. aimed to generate a European database of [{sup 123}I]FP-CIT single photon emission computed tomography (SPECT) scans of healthy controls. This study describes the characterization and harmonization of the imaging equipment of the institutions involved. {sup 123}I SPECT images of a striatal phantom filled with striatal to background ratios between 10:1 and 1:1 were acquired on all the gamma cameras with absolute ratios measured from aliquots. The images were reconstructed by a core lab using ordered subset expectation maximization (OSEM) without corrections (NC), with attenuation correction only (AC) and additional scatter and septal penetration correction (ACSC) using the triple energy window method. A quantitative parameter, the simulated specific binding ratio (sSBR), was measured using the ''Southampton'' methodology that accounts for the partial volume effect and compared against the actual values obtained from the aliquots. Camera-specific recovery coefficients were derived from linear regression and the error of the measurements was evaluated using the coefficient of variation (COV). The relationship between measured and actual sSBRs was linear across all systems. Variability was observed between different manufacturers and, to a lesser extent, between cameras of the same type. The NC and AC measurements were found to underestimate systematically the actual sSBRs, while the ACSC measurements resulted in recovery coefficients close to 100% for all cameras (AC range 69-89%, ACSC range 87-116%). The COV improved from 46% (NC) to 32% (AC) and to 14% (ACSC) (p < 0.001). A satisfactory linear response was observed across all cameras. Quantitative measurements depend upon the characteristics of the SPECT systems and their calibration is a necessary prerequisite for data pooling. Together with accounting for partial volume, the

In vivo quantification of {sup 177}Lu with planar whole-body and SPECT/CT gamma camera imaging

Energy Technology Data Exchange (ETDEWEB)

Bailey, Dale L. [Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW 2065 (Australia); Faculty of Health Sciences, University of Sydney, Cumberland, NSW (Australia); Sydney Medical School, University of Sydney, Camperdown, NSW (Australia); NETwork, Sydney Vital, St Leonards, Sydney, NSW (Australia); Hennessy, Thomas M.; Willowson, Kathy P.; Henry, E. Courtney [Institute of Medical Physics, University of Sydney, Camperdown, NSW (Australia); Chan, David L.H. [Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW 2065 (Australia); NETwork, Sydney Vital, St Leonards, Sydney, NSW (Australia); Aslani, Alireza [Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW 2065 (Australia); Roach, Paul J. [Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW 2065 (Australia); Sydney Medical School, University of Sydney, Camperdown, NSW (Australia)

2015-09-17

Advances in gamma camera technology and the emergence of a number of new theranostic radiopharmaceutical pairings have re-awakened interest in in vivo quantification with single-photon-emitting radionuclides. We have implemented and validated methodology to provide quantitative imaging of {sup 177}Lu for 2D whole-body planar studies and for 3D tomographic imaging with single-photon emission computed tomography (SPECT)/CT. Whole-body planar scans were performed on subjects to whom a known amount of [{sup 177}Lu]-DOTA-octreotate had been administered for therapy. The total radioactivity estimated from the images was compared with the known amount of the radionuclide therapy administered. In separate studies, venous blood samples were withdrawn from subjects after administration of [{sup 177}Lu]-DOTA-octreotate while a SPECT acquisition was in progress and the concentration of the radionuclide in the venous blood sample compared with that estimated from large blood pool structures in the SPECT reconstruction. The total radioactivity contained within an internal SPECT calibration standard was also assessed. In the whole-body planar scans (n = 28), the estimated total body radioactivity was accurate to within +4.6 ± 5.9 % (range −17.1 to +11.2 %) of the correct value. In the SPECT reconstructions (n = 12), the radioactivity concentration in the cardiac blood pool was accurate to within −4.0 ± 7.8 % (range −16.1 to +7.5 %) of the true value and the internal standard measurements (n = 89) were within 2.0 ± 8.5 % (range −16.3 to +24.2 %) of the known amount of radioactivity contained. In our hands, state-of-the-art hybrid SPECT/CT gamma cameras were able to provide accurate estimates of in vivo radioactivity to better than, on average, ±10 % for use in biodistribution and radionuclide dosimetry calculations.

Applications of multi-pinhole gamma camera collimation to tomography and image enhancement

International Nuclear Information System (INIS)

Simpson, D.R.

1981-01-01

Recently, multi-pinhole gamma camera collimation has been introduced in the field of emission tomography. This collimation process simultaneously produces several images covering a limited angular range, which may then be recombined to obtain tomographic slices of the object imaged. This study has investigated a possible method for improving the images obtained by this technique by two multi-pinhole views taken 90 0 apart. During the course of this work, multi-pinhole collimation was also applied to in vivo imaging of the disintegration of tablets. Collimmators were designed and built both for tomography and imaging tablet disintegration, and computer programs were written to reconstruct the images by simple backprojection and by filtered backprojection. The use of multi-pinhole collimators to image the disintegration of tablets in vivo was clearly demonstrated. Phantom tests done in vitro were capable of imaging defects as small as 5 mm 2 , while images made with real tablets both in vitro and in vivo readily showed the onset and progress of the tablet disintegration. Further experiments are planned using this technique to measure gastric emptying times disintegration times of various tablet formulations. Limitations of multi-pinhole technique included problems such as limited ranges of viewing and artifacts introduced due to incomplete sampling

Computing Installation Parameters Of CCTV Cameras for Traffic Surveillance

OpenAIRE

Pratishtha Gupta; G. N. Purohit

2013-01-01

For properly installing CCTV cameras on any intersection point for traffic surveillance, some parametersneed to be determined in order to get maximum benefit. The height, angle of placement of the CCTVcamera is used to determine the view or the area that the camera will cover with proper resolution. Theresolution should not be too high to cover less traffic and should not be too low to cover large but hardlydistinguishable traffic.This paper concerns with computation of the required CCTV inst...

A panoramic coded aperture gamma camera for radioactive hotspots localization

Science.gov (United States)

Paradiso, V.; Amgarou, K.; Blanc De Lanaute, N.; Schoepff, V.; Amoyal, G.; Mahe, C.; Beltramello, O.; Liénard, E.

2017-11-01

A known disadvantage of the coded aperture imaging approach is its limited field-of-view (FOV), which often results insufficient when analysing complex dismantling scenes such as post-accidental scenarios, where multiple measurements are needed to fully characterize the scene. In order to overcome this limitation, a panoramic coded aperture γ-camera prototype has been developed. The system is based on a 1 mm thick CdTe detector directly bump-bonded to a Timepix readout chip, developed by the Medipix2 collaboration (256 × 256 pixels, 55 μm pitch, 14.08 × 14.08 mm2 sensitive area). A MURA pattern coded aperture is used, allowing for background subtraction without the use of heavy shielding. Such system is then combined with a USB color camera. The output of each measurement is a semi-spherical image covering a FOV of 360 degrees horizontally and 80 degrees vertically, rendered in spherical coordinates (θ,phi). The geometrical shapes of the radiation-emitting objects are preserved by first registering and stitching the optical images captured by the prototype, and applying, subsequently, the same transformations to their corresponding radiation images. Panoramic gamma images generated by using the technique proposed in this paper are described and discussed, along with the main experimental results obtained in laboratories campaigns.

Design study of a Compton camera for prompts-gamma imaging during ion beam therapy

International Nuclear Information System (INIS)

Richard, Marie-Helene

2012-01-01

Ion beam therapy is an innovative radiotherapy technique using mainly carbon ion and proton irradiations. Its aim is to improve the current treatment modalities. Because of the sharpness of the dose distributions, a control of the dose if possible in real time is highly desirable. A possibility is to detect the prompt gamma rays emitted subsequently to the nuclear fragmentations occurring during the treatment of the patient. In a first time two different Compton cameras (double and single scattering) have been optimised by means of Monte Carlo simulations. The response of the camera to a photon point source with a realistic energy spectrum was studied. Then, the response of the camera to the irradiation of a water phantom by a proton beam was simulated. It was first compared with measurement performed with small-size detectors. Then, using the previous measurements, we evaluated the counting rates expected in clinical conditions. In the current set-up of the camera, these counting rates are pretty high. Pile up and random coincidences will be problematic. Finally we demonstrate that the detection system is capable to detect a longitudinal shift in the Bragg peak of ± 5 mm, even with the current reconstruction algorithm. (author)

DELTA - a computer program to analyze gamma-gamma angular correlations from unaligned states

International Nuclear Information System (INIS)

Ekstroem, L.P.

1983-10-01

A computer program to analyze gamma-gamma angular correlations from radioactive decay and from thermal-neutron capture is described. The program can, in addition to correlation data, handle mixing ratio and conversion coefficient data. (author)

Development of Camera Electronics for the Advanced Gamma-ray Imaging System (AGIS)

Science.gov (United States)

Tajima, Hiroyasu

2009-05-01

AGIS, a next generation of atmospheric Cherenkov telescope arrays, aims to achieve a sensitivity level of a milliCrab for gamma-ray observations in in the energy band of 40 GeV to 100 TeV. Such improvement requires cost reduction of individual components with high reliability in order to equip the order of 100 telescopes necessary to achieve the sensitivity goal. We are exploring several design concepts to reduce the cost of camera electronics while improving their performance. We have developed test systems for some of these concepts and are testing their performance. Here we present test results of the test systems.

Development of the monitoring system of plasma behavior using a CCD camera in the GAMMA 10 tandem mirror

International Nuclear Information System (INIS)

Kawano, Hirokazu; Nakashima, Yousuke; Higashizono, Yuta

2007-01-01

In the central-cell of the GAMMA 10 tandem mirror, a medium-speed camera (CCD camera, 400 frames per second, 216 x 640 pixel) has been installed for the observation of plasma behavior. This camera system is designed for monitoring the plasma position and movement in the whole discharge duration. The captured two-dimensional (2-D) images are automatically displayed just after the plasma shot and stored sequentially shot by shot. This system has been established as a helpful tool for optimizing the plasma production and heating systems by measuring the plasma behavior in several experimental conditions. The camera system shows that the intensity of the visible light emission on the central-cell limiter accompanied by central electron cyclotron heating (C-ECH) correlate with the wall conditioning and immersion length of a movable limiter (iris limiter) in the central cell. (author)

Gamma camera system with improved means for correcting nonuniformity

International Nuclear Information System (INIS)

Lange, K.; Jeppesen, J.

1979-01-01

In a gamma camera system, means are provided for correcting nonuniformity or lack of correspondence between the positions of scintillations and their calculated and displayed by x-y coordinates. In an accumulation mode, pulse counts corresponding with scintillations in various areas of the radiation field are stored in memory locations corresponding with their locations in the radiation field. A uniform radiation source is presented to the detectors during the accumulation is interrupted at which time other locations have fewer counts in them. In the run mode, counts are stored in corresponding locations of a memory and these counts are compared continuously with those stored in the accumulation mode. Means are provided for injecting a number of counts during the run mode proportional to the difference between the counts accumulated during the accumulation mode in a given area increment and the counts that should have been obtained from a uniform source

Test of Compton camera components for prompt gamma imaging at the ELBE bremsstrahlung beam

Science.gov (United States)

Hueso-González, F.; Golnik, C.; Berthel, M.; Dreyer, A.; Enghardt, W.; Fiedler, F.; Heidel, K.; Kormoll, T.; Rohling, H.; Schöne, S.; Schwengner, R.; Wagner, A.; Pausch, G.

2014-05-01

In the context of ion beam therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density map, which is correlated with the dose distribution. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a Compton camera setup is being developed consisting of two scatter planes: two CdZnTe (CZT) cross strip detectors, and an absorber consisting of one Lu2SiO5 (LSO) block detector. The data acquisition is based on VME electronics and handled by software developed on the ROOT framework. The setup has been tested at the linear electron accelerator ELBE at HZDR, which is used in this experiment to produce bunched bremsstrahlung photons with up to 12.5 MeV energy and a repetition rate of 13 MHz. Their spectrum has similarities with the shape expected from prompt gamma rays in the clinical environment, and the flux is also bunched with the accelerator frequency. The charge sharing effect of the CZT detector is studied qualitatively for different energy ranges. The LSO detector pixel discrimination resolution is analyzed and it shows a trend to improve for high energy depositions. The time correlation between the pulsed prompt photons and the measured detector signals, to be used for background suppression, exhibits a time resolution of 3 ns FWHM for the CZT detector and of 2 ns for the LSO detector. A time walk correction and pixel-wise calibration is applied for the LSO detector, whose resolution improves up to 630 ps. In conclusion, the detector setup is suitable for time-resolved background suppression in pulsed clinical particle accelerators. Ongoing tasks are the quantitative comparison with simulations and the test of imaging algorithms. Experiments at proton

Test of Compton camera components for prompt gamma imaging at the ELBE bremsstrahlung beam

International Nuclear Information System (INIS)

Hueso-González, F; Golnik, C; Berthel, M; Dreyer, A; Enghardt, W; Kormoll, T; Rohling, H; Pausch, G; Fiedler, F; Heidel, K; Schöne, S; Schwengner, R; Wagner, A

2014-01-01

In the context of ion beam therapy, particle range verification is a major challenge for the quality assurance of the treatment. One approach is the measurement of the prompt gamma rays resulting from the tissue irradiation. A Compton camera based on several position sensitive gamma ray detectors, together with an imaging algorithm, is expected to reconstruct the prompt gamma ray emission density map, which is correlated with the dose distribution. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a Compton camera setup is being developed consisting of two scatter planes: two CdZnTe (CZT) cross strip detectors, and an absorber consisting of one Lu 2 SiO 5 (LSO) block detector. The data acquisition is based on VME electronics and handled by software developed on the ROOT framework. The setup has been tested at the linear electron accelerator ELBE at HZDR, which is used in this experiment to produce bunched bremsstrahlung photons with up to 12.5 MeV energy and a repetition rate of 13 MHz. Their spectrum has similarities with the shape expected from prompt gamma rays in the clinical environment, and the flux is also bunched with the accelerator frequency. The charge sharing effect of the CZT detector is studied qualitatively for different energy ranges. The LSO detector pixel discrimination resolution is analyzed and it shows a trend to improve for high energy depositions. The time correlation between the pulsed prompt photons and the measured detector signals, to be used for background suppression, exhibits a time resolution of 3 ns FWHM for the CZT detector and of 2 ns for the LSO detector. A time walk correction and pixel-wise calibration is applied for the LSO detector, whose resolution improves up to 630 ps. In conclusion, the detector setup is suitable for time-resolved background suppression in pulsed clinical particle accelerators. Ongoing tasks are the quantitative comparison with simulations and the test of imaging algorithms. Experiments at proton

Expanding of FOV of NaI(Tl) gamma camera detectors-Is it possible?

International Nuclear Information System (INIS)

Gayshan, Vadim L.; Gektin, A.V.; Boyarintsev, A.; Pedash, V.

2006-01-01

Every gamma camera detector used for medical imaging of conventional design faces the problem of distorted or no information readout at the areas closer to the edge of detectors. Obtaining position and energy information becomes almost impossible at distance 0-12 of PMT size from the edge. Therefore, in some designs were proposed losing of edge energy resolution while improving in spatial uniformity when it comes to imaging at the edges. This work is dedicated to understanding of the problem, mathematical simulations, practical tests and recommendations to build detectors with larger usable FOV without increasing in dimensions. To study the problem we built the test jig with linear motion source and readout electronics to simulate gamma cameras of PMTs. Based on simulation results the idea of modifying of crystal shape combined with specific light redirection system of baffles was tested and allowed to expand usable FOV. The results are presented and showed that for traditional NaI(Tl) scintillators using 2'' PMT may be possible to obtain relatively good spatial resolution starting from 4-5mm from the edge of a detector. The question of economical efficiency of proposed method is being investigated and a special detector manufacturing technology must be developed to accommodate this. While we believe that achieved results are very important for small size detectors (<20cm) they could be beneficial even for larger detectors used in whole body imaging systems

Computational imaging with multi-camera time-of-flight systems

KAUST Repository

Shrestha, Shikhar; Heide, Felix; Heidrich, Wolfgang; Wetzstein, Gordon

2016-01-01

Depth cameras are a ubiquitous technology used in a wide range of applications, including robotic and machine vision, human computer interaction, autonomous vehicles as well as augmented and virtual reality. In this paper, we explore the design

Measurement of spleen size using gamma camera scintigraphy in essential thrombocythaemia

Energy Technology Data Exchange (ETDEWEB)

Revesz, P. (Department of Medicine, Oestra Hospital, University of Goeteborg, Goeteborg (Sweden)); Carneskog, J.; Wadenvik, H.; Kutti, J. (Haematology Section, Department of Medicine, Sahlgrenska Hospital, University of Goeteborg, Goeteborg (Sweden)); Jarneborn, L. (Department of Clinical Physiology, Oestra Hospital, University of Goeteborg, Goeteborg (Sweden))

1993-09-01

By using gamma camera imaging the spleen size was determined in 33 consecutive patients with essential thrombocythaemia (ET) and in 33 consecutive patients with reactive thrombocytosis (RT). All ET patients were newly diagnosed and had not received myelosuppressive treatment prior to study; they all fulfilled the criteria for ET as established by the Polycythemia Vera Study Group. In both posterior and lateral projections, the spleen area in the group of ET patients was significantly larger than in the RT patients. The present study has shown that 39% of ET patients at diagnosis have splenic enlargement. Evaluation of Spleen size is therefore a useful diagnostic test in patients presenting with unexplained thrombocytosis. (au) (15 refs.).

Principle of some gamma cameras (efficiencies, limitations, development)

International Nuclear Information System (INIS)

Allemand, R.; Bourdel, J.; Gariod, R.; Laval, M.; Levy, G.; Thomas, G.

1975-01-01

The quality of scintigraphic images is shown to depend on the efficiency of both the input collimator and the detector. Methods are described by which the quality of these images may be improved by adaptations to either the collimator (Fresnel zone camera, Compton effect camera) or the detector (Anger camera, image amplification camera). The Anger camera and image amplification camera are at present the two main instruments whereby acceptable space and energy resolutions may be obtained. A theoretical comparative study of their efficiencies is carried out, independently of their technological differences, after which the instruments designed or under study at the LETI are presented: these include the image amplification camera, the electron amplifier tube camera using a semi-conductor target CdTe and HgI 2 detector [fr

A 3D high-resolution gamma camera for radiopharmaceutical studies with small animals

CERN Document Server

Loudos, G K; Giokaris, N D; Styliaris, E; Archimandritis, S C; Varvarigou, A D; Papanicolas, C N; Majewski, S; Weisenberger, D; Pani, R; Scopinaro, F; Uzunoglu, N K; Maintas, D; Stefanis, K

2003-01-01

The results of studies conducted with a small field of view tomographic gamma camera based on a Position Sensitive Photomultiplier Tube are reported. The system has been used for the evaluation of radiopharmaceuticals in small animals. Phantom studies have shown a spatial resolution of 2 mm in planar and 2-3 mm in tomographic imaging. Imaging studies in mice have been carried out both in 2D and 3D. Conventional radiopharmaceuticals have been used and the results have been compared with images from a clinically used system.

Measurement of prompt gamma profiles in inhomogeneous targets with a knife-edge slit camera during proton irradiation

International Nuclear Information System (INIS)

Priegnitz, M; Helmbrecht, S; Fiedler, F; Janssens, G; Smeets, J; Vander Stappen, F; Perali, I; Sterpin, E

2015-01-01

Proton and ion beam therapies become increasingly relevant in radiation therapy. To fully exploit the potential of this irradiation technique and to achieve maximum target volume conformality, the verification of particle ranges is highly desirable. Many research activities focus on the measurement of the spatial distributions of prompt gamma rays emitted during irradiation. A passively collimating knife-edge slit camera is a promising option to perform such measurements. In former publications, the feasibility of accurate detection of proton range shifts in homogeneous targets could be shown with such a camera. We present slit camera measurements of prompt gamma depth profiles in inhomogeneous targets. From real treatment plans and their underlying CTs, representative beam paths are selected and assembled as one-dimensional inhomogeneous targets built from tissue equivalent materials. These phantoms have been irradiated with monoenergetic proton pencil beams. The accuracy of range deviation estimation as well as the detectability of range shifts is investigated in different scenarios. In most cases, range deviations can be detected within less than 2 mm. In close vicinity to low-density regions, range detection is challenging. In particular, a minimum beam penetration depth of 7 mm beyond a cavity is required for reliable detection of a cavity filling with the present setup. Dedicated data post-processing methods may be capable of overcoming this limitation. (paper)

Computational cameras for moving iris recognition

Science.gov (United States)

McCloskey, Scott; Venkatesha, Sharath

2015-05-01

Iris-based biometric identification is increasingly used for facility access and other security applications. Like all methods that exploit visual information, however, iris systems are limited by the quality of captured images. Optical defocus due to a small depth of field (DOF) is one such challenge, as is the acquisition of sharply-focused iris images from subjects in motion. This manuscript describes the application of computational motion-deblurring cameras to the problem of moving iris capture, from the underlying theory to system considerations and performance data.

Nema tests in gamma-cameras. Independent implementation of manufacturer; Pruebas Nema en gammacamaras. Implementacion independiente del fabricante

Energy Technology Data Exchange (ETDEWEB)

Ramos Pacho, J. A.; Montes Fuentes, C.; Verde Velasco, J. M.; Perez Alvarez, M. E.; Delgado Aparicio, J. M.; Cons Perez, N.; Gomez Gonzalez, N.; Garcia Repiso, S.; Saez Beltran, M.; Gomez Llorente, P. L.

2013-07-01

The analysis of test results of quality control in gamma cameras, as extrinsic planar uniformity and the spatial resolution is often limited by intrinsic equipment tools and procedures. With the objective of an independent assessment of such evidence and better management and monitoring of the data obtained are made two separate programs in Matlab. (Author)

Application of imaging to gamma ray astronomy: Progress report, 1986-87

International Nuclear Information System (INIS)

1987-01-01

In March 1986, the Mark II Iowas State camera electronics utilizing CAMAC modules interfaced to an LSI-11/73 computer was installed and tested at the Whipple Observatory. A study of the noise, gains, and spectral response of the photomultiplier tubes which comprise the camera was made. Also, detections of pulsed neutron star spin periods have provided an opportunity for tests of various techniques of signal-background discrimination. Observation have concentrated on x-ray binaries. As a preliminary step to constructing a full size camera, a new 37 element mini-camera is being constructed. Short summaries are presented on new computer equipment, testing of the Cherenkov detectors under moonlight, the construction of a muon telescope, and the design and testing of a fast trigger for the gamma ray camera system

Advances in Gamma-Ray Imaging with Intensified Quantum-Imaging Detectors

Science.gov (United States)

Han, Ling

Nuclear medicine, an important branch of modern medical imaging, is an essential tool for both diagnosis and treatment of disease. As the fundamental element of nuclear medicine imaging, the gamma camera is able to detect gamma-ray photons emitted by radiotracers injected into a patient and form an image of the radiotracer distribution, reflecting biological functions of organs or tissues. Recently, an intensified CCD/CMOS-based quantum detector, called iQID, was developed in the Center for Gamma-Ray Imaging. Originally designed as a novel type of gamma camera, iQID demonstrated ultra-high spatial resolution (advancing this conceptually-proven gamma-ray imaging technology to make it ready for both preclinical and clinical applications. To start with, a Monte Carlo simulation of the key light-intensification device, i.e. the image intensifier, was developed, which revealed the dominating factor(s) that limit energy resolution performance of the iQID cameras. For preclinical imaging applications, a previously-developed iQID-based single-photon-emission computed-tomography (SPECT) system, called FastSPECT III, was fully advanced in terms of data acquisition software, system sensitivity and effective FOV by developing and adopting a new photon-counting algorithm, thicker columnar scintillation detectors, and system calibration method. Originally designed for mouse brain imaging, the system is now able to provide full-body mouse imaging with sub-350-micron spatial resolution. To further advance the iQID technology to include clinical imaging applications, a novel large-area iQID gamma camera, called LA-iQID, was developed from concept to prototype. Sub-mm system resolution in an effective FOV of 188 mm x 188 mm has been achieved. The camera architecture, system components, design and integration, data acquisition, camera calibration, and performance evaluation are presented in this work. Mounted on a castered counter-weighted clinical cart, the camera also features

Realization and study of spectral properties of the ISGRI gamma-ray camera

International Nuclear Information System (INIS)

Limousin, O.

2001-11-01

This work evaluates spectroscopic and physical properties of CdTe detectors in view of assembling a large number on a new generation spectro-imager for space gamma-ray astronomy. Study, optimization, realization and calibration of modular detection units of the ISGRI camera are described. After a description of the experimental context of the INTEGRAL program and a review of the physical processes involved in gamma-ray photon detectors, we present an analysis of the properties of CdTe detectors attempting to be so exhaustive as possible. We propose the base point of a global model, which relates charge transport properties, spectral response and possible instabilities in the detectors. We propose a new formulation of the Hecht relation that describes charge loss as a function of the detector charge transport properties. We discuss at length the method of charge loss correction and its consequences on the associated integrated electronics definition. Finally, we illustrate our instrument capabilities using as an example the observation of titanium 44 lines in historical supernovae. (author)

Centering mount for a gamma camera

International Nuclear Information System (INIS)

Mirkhodzhaev, A.Kh.; Kuznetsov, N.K.; Ostryj, Yu.E.

1988-01-01

A device for centering a γ-camera detector in case of radionuclide diagnosis is described. It permits the use of available medical coaches instead of a table with a transparent top. The device can be used for centering a detector (when it is fixed at the low end of a γ-camera) on a required area of the patient's body

The Advanced Gamma-ray Imaging System (AGIS): Camera Electronics Designs

Science.gov (United States)

Tajima, H.; Buckley, J.; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Holder, J.; Horan, D.; Krawczynski, H.; Ong, R.; Swordy, S.; Wagner, R.; Williams, D.

2008-04-01

AGIS, a next generation of atmospheric Cherenkov telescope arrays, aims to achieve a sensitivity level of a milliCrab for gamma-ray observations in the energy band of 40 GeV to 100 TeV. Such improvement requires cost reduction of individual components with high reliability in order to equip the order of 100 telescopes necessary to achieve the sensitivity goal. We are exploring several design concepts to reduce the cost of camera electronics while improving their performance. These design concepts include systems based on multi-channel waveform sampling ASIC optimized for AGIS, a system based on IIT (image intensifier tube) for large channel (order of 1 million channels) readout as well as a multiplexed FADC system based on the current VERITAS readout design. Here we present trade-off in the studies of these design concepts.

BrachyView: proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy.

Science.gov (United States)

Petasecca, M; Loo, K J; Safavi-Naeini, M; Han, Z; Metcalfe, P E; Meikle, S; Pospisil, S; Jakubek, J; Bucci, J A; Zaider, M; Lerch, M L F; Qi, Y; Rosenfeld, A B

2013-04-01

The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5-3 mm for a 10-60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for real-time imaging (using a 3 s

BrachyView: Proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy

International Nuclear Information System (INIS)

Petasecca, M.; Loo, K. J.; Safavi-Naeini, M.; Han, Z.; Metcalfe, P. E.; Lerch, M. L. F.; Qi, Y.; Rosenfeld, A. B.; Meikle, S.; Pospisil, S.; Jakubek, J.; Bucci, J. A.; Zaider, M.

2013-01-01

Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. Methods: BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. Results: The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5–3 mm for a 10–60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for

High resolution RGB color line scan camera

Science.gov (United States)

Lynch, Theodore E.; Huettig, Fred

1998-04-01

A color line scan camera family which is available with either 6000, 8000 or 10000 pixels/color channel, utilizes off-the-shelf lenses, interfaces with currently available frame grabbers, includes on-board pixel by pixel offset correction, and is configurable and controllable via RS232 serial port for computer controlled or stand alone operation is described in this paper. This line scan camera is based on an available 8000 element monochrome line scan camera designed by AOA for OEM use. The new color version includes improvements such as better packaging and additional user features which make the camera easier to use. The heart of the camera is a tri-linear CCD sensor with on-chip color balancing for maximum accuracy and pinned photodiodes for low lag response. Each color channel is digitized to 12 bits and all three channels are multiplexed together so that the resulting camera output video is either a 12 or 8 bit data stream at a rate of up to 24Megpixels/sec. Conversion from 12 to 8 bit, or user-defined gamma, is accomplished by on board user-defined video look up tables. The camera has two user-selectable operating modes; lows speed, high sensitivity mode or high speed, reduced sensitivity mode. The intended uses of the camera include industrial inspection, digital archiving, document scanning, and graphic arts applications.

Quantitative studies with the gamma-camera: correction for spatial and energy distortion

International Nuclear Information System (INIS)

Soussaline, F.; Todd-Pokropek, A.E.; Raynaud, C.

1977-01-01

The gamma camera sensitivity distribution is an important source of error in quantitative studies. In addition, spatial distortion produces apparent variations in count density which degrades quantitative studies. The flood field image takes into account both effects and is influenced by the pile-up of the tail distribution. It is essential to measure separately each of these parameters. These were investigated using a point source displaced by a special scanning table with two X, Y stepping motors of 10 micron precision. The spatial distribution of the sensitivity, spatial distortion and photopeak in the field of view were measured and compared for different setting-up of the camera and PM gains. For well-tuned cameras, the sensitivity is fairly constant, while the variations appearing in the flood field image are primarily due to spatial distortion, the former more dependent than the latter on the energy window setting. This indicates why conventional flood field uniformity correction must not be applied. A correction technique to improve the results in quantitative studies has been tested using a continuously matched energy window at every point within the field. A method for correcting spatial distortion is also proposed, where, after an adequately sampled measurement of this error, a transformation can be applied to calculate the true position of events. The knowledge of the magnitude of these parameters is essential in the routine use and design of detector systems

Computer-controlled gamma-ray scanner for irradiated reactor fuel

International Nuclear Information System (INIS)

Mandler, J.W.; Coates, R.A.; Killian, E.W.

1979-01-01

Gamma-ray scanning of irradiated fuel is an important nondestructive technique used in the thermal fuels behavior program currently under way at the Idaho National Engineering Laboratory. This paper is concerned with the computer-controlled isotopic gamma-ray-scanning system developed for postirradiation examination of fuel and includes a brief discussion of some scan results obtained from fuel rods irradiated in the Power-Burst Facility to illustrate gamma-ray spectrometry for this application. Both burnup profiles and information concerning fission-product migration in irradiated fuel are routinely obtained with the computer-controlled system

SU-C-201-07: Validation of a GATE Gamma Camera Model for the Siemens Symbia

International Nuclear Information System (INIS)

Mikell, J; Siman, W; Kappadath, S; Mourtada, F

2015-01-01

Purpose: To develop a simulation model of a clinical gamma camera/SPECT system and to validate the model using experimental and published measurements from the clinical system. Methods: Geant4 Application for Tomographic Emission (GATE) was used to create a model of the Siemens Symbia gamma camera. A modular model was implemented that allows specifying combinations of crystal thickness (3/8”, 5/8”) and collimator (LEHR, MELP, HE). Shielding, energy resolution, intrinsic resolution, crystal thickness, and collimator properties were set based on manufacturer specifications. Validation of the model was performed by simulating NEMA 2007 gamma camera tests including spatial resolution and sensitivity for Tc99; these were compared with experimental and published data for the scanner. The simulated energy spectra of a Tc99 line source in acrylic blocks was visually compared with the corresponding experimental acquisition. For a 4 cm diameter sphere filled with Tc99, the attenuation maps were generated from simulation data, and the photopeak and scatter window were extracted from GATE output using ROOT to create DICOM files to use in the clinical reconstruction. Results: Simulated spatial resolutions for LEHR 3/8” crystal at 0, 10 cm, 10 cm (with scatter), and 30 cm were 4, 6.7, 7.9, and 14.5 mm FWHM; these were 9% less than published data. For 5/8” crystal the spatial resolutions were 4.5, 7.0, 8.5, and 14.7 mm FWHM; these were 4% to 10% less than published data. Simulated sensitivity was within 3.5% of published data for both LEHR 3/8” and 5/8”. The simulated energy spectra matched the photopeak and scatter window well, but did overestimate the counts below 90 keV. The simulated attenuation map and projection data were successfully reconstructed with the clinical software, and the passed visual inspection. Conclusions: Validation of a specific clinical scanner allows future studies of quantification accuracy for both planar and SPECT imaging. Research

SU-C-201-07: Validation of a GATE Gamma Camera Model for the Siemens Symbia

Energy Technology Data Exchange (ETDEWEB)

Mikell, J; Siman, W; Kappadath, S [Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX (United States); Mourtada, F [Christiana Care Hospital, Newark, DE (United States); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston TX (United States); Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, PA (United States)

2015-06-15

Purpose: To develop a simulation model of a clinical gamma camera/SPECT system and to validate the model using experimental and published measurements from the clinical system. Methods: Geant4 Application for Tomographic Emission (GATE) was used to create a model of the Siemens Symbia gamma camera. A modular model was implemented that allows specifying combinations of crystal thickness (3/8”, 5/8”) and collimator (LEHR, MELP, HE). Shielding, energy resolution, intrinsic resolution, crystal thickness, and collimator properties were set based on manufacturer specifications. Validation of the model was performed by simulating NEMA 2007 gamma camera tests including spatial resolution and sensitivity for Tc99; these were compared with experimental and published data for the scanner. The simulated energy spectra of a Tc99 line source in acrylic blocks was visually compared with the corresponding experimental acquisition. For a 4 cm diameter sphere filled with Tc99, the attenuation maps were generated from simulation data, and the photopeak and scatter window were extracted from GATE output using ROOT to create DICOM files to use in the clinical reconstruction. Results: Simulated spatial resolutions for LEHR 3/8” crystal at 0, 10 cm, 10 cm (with scatter), and 30 cm were 4, 6.7, 7.9, and 14.5 mm FWHM; these were 9% less than published data. For 5/8” crystal the spatial resolutions were 4.5, 7.0, 8.5, and 14.7 mm FWHM; these were 4% to 10% less than published data. Simulated sensitivity was within 3.5% of published data for both LEHR 3/8” and 5/8”. The simulated energy spectra matched the photopeak and scatter window well, but did overestimate the counts below 90 keV. The simulated attenuation map and projection data were successfully reconstructed with the clinical software, and the passed visual inspection. Conclusions: Validation of a specific clinical scanner allows future studies of quantification accuracy for both planar and SPECT imaging. Research

Gamma tomography apparatus

International Nuclear Information System (INIS)

Span, F.J.

1988-01-01

The patent concerns a gamma tomography apparatus for medical diagnosis. The apparatus comprises a gamma scintillation camera head and a suspension system for supporting and positioning the camera head with respect for the patient. Both total body scanning and single photon emission tomography can be carried out with the apparatus. (U.K.)

TH-C-BRD-01: Analytical Computation of Prompt Gamma Ray Emission and Detection for Proton Range Verification

International Nuclear Information System (INIS)

Sterpin, E; Vynckier, S; Janssens, G; Smeets, J; Prieels, D

2014-01-01

Purpose: A prompt gamma (PG) slit camera prototype demonstrated that on-line range monitoring within 1–2 mm could be performed by comparing expected and measured PG detection profiles. Monte Carlo (MC) can simulate the expected PG profile but this would result in prohibitive computation time for a complete pencil beam treatment plan. We implemented a much faster method that is based on analytical processing of pre-computed MC data. Methods: The formation of the PG detection signal can be separated into: 1) production of PGs and 2) detection by the camera detectors after PG transport in geometry. For proton energies from 40 to 230 MeV, PG productions in depth were pre-computed by MC (PENH) for 12C, 14N, 16O, 31P and 40Ca. The PG production was then modeled analytically by adding the PG production for each element according to local proton energy and tissue composition.PG transport in the patient/camera geometries and the detector response were modeled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to pre-computed MC data (PENELOPE). The database was generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to PENH for a water phantom, a phantom with different slabs (adipose, muscle, lung) and a thoracic CT. Results: Good agreement (within 5%) was observed between the analytical model and PENH for the PG production. Similar accuracy for detecting range shifts was also observed. Speed of around 250 ms per profile was achieved (single CPU) using a non-optimized MatLab implementation. Conclusion: We devised a fast analytical model for generating PG detection profiles. In the test cases considered in this study, similar accuracy than MC was achieved for detecting range shifts. This research is supported by IBA

Computational imaging with multi-camera time-of-flight systems

KAUST Repository

Shrestha, Shikhar

2016-07-11

Depth cameras are a ubiquitous technology used in a wide range of applications, including robotic and machine vision, human computer interaction, autonomous vehicles as well as augmented and virtual reality. In this paper, we explore the design and applications of phased multi-camera time-of-flight (ToF) systems. We develop a reproducible hardware system that allows for the exposure times and waveforms of up to three cameras to be synchronized. Using this system, we analyze waveform interference between multiple light sources in ToF applications and propose simple solutions to this problem. Building on the concept of orthogonal frequency design, we demonstrate state-of-the-art results for instantaneous radial velocity capture via Doppler time-of-flight imaging and we explore new directions for optically probing global illumination, for example by de-scattering dynamic scenes and by non-line-of-sight motion detection via frequency gating. © 2016 ACM.

Use of dual-head gamma camera in radionuclide internal contamination monitoring on radiation workers from a nuclear medicine department

International Nuclear Information System (INIS)

Rodriguez-Laguna, A.; Brandan, M.E.

2008-01-01

As a part of an internal dosimetry program that is performed at the Mexican National Institute of Cancerology - Nuclear Medicine Department, in the present work we suggest a procedure for the routinely monitoring of internal contamination on radiation workers and nuclear medicine staff. The procedure is based on the identification and quantification of contaminating radionuclides in human body by using a dual-head whole-body gamma camera. The results have shown that the procedures described in this study can be used to implement a method to quantify minimal accumulated activity in the main human organs to evaluate internal contamination with radionuclides. The high sensitivity of the uncollimated gamma camera is advantageous for the routinely detection and identification of small activities of internal contamination. But, the null spatial resolution makes impossible the definition of contaminated region of interest. Then, the use of collimators is necessary to the quantification of incorporated radionuclides activities in the main human organs and for the internal doses assessment. (author)

[Evaluation of the efficacy of sentinel node detection in breast cancer: chronological course and influence of the incorporation of an intra-operative portable gamma camera].

Science.gov (United States)

Goñi Gironés, E; Vicente García, F; Serra Arbeloa, P; Estébanez Estébanez, C; Calvo Benito, A; Rodrigo Rincón, I; Camarero Salazar, A; Martínez Lozano, M E

2013-01-01

To define the sentinel node identification rate in breast cancer, the chronological evolution of this parameter and the influence of the introduction of a portable gamma camera. A retrospective study was conducted using a prospective database of 754 patients who had undergone a sentinel lymph node biopsy between January 2003 and December 2011. The technique was mixed in the starting period and subsequently was performed with radiotracer intra-peritumorally administered the day before of the surgery. Until October 2009, excision of the sentinel node was guided by a probe. After that date, a portable gamma camera was introduced for intrasurgical detection. The SN was biopsied in 725 out of the 754 patients studied. The resulting technique global effectiveness was 96.2%. In accordance with the year of the surgical intervention, the identification percentage was 93.5% in 2003, 88.7% in 2004, 94.3% in 2005, 95.7% in 2006, 93.3% in 2007, 98.8% in 2008, 97.1% in 2009 and 99.1% in 2010 and 2011. There was a significant difference in the proportion of identification before and after the incorporation of the portable gamma camera of 4.6% (95% CI of the difference 2-7.2%, P = 0.0037). The percentage of global identification exceeds the recommended level following the current guidelines. Chronologically, the improvement for this parameter during the study period has been observed. These data suggest that the incorporation of a portable gamma camera had an important role. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

Measurement of total-body cobalt-57 vitamin B12 absorption with a gamma camera

International Nuclear Information System (INIS)

Cardarelli, J.A.; Slingerland, D.W.; Burrows, B.A.; Miller, A.

1985-01-01

Previously described techniques for the measurement of the absorption of [ 57 Co]vitamin B 12 by total-body counting have required an iron room equipped with scanning or multiple detectors. The present study uses simplifying modifications which make the technique more available and include the use of static geometry, the measurement of body thickness to correct for attenuation, a simple formula to convert the capsule-in-air count to a 100% absorption count, and finally the use of an adequately shielded gamma camera obviating the need of an iron room

Study of the feasibility of a compact gamma camera for real-time cancer assessment

CERN Document Server

Caballero Ontanaya, Luis

2017-01-01

Results from the simulations of a Compton gamma camera based on compact configuration of detectors consisting in two detection modules, each of them having two stages of high-resolution position- and energy sensitive radiation detectors operated in time-coincidence are presented. Monolithic scintillation crystals instead of pixelated crystals in order to reduce dead areas have been simulated. In order to study the system feasibility to produce real-time images, different setups are considered. Performance in terms of acquisition times have been calculated to determine the real-time capabilities and limitations of such a system.

Development of a Compton camera for prompt-gamma medical imaging

Science.gov (United States)

Aldawood, S.; Thirolf, P. G.; Miani, A.; Böhmer, M.; Dedes, G.; Gernhäuser, R.; Lang, C.; Liprandi, S.; Maier, L.; Marinšek, T.; Mayerhofer, M.; Schaart, D. R.; Lozano, I. Valencia; Parodi, K.

2017-11-01

A Compton camera-based detector system for photon detection from nuclear reactions induced by proton (or heavier ion) beams is under development at LMU Munich, targeting the online range verification of the particle beam in hadron therapy via prompt-gamma imaging. The detector is designed to be capable to reconstruct the photon source origin not only from the Compton scattering kinematics of the primary photon, but also to allow for tracking of the secondary Compton-scattered electrons, thus enabling a γ-source reconstruction also from incompletely absorbed photon events. The Compton camera consists of a monolithic LaBr3:Ce scintillation crystal, read out by a multi-anode PMT acting as absorber, preceded by a stacked array of 6 double-sided silicon strip detectors as scatterers. The detector components have been characterized both under offline and online conditions. The LaBr3:Ce crystal exhibits an excellent time and energy resolution. Using intense collimated 137Cs and 60Co sources, the monolithic scintillator was scanned on a fine 2D grid to generate a reference library of light amplitude distributions that allows for reconstructing the photon interaction position using a k-Nearest Neighbour (k-NN) algorithm. Systematic studies were performed to investigate the performance of the reconstruction algorithm, revealing an improvement of the spatial resolution with increasing photon energy to an optimum value of 3.7(1)mm at 1.33 MeV, achieved with the Categorical Average Pattern (CAP) modification of the k-NN algorithm.

TPASS: a gamma-ray spectrum analysis and isotope identification computer code

International Nuclear Information System (INIS)

Dickens, J.K.

1981-03-01

The gamma-ray spectral data-reduction and analysis computer code TPASS is described. This computer code is used to analyze complex Ge(Li) gamma-ray spectra to obtain peak areas corrected for detector efficiencies, from which are determined gamma-ray yields. These yields are compared with an isotope gamma-ray data file to determine the contributions to the observed spectrum from decay of specific radionuclides. A complete FORTRAN listing of the code and a complex test case are given

Angiocardiography with 99mTc-albumin bymass of gamma camera associated with examinations in the morphological and dynamic study of the congenital heart disease

Energy Technology Data Exchange (ETDEWEB)

Esposti, A D; Abbati, A

1975-03-03

A. Degli Esposti and A. Abbati: Computerised gamma-camera 99/sup m/ Tc-albumin angiocardiography in the morphological and dynamic examination of children with congenital heart disease. A number of cases in which computerised gamma-camera 99/sup m/ Tc-albumin angiocardiography was employed in children with congenital heart diseases are described. Comparison is made with the data obtained contrastographically, or during surgery or necropsy. The preliminary results, particularly in recently examined subjects, whose data were processed in a more efficient manner, point to the usefulness of the method. Though incapable of offering the same morphological precision as contrastography, it has the advantage of being absolute harmless and, above all, repeatable.

Methodology for Gamma cameras calibration for I-131 uptake quantification in Hyperthyroidism diseases

International Nuclear Information System (INIS)

Lopez Diaz, A.; Palau San Pedro, A.; Martin Escuela, J. M.; Reynosa Montejo, R.; Castillo, J.; Torres Aroche, L.

2015-01-01

Optimization and verification of Patient-Specific Treatment Planning with unsealed I-131 sources is a desirable goal from medical and radiation protection point of view. To obtain a practical protocol to combine the estimation of the related parameters with patient's specific treatment dose in hyperthyroidism disease, 3 equipment were studied (Iodine Probe, a Philips Forte Camera with pin-hole collimators and a Mediso Nucline with HEGP for planar and SPECT techniques) and crossed calibrated. The linear behaviour on diagnostic and therapeutic activity range was verified, showing a linear correlation fitting factor R 2 > 0.99. The differences between thyroid uptake determinations in all equipment were less than 6% for therapeutic activities and less than 1.1% in the diagnostic range. The combined protocol to calculate, with only one administration of I 131 , all the necessary parameters to the treatment dose estimation in 2D or 3D, avoiding wasting time with gamma cameras, was established and verified. Following this protocol the difference between apparent and calculated activities were less than 3%. (Author)

Assessment of gamma camera performance at some Sudanese hospitals

International Nuclear Information System (INIS)

Ibrahim, Nour El huda Ibrahim Ali

2016-05-01

The study aims to investigate the performance quality of the gamma cameras used in three public hospitals in Sudan. It is widely recognized that the attainment of high standards of efficiency and reliability in the practice of nuclear medicine, as in other specialties based on advanced technology, requires an appropriate quality assurance program. In this study we have focused on four of the main tests in order to assess the performance of the three units in question, such as uniformity, resolution/ linearity, center of rotation, photopeak. The values were within the acceptable range (according to the adopted protocols). Overall performance of the units was acceptable. Although all the results were within the acceptable range, some of them were at border, thus an action of preventive maintenance should be considered. It is noticed that a minor to negligible co-operation exists between the centers experts and /or equipment. The establishment of an external and internal auditing program is recommended. More co-operation between the centers should be considered.(Author)

Emission computed tomography using rotating gamma cameras for stress 201Tl myocardial imaging

International Nuclear Information System (INIS)

Takeda, Kan; Maeda, Hisato; Nakagawa, Tsuyoshi; Yamaguchi, Nobuo; Taguchi, Mitsuo

1983-01-01

The purpose of this study is to evaluate the efficacy of emission computed tomography (ECT) for stress 201 Tl myocardial imaging to localize coronary artery disease (CAD) in comparison with planar (PL) images. In a series of 14 normal subjects and 53 patients with CAD proved coronary arteriography, ECT and PL imaging were performed successively. ECT data were collected for 90 projections in a 64 x 64 matrix form with a total aquisition time of 6 munutes over 180 0 of opposed dual cameras ratation and tomographic sections oriented perpendicular and parallel to the long axis of left ventricle were reconstructed. PL images were obtained for left lateral, left anterior oblique (30 0 and 45 0 ) and anterior projections. Both ECT and PL myocardial images were divided into 8 segments and segmental analysis was performed by visual interpretation. The ECT images remarkably increased sensitivity over the PL images in left anterior descending (LAD) artery (from 56% to 76%), right coronary artery (RCA) (from 50% to 96%), and circumflex artery (CX) (from 56% to 69%) lesions. The specificity for ECT images, as compared with PL images, was higher in LAD (88% against 85%) but slightly lower in RCA (70% ag ainst 72%) and CX (84% against 88%). Overall accuracy, therefore, was improved in LAD (from 67% to 81%) and RCA (from 64% to 79%) but equal in CX (81%). We conclude that stress 201 Tl ECT imaging result in a remarkable improvement in the localization of CAD, especially in patients with RCA lesions and multi-vessel disease. (author)

A camera specification for tendering purposes

International Nuclear Information System (INIS)

Lunt, M.J.; Davies, M.D.; Kenyon, N.G.

1985-01-01

A standardized document is described which is suitable for sending to companies which are being invited to tender for the supply of a gamma camera. The document refers to various features of the camera, the performance specification of the camera, maintenance details, price quotations for various options and delivery, installation and warranty details. (U.K.)

Localization of sentinel nodes in breast cancer: novel method and device to help pen marking of active nodes during gamma camera imaging

International Nuclear Information System (INIS)

Laasanen, Mikko S; Heikkinen, Jari O; Saarakkala, Simo; Paajanen, Hannu

2005-01-01

Gamma camera imaging with Tc-99m marking is a widely used method to locate sentinel lymph nodes (SNs) in breast cancer patients. Prior to SN biopsy, the anterior and lateral location of the SN is marked on the patient's skin using an ink pen. The pen marks guide the surgeon during an operation. However, in many cases the marking is difficult due to limited space under the detectors of a gamma camera. The aim of this study was to improve the pen marking method. Eleven female patients were imaged 3-4 h after injection of Tc-99m labelled Nanocol(copyright) . Injection was performed to parenchyma surrounding the breast tumour. To facilitate pen marking, two polycarbonate (PC) plates with 40 x 32 holes (spacing = 10 mm) were engineered for anterior and lateral side imaging and then installed on the bed of a dual-head gamma camera. Two drops of Tc-99m were placed into the top corners of both the PC plates, in order to trace the corresponding x-y coordinates first from the acquired images and then from the plates. After imaging, the x-y coordinates of the SN(s) were determined from the anterior and lateral side images. Subsequently, the location of each SN was marked with an ink pen on the skin through the small holes in the PC plates. According to the surgeon's evaluation, the distance between the marks and the true location of the SNs was 4.5 ± 6.9 mm. Measurements with a custom made phantom revealed that the accuracy of the novel method was significantly (P 0.06) higher as compared with the traditional method (2.7 ± 3.0 mm versus 9.2 ± 3.0 mm). In addition, we were not able to mark the weakest activity (0.02 MBq) with the traditional method. Taken together, the marking process was considerably easier with the novel method, it had better accuracy and sensitivity than the traditional method and the device is simple enough to be adapted for most gamma cameras. (note)

A study of effects of scattered reaction on physical parameters of a new gamma camera used in nuclear medicine

International Nuclear Information System (INIS)

Maury, Martine.

1979-01-01

This work is devoted to the analysis of the performance of a new gamma camera. This camera is characterized by the introduction of an image amplifier between the crystal detector and the localization system which compound four photomultipliers. The appreciation of performances of this new instrument is based on the measure of the physical parameters usually studied in this purpose: energy resolution, spatial resolution, modulation transfert fonction and contrast, sensitivity and deadtime. Furthermore, we have studied the influence of scattered radiation on the value of these parameters. Two studies complete this work: the artificial deterioration of the energy resolution of the camera inserting a noise, to estimate the importance of the energy resolution on the image contrast; the scanning of pulse amplitude spectra obtained from brain of patients in order to evaluate the participation of scattered radiation in the peak's constitution. We present, at last, a quality control programm for scintillation camera [fr

New readout and data-acquisition system in an electron-tracking Compton camera for MeV gamma-ray astronomy (SMILE-II)

Energy Technology Data Exchange (ETDEWEB)

Mizumoto, T., E-mail: mizumoto@cr.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Matsuoka, Y. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Mizumura, Y. [Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Tanimori, T. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Unit of Synergetic Studies for Space, Kyoto University, 606-8502 Kyoto (Japan); Kubo, H.; Takada, A.; Iwaki, S.; Sawano, T.; Nakamura, K.; Komura, S.; Nakamura, S.; Kishimoto, T.; Oda, M.; Miyamoto, S.; Takemura, T.; Parker, J.D.; Tomono, D.; Sonoda, S. [Department of Physics, Kyoto University, 606-8502 Kyoto (Japan); Miuchi, K. [Department of Physics, Kobe University, 658-8501 Kobe (Japan); Kurosawa, S. [Institute for Materials Research, Tohoku University, 980-8577 Sendai (Japan)

2015-11-11

For MeV gamma-ray astronomy, we have developed an electron-tracking Compton camera (ETCC) as a MeV gamma-ray telescope capable of rejecting the radiation background and attaining the high sensitivity of near 1 mCrab in space. Our ETCC comprises a gaseous time-projection chamber (TPC) with a micro pattern gas detector for tracking recoil electrons and a position-sensitive scintillation camera for detecting scattered gamma rays. After the success of a first balloon experiment in 2006 with a small ETCC (using a 10×10×15 cm{sup 3} TPC) for measuring diffuse cosmic and atmospheric sub-MeV gamma rays (Sub-MeV gamma-ray Imaging Loaded-on-balloon Experiment I; SMILE-I), a (30 cm){sup 3} medium-sized ETCC was developed to measure MeV gamma-ray spectra from celestial sources, such as the Crab Nebula, with single-day balloon flights (SMILE-II). To achieve this goal, a 100-times-larger detection area compared with that of SMILE-I is required without changing the weight or power consumption of the detector system. In addition, the event rate is also expected to dramatically increase during observation. Here, we describe both the concept and the performance of the new data-acquisition system with this (30 cm){sup 3} ETCC to manage 100 times more data while satisfying the severe restrictions regarding the weight and power consumption imposed by a balloon-borne observation. In particular, to improve the detection efficiency of the fine tracks in the TPC from ~10% to ~100%, we introduce a new data-handling algorithm in the TPC. Therefore, for efficient management of such large amounts of data, we developed a data-acquisition system with parallel data flow.

The HURRA filter: An easy method to eliminate collimator artifacts in high-energy gamma camera images.

Science.gov (United States)

Perez-Garcia, H; Barquero, R

The correct determination and delineation of tumor/organ size is crucial in 2-D imaging in 131 I therapy. These images are usually obtained using a system composed of a Gamma camera and high-energy collimator, although the system can produce artifacts in the image. This article analyses these artifacts and describes a correction filter that can eliminate those collimator artifacts. Using free software, ImageJ, a central profile in the image is obtained and analyzed. Two components can be seen in the fluctuation of the profile: one associated with the stochastic nature of the radiation, plus electronic noise and the other periodically across the position in space due to the collimator. These frequencies are analytically obtained and compared with the frequencies in the Fourier transform of the profile. A specially developed filter removes the artifacts in the 2D Fourier transform of the DICOM image. This filter is tested using a 15-cm-diameter Petri dish with 131 I radioactive water (big object size) image, a 131 I clinical pill (small object size) image, and an image of the remainder of the lesion of two patients treated with 3.7GBq (100mCi), and 4.44GBq (120mCi) of 131 I, respectively, after thyroidectomy. The artifact is due to the hexagonal periodic structure of the collimator. The use of the filter on large-sized images reduces the fluctuation by 5.8-3.5%. In small-sized images, the FWHM can be determined in the filtered image, while this is impossible in the unfiltered image. The definition of tumor boundary and the visualization of the activity distribution inside patient lesions improve drastically when the filter is applied to the corresponding images obtained with HE gamma camera. The HURRA filter removes the artifact of high-energy collimator artifacts in planar images obtained with a Gamma camera without reducing the image resolution. It can be applied in any study of patient quantification because the number of counts remains invariant. The filter makes

Risk analysis for working with an analyzer for gamma cameras diagnostic

International Nuclear Information System (INIS)

Oramas Polo, Ivon; Figueroa del Valle, Diana G.

2014-01-01

In this work, an analysis of the risks for working with an analyzer for gamma cameras diagnostic was made. The method employed is based on determining the Hazard Rating Number (HRN). The results showed that the risks with higher value of HRN are electrocution with 100 and touch source container with hands with 75. These risks were classified as 'Very High' and 'High' respectively. The following risks were classified as 'Important': Fall of the source container (HRN = 25), high dose of the sample in the container (HRN = 20) and fracture of glass detector (HRN = 30). The wrong shielding of the source container (HRN = 10) is a risk that was classified as L ow . Safety rules for use of the system are indicated. An action plan for risk management is also presented. (author)

Adaptation Computing Parameters of Pan-Tilt-Zoom Cameras for Traffic Monitoring

Directory of Open Access Journals (Sweden)

Ya Lin WU

2014-01-01

Full Text Available The Closed- CIRCUIT television (CCTV cameras have been widely used in recent years for traffic monitoring and surveillance applications. We can use CCTV cameras to extract automatically real-time traffic parameters according to the image processing and tracking technologies. Especially, the pan-tilt-zoom (PTZ cameras can provide flexible view selection as well as a wider observation range, and this makes the traffic parameters can be accurately calculated. Therefore, that the parameters of PTZ cameras are calibrated plays an important role in vision-based traffic applications. However, in the specific traffic environment, which is that the license plate number of the illegal parking is located, the parameters of PTZ cameras have to be updated according to the position and distance of illegal parking. In proposed traffic monitoring systems, we use the ordinary webcam and PTZ camera. We get vanishing-point of traffic lane lines in the pixel-based coordinate system by fixed webcam. The parameters of PTZ camera can be initialized by distance of the traffic monitoring and specific objectives and vanishing-point. And then we can use the coordinate position of the illegally parked car to update the parameters of PTZ camera and then get the real word coordinate position of the illegally parked car and use it to compute the distance. The result shows the error of the tested distance and real distance is only 0.2064 meter.

Survey of potential use of dynamic line phantom for quality control of Gamma camera

International Nuclear Information System (INIS)

Trindev, P.; Ozturk, N.

2004-01-01

Different phantoms, used to evaluate the essential for image quality parameters of gamma cameras in order to avoid artefacts, are presented. The prices are significant and it is a sensible approach to optimise the type and number of phantoms necessary for quality control. Among all phantoms the price of 'Dynamic Line Phantom' (DLP) is impressive, but it is announced to substitute several 'passive' and 'active' phantoms. The goal of this paper is to justify this statement. The programs, based on image profile are discussed in the paper and the practical uses of the different programs are given

F-18 FDG PET with coincidence detection, dual-head gamma camera, initial experience in oncology

Energy Technology Data Exchange (ETDEWEB)

Chu, J.M.G.; Pocock, N.; Quach, T.; Camden, B.M.C. [Liverpool Health Services, Liverpool, NSW (Australia). Department of Nuclear Medicine and Clinical Ultrasound

1998-06-01

Full text: The development of Co-incidence Detection (CD) in gamma camera technology has allowed the use of positron radiopharmaceuticals in clinical practice without dedicated PET facilities. We report our initial experience of this technology in Oncological applications. All patients were administered 200 MBq of F- 18 FDG intravenously in a fasting state, with serum glucose below 8.9 mmol/L., and hydration well maintained. Tomography was performed using an ADAC Solus Molecular Co-incidence Detection (MCD) dual-head gamma camera, 60 minutes after administration and immediately after voiding. Tomography of the torso required up to three collections depending on the length of the patient, with each collection requiring 32 steps of 40 second duration, and a 50% overlap. Tomography of the brain required a single collection with 32 steps of 80 seconds. Patients were scanned in the supine position. An iterative reconstruction algorithm was employed without attenuation correction. All patients had histologically confirmed malignancy. Scan findings were correlated with results of all conventional diagnostic imaging procedures that were pertinent to the evaluation and management of each individual patient`s disease. Correlation with tumour type and treatment status was also undertaken. F-18 FDG uptake as demonstrated by CD-PET was increased in tumour bearing sites. The degree of increased uptake varied with tumour type and with treatment status. Our initial experience with CD-PET has been very encouraging, and has led us to undertake prospective short and long term studies to define its role in oncology

A Portable, Inexpensive, Nonmydriatic Fundus Camera Based on the Raspberry Pi® Computer

Directory of Open Access Journals (Sweden)

Bailey Y. Shen

2017-01-01

Full Text Available Purpose. Nonmydriatic fundus cameras allow retinal photography without pharmacologic dilation of the pupil. However, currently available nonmydriatic fundus cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a nonmydriatic fundus camera that was affordable and could be carried in a white coat pocket. Methods. We built a point-and-shoot prototype camera using a Raspberry Pi computer, an infrared-sensitive camera board, a dual infrared and white light light-emitting diode, a battery, a 5-inch touchscreen liquid crystal display, and a disposable 20-diopter condensing lens. Our prototype camera was based on indirect ophthalmoscopy with both infrared and white lights. Results. The prototype camera measured 133mm×91mm×45mm and weighed 386 grams. The total cost of the components, including the disposable lens, was $185.20. The camera was able to obtain good-quality fundus images without pharmacologic dilation of the pupils. Conclusion. A fully functional, inexpensive, handheld, nonmydriatic fundus camera can be easily assembled from a relatively small number of components. With modest improvements, such a camera could be useful for a variety of healthcare professionals, particularly those who work in settings where a traditional table-mounted nonmydriatic fundus camera would be inconvenient.

Comparison of the barium test meal and the gamma camera scanning technic in measuring gastric emptying

Energy Technology Data Exchange (ETDEWEB)

Perkel, M.S.; Fajman, W.A.; Hersh, T.

1981-09-01

In 21 patients with nonresected stomachs and symptoms of delayed gastric emptying, obstruction was excluded by upper gastrointestinal series and upper endoscopy; all had abnormal results of barium test meal (BTM) study. Each had repeat BTM after the administration of 10 mg of metoclopramide. Each patient also had two gamma camera studies after a technetium Tc 99m sulfur colloid labeled meal; normal saline or metoclopramide was administered before each test in a blinded and random manner. Half-time (T 1/2) and percentage of isotope remaining at six hours (GC6) were recorded. Ten asymptomatic controls had a gamma camera scanning study, and seven of these had a BTM. Nine of 19 patients had a T 1/2 in the normal range, and in 12 of 19 patients the GC6 was in the normal range. The magnitude of retention of barium at six hours on the BTM did not correlate with the T 1/2 (r = 0.076) or the GC6 (r = 0.296). Thus, these tests were not comparable in this study. By regression analysis, a significant reduction was shown in the amount of retained food and barium (P < .01), the T 1/2 (P < .01), and the GC6 (P < .01) after intramuscular administration of metoclopramide, indicating that both tests were able to evaluate the effects of this drug.

Comparison of the barium test meal and the gamma camera scanning technic in measuring gastric emptying

Energy Technology Data Exchange (ETDEWEB)

Perkel, M.S.; Fajman, W.A.; Hersh, T.; Moore, C.; Davidson, E.D.; Haun, C.

1981-09-01

In 21 patients with nonresected stomachs and symptoms of delayed gastric emptying, obstruction was excluded by upper gastrointestinal series and upper endoscopy; all had abnormal results of barium test meal (BTM) study. Each had repeat BTM after the administration of 10 mg of metoclopramide. Each patient also had two gamma camera studies after a technetium Tc 99m sulfur colloid labeled meal; normal saline or metoclopramide was administered before each test in a blinded and random manner. Half-time (T1/2) and percentage of isotope remaining at six hours (GC6) were recorded. Ten asymptomatic controls had a gamma camera scanning study, and seven of these had a BTM. Nine of 19 patients had a T1/2 in the normal range, and in 12 of 19 patients the GC6 was in the normal range. The magnitude of retention of barium at six hours on the BTM did not correlate with the T1/2 (r . 0.076) or the GC6 (r. 0.296). Thus, these tests were not comparable in this study. By regression analysis, a significant reduction was shown in the amount of retained food and barium (P less than .01), the T1/2 (P less than .01), and the GC6 (P less than .01) after intramuscular administration of metoclopramide, indicating that both tests were able to evaluate the effects of this drug.

Children's (Pediatric) Nuclear Medicine

Medline Plus

Full Text Available ... computer aids in creating the images from the data obtained by the gamma camera. A probe is ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

Thyroid Scan and Uptake

Medline Plus

Full Text Available ... computer aids in creating the images from the data obtained by the gamma camera. A probe is ... at these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2018 ...

Testing and Performance Validation of a Sensitive Gamma Ray Camera Designed for Radiation Detection and Decommissioning Measurements in Nuclear Facilities-13044

International Nuclear Information System (INIS)

Mason, John A.; Looman, Marc R.; Poundall, Adam J.; Towner, Antony C.N.; Creed, Richard; Pancake, Daniel

2013-01-01

This paper describes the measurements, testing and performance validation of a sensitive gamma ray camera designed for radiation detection and quantification in the environment and decommissioning and hold-up measurements in nuclear facilities. The instrument, which is known as RadSearch, combines a sensitive and highly collimated LaBr 3 scintillation detector with an optical (video) camera with controllable zoom and focus and a laser range finder in one detector head. The LaBr 3 detector has a typical energy resolution of between 2.5% and 3% at the 662 keV energy of Cs-137 compared to that of NaI detectors with a resolution of typically 7% to 8% at the same energy. At this energy the tungsten shielding of the detector provides a shielding ratio of greater than 900:1 in the forward direction and 100:1 on the sides and from the rear. The detector head is mounted on a pan/tile mechanism with a range of motion of ±180 degrees (pan) and ±90 degrees (tilt) equivalent to 4 π steradians. The detector head with pan/tilt is normally mounted on a tripod or wheeled cart. It can also be mounted on vehicles or a mobile robot for access to high dose-rate areas and areas with high levels of contamination. Ethernet connects RadSearch to a ruggedized notebook computer from which it is operated and controlled. Power can be supplied either as 24-volts DC from a battery or as 50 volts DC supplied by a small mains (110 or 230 VAC) power supply unit that is co-located with the controlling notebook computer. In this latter case both power and Ethernet are supplied through a single cable that can be up to 80 metres in length. If a local battery supplies power, the unit can be controlled through wireless Ethernet. Both manual operation and automatic scanning of surfaces and objects is available through the software interface on the notebook computer. For each scan element making up a part of an overall scanned area, the unit measures a gamma ray spectrum. Multiple radionuclides may be

Testing and Performance Validation of a Sensitive Gamma Ray Camera Designed for Radiation Detection and Decommissioning Measurements in Nuclear Facilities-13044

Energy Technology Data Exchange (ETDEWEB)

Mason, John A.; Looman, Marc R.; Poundall, Adam J.; Towner, Antony C.N. [ANTECH, A. N. Technology Ltd., Unit 6, Thames Park, Wallingford, Oxfordshire, OX10 9TA (United Kingdom); Creed, Richard; Pancake, Daniel [Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States)

2013-07-01

This paper describes the measurements, testing and performance validation of a sensitive gamma ray camera designed for radiation detection and quantification in the environment and decommissioning and hold-up measurements in nuclear facilities. The instrument, which is known as RadSearch, combines a sensitive and highly collimated LaBr{sub 3} scintillation detector with an optical (video) camera with controllable zoom and focus and a laser range finder in one detector head. The LaBr{sub 3} detector has a typical energy resolution of between 2.5% and 3% at the 662 keV energy of Cs-137 compared to that of NaI detectors with a resolution of typically 7% to 8% at the same energy. At this energy the tungsten shielding of the detector provides a shielding ratio of greater than 900:1 in the forward direction and 100:1 on the sides and from the rear. The detector head is mounted on a pan/tile mechanism with a range of motion of ±180 degrees (pan) and ±90 degrees (tilt) equivalent to 4 π steradians. The detector head with pan/tilt is normally mounted on a tripod or wheeled cart. It can also be mounted on vehicles or a mobile robot for access to high dose-rate areas and areas with high levels of contamination. Ethernet connects RadSearch to a ruggedized notebook computer from which it is operated and controlled. Power can be supplied either as 24-volts DC from a battery or as 50 volts DC supplied by a small mains (110 or 230 VAC) power supply unit that is co-located with the controlling notebook computer. In this latter case both power and Ethernet are supplied through a single cable that can be up to 80 metres in length. If a local battery supplies power, the unit can be controlled through wireless Ethernet. Both manual operation and automatic scanning of surfaces and objects is available through the software interface on the notebook computer. For each scan element making up a part of an overall scanned area, the unit measures a gamma ray spectrum. Multiple

A new computationally-efficient computer program for simulating spectral gamma-ray logs

International Nuclear Information System (INIS)

Conaway, J.G.

1995-01-01

Several techniques to improve the accuracy of radionuclide concentration estimates as a function of depth from gamma-ray logs have appeared in the literature. Much of that work was driven by interest in uranium as an economic mineral. More recently, the problem of mapping and monitoring artificial gamma-emitting contaminants in the ground has rekindled interest in improving the accuracy of radioelement concentration estimates from gamma-ray logs. We are looking at new approaches to accomplishing such improvements. The first step in this effort has been to develop a new computational model of a spectral gamma-ray logging sonde in a borehole environment. The model supports attenuation in any combination of materials arranged in 2-D cylindrical geometry, including any combination of attenuating materials in the borehole, formation, and logging sonde. The model can also handle any distribution of sources in the formation. The model considers unscattered radiation only, as represented by the background-corrected area under a given spectral photopeak as a function of depth. Benchmark calculations using the standard Monte Carlo model MCNP show excellent agreement with total gamma flux estimates with a computation time of about 0.01% of the time required for the MCNP calculations. This model lacks the flexibility of MCNP, although for this application a great deal can be accomplished without that flexibility

Risks assessment associated with the use of an analyzer for gamma cameras diagnostic

International Nuclear Information System (INIS)

Oramas Polo, I.; Figueroa del Valle, D. G.

2013-01-01

Technological development experienced by the industrialized countries has been accompanied by a significant improvement in living standards. Likewise, the proliferation of facilities and transportation of certain materials have involved the emergence of new risks, which could cause accidents with a strong impact on people and the environment. The paper makes a risk assessment associated with the use of an analyzer for Gamma Cameras diagnostic. The method is bases on determining the number of risks HRN (Hazard Rating Number). As a result of the methodology used was obtained the risks that have more implications in the use of this system and sets safety rules for their use and an action plan for managing them. (Author)

Real-time vehicle matching for multi-camera tunnel surveillance

Science.gov (United States)

Jelača, Vedran; Niño Castañeda, Jorge Oswaldo; Frías-Velázquez, Andrés; Pižurica, Aleksandra; Philips, Wilfried

2011-03-01

Tracking multiple vehicles with multiple cameras is a challenging problem of great importance in tunnel surveillance. One of the main challenges is accurate vehicle matching across the cameras with non-overlapping fields of view. Since systems dedicated to this task can contain hundreds of cameras which observe dozens of vehicles each, for a real-time performance computational efficiency is essential. In this paper, we propose a low complexity, yet highly accurate method for vehicle matching using vehicle signatures composed of Radon transform like projection profiles of the vehicle image. The proposed signatures can be calculated by a simple scan-line algorithm, by the camera software itself and transmitted to the central server or to the other cameras in a smart camera environment. The amount of data is drastically reduced compared to the whole image, which relaxes the data link capacity requirements. Experiments on real vehicle images, extracted from video sequences recorded in a tunnel by two distant security cameras, validate our approach.

Use of digital computers for correction of gamma method and neutron-gamma method indications

International Nuclear Information System (INIS)

Lakhnyuk, V.M.

1978-01-01

The program for the NAIRI-S computer is described which is intended for accounting and elimination of the effect of by-processes when interpreting gamma and neutron-gamma logging indications. By means of slight corrections it is possible to use the program as a mathematical basis for logging diagram standardization by the method of multidimensional regressive analysis and estimation of rock reservoir properties

Effects of use of the lodine contrast medium on gamma camera imaging

Energy Technology Data Exchange (ETDEWEB)

Pyo, Sung Jae; Cho, Yun Ho [Dept. of Nuclear Medicine, Inha University hospital, Incheon (Korea, Republic of); Choi, Jae Ho [Dept. of Radiological Technology, Ansan College, Ansan (Korea, Republic of)

2016-12-15

Effects of Gamma camera imaging on gamma ray counting rates as a function of use and density of the iodine contrast medium currently in primary use for clinics, and changes in gamma ray counting rates as a function of the contrast medium status upon attenuation correction using a CT absorption coefficientin an SPECT/CT attenuation correction will be considered herein. For experimental materials used 99mTcO4 370 MBq and Pamiray 370 mg, Iomeron 350 mg, Visipaque 320 mg, Bonorex 300 mg of iodine contrast medium. For image acquisition, planar imaging was consecutively filmed for 1, 2, 3, 4, 5 min, respectively, 30 min after administration of 99mTcO4. while 60 views were filmed per frame for 20 min at 55 min for the SPECT/CT imaging. In planar imaging, the gamma ray counting rates as a function of filming time were reduced showing a statistically significant difference when mixed according to the type of contrast medium density rather than when the radioactive isotope 99mTcO4 and the saline solution were mixed. In the tomography for mixing of the radioactive isotope 99mTcO4 and saline solution, the mean counting rate without correction by the CT absorption coefficient is 182±26 counts, while the counting rate with correction by the CT absorption coefficient is 531.3±34 counts. In the tomography for mixing of the radioactive isotope 99mTcO4 and the saline solution with the contrast medium, the mean values before attenuation correction by CT absorption coefficient were 166±29, 158.3±17, 154±36, and 150±33 counts depending on the densities of the contrast medium, while the mean values after attenuation correction were 515±03, 503±10, 496±31, and 488.7±33 counts, showing significant differences in both cases when comparatively evaluated with the imaging for no mixing of the contrast medium. Iodine contrast medium affects the rate of gamma ray. Therefore, You should always be preceded before another test on the day of diagnosis.

Correlation between glomerular filtration rate with gamma camera and estimated serum creatinine clearance from Cockcroft and Gault's formula

International Nuclear Information System (INIS)

Bhushan, Shivanand; Kumar, Rajesh

2012-01-01

The purpose of the present study is to find out the correlation between the glomerular filtration rate (GFR by Gates gamma camera method) and serum creatinine clearance (SCrCl by Cockcroft and Gault's method) within ± 3 weeks’ time difference. Study design retrospectively in 59 patients with serum creatinine value calculated for SCrCl with Cockcroft and Gault's formula as an index parameter for kidney function underwent the 99m-Technitium labeled Di-ethyl Triamine Penta Acetic Acid (99mTc-DTPA) renogram with ECIL planar gamma camera. All data of 59 patients has been divided into Group- I, II, and III based on the time difference of serum creatinine test from 99mTc-DTPA renal GFR tests performed on the same subjects. Serum Creatinine test was carried out within ± 3 days, between ± 4 days and ± 7 days, and between ± 8 days and ± 21 days from the DTPA GFR Test performed in the Group-I, II, and III respectively. Correlation coefficient of Group-I (n = 15) patients showed 0.8198 and P value < 0.001 for GFR and S. Creatinine within ± 3 days. Group-II (n = 17) and Group-III (n = 27) patients having correlation coefficient 0.6194 and 0.589 and P value <0.01 respectively, within ± 21 days. The two methods gave almost identical estimate of GFR even at 3 weeks interval. Study concludes that SCrCl using Cockcroft and Gault's formula could serve as an instant, easy, and reliable method for assessing kidney function. SCrCl with Cockcroft and Gault's formula is more useful for rapid estimation of global GFR for those patients who are not accessible to DTPA renogram with gamma camera. Correlation can be established further with the prospective study in various renal pathophysiological conditions

Computers in activation analysis and gamma-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Carpenter, B. S.; D' Agostino, M. D.; Yule, H. P. [eds.

1979-01-01

Seventy-three papers are included under the following session headings: analytical and mathematical methods for data analysis; software systems for ..gamma..-ray and x-ray spectrometry; ..gamma..-ray spectra treatment, peak evaluation; least squares; IAEA intercomparison of methods for processing spectra; computer and calculator utilization in spectrometer systems; and applications in safeguards, fuel scanning, and environmental monitoring. Separate abstracts were prepared for 72 of those papers. (DLC)

Radiotracer study of wash load movement in a drum-type fabric washing machine using a gamma camera

Energy Technology Data Exchange (ETDEWEB)

Balt, A.P.; Brekel, L.D.M. van den; Vandecasteele, C.; Kolar, Z.

1987-01-01

A study was made of the movement of the wash loads in a drum-type washing machine. For this purpose a sup(99m)Tc source was attached to one or two separate textile pieces and the subsequent source positions were determined by means of a gamma-camera. The wash load movement pattern appears to depend on the type of textile material and its amount, as well as on the volume of water present in the washing machine.

Radiotracer study of wash load movement in a drum-type fabric washing machine using a gamma camera

International Nuclear Information System (INIS)

Balt, A.P.; Brekel, L.D.M. van den; Vandecasteele, C.; Kolar, Z.

1987-01-01

A study was made of the movement of the wash loads in a drum-type washing machine. For this purpose a sup(99m)Tc source was attached to one or two separate textile pieces and the subsequent source positions were determined by means of a gamma-camera. The wash load movement pattern appears to depend on the type of textile material and its amount, as well as on the volume of water present in the washing machine. (author)

The image camera of the 17 m diameter air Cherenkov telescope MAGIC

CERN Document Server

Ostankov, A P

2001-01-01

The image camera of the 17 m diameter MAGIC telescope, an air Cherenkov telescope currently under construction to be installed at the Canary island La Palma, is described. The main goal of the experiment is to cover the unexplored energy window from approx 10 to approx 300 GeV in gamma-ray astrophysics. In its first phase with a classical PMT camera the MAGIC telescope is expected to reach an energy threshold of approx 30 GeV. The operational conditions, the special characteristics of the developed PMTs and their use with light concentrators, the fast signal transfer scheme using analog optical links, the trigger and DAQ organization as well as image reconstruction strategy are described. The different paths being explored towards future camera improvements, in particular the constraints in using silicon avalanche photodiodes and GaAsP hybrid photodetectors in air Cherenkov telescopes are discussed.

Analytical computation of prompt gamma ray emission and detection for proton range verification

International Nuclear Information System (INIS)

Sterpin, E; Vynckier, S; Janssens, G; Smeets, J; Stappen, François Vander; Prieels, D; Priegnitz, Marlen; Perali, Irene

2015-01-01

A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1–2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions.Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12 C, 14 N, 16 O, 31 P or 40 Ca, with 10% of 1 H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the

Physical and mechanical properties of gamma radiation cross-linked polyethylene

International Nuclear Information System (INIS)

Gonzalez, Maria E.; Romero, G.; Smolko, Eduardo E.

1999-01-01

Granulated LDPE 2003 polyethylene was extruded and irradiated under nitrogen with 150, 200 and 300 kGy gamma rays doses to produce cross-linking. The study of the physical and mechanical properties shows that the product has a high degree of molecular cross-linking, can be heated up to 200 C for 2 hours without deformation and that the mechanical properties improve. Preliminary aging tests indicate that after heating at 60 C for 4 weeks no physical or mechanical deterioration can be observed. (author)

Measuring neutron fluences and gamma/x-ray fluxes with CCD cameras

International Nuclear Information System (INIS)

Yates, G.J.; Smith, G.W.; Zagarino, P.; Thomas, M.C.

1991-01-01

The capability to measure bursts of neutron fluences and gamma/x-ray fluxes directly with charge coupled device (CCD) cameras while being able to distinguish between the video signals produced by these two types of radiation, even when they occur simultaneously, has been demonstrated. Volume and area measurements of transient radiation-induced pixel charge in English Electric Valve (EEV) Frame Transfer (FT) charge coupled devices (CCDs) from irradiation with pulsed neutrons (14 MeV) and Bremsstrahlung photons (4--12 MeV endpoint) are utilized to calibrate the devices as radiometric imaging sensors capable of distinguishing between the two types of ionizing radiation. Measurements indicate ∼.05 V/rad responsivity with ≥1 rad required for saturation from photon irradiation. Neutron-generated localized charge centers or ''peaks'' binned by area and amplitude as functions of fluence in the 10 5 to 10 7 n/cm 2 range indicate smearing over ∼1 to 10% of CCD array with charge per pixel ranging between noise and saturation levels

SU-G-IeP4-12: Performance of In-111 Coincident Gamma-Ray Counting: A Monte Carlo Simulation

Energy Technology Data Exchange (ETDEWEB)

Pahlka, R; Kappadath, S; Mawlawi, O [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: The decay of In-111 results in a non-isotropic gamma-ray cascade, which is normally imaged using a gamma camera. Creating images with a gamma camera using coincident gamma-rays from In-111 has not been previously studied. Our objective was to explore the feasibility of imaging this cascade as coincidence events and to determine the optimal timing resolution and source activity using Monte Carlo simulations. Methods: GEANT4 was used to simulate the decay of the In-111 nucleus and to model the gamma camera. Each photon emission was assigned a timestamp, and the time delay and angular separation for the second gamma-ray in the cascade was consistent with the known intermediate state half-life of 85ns. The gamma-rays are transported through a model of a Siemens dual head Symbia “S” gamma camera with a 5/8-inch thick crystal and medium energy collimators. A true coincident event was defined as a single 171keV gamma-ray followed by a single 245keV gamma-ray within a specified time window (or vice versa). Several source activities (ranging from 10uCi to 5mCi) with and without incorporation of background counts were then simulated. Each simulation was analyzed using varying time windows to assess random events. The noise equivalent count rate (NECR) was computed based on the number of true and random counts for each combination of activity and time window. No scatter events were assumed since sources were simulated in air. Results: As expected, increasing the timing window increased the total number of observed coincidences albeit at the expense of true coincidences. A timing window range of 200–500ns maximizes the NECR at clinically-used source activities. The background rate did not significantly alter the maximum NECR. Conclusion: This work suggests coincident measurements of In-111 gamma-ray decay can be performed with commercial gamma cameras at clinically-relevant activities. Work is ongoing to assess useful clinical applications.

Reconfigurable FPGA architecture for computer vision applications in Smart Camera Networks

OpenAIRE

Maggiani , Luca; Salvadori , Claudio; Petracca , Matteo; Pagano , Paolo; Saletti , Roberto

2013-01-01

International audience; Smart Camera Networks (SCNs) is nowadays an emerging research field which represents the natural evolution of centralized computer vision applications towards full distributed and pervasive systems. In such a scenario, one of the biggest effort is in the definition of a flexible and reconfigurable SCN node architecture able to remotely support the possibility of updating the application parameters and changing the running computer vision applications at run-time. In th...

Towards Adaptive Virtual Camera Control In Computer Games

DEFF Research Database (Denmark)

Burelli, Paolo; Yannakakis, Georgios N.

2011-01-01

Automatic camera control aims to define a framework to control virtual camera movements in dynamic and unpredictable virtual environments while ensuring a set of desired visual properties. We inves- tigate the relationship between camera placement and playing behaviour in games and build a user...... model of the camera behaviour that can be used to control camera movements based on player preferences. For this purpose, we collect eye gaze, camera and game-play data from subjects playing a 3D platform game, we cluster gaze and camera information to identify camera behaviour profiles and we employ...... camera control in games is discussed....

Very high energy gamma ray astrophysics: Progress report for period May 1, 1986-February 15, 1987

International Nuclear Information System (INIS)

Lamb, R.C.; Lewis, D.A.

1987-02-01

Highlights of research are noted. These include new electronics, noise and gain analysis, tests of imaging, new sources of gamma radiation observed, development of a 37-element mini camera, computer capabilities, and new detector capabilities

Gamma camera with reflectivity mask

International Nuclear Information System (INIS)

Stout, K.J.

1980-01-01

In accordance with the present invention there is provided a radiographic camera comprising: a scintillator; a plurality of photodectors positioned to face said scintillator; a plurality of masked regions formed upon a face of said scintillator opposite said photdetectors and positioned coaxially with respective ones of said photodetectors for decreasing the amount of internal reflection of optical photons generated within said scintillator. (auth)

Marking system for scintillation camera and computer, and its clinical application

Energy Technology Data Exchange (ETDEWEB)

Narabayashi, I [Kinki Univ., Higashi-Osaka, Osaka (Japan); Ito, K; Yoshida, S; Yamaguchi, H; Kahata, S

1976-03-01

In routine clinical studies, we have noted that in some cases anatomical marks have been transferred to scintigrams through the scintillation camera. It was thought that radioactive point sources could be used as anatomical marks. However, this method resulted in an ill-defined area of brightness. The marking equipment for the scintillation camera used in this study consisted of a linear potentiometer and a sine-cosine potentiometer. We designed a marking method for a data processing system using the marking equipment for a scintillation camera. The data processing system of a scintillation camera is composed of EDR-4000 (8K core memories), MT recorder, CRT display, and graphic display unit and it is connected by on-line to the scintillation camera. A marking program was made in order to record marking addresses on a processed image. Using this soft program and graphpen of the graphic display unit, we transferred marks to processed image by points and lines. Subtraction scintigraphy using /sup 198/Au-colloid and /sup 75/Se-selenomethionine was performed on cases of pancreas carcinoma. After marking addresses were recorded on a processed image by this marking method, the signals from the scintillation camera were fed into the input controller. Then these signals with marking points were transferred from the computer to the MT recorder. Subtraction scintigraphy by this system made it possible to examine each picture with /sup 198/Au-colloid of /sup 75/Se-selenomethionine at different times.

Positron emission tomography with gamma camera in coincidence mode

International Nuclear Information System (INIS)

Hertel, A.; Hoer, G.

1999-01-01

Positron emission tomography using F-18 FDG has been estbalished in clinical diagnostics with first indications especially in oncology. To install a conventional PET tomography (dedicated PET) is financially costly and restricted to PET examinations only. Increasing demand for PET diagnostics on one hand and restricted financial resources in the health system on the other hand led industry to develop SPECT cameras to be operated in coincidence mode (camera PET) in order to offer nuclear medicine physicians cost-effective devices for PET diagnostic. At the same time camera PET is inferior to conventional PET regarding sensitivity and detection-efficiency for 511 keV photons. Does camera-PET offer a reliable alternative to conventional PET? The first larger comparative studies are now available, so a first apraisal about the technical clinical performance of camera-PET can be done. (orig.) [de

Performance Analysis of Polarization Modulated DirectDetection Optical CDMA Systems over Turbulent FSO LinksModeled by the Gamma-Gamma Distribution

Directory of Open Access Journals (Sweden)

Fan Bai

2015-01-01

Full Text Available This paper proposes a theoretical study to characterize the transmission of optical code division multiple access (CDMA systems deploying polarization shift keying (PolSK over a free space optical (FSO link under the impact of atmospheric turbulence. In our analysis, a novel transceiver architecture for atmospheric OCDMA FSO systems based on polarization modulation with direct detection is proposed and discussed. A detailed analytical model for PolSK-OCDMA systems over a turbulent FSO link is provided. Further, we derive a closed-form bit error ratio (BER and outage probability expressions, taking into account the multiple-access interference (MAI, optical noise and the atmospheric turbulence effect on the FSO link modeled by the Gamma-Gamma distribution. Finally, the results of this study show the most significant parameters that degrade the transmission performance of the PolSK-OCDMA signal over FSO links and indicate that the proposed approach offers improved bit error ratio (BER performances compared to the on-off-keying (OOK modulation scheme in the presence of turbulence.

In-camera video-stream processing for bandwidth reduction in web inspection

Science.gov (United States)

Jullien, Graham A.; Li, QiuPing; Hajimowlana, S. Hossain; Morvay, J.; Conflitti, D.; Roberts, James W.; Doody, Brian C.

1996-02-01

Automated machine vision systems are now widely used for industrial inspection tasks where video-stream data information is taken in by the camera and then sent out to the inspection system for future processing. In this paper we describe a prototype system for on-line programming of arbitrary real-time video data stream bandwidth reduction algorithms; the output of the camera only contains information that has to be further processed by a host computer. The processing system is built into a DALSA CCD camera and uses a microcontroller interface to download bit-stream data to a XILINXTM FPGA. The FPGA is directly connected to the video data-stream and outputs data to a low bandwidth output bus. The camera communicates to a host computer via an RS-232 link to the microcontroller. Static memory is used to both generate a FIFO interface for buffering defect burst data, and for off-line examination of defect detection data. In addition to providing arbitrary FPGA architectures, the internal program of the microcontroller can also be changed via the host computer and a ROM monitor. This paper describes a prototype system board, mounted inside a DALSA camera, and discusses some of the algorithms currently being implemented for web inspection applications.

Temperature resolution enhancing of commercially available THz passive cameras due to computer processing of images

Science.gov (United States)

Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Kuchik, Igor E.

2014-06-01

As it is well-known, application of the passive THz camera for the security problems is very promising way. It allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. Efficiency of using the passive THz camera depends on its temperature resolution. This characteristic specifies possibilities of the detection of concealed object: minimal size of the object, maximal distance of the detection, image detail. One of probable ways for a quality image enhancing consists in computer processing of image. Using computer processing of the THz image of objects concealed on the human body, one may improve it many times. Consequently, the instrumental resolution of such device may be increased without any additional engineering efforts. We demonstrate new possibilities for seeing the clothes details, which raw images, produced by the THz cameras, do not allow to see. We achieve good quality of the image due to applying various spatial filters with the aim to demonstrate independence of processed images on math operations. This result demonstrates a feasibility of objects seeing. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp., and Capital Normal University (Beijing, China).

A Compton camera application for the GAMOS GEANT4-based framework

Energy Technology Data Exchange (ETDEWEB)

Harkness, L.J., E-mail: ljh@ns.ph.liv.ac.uk [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Arce, P. [Department of Basic Research, CIEMAT, Madrid (Spain); Judson, D.S.; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Dormand, J.; Jones, M.; Nolan, P.J.; Sampson, J.A.; Scraggs, D.P.; Sweeney, A. [Oliver Lodge Laboratory, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Daresbury, Warrington WA4 4AD (United Kingdom)

2012-04-11

Compton camera systems can be used to image sources of gamma radiation in a variety of applications such as nuclear medicine, homeland security and nuclear decommissioning. To locate gamma-ray sources, a Compton camera employs electronic collimation, utilising Compton kinematics to reconstruct the paths of gamma rays which interact within the detectors. The main benefit of this technique is the ability to accurately identify and locate sources of gamma radiation within a wide field of view, vastly improving the efficiency and specificity over existing devices. Potential advantages of this imaging technique, along with advances in detector technology, have brought about a rapidly expanding area of research into the optimisation of Compton camera systems, which relies on significant input from Monte-Carlo simulations. In this paper, the functionality of a Compton camera application that has been integrated into GAMOS, the GEANT4-based Architecture for Medicine-Oriented Simulations, is described. The application simplifies the use of GEANT4 for Monte-Carlo investigations by employing a script based language and plug-in technology. To demonstrate the use of the Compton camera application, simulated data have been generated using the GAMOS application and acquired through experiment for a preliminary validation, using a Compton camera configured with double sided high purity germanium strip detectors. Energy spectra and reconstructed images for the data sets are presented.

Design and implementation of a quality assurance program for gamma cameras

International Nuclear Information System (INIS)

Montoya M, A.; Rodriguez L, A.; Trujillo Z, F. E.

2010-09-01

In nuclear medicine more than 90% of the carried out procedures are diagnostic. To assure an appropriate diagnostic quality of the images and the doses optimization received by the patients originated in the radioactive material, it is indispensable the periodic surveillance of the operation and performance of the equipment s by means of quality assurance tests. This work presents a proposal of a quality assurance program for gamma cameras based on recommendations of the IAEA, the American Association of Medical Physics and the National Electrical Manufacturers Association. Some tests of the program were applied to an e.cam gamma camera (Siemens) of the Nuclear Medicine Department of the National Institute of Cancer. The intrinsic and extrinsic uniformity, the intrinsic spatial resolution and the extrinsic sensibility were verified. For intrinsic uniformity the average daily values of the integral uniformity and differential uniformity in the useful vision field were 2.61% and 1.58% respectively, the average monthly values of intrinsic uniformity for the integral and differential uniformity in the useful vision field were 4.10% and 1.66% respectively. The used acceptance criterions were respectively of 3.74% and 2.74%. The average values of extrinsic uniformity for the useful vision field were of 7.65% (intrinsic uniformity) and 2.69% (extrinsic uniformity), in this case the acceptance criterion is a value of 6.00%. The average value of intrinsic spatial resolution went 4.67 mm superior to 4.4. mm that is the acceptance limit. Finally, maximum variations of 1.8% were observed (minors than 2% that is the acceptance criterion) for the extrinsic sensibility measured in different regions of the detector. Significant variations of extrinsic sensibility were not observed among the monthly lectures. Of the realized measurements was concluded that the system requires of a maintenance service by part of the manufacturer, which one carries out later on to this work. The

Extra-light gamma-ray imager for safeguards and homeland security

Energy Technology Data Exchange (ETDEWEB)

Ivanov, Oleg P.; Semin, Ilya A.; Potapov, Victor N.; Stepanov, Vyacheslav E. [National Research Centre Kurchatov Institute, Moscow, 123182, (Russian Federation)

2015-07-01

Gamma-ray imaging is the most important way to identify unknown gamma-ray emitting objects in decommissioning, security, overcoming accidents. Over the past two decades a system for producing of gamma images in these conditions became more or less portable devices. But in recent years these systems have become the hand-held devices. This is very important, especially in emergency situations, and measurements for safety reasons. We describe the first integrated hand-held instrument for emergency and security applications. The device is based on the coded aperture image formation, position sensitive gamma-ray (X-ray) detector Medipix2 (detectors produces by X-ray Imaging Europe) and tablet computer. The development was aimed at creating a very low weight system with high angular resolution. We present some sample gamma-ray images by camera. Main estimated parameters of the system are the following. The field of view video channel ∼ 490 deg. The field of view gamma channel ∼ 300 deg. The sensitivity of the system with a hexagonal mask for the source of Cs-137 (Eg = 662 keV), is in units of dose D ∼ 100 mR. This option is less then order of magnitude worse than for the heavy, non-hand-held systems (e.g., gamma-camera Cartogam, by Canberra.) The angular resolution of the gamma channel for the sources of Cs-137 (Eg = 662 keV) is about 1.20 deg. (authors)

PET with coincidence gamma cameras - clinical benefit from the radiooncologists' point of view

International Nuclear Information System (INIS)

Richter, E.; Feyerabend, T.; Stallmann, C.; Lauer, I.; Baehre, M.

2001-01-01

Positron emission tomography with FDG (FDG-PET) is a new technique, which displays the cellular metabolic activity. Since tumors exhibit an increased metabolic activity when compared to normal tissue, this imaging modality has a particularly high importance. FDG-PET is not only useful for localizing and staging of malignant tumors, but also to evaluate therapy response. In this context, PET is superior to morphologically orientated modalities, because therapeutically induced changes in glucose metabolism precede morphologic alterations. Numerous studies indicate, that PET will play an important role in radiooncology concerning therapy planning and monitoring the effects of therapy during and after treatment. Further clinical studies are necessary to evaluate the information provided by FDG-PET more precisely. Coincidence gamma cameras with adequate imaging characteristics will gain enhanced importance to meet these increasing demands. (orig.) [de

Approaches to contamination problems of agricultural land using Na(I) Tl spectrometer and gamma camera

International Nuclear Information System (INIS)

Yin, Yong-Gen; Suzui, Nobuo; Kawachi, Naoki; Ishii, Satomi; Fujimaki, Shu; Yamaguchi, Mitsutaka; Tanoi, Keitaro; Nakanishi, Tomoko M.; Chino, Mitsuo; Nakamura, Shin-ichi; Watabe, Hiroshi; Yamamoto, Seiichi

2012-01-01

The severe accident of Fukushima Daiichi Nuclear Power Plant made a large area of agricultural land contaminated with radioactive cesium (Cs-134 and 137). Quantitative analysis for radioactivity (discriminating for Cs-134 and Cs-137) taken in vegetables from the land was carried out using NaI (Tl) scintillation spectrometer. Development of gamma camera for their imaging due to Cs 137 was performed. The shape of the peaks in the spectrum, baseline suppression, a solution of lines overlapping, enhancement of high-resolution were studied. Furthermore, the effect of water on cesium absorbing and transferring process from the root to the tissue was studied. (S. Ohno)

CAMAC based computer--computer communications via microprocessor data links

International Nuclear Information System (INIS)

Potter, J.M.; Machen, D.R.; Naivar, F.J.; Elkins, E.P.; Simmonds, D.D.

1976-01-01

Communications between the central control computer and remote, satellite data acquisition/control stations at The Clinton P. Anderson Meson Physics Facility (LAMPF) is presently accomplished through the use of CAMAC based Data Link Modules. With the advent of the microprocessor, a new philosophy for digital data communications has evolved. Data Link modules containing microprocessor controllers provide link management and communication network protocol through algorithms executed in the Data Link microprocessor

Collimator trans-axial tomographic scintillation camera

International Nuclear Information System (INIS)

Jaszczak, Ronald J.

1979-01-01

An improved collimator is provided for a scintillation camera system that employs a detector head for transaxial tomographic scanning. One object of this invention is to significantly reduce the time required to obtain statistically significant data in radioisotope scanning using a scintillation camera. Another is to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a radiation source of known strength without sacrificing spatial resolution. A further object is to reduce the necessary scanning time without degrading the images obtained. The collimator described has apertures defined by septa of different radiation transparency. The septa are aligned to provide greater radiation shielding from gamma radiation travelling within planes perpendicular to the cranial-caudal axis and less radiation shielding from gamma radiation travelling within other planes. Septa may also define apertures such that the collimator provides high spatial resolution of gamma rays traveling within planes perpendicular to the cranial-caudal axis and directed at the detector and high radiation sensitivity to gamma radiation travelling other planes and indicated at the detector. (LL)

Preliminary study for pixel identification on a modular gamma camera

Energy Technology Data Exchange (ETDEWEB)

Soluri, A., E-mail: soluri@isib.cnr.it; Atzeni, G.; Ucci, A.; Cusanno, F.; Massari, R.

2014-02-01

Our group has recently investigated and produced new scintigraphic prototypes based on advanced scintillation structure. The aim of this study is to demonstrate the use of scintillation matrices with size equal to the overall area of the Position Sensitive Photomultiplier Tube (PSPMT), to design a modular gamma camera and study the solution of the dead area problems optimizing the overall pixel identification. In this paper we investigate the response of different combinations with crystals integrated within tungsten structure, coupled with H8500, R8900-C12 and R11265-M64 Hamamatsu PSPMTs. Several scintillation matrices, whose dimensions match to the physical area of the PSPMT, have been analysed so that we have also studied limits of detection for the elements of the matrix in the critical zones of the PSPMT, i.e. corners and borders. In order to enhance the detectability of scintillation elements we improved the light collection by depositing metallic layers or treating the tungsten structure with different coating materials, and shaping the external elements of the scintillation matrices. The results have shown good energy resolution and the proposed method can be applied in medical imaging for obtaining high efficiency scintillation devices.

Optimal configuration of a low-dose breast-specific gamma camera based on semiconductor CdZnTe pixelated detectors

Science.gov (United States)

Genocchi, B.; Pickford Scienti, O.; Darambara, DG

2017-05-01

Breast cancer is one of the most frequent tumours in women. During the ‘90s, the introduction of screening programmes allowed the detection of cancer before the palpable stage, reducing its mortality up to 50%. About 50% of the women aged between 30 and 50 years present dense breast parenchyma. This percentage decreases to 30% for women between 50 to 80 years. In these women, mammography has a sensitivity of around 30%, and small tumours are covered by the dense parenchyma and missed in the mammogram. Interestingly, breast-specific gamma-cameras based on semiconductor CdZnTe detectors have shown to be of great interest to early diagnosis. Infact, due to the high energy, spatial resolution, and high sensitivity of CdZnTe, molecular breast imaging has been shown to have a sensitivity of about 90% independently of the breast parenchyma. The aim of this work is to determine the optimal combination of the detector pixel size, hole shape, and collimator material in a low dose dual head breast specific gamma camera based on a CdZnTe pixelated detector at 140 keV, in order to achieve high count rate, and the best possible image spatial resolution. The optimal combination has been studied by modeling the system using the Monte Carlo code GATE. Six different pixel sizes from 0.85 mm to 1.6 mm, two hole shapes, hexagonal and square, and two different collimator materials, lead and tungsten were considered. It was demonstrated that the camera achieved higher count rates, and better signal-to-noise ratio when equipped with square hole, and large pixels (> 1.3 mm). In these configurations, the spatial resolution was worse than using small pixel sizes (< 1.3 mm), but remained under 3.6 mm in all cases.

Physical assessment of the GE/CGR Neurocam and comparison with a single rotating gamma-camera

International Nuclear Information System (INIS)

Kouris, K.; Jarritt, P.H.; Costa, D.C.; Ell, P.J.

1992-01-01

The GE/CGR Neurocam is a triple-headed single photon emission tomography (SPET) system dedicated to multi-slice brain tomography. We have assessed its physical performance in terms of sensitivity and resolution, and its clinical efficacy in comparison with a modern, single, rotating gamma-camera (GE 400XCT). Using a water-filled cylinder containing TC-99m, the tomographic volume sensitivity of the Neurocam was 30.0 and 50.7 kcps/MBq.ml.cm for the high-resolution and general-purpose collimators, respectively; the corresponding values for the single rotating camera were 7.6 and 12.8 kcps/MBq.ml.cm. Tomographic resolution was measured in air and in water. In air, the Neurocam resolution at the centre of the field-of-view is 9.0 and 10.7 mm full width at half-maximum (FWHM) with the collimators, respectively, and is isotropic in the three orthogonal planes; the resolution of the GE 400XCT with its 13-cm radius of rotation is 10.3 and 11.7 mm, respectively. For the Neurocam with the HR collimator, the transaxial FWHM values in water were 9.7 mm at the centre and 9.5 mm radial (6.6 mm tangential) at 8 cm from the centre. The physical characteristics of the Neurocam enable the routine acquisition of brain perfusion data with Tc-99m hexamethyl-propylene amine oxime in about 14 min, yielding better image quality than with a single rotating camera in 40 min. (orig./HP)

Renal scintiscanning: Methodology and normal findings using 131I hippurane and a gamma camera

International Nuclear Information System (INIS)

Ruppik, G.

1982-01-01

The methodological and mathematical fundamentals of renal functional scintiscanning using a gamma camera and 131 I-hippurane are described for ING, whole-body clearance, plasma clearance, and unilateral clearance. Methods are compared introducing the Tuebingen method of unilateral clearance with tolerance limits. The data of the patients are presented as standard values with a limit of two standard deviations for whole-body clearance unilateral clearance, the parenchymal phase and the excretion phase including a percentage of excretion. Comparative studies are presented for the main parameters of clearance and unilateral clearance, and the data obtained are documented in tables and graphs together with the initial data and the standard values. The results and problems of the method are gone into. (orig./MG) [de

Portable high energy gamma ray imagers

International Nuclear Information System (INIS)

Guru, S.V.; Squillante, M.R.

1996-01-01

To satisfy the needs of high energy gamma ray imagers for industrial nuclear imaging applications, three high energy gamma cameras are presented. The RMD-Pinhole camera uses a lead pinhole collimator and a segmented BGO detector viewed by a 3 in. square position sensitive photomultiplier tube (PSPMT). This pinhole gamma camera displayed an energy resolution of 25.0% FWHM at the center of the camera at 662 keV and an angular resolution of 6.2 FWHM at 412 keV. The fixed multiple hole collimated camera (FMCC), used a multiple hole collimator and a continuous slab of NaI(Tl) detector viewed by the same PSPMT. The FMCC displayed an energy resolution of 12.4% FWHM at 662 keV at the center of the camera and an angular resolution of 6.0 FWHM at 412 keV. The rotating multiple hole collimated camera (RMCC) used a 180 antisymmetric rotation modulation collimator and CsI(Tl) detectors coupled to PIN silicon photodiodes. The RMCC displayed an energy resolution of 7.1% FWHM at 662 keV and an angular resolution of 4.0 FWHM at 810 keV. The performance of these imagers is discussed in this paper. (orig.)

Regional exploration of pulmonary function using xenon 133. Value of the gamma camera connected to a computer

Energy Technology Data Exchange (ETDEWEB)

Moyses, B; Gerard, G; Methlin, G [Centre Paul-Strauss, 67 - Strasbourg (France); Weitzenblum, E [Centre Hospitalier Universitaire, 67 - Strasbourg (France)

1978-06-17

Regional isotopic exploration of ventilation and pulmonary perfusion is not yet widely applied in clinical practice, by virtue of the complexity of the equipment required, but also because of the complicated and lengthy analysis of the results. In this respect, connection of the scintillation camera to a computer represents a major advance which other authors have already emphasized. Our own experience in this area and our method of exploration in a group of 43 cases of chronic obstructive lung disease (33 patients of the chronic bronchitis type, 10 patients with emphysema) are analysed and discussed. The results indicate the following: in chronic bronchitis, a very marked fall in ventilation of the bases with inversion of the normal vertical ventilation gradient, and a fall in the ventilation/perfusion ratio of the bases; in emphysema, a fall in ventilation, but also and above all in regional perfusion of all territories with preservation of normal or even increased regional ventilation/perfusion ratios. Regional exploration may also be of value in the detection of early stages of obstructive lung disease, and in pre-operative assessment in thoracic surgery.

Very high energy gamma ray astrophysics

International Nuclear Information System (INIS)

Lamb, R.C.; Lewis, D.A.

1991-01-01

The Whipple Observatory High Resolution Camera will be used in a vigorous program of observations to search for new sources of very-high-energy gamma rays. In addition, a search for antimatter using the moon-earth system as an ion spectrometer will be begun. The first phase of GRANITE, the new 37-element 11-m camera, will be concluded with first light scheduled for September, 1991. The two cameras will operate in support of the Gamma Ray Observatory mission in the winter of 1991/2

Development of the computer code to monitor gamma radiation in the nuclear facility environment

International Nuclear Information System (INIS)

Akhmad, Y. R.; Pudjiyanto, M.S.

1998-01-01

Computer codes for gamma radiation monitoring in the vicinity of nuclear facility which have been developed could be introduced to the commercial potable gamma analyzer. The crucial stage of the first year activity was succeeded ; that is the codes have been tested to transfer data file (pulse high distribution) from Micro NOMAD gamma spectrometer (ORTEC product) and the convert them into dosimetry and physics quantities. Those computer codes are called as GABATAN (Gamma Analyzer of Batan) and NAGABAT (Natural Gamma Analyzer of Batan). GABATAN code can isable to used at various nuclear facilities for analyzing gamma field up to 9 MeV, while NAGABAT could be used for analyzing the contribution of natural gamma rays to the exposure rate in the certain location

Inversion of the conical Radon transform with vertices on a surface of revolution arising in an application of a Compton camera

International Nuclear Information System (INIS)

Moon, Sunghwan

2017-01-01

A Compton camera has been introduced for use in single photon emission computed tomography to improve the low efficiency of a conventional gamma camera. In general, a Compton camera brings about the conical Radon transform. Here we consider a conical Radon transform with the vertices on a rotation symmetric set with respect to a coordinate axis. We show that this conical Radon transform can be decomposed into two transforms: the spherical sectional transform and the weighted fan beam transform. After finding inversion formulas for these two transforms, we provide an inversion formula for the conical Radon transform. (paper)

Integral transport computation of gamma detector response with the CPM2 code

International Nuclear Information System (INIS)

Jones, D.B.

1989-12-01

CPM-2 Version 3 is an enhanced version of the CPM-2 lattice physics computer code which supports the capabilities to (1) perform a two-dimensional gamma flux calculation and (2) perform Restart/Data file maintenance operations. The Gamma Calculation Module implemented in CPM-2 was first developed for EPRI in the CASMO-1 computer code by Studsvik Energiteknik under EPRI Agreement RP2352-01. The gamma transport calculation uses the CPM-HET code module to calculate the transport of gamma rays in two dimensions in a mixed cylindrical-rectangular geometry, where the basic fuel assembly and component regions are maintained in a rectangular geometry, but the fuel pins are represented as cylinders within a square pin cell mesh. Such a capability is needed to represent gamma transport in an essentially transparent medium containing spatially distributed ''black'' cylindrical pins. Under a subcontract to RP2352-01, RPI developed the gamma production and gamma interaction library used for gamma calculation. The CPM-2 gamma calculation was verified against reference results generated by Studsvik using the CASMO-1 program. The CPM-2 Restart/Data file maintenance capabilities provide the user with options to copy files between Restart/Data tapes and to purge files from the Restart/Data tapes

A study of quantitative scale display of the organ uptake with gamma-camera

Energy Technology Data Exchange (ETDEWEB)

Ishigami, K; Matsumoto, M [Kumamoto Univ. (Japan) School of Medicine

1975-05-01

The fundamental study of quantitative scale display of the organ uptake with ..gamma..-camera was performed in special respect of the thyroid gland and the pancreas. As one of the measurements on certain dimension of the organ, an optical progression outside the digital image was expressed, and was subjected to the quantitative scale with the use of the threshold level. And a rather satisfactory correlation was clinically obtained between the scale display and the thyroidal /sup 131/I uptake. For the purpose of revising the above scale display, the organ depth was measured with RI by the aid of the phantom. Then the pancreas depth determined by the count rate ratio curve of 140 and 270 keV peak of /sup 75/Se energies. However, the body background and the radioactive rays from the neighboring organs interfered with this curve.

Compton camera study for high efficiency SPECT and benchmark with Anger system

Science.gov (United States)

Fontana, M.; Dauvergne, D.; Létang, J. M.; Ley, J.-L.; Testa, É.

2017-12-01

Single photon emission computed tomography (SPECT) is at present one of the major techniques for non-invasive diagnostics in nuclear medicine. The clinical routine is mostly based on collimated cameras, originally proposed by Hal Anger. Due to the presence of mechanical collimation, detection efficiency and energy acceptance are limited and fixed by the system’s geometrical features. In order to overcome these limitations, the application of Compton cameras for SPECT has been investigated for several years. In this study we compare a commercial SPECT-Anger device, the General Electric HealthCare Infinia system with a High Energy General Purpose (HEGP) collimator, and the Compton camera prototype under development by the French collaboration CLaRyS, through Monte Carlo simulations (GATE—GEANT4 Application for Tomographic Emission—version 7.1 and GEANT4 version 9.6, respectively). Given the possible introduction of new radio-emitters at higher energies intrinsically allowed by the Compton camera detection principle, the two detectors are exposed to point-like sources at increasing primary gamma energies, from actual isotopes already suggested for nuclear medicine applications. The Compton camera prototype is first characterized for SPECT application by studying the main parameters affecting its imaging performance: detector energy resolution and random coincidence rate. The two detector performances are then compared in terms of radial event distribution, detection efficiency and final image, obtained by gamma transmission analysis for the Anger system, and with an iterative List Mode-Maximum Likelihood Expectation Maximization (LM-MLEM) algorithm for the Compton reconstruction. The results show for the Compton camera a detection efficiency increased by a factor larger than an order of magnitude with respect to the Anger camera, associated with an enhanced spatial resolution for energies beyond 500 keV. We discuss the advantages of Compton camera application

Use of calibration methodology of gamma cameras for the workers surveillance using a thyroid simulator; Uso de una metodologia de calibracion de camaras gamma para la vigilancia de trabajadores usando un simulador de tiroides

Energy Technology Data Exchange (ETDEWEB)

Alfaro, M.; Molina, G.; Vazquez, R.; Garcia, O., E-mail: mercedes.alfaro@inin.gob.m [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2010-09-15

In Mexico there are a significant number of nuclear medicine centers in operation. For what the accidents risk related to the transport and manipulation of open sources used in nuclear medicine can exist. The National Institute of Nuclear Research (ININ) has as objective to establish a simple and feasible methodology for the workers surveillance related with the field of the nuclear medicine. This radiological surveillance can also be applied to the public in the event of a radiological accident. To achieve this it intends to use the available equipment s in the nuclear medicine centers, together with the neck-thyroid simulators elaborated by the ININ to calibrate the gamma cameras. The gamma cameras have among their component elements that conform spectrometric systems like the employees in the evaluation of the internal incorporation for direct measurements, reason why, besides their use for diagnostic for image, they can be calibrated with anthropomorphic simulators and also with punctual sources for the quantification of the radionuclides activity distributed homogeneously in the human body, or located in specific organs. Inside the project IAEA-ARCAL-RLA/9/049-LXXVIII -Procedures harmonization of internal dosimetry- where 9 countries intervened (Argentina, Brazil, Colombia, Cuba, Chile, Mexico, Peru, Uruguay and Spain). It was developed a protocol of cameras gamma calibration for the determination in vivo of radionuclides. The protocol is the base to establish and integrated network in Latin America to attend in response to emergencies, using nuclear medicine centers of public hospitals of the region. The objective is to achieve the appropriate radiological protection of the workers, essential for the sure and acceptable radiation use, the radioactive materials and the nuclear energy. (Author)

The influence of distrubing effects on the performance of a wide field coded mask X-ray camera

International Nuclear Information System (INIS)

Sims, M.R.; Turner, M.J.L.; Willingale, R.

1985-01-01

The coded aperture telescope, or Dicke camera, is seen as an instrument suitable for many applications in X-ray and gamma ray imaging. In this paper the effects of a partially obscuring window mask support or collimator, a detector with limited spatial resolution, and motion of the camera during image integration are considered using a computer simulation of the performance of such a camera. Cross correlation and the Wiener filter are used to deconvolve the data. It is shown that while these effects cause a degradation in performance this is in no case catastrophic. Deterioration of the image is shown to be greatest where strong sources are present in the field of view and is quite small (proportional 10%) when diffuse background is the major element. A comparison between the cyclic mask camera and the single mask camera is made under various conditions and it is shown the single mask camera has a moderate advantage particularly when imaging a wide field of view. (orig.)

DUBNA-GRAN SASSO: Satellite computer link

International Nuclear Information System (INIS)

Anon.

1994-01-01

In April a 64 kbit/s computer communication link was set up between the Joint Institute for Nuclear Research (JINR), Dubna (Russia) and Gran Sasso (Italy) Laboratories via nearby ground satellite stations using the INTELSAT V satellite. Previously the international community of Dubna's experimentalists and theorists (high energy physics, condensed matter physics, low energy nuclear and neutron physics, accelerator and applied nuclear physics) had no effective computer links with scientific centres worldwide

Measuring of main parameters of blood circulation at small laboratory animals in chronic experiment by means of computerized gamma-camera

International Nuclear Information System (INIS)

Rutskij, A.V.; Kovalenko, Yu.D.; Rudenko, F.V.; Ioda, G.I.; Kaminskij, M.P.

1996-01-01

Technique for studding of a state systemic and regional hemodynamics at small laboratory animals (rats) by using short-lived isotopes (technetium 99 m) and computerized gamma-camera are described. One gives possibility to make the repeated measuring in condition long-tome experiment. The proposed technique of radiocardiocirculography gives possibility simultaneously to measure linear parameters of both arterial and vein blood circulation too. 3 refs., 1 tab., 2 figs

Front-illuminated versus back-illuminated photon-counting CCD-based gamma camera: important consequences for spatial resolution and energy resolution

International Nuclear Information System (INIS)

Heemskerk, Jan W T; Westra, Albert H; Linotte, Peter M; Ligtvoet, Kees M; Zbijewski, Wojciech; Beekman, Freek J

2007-01-01

Charge-coupled devices (CCDs) coupled to scintillation crystals can be used for high-resolution imaging with x-rays and gamma rays. When the CCD images can be read out fast enough, the energy and interaction position of individual gamma quanta can be estimated by a real-time image analysis of the scintillation light flashes ('photon-counting mode'). The electron-multiplying CCD (EMCCD) is well suited for fast read out, since even at high frame rates it has extremely low read-out noise. Back-illuminated (BI) EMCCDs have much higher quantum efficiency than front-illuminated (FI) EMCCDs. Here we compare the spatial and energy resolution of gamma cameras based on FI and BI EMCCDs. The CCDs are coupled to a 1000 μm thick columnar CsI(Tl) crystal for the purpose of Tc-99m and I-125 imaging. Intrinsic spatial resolutions of 44 μm for I-125 and 49 μm for Tc-99m were obtained when using a BI EMCCD, which is an improvement by a factor of about 1.2-2 over the FI EMCCD. Furthermore, in the energy spectrum of the BI EMCCD, the I-125 signal could be clearly separated from the background noise, which was not the case for the FI EMCCD. The energy resolution of a BI EMCCD for Tc-99m was estimated to be approximately 36 keV, full width at half maximum, at 141 keV. The excellent results for the BI EMCCD encouraged us to investigate the cooling requirements for our setup. We have found that for the BI EMCCD, the spatial and energy resolution, as well as image noise, remained stable over a range of temperatures from -50 deg. C to -15 deg. C. This is a significant advantage over the FI EMCCD, which suffered from loss of spatial and especially energy resolution at temperatures as low as -40 deg. C. We conclude that the use of BI EMCCDs may significantly improve the imaging capabilities and the cost efficiency of CCD-based high-resolution gamma cameras. (note)

Computational model of gamma irradiation room at ININ

Science.gov (United States)

Rodríguez-Romo, Suemi; Patlan-Cardoso, Fernando; Ibáñez-Orozco, Oscar; Vergara Martínez, Francisco Javier

2018-03-01

In this paper, we present a model of the gamma irradiation room at the National Institute of Nuclear Research (ININ is its acronym in Spanish) in Mexico to improve the use of physics in dosimetry for human protection. We deal with air-filled ionization chambers and scientific computing made in house and framed in both the GEANT4 scheme and our analytical approach to characterize the irradiation room. This room is the only secondary dosimetry facility in Mexico. Our aim is to optimize its experimental designs, facilities, and industrial applications of physical radiation. The computational results provided by our model are supported by all the known experimental data regarding the performance of the ININ gamma irradiation room and allow us to predict the values of the main variables related to this fully enclosed space to within an acceptable margin of error.

Coincidence detection of photons of 511 keV from positon annihilation on a conventional gamma camera: optimization and analysis of potentialities

International Nuclear Information System (INIS)

Brasse, David

1999-01-01

The feasibility of acquiring clinical oncology studies on a gamma camera designed for the imaging of low energy single photons was investigated. The first prototype used two Nal(Tl) detectors of 40 cm by 30 cm with a 3/8 inch height and the second prototype was equipped with two large Nal(Tl) detectors of 40 cm by 54 cm with a 4/8 inch height. The optimization of such devices was mainly an optimization of the count rates obtained for reconstruct an image as a function of the angular axial aperture of the projections, with and without axial collimators. This optimization was performed experimentally using an anthropomorphic whole body phantom and the noise equivalent count rate as the figure of merit. An original correction for the random coincidences was also designed in order to optimize the contrast recovery and the contrast to noise ratio of small tumors (16 mm and 19 mm diameter). Finally, the optimal dose of FDG that can be injected to the subjects for an acquisition of that machine was determined and data acquired on an ECAT HR+ were compared with those acquired on the gamma camera for five subjects. (author) [fr

Technology for computer-stabilized peak of NaI(Tl) gamma spectrum

International Nuclear Information System (INIS)

Chen Jianzhen; Guo Lanying; Ling Qiu; Qu Guopu; Zhao Lihong; Hu Chuangye

2005-01-01

An improved technology for spectrum stabilization of NaI(Tl) gamma spectrum was introduced. This technology is based on the system using a reference peak, which is equivalent gamma peak of 241 Am source. The computer seeks peak's position deviation and computes adjust value of programmable amplifier and controls programmable amplifier to stabilize spectrum by digital PID. This is a technology of spectrum stabilizing with 'hardware + reference-peak + software' and has high stability and fast speed of spectrum stabilizing. (author)

A prototype small CdTe gamma camera for radioguided surgery and other imaging applications.

Science.gov (United States)

Tsuchimochi, Makoto; Sakahara, Harumi; Hayama, Kazuhide; Funaki, Minoru; Ohno, Ryoichi; Shirahata, Takashi; Orskaug, Terje; Maehlum, Gunnar; Yoshioka, Koki; Nygard, Einar

2003-12-01

Gamma probes have been used for sentinel lymph node biopsy in melanoma and breast cancer. However, these probes can provide only radioactivity counts and variable pitch audio output based on the intensity of the detected radioactivity. We have developed a small semiconductor gamma camera (SSGC) that allows visualisation of the size, shape and location of the target tissues. This study is designed to characterise the performance of the SSGC for radioguided surgery of metastatic lesions and for other imaging applications amenable to the smaller format of this prototype imaging system. The detector head had 32 cadmium telluride semiconductor arrays with a total of 1,024 pixels, and with application-specific integrated circuits (ASICs) and a tungsten collimator. The entire assembly was encased in a lead housing measuring 152 mmx166 mmx65 mm. The effective visual field was 44.8 mmx44.8 mm. The energy resolution and imaging aspects were tested. Two spherical 5-mm- and 15-mm-diameter technetium-99m radioactive sources that had activities of 0.15 MBq and 100 MBq, respectively, were used to simulate a sentinel lymph node and an injection site. The relative detectability of these foci by the new detector and a conventional scintillation camera was studied. The prototype was also examined in a variety of clinical applications. Energy resolution [full-width at half-maximum (FWHM)] for a single element at the centre of the field of view was 4.2% at 140 keV (99mTc), and the mean energy resolution of the CdTe detector arrays was approximately 7.8%. The spatial resolution, represented by FWHM, had a mean value of 1.56 +/- 0.05 mm. Simulated node foci could be visualised clearly by the SSGC using a 15-s acquisition time. In preliminary clinical tests, the SSGC successfully imaged diseases in a variety of tissues, including salivary and thyroid glands, temporomandibular joints and sentinel lymph nodes. The SSGC has significant potential for diagnosing diseases and facilitating

A prototype small CdTe gamma camera for radioguided surgery and other imaging applications

Energy Technology Data Exchange (ETDEWEB)

Tsuchimochi, Makoto; Hayama, Kazuhide [Department of Oral and Maxillofacial Radiology, The Nippon Dental University School of Dentistry at Niigata, 1-8 Hamaura-cho, 951-8580, Niigata (Japan); Sakahara, Harumi [Department of Radiology, Hamamatsu University School of Medicine, Hamamatsu (Japan); Funaki, Minoru; Ohno, Ryoichi; Shirahata, Takashi [Acrorad Co. Ltd., Tokyo (Japan); Orskaug, Terje; Maehlum, Gunnar; Yoshioka, Koki; Nygard, Einar [Integrated Detector and Electronics A.S (IDE AS), Hovik (Norway)

2003-12-01

Gamma probes have been used for sentinel lymph node biopsy in melanoma and breast cancer. However, these probes can provide only radioactivity counts and variable pitch audio output based on the intensity of the detected radioactivity. We have developed a small semiconductor gamma camera (SSGC) that allows visualisation of the size, shape and location of the target tissues. This study is designed to characterise the performance of the SSGC for radioguided surgery of metastatic lesions and for other imaging applications amenable to the smaller format of this prototype imaging system. The detector head had 32 cadmium telluride semiconductor arrays with a total of 1,024 pixels, and with application-specific integrated circuits (ASICs) and a tungsten collimator. The entire assembly was encased in a lead housing measuring 152 mm x 166 mm x 65 mm. The effective visual field was 44.8 mm x 44.8 mm. The energy resolution and imaging aspects were tested. Two spherical 5-mm- and 15-mm-diameter technetium-99m radioactive sources that had activities of 0.15 MBq and 100 MBq, respectively, were used to simulate a sentinel lymph node and an injection site. The relative detectability of these foci by the new detector and a conventional scintillation camera was studied. The prototype was also examined in a variety of clinical applications. Energy resolution [full-width at half-maximum (FWHM)] for a single element at the centre of the field of view was 4.2% at 140 keV ({sup 99m}Tc), and the mean energy resolution of the CdTe detector arrays was approximately 7.8%. The spatial resolution, represented by FWHM, had a mean value of 1.56{+-}0.05 mm. Simulated node foci could be visualised clearly by the SSGC using a 15-s acquisition time. In preliminary clinical tests, the SSGC successfully imaged diseases in a variety of tissues, including salivary and thyroid glands, temporomandibular joints and sentinel lymph nodes. The SSGC has significant potential for diagnosing diseases and

A prototype small CdTe gamma camera for radioguided surgery and other imaging applications

International Nuclear Information System (INIS)

Tsuchimochi, Makoto; Hayama, Kazuhide; Sakahara, Harumi; Funaki, Minoru; Ohno, Ryoichi; Shirahata, Takashi; Orskaug, Terje; Maehlum, Gunnar; Yoshioka, Koki; Nygard, Einar

2003-01-01

Gamma probes have been used for sentinel lymph node biopsy in melanoma and breast cancer. However, these probes can provide only radioactivity counts and variable pitch audio output based on the intensity of the detected radioactivity. We have developed a small semiconductor gamma camera (SSGC) that allows visualisation of the size, shape and location of the target tissues. This study is designed to characterise the performance of the SSGC for radioguided surgery of metastatic lesions and for other imaging applications amenable to the smaller format of this prototype imaging system. The detector head had 32 cadmium telluride semiconductor arrays with a total of 1,024 pixels, and with application-specific integrated circuits (ASICs) and a tungsten collimator. The entire assembly was encased in a lead housing measuring 152 mm x 166 mm x 65 mm. The effective visual field was 44.8 mm x 44.8 mm. The energy resolution and imaging aspects were tested. Two spherical 5-mm- and 15-mm-diameter technetium-99m radioactive sources that had activities of 0.15 MBq and 100 MBq, respectively, were used to simulate a sentinel lymph node and an injection site. The relative detectability of these foci by the new detector and a conventional scintillation camera was studied. The prototype was also examined in a variety of clinical applications. Energy resolution [full-width at half-maximum (FWHM)] for a single element at the centre of the field of view was 4.2% at 140 keV ( 99m Tc), and the mean energy resolution of the CdTe detector arrays was approximately 7.8%. The spatial resolution, represented by FWHM, had a mean value of 1.56±0.05 mm. Simulated node foci could be visualised clearly by the SSGC using a 15-s acquisition time. In preliminary clinical tests, the SSGC successfully imaged diseases in a variety of tissues, including salivary and thyroid glands, temporomandibular joints and sentinel lymph nodes. The SSGC has significant potential for diagnosing diseases and facilitating

A novel dual mode neutron-gamma imager

International Nuclear Information System (INIS)

Cooper, Robert Lee; Gerling, Mark; Brennan, James S.; Mascarenhas, Nicholas; Mrowka, Stanley; Marleau, Peter

2010-01-01

The Neutron Scatter Camera (NSC) can image fission sources and determine their energy spectra at distances of tens of meters and through significant thicknesses of intervening materials in relatively short times (1). We recently completed a 32 element scatter camera and will present recent advances made with this instrument. A novel capability for the scatter camera is dual mode imaging. In normal neutron imaging mode we identify and image neutron events using pulse shape discrimination (PSD) and time of flight in liquid scintillator. Similarly gamma rays are identified from Compton scatter in the front and rear planes for our segmented detector. Rather than reject these events, we show it is possible to construct a gamma-ray image by running the analysis in a 'Compton mode'. Instead of calculating the scattering angle by the kinematics of elastic scatters as is appropriate for neutron events, it can be found by the kinematics of Compton scatters. Our scatter camera has not been optimized as a Compton gamma-ray imager but is found to work reasonably. We studied imaging performance using a Cs137 source. We find that we are able to image the gamma source with reasonable fidelity. We are able to determine gamma energy after some reasonable assumptions. We will detail the various algorithms we have developed for gamma image reconstruction. We will outline areas for improvement, include additional results and compare neutron and gamma mode imaging.

Evaluation of list-mode ordered subset expectation maximization image reconstruction for pixelated solid-state compton gamma camera with large number of channels

Science.gov (United States)

Kolstein, M.; De Lorenzo, G.; Chmeissani, M.

2014-04-01

The Voxel Imaging PET (VIP) Pathfinder project intends to show the advantages of using pixelated solid-state technology for nuclear medicine applications. It proposes designs for Positron Emission Tomography (PET), Positron Emission Mammography (PEM) and Compton gamma camera detectors with a large number of signal channels (of the order of 106). For Compton camera, especially with a large number of readout channels, image reconstruction presents a big challenge. In this work, results are presented for the List-Mode Ordered Subset Expectation Maximization (LM-OSEM) image reconstruction algorithm on simulated data with the VIP Compton camera design. For the simulation, all realistic contributions to the spatial resolution are taken into account, including the Doppler broadening effect. The results show that even with a straightforward implementation of LM-OSEM, good images can be obtained for the proposed Compton camera design. Results are shown for various phantoms, including extended sources and with a distance between the field of view and the first detector plane equal to 100 mm which corresponds to a realistic nuclear medicine environment.

Single-acquisition method for simultaneous determination of extrinsic gamma-camera sensitivity and spatial resolution

Energy Technology Data Exchange (ETDEWEB)

Santos, J.A.M. [Servico de Fisica Medica, Instituto Portugues de Oncologia Francisco Gentil do Porto, E.P.E., Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)], E-mail: a.miranda@portugalmail.pt; Sarmento, S. [Servico de Fisica Medica, Instituto Portugues de Oncologia Francisco Gentil do Porto, E.P.E., Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Alves, P.; Torres, M.C. [Departamento de Fisica da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Bastos, A.L. [Servico de Medicina Nuclear, Instituto Portugues de Oncologia Francisco Gentil do Porto, E.P.E., Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal); Ponte, F. [Servico de Fisica Medica, Instituto Portugues de Oncologia Francisco Gentil do Porto, E.P.E., Rua Dr. Antonio Bernardino de Almeida, 4200-072 Porto (Portugal)

2008-01-15

A new method for measuring simultaneously both the extrinsic sensitivity and spatial resolution of a gamma-camera in a single planar acquisition was implemented. A dual-purpose phantom (SR phantom; sensitivity/resolution) was developed, tested and the results compared with other conventional methods used for separate determination of these two important image quality parameters. The SR phantom yielded reproducible and accurate results, allowing an immediate visual inspection of the spatial resolution as well as the quantitative determination of the contrast for six different spatial frequencies. It also proved to be useful in the estimation of the modulation transfer function (MTF) of the image formation collimator/detector system at six different frequencies and can be used to estimate the spatial resolution as function of the direction relative to the digital matrix of the detector.

Single-acquisition method for simultaneous determination of extrinsic gamma-camera sensitivity and spatial resolution

International Nuclear Information System (INIS)

Santos, J.A.M.; Sarmento, S.; Alves, P.; Torres, M.C.; Bastos, A.L.; Ponte, F.

2008-01-01

A new method for measuring simultaneously both the extrinsic sensitivity and spatial resolution of a gamma-camera in a single planar acquisition was implemented. A dual-purpose phantom (SR phantom; sensitivity/resolution) was developed, tested and the results compared with other conventional methods used for separate determination of these two important image quality parameters. The SR phantom yielded reproducible and accurate results, allowing an immediate visual inspection of the spatial resolution as well as the quantitative determination of the contrast for six different spatial frequencies. It also proved to be useful in the estimation of the modulation transfer function (MTF) of the image formation collimator/detector system at six different frequencies and can be used to estimate the spatial resolution as function of the direction relative to the digital matrix of the detector

A basic component for ISGRI, the CdTe gamma camera on board the INTEGRAL satellite

International Nuclear Information System (INIS)

Arques, M.; Baffert, N.; Lattard, D.

1999-01-01

A basic component, called Polycell, has been developed for the ISGRI (INTEGRAL Soft Gamma Ray Imager) CdTe camera on board the INTEGRAL (INTErnational Gamma-Ray Astrophysics Laboratory) satellite. Operating at room temperature, it covers the 20 keV--1 MeV energy range. It features a sub-ensemble of 16 CdTe detectors and their associated front end electronics. This electronics is based on 4-channel analog-digital ASICs. Their analog part features a low noise preamplifier, allowing a threshold below 20 keV and a pulse rise-time measurement which permits a charge loss correction. The digital part ensures the internal acquisition timing sequence as well as the dialogue with external electronics. Two versions of the ISGRI ASIC have been developed in a collaboration of two CEA microelectronics teams from CEA/DTA/LETI/DSYS and CEA/DSM/DAPNIA/SEI, respectively on a standard CMOS AMS process hardened against radiation by lay-out, and on a Silicon On Insulator process (DMILL MHS), the latter being latch-up free. This paper presents the ASIC and polycell architecture as well as experimental results obtained with polycells equipped with AMS ASICs

Link failure detection in a parallel computer

Science.gov (United States)

Archer, Charles J.; Blocksome, Michael A.; Megerian, Mark G.; Smith, Brian E.

2010-11-09

Methods, apparatus, and products are disclosed for link failure detection in a parallel computer including compute nodes connected in a rectangular mesh network, each pair of adjacent compute nodes in the rectangular mesh network connected together using a pair of links, that includes: assigning each compute node to either a first group or a second group such that adjacent compute nodes in the rectangular mesh network are assigned to different groups; sending, by each of the compute nodes assigned to the first group, a first test message to each adjacent compute node assigned to the second group; determining, by each of the compute nodes assigned to the second group, whether the first test message was received from each adjacent compute node assigned to the first group; and notifying a user, by each of the compute nodes assigned to the second group, whether the first test message was received.

Explosive Transient Camera (ETC) Program

Science.gov (United States)

Ricker, George

1991-01-01

Since the inception of the ETC program, a wide range of new technologies was developed to support this astronomical instrument. The prototype unit was installed at ETC Site 1. The first partially automated observations were made and some major renovations were later added to the ETC hardware. The ETC was outfitted with new thermoelectrically-cooled CCD cameras and a sophisticated vacuum manifold, which, together, made the ETC a much more reliable unit than the prototype. The ETC instrumentation and building were placed under full computer control, allowing the ETC to operate as an automated, autonomous instrument with virtually no human intervention necessary. The first fully-automated operation of the ETC was performed, during which the ETC monitored the error region of the repeating soft gamma-ray burster SGR 1806-21.

Camera Trajectory fromWide Baseline Images

Science.gov (United States)

Havlena, M.; Torii, A.; Pajdla, T.

2008-09-01

Camera trajectory estimation, which is closely related to the structure from motion computation, is one of the fundamental tasks in computer vision. Reliable camera trajectory estimation plays an important role in 3D reconstruction, self localization, and object recognition. There are essential issues for a reliable camera trajectory estimation, for instance, choice of the camera and its geometric projection model, camera calibration, image feature detection and description, and robust 3D structure computation. Most of approaches rely on classical perspective cameras because of the simplicity of their projection models and ease of their calibration. However, classical perspective cameras offer only a limited field of view, and thus occlusions and sharp camera turns may cause that consecutive frames look completely different when the baseline becomes longer. This makes the image feature matching very difficult (or impossible) and the camera trajectory estimation fails under such conditions. These problems can be avoided if omnidirectional cameras, e.g. a fish-eye lens convertor, are used. The hardware which we are using in practice is a combination of Nikon FC-E9 mounted via a mechanical adaptor onto a Kyocera Finecam M410R digital camera. Nikon FC-E9 is a megapixel omnidirectional addon convertor with 180° view angle which provides images of photographic quality. Kyocera Finecam M410R delivers 2272×1704 images at 3 frames per second. The resulting combination yields a circular view of diameter 1600 pixels in the image. Since consecutive frames of the omnidirectional camera often share a common region in 3D space, the image feature matching is often feasible. On the other hand, the calibration of these cameras is non-trivial and is crucial for the accuracy of the resulting 3D reconstruction. We calibrate omnidirectional cameras off-line using the state-of-the-art technique and Mičušík's two-parameter model, that links the radius of the image point r to the

A digital variable persistence oscilloscope for gamma cameras

International Nuclear Information System (INIS)

Fenwick, J.D.; Thompson, A.

1981-01-01

The system briefly described is intended as a direct replacement for the analogue persistence oscilloscope, particularly in systems without a computer processor. It uses digital and video techniques to produce an image quality suitable for use in positioning patients under the camera at a low cost (total cost of materials used, Pound500). The performance is superior to the analogue oscilloscope in that the image is displayed with 16 shades of grey. It incorporates an automatic brightness control which ensures that the image does not saturate at high count density, and the saturation can be changed manually allowing areas of low counts to be examined in the presence of high counts. The digital inability to store each single event as a dot which fades exponentially with time has been solved by adding each event into the appropriate cell of a digital display matrix, and then periodically dividing the contents of each image cell by two. The cells are addressed and divided in a pseudo-random pattern so that, to the observer, the whole image appears to fade smoothly and evenly. (U.K.)

Statistical pixelwise inference models for planar data analysis: an application to gamma-camera uniformity monitoring

Energy Technology Data Exchange (ETDEWEB)

Kalemis, A [Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom); Bailey, D L [Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, NSW 2065 (Australia); Flower, M A [Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom); Lord, S K [Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom); Ott, R J [Joint Department of Physics, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom)

2004-07-21

In this paper two tests based on statistical models are presented and used to assess, quantify and provide positional information of the existence of bias and/or variations between planar images acquired at different times but under similar conditions. In the first test a linear regression model is fitted to the data in a pixelwise fashion, using three mathematical operators. In the second test a comparison using z-scoring is used based on the assumption that Poisson statistics are valid. For both tests the underlying assumptions are as simple and few as possible. The results are presented as parametric maps of either the three operators or the z-score. The z-score maps can then be thresholded to show the parts of the images which demonstrate change. Three different thresholding methods (naive, adaptive and multiple) are presented: together they cover almost all the needs for separating the signal from the background in the z-score maps. Where the expected size of the signal is known or can be estimated, a spatial correction technique (referred to as the reef correction) can be applied. These tests were applied to flood images used for the quality control of gamma camera uniformity. Simulated data were used to check the validity of the methods. Real data were acquired from four different cameras from two different institutions using a variety of acquisition parameters. The regression model found the bias in all five simulated cases and it also found patterns of unstable regions in real data where visual inspection of the flood images did not show any problems. In comparison the z-map revealed the differences in the simulated images from as low as 1.8 standard deviations from the mean, corresponding to a differential uniformity of 2.2% over the central field of view. In all cases studied, the reef correction increased significantly the sensitivity of the method and in most cases the specificity as well. The two proposed tests can be used either separately or in

Statistical pixelwise inference models for planar data analysis: an application to gamma-camera uniformity monitoring

International Nuclear Information System (INIS)

Kalemis, A; Bailey, D L; Flower, M A; Lord, S K; Ott, R J

2004-01-01

In this paper two tests based on statistical models are presented and used to assess, quantify and provide positional information of the existence of bias and/or variations between planar images acquired at different times but under similar conditions. In the first test a linear regression model is fitted to the data in a pixelwise fashion, using three mathematical operators. In the second test a comparison using z-scoring is used based on the assumption that Poisson statistics are valid. For both tests the underlying assumptions are as simple and few as possible. The results are presented as parametric maps of either the three operators or the z-score. The z-score maps can then be thresholded to show the parts of the images which demonstrate change. Three different thresholding methods (naive, adaptive and multiple) are presented: together they cover almost all the needs for separating the signal from the background in the z-score maps. Where the expected size of the signal is known or can be estimated, a spatial correction technique (referred to as the reef correction) can be applied. These tests were applied to flood images used for the quality control of gamma camera uniformity. Simulated data were used to check the validity of the methods. Real data were acquired from four different cameras from two different institutions using a variety of acquisition parameters. The regression model found the bias in all five simulated cases and it also found patterns of unstable regions in real data where visual inspection of the flood images did not show any problems. In comparison the z-map revealed the differences in the simulated images from as low as 1.8 standard deviations from the mean, corresponding to a differential uniformity of 2.2% over the central field of view. In all cases studied, the reef correction increased significantly the sensitivity of the method and in most cases the specificity as well. The two proposed tests can be used either separately or in

Characterizing the detection module paving the ECLAIRs camera for the SVOM gamma-ray buts mission

International Nuclear Information System (INIS)

Nasser, Guillaume

2015-01-01

Gamma-ray bursts (GRBs) are short and very intense flashes of X-gamma-ray photons lasting from few milliseconds to hundreds of seconds appearing randomly over the sky. These cosmological events are thought to be due to the catastrophic formation of newly formed black holes following the collapse of some massive stars or after the coalescence of two compact objects and resulting in the launch of powerful ultra-relativistic jets orientated towards the Earth. The Sino-French mission SVOM (Space-based multi-band Variable Object Monitor) is dedicated to the study of these extreme and fascinating transient events and expected to be launched in 2020's. The satellite will implement a multi-wavelength science payload amongst which the core will be the large-field coded-mask camera ECLAIRs in charge of the detection and the localisation of GRBs in the 4-150 keV range. The ECLAIRs detection plane, DPIX, is made of 80x80 Schottky CdTe semi-conductor detectors and the front-end electronics. During my PhD, I mainly worked on the characterization of the scientific performance of the elementary detection modules called XRDPIX (i.e. a hybrid made of 8*4 detectors coupled with a low-noise ASIC) that will paved the DPIX. The main goal is then to derive the best suitable choice of the instrumental parameters in order to optimize the camera in-flight performance. In the manuscript, I discuss the methodology I used to explore the instrument parameter space. I describe the various testing protocols that I created and the different tests that I performed using several XRDPIX modules in a thermal-vacuum chamber and irradiated with radioactive sources. I discuss in detail the results and the various observables that I used to define the optimal in-flight operating zone of the detection plane. I also study the contribution of the different noise sources coming from the detectors and the electronic chain with a model I designed in order to control the quality of the hybridization process. I

Gamma dose effects valuation on micro computing components

International Nuclear Information System (INIS)

Joffre, F.

1995-01-01

Robotics in hostile environment raises the problem of micro computing components resistance with gamma radiation cumulated dose. The current aim is to reach a dose of 3000 grays with industrial components. A methodology and an instrumentation adapted to test this type of components have been developed. The aim of this work is to present the advantages and disadvantages bound to the use of industrial components in the presence of gamma radiation. After an analysis of the criteria allowing to justify the technological choices, the different steps which characterize the selection and the assessment methodology used are explained. The irradiation and measures means now operational are mentioned. Moreover, the supply aspects of the chosen components for the design of an industrialized system is taken into account. These selection and assessment components contribute to the development and design of computers for civil nuclear robotics. (O.M.)

A universal multiprocessor system for the fast acquisition and processing of positron camera data

International Nuclear Information System (INIS)

Deluigi, B.

1982-01-01

In this study the main components of a suitable detection system were worked out, and their properties were examined. For the measurement of the three-dimensional distribution of radiopharmaka marked by positron emitters in animal-experimental studies first a positron camera was constructed. For the detection of the annihilation quanta serve two opposite lying position-sensitive gamma detectors which are derived in coincidence. Two commercial camera heads working according to the Anger principle were reconstructed for these purposes and switched together by a special interface to the positron camera. By this arrangement a spatial resolution of 0.8 cm FWHM for a line source in the symmetry plane and a coincidence resolution time 2T of 16ns FW0.1M was reached. For the three-dimensional image reconstruction with the data of a positron camera a maximum-likelihood procedure was developed and tested by a Monte Carlo procedure. In view of this application an at most flexible multi-microprocessor system was developed. A high computing capacity is reached owing to the fact that several partial problems are distributed to different processors and are processed parallely. The architecture was so scheduled that the system possesses a high error tolerance and that the computing capacity can be extended without a principal limit. (orig./HSI) [de

Correction of response defects in scintillation cameras by an on-line microcomputer

International Nuclear Information System (INIS)

Hadjeris, L.

1982-07-01

A fast microprocessor device has been developed, to allow removal of non-linearity and non-uniformity effects of gamma camera signals. It slips in between a commercial gamma camera and the associated data processing system. Camera signals are digitized by fast ADC and numerically processed in real time. Corrected data are given analogic to be taken into account by process device associated to the camera. The principle is first to correct energy spatial variations by using coefficients determinated during calibration by a uniform radioactive distribution source. Then non-linearity of X and Y signals are removed by translations of them. The displacement coefficient table is given from reference images of parallel line phantom [fr

Neutron cameras for ITER

International Nuclear Information System (INIS)

Johnson, L.C.; Barnes, C.W.; Batistoni, P.

1998-01-01

Neutron cameras with horizontal and vertical views have been designed for ITER, based on systems used on JET and TFTR. The cameras consist of fan-shaped arrays of collimated flight tubes, with suitably chosen detectors situated outside the biological shield. The sight lines view the ITER plasma through slots in the shield blanket and penetrate the vacuum vessel, cryostat, and biological shield through stainless steel windows. This paper analyzes the expected performance of several neutron camera arrangements for ITER. In addition to the reference designs, the authors examine proposed compact cameras, in which neutron fluxes are inferred from 16 N decay gammas in dedicated flowing water loops, and conventional cameras with fewer sight lines and more limited fields of view than in the reference designs. It is shown that the spatial sampling provided by the reference designs is sufficient to satisfy target measurement requirements and that some reduction in field of view may be permissible. The accuracy of measurements with 16 N-based compact cameras is not yet established, and they fail to satisfy requirements for parameter range and time resolution by large margins

The added value of a portable gamma camera for intraoperative detection of sentinel lymph node in squamous cell carcinoma of the oral cavity: A case report.

Science.gov (United States)

Mayoral, M; Paredes, P; Sieira, R; Vidal-Sicart, S; Marti, C; Pons, F

2014-01-01

The use of sentinel lymph node biopsy in squamous cell carcinoma of the oral cavity is still subject to debate although some studies have reported its feasibility. The main reason for this debate is probably due to the high false-negative rate for floor-of-mouth tumors per se. We report the case of a 54-year-old man with a T1N0 floor-of-mouth squamous cell carcinoma who underwent the sentinel lymph node procedure. Lymphoscintigraphy and SPECT/CT imaging were performed for lymphatic mapping with a conventional gamma camera. Sentinel lymph nodes were identified at right Ib, left IIa and Ia levels. However, these sentinel lymph nodes were difficult to detect intraoperatively with a gamma probe owing to the activity originating from the injection site. The use of a portable gamma camera made it possible to localize and excise all the sentinel lymph nodes. This case demonstrates the usefulness of this tool to improve sentinel lymph node detecting in floor-of-mouth tumors, especially those close to the injection area. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

Optimized blind gamma-ray pulsar searches at fixed computing budget

International Nuclear Information System (INIS)

Pletsch, Holger J.; Clark, Colin J.

2014-01-01

The sensitivity of blind gamma-ray pulsar searches in multiple years worth of photon data, as from the Fermi LAT, is primarily limited by the finite computational resources available. Addressing this 'needle in a haystack' problem, here we present methods for optimizing blind searches to achieve the highest sensitivity at fixed computing cost. For both coherent and semicoherent methods, we consider their statistical properties and study their search sensitivity under computational constraints. The results validate a multistage strategy, where the first stage scans the entire parameter space using an efficient semicoherent method and promising candidates are then refined through a fully coherent analysis. We also find that for the first stage of a blind search incoherent harmonic summing of powers is not worthwhile at fixed computing cost for typical gamma-ray pulsars. Further enhancing sensitivity, we present efficiency-improved interpolation techniques for the semicoherent search stage. Via realistic simulations we demonstrate that overall these optimizations can significantly lower the minimum detectable pulsed fraction by almost 50% at the same computational expense.

Gamma camera based Positron Emission Tomography: a study of the viability on quantification

International Nuclear Information System (INIS)

Pozzo, Lorena

2005-01-01

Positron Emission Tomography (PET) is a Nuclear Medicine imaging modality for diagnostic purposes. Pharmaceuticals labeled with positron emitters are used and images which represent the in vivo biochemical process within tissues can be obtained. The positron/electron annihilation photons are detected in coincidence and this information is used for object reconstruction. Presently, there are two types of systems available for this imaging modality: the dedicated systems and those based on gamma camera technology. In this work, we utilized PET/SPECT systems, which also allows for the traditional Nuclear Medicine studies based on single photon emitters. There are inherent difficulties which affect quantification of activity and other indices. They are related to the Poisson nature of radioactivity, to radiation interactions with patient body and detector, noise due to statistical nature of these interactions and to all the detection processes, as well as the patient acquisition protocols. Corrections are described in the literature and not all of them are implemented by the manufacturers: scatter, attenuation, random, decay, dead time, spatial resolution, and others related to the properties of each equipment. The goal of this work was to assess these methods adopted by two manufacturers, as well as the influence of some technical characteristics of PET/SPECT systems on the estimation of SUV. Data from a set of phantoms were collected in 3D mode by one camera and 2D, by the other. We concluded that quantification is viable in PET/SPECT systems, including the estimation of SUVs. This is only possible if, apart from the above mentioned corrections, the camera is well tuned and coefficients for sensitivity normalization and partial volume corrections are applied. We also verified that the shapes of the sources used for obtaining these factors play a role on the final results and should be delt with carefully in clinical quantification. Finally, the choice of the region

Nuclear imaging using Fuji Computed Radiography

International Nuclear Information System (INIS)

Yodono, Hiraku; Tarusawa, Nobuko; Katto, Keiichi; Miyakawa, Takayoshi; Watanabe, Sadao; Shinozaki, Tatsuyo

1988-01-01

We studied the feasibility of the Fuji Computed Radiography system (FCR) in nuclear medicine. The basic principle of the system is the conversion of the X-ray energy pattern into digital signals utilizing scanning laser stimulated luminescence. A Rollo phantom filled with 12 mCi of Tc-99m pertechnetate was used in this study. In imaging by the FCR, a low energy high resolution parallel hole collimator for a gamma camera was placed over the phantom and photons through the collimator were stored on a single imaging plate (IP) or 3 IPs covered by the lead plate, 0.3 mm in thickness. For imaging, it took 30 minutes by a single IP and 20 minutes by 3 IPs with the lead plate respectively. Each image of the phantom by the FCR was compared with that of obtained by a gamma camera. The image by a single IP was inferior in quality than that of by a gamma camera. However using 3 IPs with the lead plate, same quality image as by a gamma camera was obtained. The image by 3 IPs is similar to that of by 3 IPs with the lead plate. Based on the results, we performed liver and lung imaging by FCR using 3 IPs. The imaging time is twenty minutes. The images obtained with FCR are as good as the scinticamera image. However it has two major flawes in that the sensitivity is poor and the imaging time is long. Furthermore, at present this method can only be employed for static imaging. However we feel that future improvements in the FCR system will overcome these problems. (author)

On the Capacity of FSO Links over Gamma-Gamma Atmospheric Turbulence Channels Using OOK Signaling

Directory of Open Access Journals (Sweden)

Antonio García-Zambrana

2010-01-01

Full Text Available A new upper bound on the capacity of power- and bandwidth-constrained optical wireless links over gamma-gamma atmospheric turbulence channels with intensity modulation and direct detection is derived when on-off keying (OOK formats are used. In this free-space optical (FSO scenario, unlike previous capacity bounds derived from the classic capacity of the well-known additive white Gaussian noise (AWGN channel with uniform input distribution, a new closed-form upper bound on the capacity is found by bounding the mutual information subject to an average optical power constraint and not only to an average electrical power constraint, showing the fact that the input distribution that maximizes the mutual information varies with the turbulence strength and the signal-to-noise ratio (SNR. Additionally, it is shown that an increase of the peak-to-average optical power ratio (PAOPR provides higher capacity values. Simulation results for the mutual information are further demonstrated to confirm the analytical results under several turbulence conditions.

The regional exploration of pulmonary function using xenon 133. Value of the gamma camera connected to a computer

International Nuclear Information System (INIS)

Moyses, B.; Gerard, G.; Methlin, G.; Weitzenblum, E.

1978-01-01

Regional isotopic exploration of ventilation and pulmonary perfusion is not yet widely applied in clinical practice, by virtue of the complexity of the equipment required, but also because of the complicated and lengthy analysis of the results. In this respect, connection of the scintillation camera to a computer represents a major advance which other authors have already emphasized. Our own experience in this area and our method of exploration in a group of 43 cases of chronic obstructive lung disease (33 patients of the chronic bronchitis type, 10 patients with emphysema) are analysed and discussed. The results indicate the following: in chronic bronchitis, a very marked fall in ventilation of the bases with inversion of the normal vertical ventilation gradient, and a fall in the ventilation/perfusion ratio of the bases; in emphysema, a fall in ventilation, but also and above all in regional perfusion of all territories with preservation of normal or even increased regional ventilation/perfusion ratios. Regional exploration may also be of value in the detection of early stages of obstructive lung disease, and in pre-operative assessment in thoracic surgery [fr

Potential role of a new hand-held miniature gamma camera in performing minimally invasive parathyroidectomy

Energy Technology Data Exchange (ETDEWEB)

Ortega, Joaquin; Lledo, Salvador [University of Valencia, Clinic University Hospital, Department of Surgery, Valencia (Spain); Ferrer-Rebolleda, Jose [Clinic University Hospital, Department of Nuclear Medicine, Valencia (Spain); Cassinello, Norberto [Clinic University Hospital, Unit of Endocrinologic and Bariatric Surgery, Valencia (Spain)

2007-02-15

Sestamibi scans have increased the use of minimally invasive parathyroidectomy (MIP) to treat primary hyperparathyroidism (PHPT) when caused by a parathyroid single adenoma. The greatest concern for surgeons remains the proper identification of pathological glands in a limited surgical field. We have studied the usefulness of a new hand-held miniature gamma camera (MGC) when used intraoperatively to locate parathyroid adenomas. To our knowledge this is the first report published on this subject in the scientific literature. Five patients with PHPT secondary to a single adenoma, positively diagnosed by preoperative sestamibi scans, underwent a MIP. A gamma probe for radioguided surgery and the new hand-held MGC were used consecutively to locate the pathological glands. This new MGC has a module composed of a high-resolution interchangeable collimator and a CsI(Na) scintillating crystal. It has dimensions of around 15 cm x 8 cm x 9 cm and weighs 1 kg. The intraoperative assay of PTH (ioPTH) was used to confirm the complete resection of pathological tissue. All cases were operated on successfully by a MIP. The ioPTH confirmed the excision of all pathological tissues. The MGC proved its usefulness in all patients, even in a difficult case in which the first attempt with the gamma probe failed. In all cases it offered real-time accurate intraoperative images. The hand-held MGC is a useful instrument in MIP for PHPT. It may be used to complement the standard tools used to date, or may even replace them, at least in selected cases of single adenomas. (orig.)

Potential role of a new hand-held miniature gamma camera in performing minimally invasive parathyroidectomy

International Nuclear Information System (INIS)

Ortega, Joaquin; Lledo, Salvador; Ferrer-Rebolleda, Jose; Cassinello, Norberto

2007-01-01

Sestamibi scans have increased the use of minimally invasive parathyroidectomy (MIP) to treat primary hyperparathyroidism (PHPT) when caused by a parathyroid single adenoma. The greatest concern for surgeons remains the proper identification of pathological glands in a limited surgical field. We have studied the usefulness of a new hand-held miniature gamma camera (MGC) when used intraoperatively to locate parathyroid adenomas. To our knowledge this is the first report published on this subject in the scientific literature. Five patients with PHPT secondary to a single adenoma, positively diagnosed by preoperative sestamibi scans, underwent a MIP. A gamma probe for radioguided surgery and the new hand-held MGC were used consecutively to locate the pathological glands. This new MGC has a module composed of a high-resolution interchangeable collimator and a CsI(Na) scintillating crystal. It has dimensions of around 15 cm x 8 cm x 9 cm and weighs 1 kg. The intraoperative assay of PTH (ioPTH) was used to confirm the complete resection of pathological tissue. All cases were operated on successfully by a MIP. The ioPTH confirmed the excision of all pathological tissues. The MGC proved its usefulness in all patients, even in a difficult case in which the first attempt with the gamma probe failed. In all cases it offered real-time accurate intraoperative images. The hand-held MGC is a useful instrument in MIP for PHPT. It may be used to complement the standard tools used to date, or may even replace them, at least in selected cases of single adenomas. (orig.)

Observation of the lymph flow in the lower extremities of edematous patients with noninvasive methods. RI-lymphography with a computer onlined gamma camera

Energy Technology Data Exchange (ETDEWEB)

Arai, Isao; Hirota, Akio; Watanabe, Sumio (Toho Univ., Tokyo (Japan). School of Medicine)

1983-09-01

An RI-lymphography with a computer onlined gamma camera was used for observing the lymph flow of edematous patients without any invasive procedures and for estimating the active movement of lymph vessels. Subjects were composed of 8 normal volunteers (group 1), 41 non-edematous patients (group 2) and 26 edematous patients (group 3). Four mCi of Tc-99m-HSA in a volume of 0.1 ml was injected subcutaneously in the pretibial region of the lower extremity, and immediately after the injection scintigram was recorded on the thigh every 5 sec. for 30 min. Results: 1) Normal volunteers; Time-activity curves showed a gradual increase in RI activity in relation to time without remarkable spike-like fluctuations. The maximum count attained was less than 200 cps in all experiments. 2) Non-edematous patients; In 46 out of 57 experiments (80.8%), the similar time-activity curves were observed as those of the normal volunteers. On the other hand, time-activity curves in 11 out of 57 (19.2%) showed a much steeper stepwise-increase simultaneously with remarkable spike-waves. The maximum count was over 200 cps in these cases. 3) Edematous patients; In 12 out of 35 experiments (34.3%), the maximum count was over 200 cps. In these edematous diseases other than lymphedema and hyperthyroidism, time-activity curves showed a rapid stepwise increase with a lot of spikes, and the maximum count was over 500 cps in 6 experiments. In 23 out of 35 (65.7%), the maximum count was less than 200 cps. In these cases, edema was attributable to secondary lymphedema, hypothyroidism, aging and so on. 4) Relationship between edema and lymph flow: When subjects were divided into 3 groups (non-edema, mild and severe edema), the maximum count 200 cps was observed in 16.7% in non-edema group, 45.8% in mild and 9.1% in severe edema group.

Theoretical considerations on the possibility of using a television camera in scintigraphy

International Nuclear Information System (INIS)

Banget Mossaz, Gaston; Cezilly, Daniel; Paccard, Michel

1969-04-01

After a presentation of the principles of scintigraphy for the exploration of human organs, of the three main parts of scintigraphic apparels (collimator, scintillator and detector) and of their characteristics (resolving power, sensitivity, contrast), this paper describes the properties of gamma radiations interacting with matter, their absorption and their detection, some statistical notions about gamma radiations (Poisson law), the properties of the collimator, of the scintillator (sodium iodide) and of the detector. The use of a television camera is then introduced with issues concerning the limitations of a camera tube, the electronic optics of the tube, camera tubes with brightness amplification, the case of a Vidicon tube, etc. and some considerations on the potential benefits of television cameras on resolution, contrast and sensitivity

Experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype for partial breast irradiation

International Nuclear Information System (INIS)

Ravi, Ananth; Caldwell, Curtis B.; Pignol, Jean-Philippe

2008-01-01

Previously, our team used Monte Carlo simulation to demonstrate that a gamma camera could potentially be used as an online image guidance device to visualize seeds during permanent breast seed implant procedures. This could allow for intraoperative correction if seeds have been misplaced. The objective of this study is to describe an experimental evaluation of an online gamma-camera imaging of permanent seed implantation (OGIPSI) prototype. The OGIPSI device is intended to be able to detect a seed misplacement of 5 mm or more within an imaging time of 2 min or less. The device was constructed by fitting a custom built brass collimator (16 mm height, 0.65 mm hole pitch, 0.15 mm septal thickness) on a 64 pixel linear array CZT detector (eValuator-2000, eV Products, Saxonburg, PA). Two-dimensional projection images of seed distributions were acquired by the use of a digitally controlled translation stage. Spatial resolution and noise characteristics of the detector were measured. The ability and time needed for the OGIPSI device to image the seeds and to detect cold spots was tested using an anthropomorphic breast phantom. Mimicking a real treatment plan, a total of 52 103 Pd seeds of 65.8 MBq each were placed on three different layers at appropriate depths within the phantom. The seeds were reliably detected within 30 s with a median error in localization of 1 mm. In conclusion, an OGIPSI device can potentially be used for image guidance of permanent brachytherapy applications in the breast and, possibly, other sites

Determination of regional cerebral blood flow curves and parameters by computed γ camera

International Nuclear Information System (INIS)

Zhu Guohong

1988-01-01

Regional CBF curves and parameters were determined in 236 subjects by Sigma 438/MCS 560 computed γ camera. Each subject was given 99m TcO 4 -370 MBq intravenously. Four CBF curves and three parameters were derived by the computer.The results from 39 normal subjects, 22 patients with cerebral embolism, 53 patients with cerebrovascular sclerosis, 56 patients with diseases of cervical vertebrae, 10 patients with concussion and 5 patients with cerebral arteritis were analyzed

Monitoring of the internal contamination of occupationally exposure personnel in services of nuclear medicine through the use of gamma cameras

International Nuclear Information System (INIS)

Teran, M.; Paolino, A.; Savio, E.; Hermida, J.C.; Dantas, B.M.

2006-01-01

The radionuclides incorporation can happen as a result of diverse activities; these include the work associated with the different stadiums of the nuclear fuel cycle, the use of radioactive sources in medicine, the scientific research, the agriculture and the industry. In Uruguay the main activities linked to the manipulation of open sources correspond those of Nuclear Medicine and from 2004, in the mark of the Project Arcal RLA 049 and being based on the Safety Guides of the IAEA it is implementing a program of internal monitoring in combined form the Nuclear Medicine Center of the Hospital of and the Radiochemistry class of the Faculty of Chemistry. In accordance with the publication of the ICRP 75 the emphasis of any monitoring program should be in the formal study of the doses in the workers to who are considered commendable of to receive in routine form an outstanding fraction of the dose limits or who work in areas where the exposures can be significant in the accident event. From April 2004, to the date has started a pilot plan by means of in that were established appropriate conditions of procedures and of safety in a reduced group of workers of the Nuclear Medicine area. In that period the first work limits, equipment adjustment, calibrations and registration systems were determined. The monitoring system implemented until the moment is carried out with a thyroid caption equipment. However these measurements are carried out in the university hospital embracing 40% of the involved workers of our country, with the purpose of reaching the covering of the biggest quantity of occupationally exposed personnel of private clinics. Also it was developed a new work proposal that allows to have an alternative measure method, in the event of not having the equipment habitually used. Among the conclusions of this work are that for the before exposed are considered the measure conditions but appropriate the following ones: Gamma Camera without collimator; Measurement

Conjugate view gamma camera method for measuring activity in 131{sup I} treatments; Metodo de la imagen conjugada para la cuantificacion de la actividad en tratamientos de 131{sup I}

Energy Technology Data Exchange (ETDEWEB)

Barquero Sanz, R.; Placios, A. M.; Perez, D. M.; Tortosa Oliver, R.; Michel, R.

2012-07-01

A quantification method is developed to determine 131{sup I} activity and its associated uncertainty using regions of interest from gamma camera images. Inside a neck phantom, a known activity source is introduced to simulate thyroid remainders in thyroid differentiated cancer. The three parameters that define the accuracy of the method are: net count rates in ROI, the air calibration factor of the gamma camera and the attenuation correction factor. In order to obtain net count rates, four methods for background subtraction are tested. The best procedure to follow is based in two energy windows acquisitions, which gives an activity result of 47 {+-} 5 {mu}Ci Bq, in good agreement with the real activity value for the source, 46 {+-} 5 {mu}Ci. (Author) 12 refs.

Resolving time of scintillation camera-computer system and methods of correction for counting loss, 2

International Nuclear Information System (INIS)

Iinuma, Takeshi; Fukuhisa, Kenjiro; Matsumoto, Toru

1975-01-01

Following the previous work, counting-rate performance of camera-computer systems was investigated for two modes of data acquisition. The first was the ''LIST'' mode in which image data and timing signals were sequentially stored on magnetic disk or tape via a buffer memory. The second was the ''HISTOGRAM'' mode in which image data were stored in a core memory as digital images and then the images were transfered to magnetic disk or tape by the signal of frame timing. Firstly, the counting-rates stored in the buffer memory was measured as a function of display event-rates of the scintillation camera for the two modes. For both modes, stored counting-rated (M) were expressed by the following formula: M=N(1-Ntau) where N was the display event-rates of the camera and tau was the resolving time including analog-to-digital conversion time and memory cycle time. The resolving time for each mode may have been different, but it was about 10 μsec for both modes in our computer system (TOSBAC 3400 model 31). Secondly, the date transfer speed from the buffer memory to the external memory such as magnetic disk or tape was considered for the two modes. For the ''LIST'' mode, the maximum value of stored counting-rates from the camera was expressed in terms of size of the buffer memory, access time and data transfer-rate of the external memory. For the ''HISTOGRAM'' mode, the minimum time of the frame was determined by size of the buffer memory, access time and transfer rate of the external memory. In our system, the maximum value of stored counting-rates were about 17,000 counts/sec. with the buffer size of 2,000 words, and minimum frame time was about 130 msec. with the buffer size of 1024 words. These values agree well with the calculated ones. From the author's present analysis, design of the camera-computer system becomes possible for quantitative dynamic imaging and future improvements are suggested. (author)

Computed temperature profile in materials exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Ping, Tso Chin; Choong, Yap Siew; Seon, Chan Kam

1987-06-01

Computed temperature profiles are presented for the materials of lead, steel, concrete and water in curved shells, when they are exposed to gamma radiation. The results are based on the usual simplified theory of thermal conduction with an exponential heat source.

A new approach to the evaluation of peripheral vascular disease using the gamma camera

International Nuclear Information System (INIS)

Gerritsen, H.A.M.

1976-01-01

To estimate the degree of impaired perfusion in legs, and the extent of improvement after treatment, a functional test was developed using a gamma camera to follow the perfusion of intravenously injected sup(99m)Tc-pertechnetate. An analysis is given of normal and pathologic curve patterns. The influence of the severity of occlusive arterial disease on the arrival and distribution of radioactivity in the leg is demonstrated. After vascular surgery, changes in the curve pattern and the imaging of activity distribution reflected the function of the inserted bypass grafts. The test proved to be useful in the differentiation between patients with false claudication complaints due to non-arterial disease and patients with true claudication. It is concluded that the technique presented in this thesis can serve as a useful, non-invasive, screening test prior to arteriography and as a functional assessment of vascular reconstruction

Gastric emptying time in normal subjects using /sup 51/Cr and a gamma camera

Energy Technology Data Exchange (ETDEWEB)

Claure, H [Hospital del Salvador, Santiago de Chile; Calderon, C; Braunschweig, T; Diaz, G

1974-12-01

Gastric emptying time of a meal consisting of 2 eggs, 50 g of white bread, and 300 ml of milk, was measured in 10 normal subjects, 5 males and 5 females, with an average age of 34.7 years. 200 uCi of Cr-51 were added to the meal and external counting was performed using a ..gamma.. camera. The rate of gastric emptying was estimated by the decrease in radiation counts over the gastric area. In 68.6 percent of the subjects the mean gastric emptying time was 60 min. The average curve showed a complex exponential slope with 2 distinct phases: a fast one between 0 and 35 min and a slow one between 40 and 60 min. These results suggest that a normal gastric emptying time consists of 2 different rate phases when a meal of mixed consistency (liquid and solid) is ingested.

Cosmological Gamma-Ray Bursts and Hypernovae Conclusively Linked

Science.gov (United States)

2003-06-01

-ray radiation. The team concludes that it is likely to be due to the nearly instantaneous, non-symmetrical collapse of the inner region of a highly developed star (known as the "collapsar" model) . The March 29 gamma-ray burst will pass into the annals of astrophysics as a rare "type-defining event", providing conclusive evidence of a direct link between cosmological gamma-ray bursts and explosions of very massive stars . PR Photo 17a/03 : Image of the optical afterglow of GRB 030329 (VLT FORS1+2). PR Photo 17b/03 : A series of VLT spectra of the optical afterglow of GRB 030329. What are Gamma-Ray Bursts? One of the currently most active fields of astrophysics is the study of the dramatic events known as "gamma-ray bursts (GRBs)" . They were first detected in the late 1960's by sensitive instruments on-board orbiting military satellites, launched for the surveillance and detection of nuclear tests. Originating, not on the Earth, but far out in space, these short flashes of energetic gamma-rays last from less than a second to several minutes. Despite major observational efforts, it is only within the last six years that it has become possible to pinpoint with some accuracy the sites of some of these events. With the invaluable help of comparatively accurate positional observations of the associated X-ray emission by various X-ray satellite observatories since early 1997, astronomers have until now identified about fifty short-lived sources of optical light associated with GRBs (the "optical afterglows"). Most GRBs have been found to be situated at extremely large ("cosmological") distances. This implies that the energy released in a few seconds during such an event is larger than that of the Sun during its entire lifetime of more than 10,000 million years. The GRBs are indeed the most powerful events since the Big Bang known in the Universe, cf. ESO PR 08/99 and ESO PR 20/00 . During the past years circumstantial evidence has mounted that GRBs signal the collapse of massive

Computational Astrophysics Consortium 3 - Supernovae, Gamma-Ray Bursts and Nucleosynthesis

Energy Technology Data Exchange (ETDEWEB)

Woosley, Stan [Univ. of California, Santa Cruz, CA (United States)

2014-08-29

Final project report for UCSC's participation in the Computational Astrophysics Consortium - Supernovae, Gamma-Ray Bursts and Nucleosynthesis. As an appendix, the report of the entire Consortium is also appended.

GammaCHI: a package for the inversion and computation of the gamma and chi-square cumulative distribution functions (central and noncentral)

NARCIS (Netherlands)

A. Gil (Amparo); J. Segura (Javier); N.M. Temme (Nico)

2015-01-01

textabstractA Fortran 90 module GammaCHI for computing and inverting the gamma and chi-square cumulative distribution functions (central and noncentral) is presented. The main novelty of this package is the reliable and accurate inversion routines for the noncentral cumulative distribution

Measurement of glomerular filtration rate using technetium-99m-DTPA and the gamma camera: A comparison of methods

International Nuclear Information System (INIS)

Russell, C.D.; Bischoff, P.G.; Kontzen, F.; Rowell, K.L.; Yester, M.V.; Lloyd, L.K.; Tauxe, W.N.; Dubovsky, E.V.

1984-01-01

A variety of methods has been proposed to estimate glomerular filtration rate (GFR) from renal uptake of Tc-99m-DTPA using a gamma camera. To compare alternative methods, the authors have calculated GFR in several different ways from measurements in 33 patients, and compared the results with an independent GFR measurement based on 8-point plasma clearance of Yb-169-DTPA. The best agreement was obtained using an algorithm that has not been described previously. This was a modification of a method used previously in which correction was made for overlap of kidneys by liver and spleen. The correlation coefficient was 0.958 and the residual standard deviation was 12.1 ml/min. This method required a single 20-min blood sample as well as the camera data. The best method not requiring a blood sample was significantly less accurate, with correlation coefficient 0.866 and residual standard deviation 21.1 ml/min. The accuracy of these methods was comparable to that reported for the creatinine clearance, the most commonly used estimate of GFR in current clinical practice

Computer model for calculating gamma-ray pulse-height spectra for logging applications

International Nuclear Information System (INIS)

Evans, M.L.

1981-01-01

A generalized computer model has been devised to simulate the emission, transport, and detection of natural gamma radiation from various logging environments. The model yields high-resolution gamma-ray pulse-height spectra that can be used to correct both gross gamma and spectral gamma-ray logs. The technique can help provide corrections to airborne and surface radiometric survey logs for the effects of varying altitude, formation composition, and overburden. Applied to borehole logging, the model can yield estimates of the effects of varying borehole fluid and casing attenuations, as well as varying formation porosity and saturation

The GCT camera for the Cherenkov Telescope Array

Science.gov (United States)

Lapington, J. S.; Abchiche, A.; Allan, D.; Amans, J.-P.; Armstrong, T. P.; Balzer, A.; Berge, D.; Boisson, C.; Bousquet, J.-J.; Bose, R.; Brown, A. M.; Bryan, M.; Buchholtz, G.; Buckley, J.; Chadwick, P. M.; Costantini, H.; Cotter, G.; Daniel, M. K.; De Franco, A.; De Frondat, F.; Dournaux, J.-L.; Dumas, D.; Ernenwein, J.-P.; Fasola, G.; Funk, S.; Gironnet, J.; Graham, J. A.; Greenshaw, T.; Hervet, O.; Hidaka, N.; Hinton, J. A.; Huet, J.-M.; Jankowsky, D.; Jegouzo, I.; Jogler, T.; Kawashima, T.; Kraus, M.; Laporte, P.; Leach, S.; Lefaucheur, J.; Markoff, S.; Melse, T.; Minaya, I. A.; Mohrmann, L.; Molyneux, P.; Moore, P.; Nolan, S. J.; Okumura, A.; Osborne, J. P.; Parsons, R. D.; Rosen, S.; Ross, D.; Rowell, G.; Rulten, C. B.; Sato, Y.; Sayede, F.; Schmoll, J.; Schoorlemmer, H.; Servillat, M.; Sol, H.; Stamatescu, V.; Stephan, M.; Stuik, R.; Sykes, J.; Tajima, H.; Thornhill, J.; Tibaldo, L.; Trichard, C.; Varner, G.; Vink, J.; Watson, J. J.; White, R.; Yamane, N.; Zech, A.; Zink, A.; Zorn, J.; CTA Consortium

2017-12-01

The Gamma Cherenkov Telescope (GCT) is one of the designs proposed for the Small Sized Telescope (SST) section of the Cherenkov Telescope Array (CTA). The GCT uses dual-mirror optics, resulting in a compact telescope with good image quality and a large field of view with a smaller, more economical, camera than is achievable with conventional single mirror solutions. The photon counting GCT camera is designed to record the flashes of atmospheric Cherenkov light from gamma and cosmic ray initiated cascades, which last only a few tens of nanoseconds. The GCT optics require that the camera detectors follow a convex surface with a radius of curvature of 1 m and a diameter of 35 cm, which is approximated by tiling the focal plane with 32 modules. The first camera prototype is equipped with multi-anode photomultipliers, each comprising an 8×8 array of 6×6 mm2 pixels to provide the required angular scale, adding up to 2048 pixels in total. Detector signals are shaped, amplified and digitised by electronics based on custom ASICs that provide digitisation at 1 GSample/s. The camera is self-triggering, retaining images where the focal plane light distribution matches predefined spatial and temporal criteria. The electronics are housed in the liquid-cooled, sealed camera enclosure. LED flashers at the corners of the focal plane provide a calibration source via reflection from the secondary mirror. The first GCT camera prototype underwent preliminary laboratory tests last year. In November 2015, the camera was installed on a prototype GCT telescope (SST-GATE) in Paris and was used to successfully record the first Cherenkov light of any CTA prototype, and the first Cherenkov light seen with such a dual-mirror optical system. A second full-camera prototype based on Silicon Photomultipliers is under construction. Up to 35 GCTs are envisaged for CTA.

GAMMA-CLOUD: a computer code for calculating gamma-exposure due to a radioactive cloud released from a point source

Energy Technology Data Exchange (ETDEWEB)

Sugimoto, O [Chugoku Electric Power Co. Inc., Hiroshima (Japan); Sawaguchi, Y; Kaneko, M

1979-03-01

A computer code, designated GAMMA-CLOUD, has been developed by specialists of electric power companies to meet requests from the companies to have a unified means of calculating annual external doses from routine releases of radioactive gaseous effluents from nuclear power plants, based on the Japan Atomic Energy Commission's guides for environmental dose evaluation. GAMMA-CLOUD is written in FORTRAN language and its required capacity is less than 100 kilobytes. The average ..gamma..-exposure at an observation point can be calculated within a few minutes with comparable precision to other existing codes.

A compact, discrete CsI(Tl) scintillator/Si photodiode gamma camera for breast cancer imaging

Energy Technology Data Exchange (ETDEWEB)

Gruber, Gregory J. [Univ. of California, Berkeley, CA (United States)

2000-01-01

Recent clinical evaluations of scintimammography (radionuclide breast imaging) are promising and suggest that this modality may prove a valuable complement to X-ray mammography and traditional breast cancer detection and diagnosis techniques. Scintimammography, however, typically has difficulty revealing tumors that are less than 1 cm in diameter, are located in the medial part of the breast, or are located in the axillary nodes. These shortcomings may in part be due to the use of large, conventional Anger cameras not optimized for breast imaging. In this thesis I present compact single photon camera technology designed specifically for scintimammography which strives to alleviate some of these limitations by allowing better and closer access to sites of possible breast tumors. Specific applications are outlined. The design is modular, thus a camera of the desired size and geometry can be constructed from an array (or arrays) of individual modules and a parallel hole lead collimator for directional information. Each module consists of: (1) an array of 64 discrete, optically-isolated CsI(Tl) scintillator crystals 3 x 3 x 5 mm³ in size, (2) an array of 64 low-noise Si PIN photodiodes matched 1-to-1 to the scintillator crystals, (3) an application-specific integrated circuit (ASIC) that amplifies the 64 photodiode signals and selects the signal with the largest amplitude, and (4) connectors and hardware for interfacing the module with a motherboard, thereby allowing straightforward computer control of all individual modules within a camera.

A compact, discrete CsI(Tl) scintillator/Si photodiode gamma camera for breast cancer imaging

International Nuclear Information System (INIS)

Gruber, Gregory J.

2000-01-01

Recent clinical evaluations of scintimammography (radionuclide breast imaging) are promising and suggest that this modality may prove a valuable complement to X-ray mammography and traditional breast cancer detection and diagnosis techniques. Scintimammography, however, typically has difficulty revealing tumors that are less than 1 cm in diameter, are located in the medial part of the breast, or are located in the axillary nodes. These shortcomings may in part be due to the use of large, conventional Anger cameras not optimized for breast imaging. In this thesis I present compact single photon camera technology designed specifically for scintimammography which strives to alleviate some of these limitations by allowing better and closer access to sites of possible breast tumors. Specific applications are outlined. The design is modular, thus a camera of the desired size and geometry can be constructed from an array (or arrays) of individual modules and a parallel hole lead collimator for directional information. Each module consists of: (1) an array of 64 discrete, optically-isolated CsI(Tl) scintillator crystals 3 x 3 x 5 mm 3 in size, (2) an array of 64 low-noise Si PIN photodiodes matched 1-to-1 to the scintillator crystals, (3) an application-specific integrated circuit (ASIC) that amplifies the 64 photodiode signals and selects the signal with the largest amplitude, and (4) connectors and hardware for interfacing the module with a motherboard, thereby allowing straightforward computer control of all individual modules within a camera

ORIS: the Oak Ridge Imaging System program listings. [Nuclear medicine imaging with rectilinear scanner and gamma camera

Energy Technology Data Exchange (ETDEWEB)

Bell, P. R.; Dougherty, J. M.

1978-04-01

The Oak Ridge Imaging System (ORIS) is a general purpose access, storage, processing and display system for nuclear medicine imaging with rectilinear scanner and gamma camera. This volume contains listings of the PDP-8/E version of ORIS Version 2. The system is designed to run under the Digital Equipment Corporation's OS/8 monitor in 16K or more words of core. System and image file mass storage is on RK8E disk; longer-time image file storage is provided on DECtape. Another version of this program exists for use with the RF08 disk, and a more limited version is for DECtape only. This latter version is intended for non-medical imaging.

A conceptual gamma shield design using the DRP model computation

Energy Technology Data Exchange (ETDEWEB)

Ahmad, E E [Reactor Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); Rahman, F A [National Center of Nuclear Safety and Radiation Control, Atomic Energy Authority, Cairo (Egypt)

1997-12-31

The purpose of this investigation is to assess basic areas of concern in the development of reactor shielding conceptual design calculations. A spherical shield model composed of low carbon steel and lead have been constructed to surround a Co-60 gamma point source. two alternative configurations have been considered in the model computation. The numerical calculations have been performed using both the ANISN code and DRP model computation together with the DLC 75-Bugle 80 data library. A resume of results for deep penetration in different shield materials with different packing densities is presented and analysed. The results showed that the gamma fluxes attenuation is increased with increasing distribution the packing density of the shield material which reflects its importance of considering it as a safety parameter in shielding design. 3 figs.

An innovative silicon photomultiplier digitizing camera for gamma-ray astronomy

Energy Technology Data Exchange (ETDEWEB)

Heller, M. [DPNC-Universite de Geneve, Geneva (Switzerland); Schioppa, E. Jr; Porcelli, A.; Pujadas, I.T.; Della Volpe, D.; Montaruli, T.; Cadoux, F.; Favre, Y.; Christov, A.; Rameez, M.; Miranda, L.D.M. [DPNC-Universite de Geneve, Geneva (Switzerland); Zietara, K.; Idzkowski, B.; Jamrozy, M.; Ostrowski, M.; Stawarz, L.; Zagdanski, A. [Jagellonian University, Astronomical Observatory, Krakow (Poland); Aguilar, J.A. [DPNC-Universite de Geneve, Geneva (Switzerland); Universite Libre Bruxelles, Faculte des Sciences, Brussels (Belgium); Prandini, E.; Lyard, E.; Neronov, A.; Walter, R. [Universite de Geneve, Department of Astronomy, Geneva (Switzerland); Rajda, P.; Bilnik, W.; Kasperek, J.; Lalik, K.; Wiecek, M. [AGH University of Science and Technology, Krakow (Poland); Blocki, J.; Mach, E.; Michalowski, J.; Niemiec, J.; Skowron, K.; Stodulski, M. [Instytut Fizyki Jadrowej im. H. Niewodniczanskiego Polskiej Akademii Nauk, Krakow (Poland); Bogacz, L. [Jagiellonian University, Department of Information Technologies, Krakow (Poland); Borkowski, J.; Frankowski, A.; Janiak, M.; Moderski, R. [Polish Academy of Science, Nicolaus Copernicus Astronomical Center, Warsaw (Poland); Bulik, T.; Grudzinska, M. [University of Warsaw, Astronomical Observatory, Warsaw (Poland); Mandat, D.; Pech, M.; Schovanek, P. [Institute of Physics of the Czech Academy of Sciences, Prague (Czech Republic); Marszalek, A.; Stodulska, M. [Instytut Fizyki Jadrowej im. H. Niewodniczanskiego Polskiej Akademii Nauk, Krakow (Poland); Jagellonian University, Astronomical Observatory, Krakow (Poland); Pasko, P.; Seweryn, K. [Centrum Badan Kosmicznych Polskiej Akademii Nauk, Warsaw (Poland); Sliusar, V. [Universite de Geneve, Department of Astronomy, Geneva (Switzerland); Taras Shevchenko National University of Kyiv, Astronomical Observatory, Kyiv (Ukraine)

2017-01-15

The single-mirror small-size telescope (SST-1M) is one of the three proposed designs for the small-size telescopes (SSTs) of the Cherenkov Telescope Array (CTA) project. The SST-1M will be equipped with a 4 m-diameter segmented reflector dish and an innovative fully digital camera based on silicon photo-multipliers. Since the SST sub-array will consist of up to 70 telescopes, the challenge is not only to build telescopes with excellent performance, but also to design them so that their components can be commissioned, assembled and tested by industry. In this paper we review the basic steps that led to the design concepts for the SST-1M camera and the ongoing realization of the first prototype, with focus on the innovative solutions adopted for the photodetector plane and the readout and trigger parts of the camera. In addition, we report on results of laboratory measurements on real scale elements that validate the camera design and show that it is capable of matching the CTA requirements of operating up to high moonlight background conditions. (orig.)

Standardization of the intrinsic uniformity control of the gamma cameras

International Nuclear Information System (INIS)

Solsona Harster, Lluis; Llopis Gonzalez, David; Pavia Segura, Javier

2001-01-01

Objective: To verify the Intrinsic Uniformity (Iu) results using different acquisition parameters in the weekly gamma camera Quality Control (Qc). Material And Methods: We made 4 experiments using Tc99 sources and modifying the orientation, distance, activity an volume parameters of a source in ten detectors with I Na photomultipliers applying the following acquisition conditions: 4000 Kc, the source 2 m far from the geometrical centre of the detectors, 0.1 ml into 1 ml syringe, and 150 Tc99m ?Ci. Results: We found better results when the distance between detector/source is getting longer, but the better point we found between 1,5 and 2 m. We also found necessary the collimator position was parallel respect to the geometrical centre field of view, because a little deviation of only two degrees can offer a bad result between +0.5%. We study the dose that we should use, and the results show us that better results are not in the highest or smallest values of activity into the source. In volume parameters, we can see that if we use a source highest than 1 ml we obtained better results. Conclusion: Following our results in the variation of IU values as for as the distance, rotation detector/source, dose and source activity, we recommend to perform this QC applying NEMA rules in same conditions every week and using the different parameters of our study to obtain better IU (Au)

Relationship between image quality and changes in spatial resolution for the gamma camera

International Nuclear Information System (INIS)

Ikeda, Hozumi; Kishimoto, Kenji; Shimonishi, Yoshihiro; Ohmura, Masahiro; Kosakai, Kazuhisa; Hamada, Kunio; Ochi, Hironobu.

1989-01-01

The purpose of this study is to examine quantitatively the relationship between visual image quality and degradation in spatial resolution for a gamma camera by the increase in distance from collimator. The relationship between the proportion (p) of images identified the difference of image quality and the difference (δFWHM) in FWHM between paired images was showed in a sigmoid curve. Using Dendy's method, minimum level to be correctly identified the difference of image quality on three out of four occasions (p=0.75) was corresponded to 0.4 mm in δFWHM. Using fuzzy theory, the level to be identified the difference of image quality was examind under various conditions. The truth-value of fuzzy sets-degraded or slightly degraded and not-degraded in image quality between paired images-was gained the peak at 0.5 mm of δFWHM. It was founded that changes of 0.4-0.5 mm in FWHM-corresponding about 2 cm distance from collimator-could be sufficiently identified in the difference of image quality. (author)

Cerebral emission computer tomography with a rotating gamma camera: clinic results with J-123 Isopropylamphetamin and J-123-Fenetyllin

International Nuclear Information System (INIS)

Biersack, H.J.; Hartmann, A.; Froescher, W.; Reske, S.-N.; Reichmann, K.; Knopp, R.; Winkler, C.

1984-01-01

Many amines can pass the blood brain barrier and accumulate in relatively large amounts in the brain tissue. For about 2 years 123-J amphetamines have, therefore, been used for brain imaging by several teams. Our experience sofar is based on 28 patients. Of these, 14 were epileptics, 10 had cerebrovascular diseases, 2 suffered from migraine and another 2 had brain tumors. In 3 patients with vascular lesions studies were repeated twice or three times. Amphetamine uptake in the brain was measured with a rotating gamma camera system (Gammatome T9000/CGR). At an examination time of 20 minutes 64 frames were acquired during one full rotation. The pulse rate was about 3000 second after injecting 6.5 mCi of 123-J amphetamine. Of the epileptics, 8 showed defects both on CT and SPECT, in 3 cases both studies were normal. While 1 patient with CT positivity had a normal SPECT, 2 cases were found to have lesions on SPECT inspite of a normal CT. The size of the lesion seen on amphetamine SPECT was lager than on CT in 3 of 9 patients. In the 10 patients with cerebrovascular lesions the 2 procedures showed concordant normal patterns in 1 and concordant abnormal patterns in 7 instances. 2 patients with normal CT were found to have a lesion on amphetamine scanning which corresponded to the neurologic findings. Regarding the size of the lesions, SPECT showed a more extensive involvement than CT in 2 cases. This again was in good agreement with the neurologic findings. Inspite of repeat studies cerebellar diaschisis was only seen in a single case with healed cerebral infarction and hemiplegia of some years' standing. Two patients suffered from migraine and compromised blood flow was identified as suggested by the neurologic findings inspite of a normal CT. (Author)

FDG scan on an ordinary coincidence gamma camera (CDET) -preliminary data in pulmonary or colorectal cancer

Energy Technology Data Exchange (ETDEWEB)

Montravers, F.; Grahek, D.; Ghazzar, N.; Younsi, N.; Kerrou, K.; Talbot, J.N. [Hopital Tenon, 75 - Paris (France). Services de Medecine Nucleaire; Wartski, M.; Zerbib, E. [Hopital Marie Lannelongue Le Plessis Robinson (France); Lumbroso, J. [Institut Gustave Roussy Villejuif (France)

1997-12-31

Full text. The purpose of this study to evaluate the impact of FDG scan performed on an ordinary CDET gamma camera on the therapeutic management of patients with pulmonary nodules or with suspicion of recurrent colorectal carcinoma. Methods: two tomoscintigrams (thorax and abdomen) were acquired, using a PICKER Prism XP 2000 coincidence gamma camera, 45 m after i.v. injection of 100-150 MBq of {sup 18} F-FDG in fasting patients. The 21 pts were explored in July or August 1997. Preliminary results: among 12 patients with pulmonary nodules, the planed surgery was replaced by chemotherapy after visualization of unknown metastases accumulating FDG in 3 patients. In another one, the high uptake of FDG by a lung nodule which has been known for 6 years, led to surgery and objectivation of an adenocarcinoma. In one case, the absence of FDG uptake corresponded to an abscess (true negative result). In the other 7 patients, the indication of surgery was confirmed but the procedure was modified in 2 cases. In case of suspicion of recurrent colorectal carcinoma (9 patients), the finding of a single focus of FDG uptake whereas CT scan was negative or inconclusive let do the decision of surgery in 3 patients. In one patient with pelvic pain without increase of tumor markers levels and with normal CT scan, a normal FDG scan confirmed the physician`s hypothesis of pain due to the previous therapy but do not recurrence. In one patient, the finding of 3 foci of uptake of FDG whereas CT scan was inconclusive confirmed the indication of chemotherapy. In 2 patients with FDG abdominal foci without morphologic abnormalities, the therapeutic strategy is not yet decided in 2 patients, no foci could be found. In conclusion, these preliminary results show that FDG scan has provided a help to the physician indecision-making for therapeutic strategy in 8 patients on 21 (38%) and a help to the surgeon in 2 more cases (48% as a whole)

FDG scan on an ordinary coincidence gamma camera (CDET) -preliminary data in pulmonary or colorectal cancer

International Nuclear Information System (INIS)

Montravers, F.; Grahek, D.; Ghazzar, N.; Younsi, N.; Kerrou, K.; Talbot, J.N.; Lumbroso, J.

1997-01-01

Full text. The purpose of this study to evaluate the impact of FDG scan performed on an ordinary CDET gamma camera on the therapeutic management of patients with pulmonary nodules or with suspicion of recurrent colorectal carcinoma. Methods: two tomoscintigrams (thorax and abdomen) were acquired, using a PICKER Prism XP 2000 coincidence gamma camera, 45 m after i.v. injection of 100-150 MBq of 18 F-FDG in fasting patients. The 21 pts were explored in July or August 1997. Preliminary results: among 12 patients with pulmonary nodules, the planed surgery was replaced by chemotherapy after visualization of unknown metastases accumulating FDG in 3 patients. In another one, the high uptake of FDG by a lung nodule which has been known for 6 years, led to surgery and objectivation of an adenocarcinoma. In one case, the absence of FDG uptake corresponded to an abscess (true negative result). In the other 7 patients, the indication of surgery was confirmed but the procedure was modified in 2 cases. In case of suspicion of recurrent colorectal carcinoma (9 patients), the finding of a single focus of FDG uptake whereas CT scan was negative or inconclusive let do the decision of surgery in 3 patients. In one patient with pelvic pain without increase of tumor markers levels and with normal CT scan, a normal FDG scan confirmed the physician's hypothesis of pain due to the previous therapy but do not recurrence. In one patient, the finding of 3 foci of uptake of FDG whereas CT scan was inconclusive confirmed the indication of chemotherapy. In 2 patients with FDG abdominal foci without morphologic abnormalities, the therapeutic strategy is not yet decided in 2 patients, no foci could be found. In conclusion, these preliminary results show that FDG scan has provided a help to the physician indecision-making for therapeutic strategy in 8 patients on 21 (38%) and a help to the surgeon in 2 more cases (48% as a whole)

Imaging performance comparison between a LaBr3: Ce scintillator based and a CdTe semiconductor based photon counting compact gamma camera.

Science.gov (United States)

Russo, P; Mettivier, G; Pani, R; Pellegrini, R; Cinti, M N; Bennati, P

2009-04-01

The authors report on the performance of two small field of view, compact gamma cameras working in single photon counting in planar imaging tests at 122 and 140 keV. The first camera is based on a LaBr3: Ce scintillator continuous crystal (49 x 49 x 5 mm3) assembled with a flat panel multianode photomultiplier tube with parallel readout. The second one belongs to the class of semiconductor hybrid pixel detectors, specifically, a CdTe pixel detector (14 x 14 x 1 mm3) with 256 x 256 square pixels and a pitch of 55 microm, read out by a CMOS single photon counting integrated circuit of the Medipix2 series. The scintillation camera was operated with selectable energy window while the CdTe camera was operated with a single low-energy detection threshold of about 20 keV, i.e., without energy discrimination. The detectors were coupled to pinhole or parallel-hole high-resolution collimators. The evaluation of their overall performance in basic imaging tasks is presented through measurements of their detection efficiency, intrinsic spatial resolution, noise, image SNR, and contrast recovery. The scintillation and CdTe cameras showed, respectively, detection efficiencies at 122 keV of 83% and 45%, intrinsic spatial resolutions of 0.9 mm and 75 microm, and total background noises of 40.5 and 1.6 cps. Imaging tests with high-resolution parallel-hole and pinhole collimators are also reported.

Use of gamma probe in 131I thyroid uptake studies

International Nuclear Information System (INIS)

Sarmento, Andrea Gondim Leitao

2002-11-01

Evaluation of thyroid uptake by administration of radioactive iodine is a well-defined procedure to assess patient thyroid function. In general, nuclear medicine institutions use gamma cameras coupled to pinhole collimators to perform uptake studies. With the growing use of intraoperative gamma probes in the radioguided surgical techniques, several institutions are purchasing this new and portable equipment, which can technically be also employed to assess patient's thyroid function, permitting further other applications of gamma cameras. The aim of the study was to compare thyroid uptake trails carried out with both gamma camera and intraoperative gamma probe, in order to evaluate the possible use of gamma probe for this purpose. At first a preliminary study of feasibility was carried out using a neck phantom to verify equipment efficiency with known activities of 131 I. Henceforth, work data from 12 patients undergone studies of thyroid uptakes were evaluated, 24 hours after oral administration of 370 kBq of 131 I. The maximum difference observed between the values obtained with both equipment was 60%, which demonstrated the feasibility of the proposed protocol and made clear that gamma probe can be useful for thyroid uptake studies. (author)

Dosimetry computer module of the gamma irradiator of ININ

International Nuclear Information System (INIS)

Ledezma F, L. E.; Baldomero J, R.; Agis E, K. A.

2012-10-01

This work present the technical specifications for the upgrade of the dosimetry module of the computer system of the gamma irradiator of the Instituto Nacional de Investigaciones Nucleares (ININ) whose result allows the integration and consultation of information in industrial dosimetry subject under an outline client-server. (Author)

Head-positioning scintillation camera and head holder therefor

International Nuclear Information System (INIS)

Kay, T.D.

1976-01-01

A holder for immobilizing the head of a patient undergoing a vertex brain scan by a Gamma Scintillation Camera is described. The holder has a uniquely designed shape capable of comfortably supporting the head. In addition, this holder can be both adjustably and removably utilized in combination with the scintillation camera so as to enable the brain scan operation to take place while the patient is in the seated position

Quality assurance procedure for a gamma guided stereotactic breast biopsy system.

Science.gov (United States)

Welch, Benjamin L; Brem, Rachel; Black, Rachel; Majewski, Stan

2006-01-01

A quality assurance procedure has been developed for a prototype gamma-ray guided stereotactic biopsy system. The system consists of a compact small-field-of-view gamma-ray camera mounted to the rotational arm of a Lorad stereotactic biopsy system. The small-field-of-view gamma-ray camera has been developed for clinical applications where mammographic X-ray localization is not possible. Marker sources that can be imaged with the gamma-camera have been designed and built for quality assurance testing and to provide a fiducial reference mark. An algorithm for determining the three dimensional location of a region of interest, such as a lesion, relative to the fiducial mark has been implemented into the software control of the camera. This system can be used to determine the three-dimensional location of a region of interest from a stereo pair of images and that information can be used to guide a biopsy needle to that site. Point source phantom tests performed with the system have demonstrated that the camera can be used to localize a point of interest to within 1 mm, which is satisfactory for its use in needle localization.

Computer code for qualitative analysis of gamma-ray spectra

International Nuclear Information System (INIS)

Yule, H.P.

1979-01-01

Computer code QLN1 provides complete analysis of gamma-ray spectra observed with Ge(Li) detectors and is used at both the National Bureau of Standards and the Environmental Protection Agency. It locates peaks, resolves multiplets, identifies component radioisotopes, and computes quantitative results. The qualitative-analysis (or component identification) algorithms feature thorough, self-correcting steps which provide accurate isotope identification in spite of errors in peak centroids, energy calibration, and other typical problems. The qualitative-analysis algorithm is described in this paper

Developments in mercuric iodide gamma ray imaging

Energy Technology Data Exchange (ETDEWEB)

Patt, B E; Beyerle, A G; Dolin, R C; Ortale, C [EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations

1989-11-01

A mercuric iodide (HgI{sub 2}) gamma ray imaging array and camera system previously described have been characterized for spatial and energy resolution. Based on these data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criteria for the new camera will be presented. (orig.).