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Sample records for head pinhole spect

  1. Simulation study on a stationary data acquisition SPECT system with multi-pinhole collimators attached to a triple-head gamma camera system.

    Science.gov (United States)

    Ogawa, Koichi; Ichimura, Yuta

    2014-10-01

    The aim of the study was to develop a new SPECT system that makes it possible to acquire projection data stationary using a triple-head gamma camera system. We evaluated several data acquisition geometry with multi-pinhole collimators attached to a triple-head gamma camera system. The number of pinholes for each camera was three to twelve, and we located these holes on collimator plates adequately. These collimator holes were tilted by predefined angles to efficiently cover the field of view of the data acquisition system. Acquired data were reconstructed with the OS-EM method. In the simulations, we used a three-dimensional point source phantom, brain phantom, and myocardial phantom. Attenuation correction was conducted with the x-ray CT image of the corresponding slice. Reconstructed images of the point source phantom showed that the spatial resolution could be improved with the small number of pinholes. On the other hand, reconstructed images of the brain phantom showed that the large number of pinholes yielded images with less artifact. The results of the simulations with the myocardial phantom showed that more than eight pinholes could yield an accurate distribution of activity when the source was distributed only in the myocardium. The results of the simulations confirmed that more than eight pinholes for each detector were required to reconstruct an artifact free image in the triple-head SPECT system for imaging of brain and myocardium.

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

    NARCIS (Netherlands)

    Wu, Chao; van der Have, Frans; Vastenhouw, Brendan; Dierckx, Rudi A. J. O.; Paans, Anne M. J.; Beekman, Freek J.

    2010-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  4. Optimization of geometrical calibration in pinhole SPECT.

    Science.gov (United States)

    Bequé, Dirk; Nuyts, Johan; Suetens, Paul; Bormans, Guy

    2005-02-01

    Previously, we developed a method to determine the acquisition geometry of a pinhole camera. This information is needed for the correct reconstruction of pinhole single photon emission computed tomography images. The method uses a calibration phantom consisting of three point sources and their positions in the field of view (FOV) influence the accuracy of the geometry estimate. This paper proposes two particular configurations of point sources with specific positions and orientations in the FOV for optimal image reconstruction accuracy. For the proposed calibration setups, inaccuracies of the geometry estimate due to noise in the calibration data, only cause subresolution inaccuracies in reconstructed images. The calibration method also uses a model of the point source configuration, which is only known with limited accuracy. The study demonstrates, however, that, with the proposed calibration setups, the error in reconstructed images is comparable to the error in the phantom model.

  5. A detector response function design in pinhole SPECT including geometrical calibration.

    Science.gov (United States)

    El Bitar, Z; Huesman, R H; Boutchko, R; Bekaert, Virgile; Brasse, David; Gullberg, G T

    2013-04-07

    Clinical single photon emission computed tomography (SPECT) equipped with pinhole collimators have a magnification factor that results in high spatial resolution images for small animal imaging. Using Monte Carlo simulations to model the acquisition process and the propagation of the photons from their point of emission to their detection point then integrating the model into an iterative reconstruction algorithm improves the signal-to-noise ratio, the contrast and the spatial resolution in the reconstructed images. However, pinhole SPECT systems are known to be very sensitive to geometrical misalignments. Geometrical misalignments are defined as the radial or axial shift of the collimator pinhole and/or twist and tilt of the detector heads and are introduced in the system each time the collimation device is changed (pinhole to parallel holes or vice versa). In this work, we present a flexible detector response function table (DRFT) design that takes into account the geometrical misalignments and avoids performing new Monte Carlo simulations for each exam in order to calculate a geometrical study-dependent system matrix. The utilization of the DRFT for the calculation of the system matrix speeds up its computation time by two orders of magnitude making it acceptable for preclinical and clinical applications.

  6. {sup 99m}Tc-MIBI pinhole SPECT in primary hyperparathyroidism: comparison with conventional SPECT, planar scintigraphy and ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, Thomas; Bodet-Milin, Caroline; Kraeber-Bodere, Francoise; Ansquer, Catherine [Hotel Dieu University Hospital, Nuclear Medicine Department, Nantes (France); INSERM CRCNA, Nantes (France); Oudoux, Aurore [Hotel Dieu University Hospital, Nuclear Medicine Department, Nantes (France); Mirallie, Eric [Hotel Dieu University Hospital, Surgery Department, Nantes (France); Seret, Alain [University of Liege, Institute of Physics, Experimental Medical Imaging, Liege (Belgium); Daumy, Isabelle [Ultrasonography Center, Nantes (France); Leux, Christophe [Saint Jacques University Hospital, PIMESP, Nantes (France)

    2008-03-15

    A pinhole collimator is routinely used to increase the resolution of scintigraphy. This prospective study was conducted to determine the interest of {sup 99m}Tc-MIBI pinhole single-photon emission computed tomography (SPECT) for the preoperative localisation of parathyroid lesions in primary hyperparathyroidism. All patients underwent a neck ultrasonography (US), {sup 99m}TcO{sub 4}{sup -} and {sup 99m}Tc-MIBI planar images and two consecutive SPECT with a parallel (C-SPECT) and a pinhole collimator (P-SPECT). P-SPECT was performed with a tilted detector equipped with a pinhole collimator and reconstructed with a dedicated OSEM algorithm. A diagnostic confidence score (CS) was assigned to each procedure considering intensity and extra-thyroidal location of suspected lesions: 0 = negative, 1 = doubtful, 2 = moderately positive, 3 = positive. The results of these preoperative localisation studies were compared with surgical, pathological and 6-month biological findings. Fifty-one patients cured after surgery were included. Surgery revealed 55 lesions (median weight 0.5 g, 11 in ectopy). Sensitivities of US, planar imaging, C-SPECT and P-SPECT were, respectively, 51, 76, 82 and 87%. Nine glands were only detected by tomography and five glands only by P-SPECT. {sup 99m}Tc-MIBI/{sup 99m}TcO{sub 4}{sup -} planar scans and P-SPECT were complementary and, when combined together, showed the highest sensitivity (93%). Compared with planar imaging and C-SPECT, P-SPECT increased CS for 42 and 53% of lesions, respectively, and contributed to markedly reduce the number of uncertain results. A combination of planar {sup 99m}Tc-MIBI/{sup 99m}TcO{sub 4}{sup -} scintigraphy and P-SPECT appears to be a highly accurate preoperative imaging procedure in primary hyperparathyroidism. (orig.)

  7. PET-based geometrical calibration of a pinhole SPECT add-on for an animal PET scanner.

    Science.gov (United States)

    Deng, Xiao; Beaudoin, Jean-François; Cadorette, Jules; Naaman, Charles; Lecomte, Roger; Yao, Rutao

    2013-04-07

    We developed SPECT imaging capability on an animal PET scanner to provide a cost effective option for animal SPECT imaging. The SPECT add-on sub-system was enabled by mechanically integrating a multiple-pinhole collimator in the PET detector ring. This study introduces a method to calibrate the geometrical parameters of the SPECT add-on using the PET imaging capability of the scanner. The proposed PET imaging-based calibration method consists of two steps: (1) paint the pinhole apertures of the collimator with a positron emitting radioactive solution; and (2) image the collimator inside the scanner in PET mode. The geometrical parameters of the multi-pinhole SPECT add-on can then be derived directly from a set of PET images by simple linear calculation and used in defining the SPECT system. The method was compared to our implementation of a SPECT calibration approach with model-based fitting of SPECT projection data. The procedure for carrying out the PET imaging-based calibration method is simpler and faster than that of our implementation of the SPECT model-based calibration method. Since it does not require model fitting, the uniqueness of the calibration result is warranted. Better quality SPECT images were reconstructed using the PET-derived calibration parameters rather than our implementation of the SPECT model-based calibration parameters. We conclude that the proposed PET imaging-based calibration method provides a highly effective means for enabling SPECT imaging on a PET scanner.

  8. Use of a compact pixellated gamma camera for small animal pinhole SPECT imaging.

    Science.gov (United States)

    Zeniya, Tsutomu; Watabe, Hiroshi; Aoi, Toshiyuki; Kim, Kyeong Min; Teramoto, Noboru; Takeno, Takeshi; Ohta, Yoichiro; Hayashi, Takuya; Mashino, Hiroyuki; Ota, Toshihiro; Yamamoto, Seiichi; Iida, Hidehiro

    2006-07-01

    Pinhole SPECT which permits in vivo high resolution 3D imaging of physiological functions in small animals facilitates objective assessment of pharmaceutical development and regenerative therapy in pre-clinical trials. For handiness and mobility, the miniature size of the SPECT system is useful. We developed a small animal SPECT system based on a compact high-resolution gamma camera fitted to a pinhole collimator and an object-rotating unit. This study was aimed at evaluating the basic performance of the detection system and the feasibility of small animal SPECT imaging. The gamma camera consists of a 22 x 22 pixellated scintillator array of 1.8 mm x 1.8 mm x 5 mm NaI(Tl crystals with 0.2-mm gap between the crystals coupled to a 2" flat panel position-sensitive photomultiplier tube (Hamamatsu H8500) with 64 channels. The active imaging region of the camera was 43.8 mm x 43.8 mm. Data acquisition is controlled by a personal computer (Microsoft Windows) through the camera controller. Projection data over 360 degrees for SPECT images are obtained by synchronizing with the rotating unit. The knife-edge pinhole collimators made of tungsten are attached on the camera and have 0.5-mm and 1.0-mm apertures. The basic performance of the detection system was evaluated with 99mTc and 201Tl solutions. Energy resolution, system spatial resolution and linearity of count rate were measured. Rat myocardial perfusion SPECT scans were sequentially performed following intravenous injection of 201TlCl. Projection data were reconstructed using a previously validated pinhole 3D-OSEM method. The energy resolution at 140 keV was 14.8% using a point source. The system spatial resolutions were 2.8-mm FWHM and 2.5-mm FWHM for 99mTc and 201Tl line sources, respectively, at 30-mm source distance (magnification factor of 1.3) using a 1.0-mm pinhole. The linearity between the activity and count rate was good up to 10 kcps. In a rat study, the left ventricular walls were clearly visible in all

  9. A line-source method for aligning on-board and other pinhole SPECT systems

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Susu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Bowsher, James; Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 and Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2013-12-15

    Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems.Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot.Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by

  10. 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)

  11. Imaging of intestinal lymphocyte homing by means of pinhole SPECT in a TNBS colitis mouse model

    Energy Technology Data Exchange (ETDEWEB)

    Bennink, Roelof J. E-mail: r.bennink@amc.uva.nl; Montfrans, Catherine van; Jonge, Wouter J. de; Bruin, Kora de; Deventer, Sander J. van; Velde, Anje A. te

    2004-01-01

    Background and aims: The increasing knowledge of the molecular basis of leukocyte trafficking results in the development of novel anti-inflammatory strategies for inflammatory bowel disease (IBD). For optimal evaluation of therapy efficacy, information about inflammatory activity in bowel segments or lymphocyte recirculation and kinetics in the follow-up of experimental treatment for IBD is needed. The aim of this study was to evaluate a non-invasive scintigraphic technique, able to assess lymphocyte trafficking in a trinitrobenzene sulfonic acid (TNBS) induced mouse colitis model of IBD. Methods: TNBS sensitized and non-sensitized murine total splenocytes were labeled in vitro with {sup 111}In-oxine and injected into either control or TNBS colitis BALB/c mice. Biodistribution and specific radioactive uptake, representing transferred cells, were determined by serial dedicated animal planar scintigraphy and pinhole SPECT of the abdomen 4, 24 and 48h post injection of labeled cells. In addition, the severity of inflammation was. Results: Migration of {sup 111}In labeled splenocytes to the colon increased in time and was maximal at 48h after administration. The highest specific radioactive uptake ratio in the colon after 48h was observed in mice with TNBS colitis that received TNBS sensitized lymphocytes. Histological scoring confirmed the presence of colitis in the TNBS treated groups. Conclusion: Homing of TNBS-sensitized lymphocytes can be assessed in vivo by means of dedicated animal pinhole SPECT. Generally, this technique enables serial measurement of specific cell trafficking with potential of in vivo evaluation of novel anti-inflammatory strategies in inflammatory bowel disease.

  12. {sup 99m}Tc-M.I.B.I. pinhole SPECT in primary hyperparathyroidism; Tomographie stenopeique au {sup 99m}Tc-MIBI dans l'hyperparathyroidie primaire

    Energy Technology Data Exchange (ETDEWEB)

    Oudoux, A.; Carlier, T.; Bodet-Milin, C.; Kraeber-Bodere, F.; Ansquer, C. [Centre Hospitalier Universitaire, Service de Medecine Nucleaire, Hotel-Dieu, 44 - Nantes (France); Mirallie, E. [Centre Hospitalier Universitaire, Service de Chirurgie, Hotel-Dieu, 44 - Nantes (France); Seret, A. [Liege Univ. (Belgium). Inst. de Physique; Aubron, F.; Daumy, I. [Centre d' Echographie de l' ile Gloriette, 44 - Nantes (France); Leux, C. [Centre Hospitalier Universitaire, PIMESP, Hopital Saint-Jacques, 44 - Nantes (France)

    2007-10-15

    Purpose: this prospective study was conducted to determine the interest of 99 mTc-M.I.B.I. pinhole SPECT compared with conventional SPECT, planar scintigraphy and ultrasonography, for the preoperative localization of parathyroid lesions in primary hyperparathyroidism. Methods: fifty-one patients cured after surgery were studied. Pinhole SPECT was reconstructed with a dedicated O.S.E.M. algorithm. Scintigraphies were analyzed visually. A diagnostic confidence score (C.S.) was assigned to each procedure considering intensity and extra thyroidal location of suspected lesions and was defined as follows: 0 = negative, 1 = doubtful, 2 = moderately positive, 3 positive. Results: surgery revealed 55 lesions. Sensitivity of ultrasonography, planar imaging, conventional SPECT and pinhole SPECT were respectively, 51, 76, 82 and 87%. Five glands were only detected by pinhole SPECT. Combination of ultrasonography, planar and pinhole SPECT showed the highest sensitivity (94.5%). The mean C.S. of the 55 pathologic glands was significantly higher with pinhole SPECT compared with planar imaging and conventional SPECT (p < 0.0001). Compared with planar imaging and conventional SPECT, pinhole SPECT increased C.S. for 42 and 53% of parathyroid lesions, respectively, and contributed to markedly reduce the number of uncertain results. Nevertheless, planar imaging and ultrasonography were useful to analyze thyroid morphology and to detect some ectopic glands. Conclusion: the use of pinhole SPECT increases sensitivity and C.S. of scintigraphy. Combination of ultrasonography, planar and pinhole SPECT appears the optimal preoperative imaging procedure in primary hyperparathyroidism. (authors)

  13. Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Spain and Grupo de Imaxe Molecular, IDIS, Santiago de Compostela 15706 (Spain); Pino, Francisco [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Spain and Servei de Física Médica i Protecció Radiológica, Institut Catalá d' Oncologia, Barcelona 08036 (Spain); Silva-Rodríguez, Jesús [Fundación Ramón Domínguez, Medicina Nuclear, CHUS, Santiago de Compostela 15706 (Spain); Pavía, Javier [Servei de Medicina Nuclear, Hospital Clínic, Barcelona (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ros, Doménec [Unitat de Biofísica, Facultat de Medicina, Casanova 143 (Spain); Institut d' Investigacions Biomèdiques August Pí i Sunyer (IDIBAPS) (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Ruibal, Álvaro [Servicio Medicina Nuclear, CHUS (Spain); Grupo de Imaxe Molecular, Facultade de Medicina (USC), IDIS, Santiago de Compostela 15706 (Spain); Fundación Tejerina, Madrid (Spain); and others

    2014-03-15

    Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the

  14. Pinhole SPECT imaging of dopamine transporters correlates with dopamine transporter immunohistochemical analysis in the MPTP mouse model of Parkinson's disease.

    Science.gov (United States)

    Andringa, Gerda; Drukarch, Benjamin; Bol, John G J M; de Bruin, Kora; Sorman, Karolina; Habraken, Jan B A; Booij, Jan

    2005-07-15

    The in vivo analysis of dopaminergic degeneration in animal models of Parkinson's disease (PD), using pinhole single photon emission computed tomography (SPECT), ideally should afford a serial study design, enabling the analysis of the degenerative process as well as the potential neuroprotective and/or restorative properties of drugs over time in living animals. Previously, we demonstrated that striatal dopamine transporter (DAT) levels in rats could be analyzed reproducibly, using pinhole SPECT with the DAT probe [(123)I]N-omega-fluoropropyl-2beta-carbomethoxy-3beta-{4-iodophenyl}nortropane (FP-CIT). However, the capacity of this approach to accurately detect a range of striatal DAT levels in the most widely used animal model of PD, i.e., the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mouse, remains to be determined. For this purpose, various levels of DAT were induced by treating c57BL/6J mice for 1, 3, or 5 days with MPTP (25 mg/kg ip), respectively. [(123)I]FP-CIT SPECT scans were performed 5 days after the last MPTP injection. Mice were perfused 6 days after the last MPTP injection, and the SPECT data were compared to ex vivo striatal and nigral DAT levels as measured by immunohistochemistry within the same animals. The analysis of striatal DAT levels using SPECT and DAT immunohistochemistry yielded highly comparable results on the percentage of DAT reduction in each MPTP group. The in vivo data showed a decrease of specific striatal to non-specific binding ratios by 59%, 82%, and 76% in mice treated for 1, 3, and 5 days, respectively. Moreover, a strong, positive correlation was observed between the in vivo and ex vivo parameters. The present study provides the first evidence that [(123)I]FP-CIT pinhole SPECT allows the accurate detection of a range of striatal DAT (i.e., losses of approximately 60-80%) levels in mice. Since such large dopaminergic lesions could be detected, this SPECT method may at least be useful for analyzing

  15. In vivo imaging of dopamine transporter function in rat striatum using pinhole SPECT and 123I-beta-CIT coregistered with small animal MRI

    CERN Document Server

    Dierkes, K

    2001-01-01

    The aim of this study was to establish in vivo imaging of dopamine transporter function in a small animal model of Parkinson's disease using pinhole SPECT and 123I labeled beta-CIT. Since functional imaging of small animals can hardly be interpreted without localization to related anatomical structures, MRI-SPECT coregistration secondly was established as an inexpensive tool for in vivo monitoring of physiological and pathological alterations in striatal dopamine transporters using beta-CIT as an specific radionuclear ligand.

  16. Improved image quality in pinhole SPECT by accurate modeling of the point spread function in low magnification systems

    Energy Technology Data Exchange (ETDEWEB)

    Pino, Francisco [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Barcelona 08036, Spain and Servei de Física Mèdica i Protecció Radiològica, Institut Català d’Oncologia, L’Hospitalet de Llobregat 08907 (Spain); Roé, Nuria [Unitat de Biofísica, Facultat de Medicina, Universitat de Barcelona, Barcelona 08036 (Spain); Aguiar, Pablo, E-mail: pablo.aguiar.fernandez@sergas.es [Fundación Ramón Domínguez, Complexo Hospitalario Universitario de Santiago de Compostela 15706, Spain and Grupo de Imagen Molecular, Instituto de Investigacións Sanitarias de Santiago de Compostela (IDIS), Galicia 15782 (Spain); Falcon, Carles; Ros, Domènec [Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain and CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); Pavía, Javier [Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 080836 (Spain); CIBER en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona 08036 (Spain); and Servei de Medicina Nuclear, Hospital Clínic, Barcelona 08036 (Spain)

    2015-02-15

    Purpose: Single photon emission computed tomography (SPECT) has become an important noninvasive imaging technique in small-animal research. Due to the high resolution required in small-animal SPECT systems, the spatially variant system response needs to be included in the reconstruction algorithm. Accurate modeling of the system response should result in a major improvement in the quality of reconstructed images. The aim of this study was to quantitatively assess the impact that an accurate modeling of spatially variant collimator/detector response has on image-quality parameters, using a low magnification SPECT system equipped with a pinhole collimator and a small gamma camera. Methods: Three methods were used to model the point spread function (PSF). For the first, only the geometrical pinhole aperture was included in the PSF. For the second, the septal penetration through the pinhole collimator was added. In the third method, the measured intrinsic detector response was incorporated. Tomographic spatial resolution was evaluated and contrast, recovery coefficients, contrast-to-noise ratio, and noise were quantified using a custom-built NEMA NU 4–2008 image-quality phantom. Results: A high correlation was found between the experimental data corresponding to intrinsic detector response and the fitted values obtained by means of an asymmetric Gaussian distribution. For all PSF models, resolution improved as the distance from the point source to the center of the field of view increased and when the acquisition radius diminished. An improvement of resolution was observed after a minimum of five iterations when the PSF modeling included more corrections. Contrast, recovery coefficients, and contrast-to-noise ratio were better for the same level of noise in the image when more accurate models were included. Ring-type artifacts were observed when the number of iterations exceeded 12. Conclusions: Accurate modeling of the PSF improves resolution, contrast, and recovery

  17. Targeting murine heart and brain: visualisation conditions for multi-pinhole SPECT with (99m)Tc- and (123)I-labelled probes.

    Science.gov (United States)

    Pissarek, M; Meyer-Kirchrath, J; Hohlfeld, T; Vollmar, S; Oros-Peusquens, A M; Flögel, U; Jacoby, C; Krügel, U; Schramm, N

    2009-09-01

    The study serves to optimise conditions for multi-pinhole SPECT small animal imaging of (123)I- and (99m)Tc-labelled radiopharmaceuticals with different distributions in murine heart and brain and to investigate detection and dose range thresholds for verification of differences in tracer uptake. A Triad 88/Trionix system with three 6-pinhole collimators was used for investigation of dose requirements for imaging of the dopamine D(2) receptor ligand [(123)I]IBZM and the cerebral perfusion tracer [(99m)Tc]HMPAO (1.2-0.4 MBq/g body weight) in healthy mice. The fatty acid [(123)I]IPPA (0.94 +/- 0.05 MBq/g body weight) and the perfusion tracer [(99m)Tc]sestamibi (3.8 +/- 0.45 MBq/g body weight) were applied to cardiomyopathic mice overexpressing the prostaglandin EP(3) receptor. In vivo imaging and in vitro data revealed 45 kBq total cerebral uptake and 201 kBq cardiac uptake as thresholds for visualisation of striatal [(123)I]IBZM and of cardiac [(99m)Tc]sestamibi using 100 and 150 s acquisition time, respectively. Alterations of maximal cerebral uptake of [(123)I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake. The labelling with [(99m)Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [(123)I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight. Multi-pinhole SPECT enables detection of alterations of the cerebral uptake of (123)I- and (99m)Tc-labelled tracers in an appropriate dose range in murine models targeting physiological processes in brain and heart. The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers.

  18. Optimization of pinhole single photon emission computed tomography (pinhole SPECT) reconstruction; Optimisation de la reconstruction en tomographie d'emission monophotonique avec colimateur stenope

    Energy Technology Data Exchange (ETDEWEB)

    Israel-Jost, V

    2006-11-15

    In SPECT small animal imaging, it is highly recommended to accurately model the response of the detector in order to improve the low spatial resolution. The volume to reconstruct is thus obtained both by back-projecting and de-convolving the projections. We chose iterative methods, which permit one to solve the inverse problem independently from the model's complexity. We describe in this work a Gaussian model of point spread function (PSF) whose position, width and maximum are computed according to physical and geometrical parameters. Then we use the rotation symmetry to replace the computation of P projection operators, each one corresponding to one position of the detector around the object, by the computation of only one of them. This is achieved by choosing an appropriate polar discretization, for which we control the angular density of voxels to avoid over-sampling the center of the field of view. Finally, we propose a new family of algorithms, the so-called frequency adapted algorithms, which enable to optimize the reconstruction of a given band in the frequency domain on both the speed of convergence and the quality of the image. (author)

  19. Targeting murine heart and brain: visualisation conditions for multi-pinhole SPECT with {sup 99m}Tc- and {sup 123}I-labelled probes

    Energy Technology Data Exchange (ETDEWEB)

    Pissarek, M. [Research Centre Juelich, Institute of Neurosciences and Biophysics-Nuclear Chemistry (INB-4), Juelich (Germany); Meyer-Kirchrath, J.; Hohlfeld, T. [Heinrich Heine University, Institute of Pharmacology and Clinical Pharmacology, Duesseldorf (Germany); Vollmar, S. [Max Planck Institute for Neurological Research, Cologne (Germany); Oros-Peusquens, A.M. [Research Centre Juelich, Institute of Neurosciences and Biophysics-Medicine (INB-3), Juelich (Germany); Floegel, U.; Jacoby, C. [Heinrich Heine University, Institute of Heart and Circulation Physiology, Duesseldorf (Germany); Kruegel, U. [University of Leipzig, Rudolf Boehm Institute of Pharmacology and Toxicology, Leipzig (Germany); Schramm, N. [Research Centre Juelich, Central Institute for Electronics, Juelich (Germany)

    2009-09-15

    The study serves to optimise conditions for multi-pinhole SPECT small animal imaging of {sup 123}I- and {sup 99m}Tc-labelled radiopharmaceuticals with different distributions in murine heart and brain and to investigate detection and dose range thresholds for verification of differences in tracer uptake. A Triad 88/Trionix system with three 6-pinhole collimators was used for investigation of dose requirements for imaging of the dopamine D{sub 2} receptor ligand [{sup 123}I]IBZM and the cerebral perfusion tracer [{sup 99m}Tc]HMPAO (1.2-0.4 MBq/g body weight) in healthy mice. The fatty acid [{sup 123}I]IPPA (0.94 {+-} 0.05 MBq/g body weight) and the perfusion tracer [{sup 99m}Tc]sestamibi (3.8 {+-} 0.45 MBq/g body weight) were applied to cardiomyopathic mice overexpressing the prostaglandin EP{sub 3} receptor. In vivo imaging and in vitro data revealed 45 kBq total cerebral uptake and 201 kBq cardiac uptake as thresholds for visualisation of striatal [{sup 123}I]IBZM and of cardiac [{sup 99m}Tc]sestamibi using 100 and 150 s acquisition time, respectively. Alterations of maximal cerebral uptake of [{sup 123}I]IBZM by >20% (116 kBq) were verified with the prerequisite of 50% striatal of total uptake. The labelling with [{sup 99m}Tc]sestamibi revealed a 30% lower uptake in cardiomyopathic hearts compared to wild types. [{sup 123}I]IPPA uptake could be visualised at activity doses of 0.8 MBq/g body weight. Multi-pinhole SPECT enables detection of alterations of the cerebral uptake of {sup 123}I- and {sup 99m}Tc-labelled tracers in an appropriate dose range in murine models targeting physiological processes in brain and heart. The thresholds of detection for differences in the tracer uptake determined under the conditions of our experiments well reflect distinctions in molar activity and uptake characteristics of the tracers. (orig.)

  20. Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

    Science.gov (United States)

    Lienemann, Philipp S.; Metzger, Stéphanie; Kiveliö, Anna-Sofia; Blanc, Alain; Papageorgiou, Panagiota; Astolfo, Alberto; Pinzer, Bernd R.; Cinelli, Paolo; Weber, Franz E.; Schibli, Roger; Béhé, Martin; Ehrbar, Martin

    2015-05-01

    Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

  1. Two-Level Multi-Pinhole Collimator for SPECT Imaging Using a Small-Field-of-View Gamma Camera

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jaekeon; Bae, Seungbin; Lee, Soo-young; Lee, Kisung [Korea University, Seoul (Korea, Republic of); Kim, Yongkwon; Joung, Jinhun [NuCare Inc., Incheon (Korea, Republic of); Kim, MinHo; Kim, Kyeong Min [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2017-01-15

    The aim of this study was to develop a high-throughput imaging method for single-photon emission computed tomography. We developed a target-oriented multi-pinhole collimator and limited angle method for scanning small organs such as the thyroid. To maximize the resolution and the sensitivity of the collimator, we designed a two-level multi-pinhole collimator whose levels were optimized for concave body contours. One level had a center hole whereas the other had surrounding holes. The limited-angle scanning method was employed to obtain tomographic images by using the collimator located near the body contour of the target, and a corresponding image reconstruction algorithm was implemented. A small-field-of-view gamma camera was used to achieve a smaller footprint. The design of the collimator also considered the dimensions of used gamma camera. Evaluation studies were conducted using the Geant4 application for tomographic emission. The results showed the resolution of the proposed collimator to be more than twice that of the previously designed multi-pinhole collimator while maintaining the same efficiency. Given that the designed collimator can be changed by simply replacing the center hole, the suggested imaging method is suitable for studying not only the thyroid but also any organ whose diameter is less than 90 mm.

  2. Imaging dynamics of organs and drugs at sub-half-MM and sub-minite resolution using focusing pinhole spect

    NARCIS (Netherlands)

    Beekman, F.J.; Van der Have, F.; Vastenhouw, B.; Branderhorst, W.J.; Van der Linden, A.; Smidt, M.P.

    We demonstrate new technologies for SPECT imaging with unsurpassed resolution in mice and rats. Results of the imaging of living animals will be shown. In addition development of detectors for next generation systems with an even higher resolution will be shown.

  3. SPECT/CT for sentinel lymph node mapping in head and neck melanoma.

    Science.gov (United States)

    Vermeeren, Lenka; Valdés Olmos, Renato A; Klop, W Martin C; van der Ploeg, Iris M C; Nieweg, Omgo E; Balm, Alfons J M; van den Brekel, Michiel W M

    2011-01-01

    The additional value of single photon emission computed tomography with CT (SPECT/CT) for detection and localization of sentinel nodes in patients with a melanoma of the head and neck was determined. Thirty-eight patients received conventional lymphoscintigraphy followed by hybrid SPECT/CT. The number of sentinel nodes visualized and anatomic information provided were analyzed. Changes in surgical approach due to additional information from the SPECT/CT were evaluated in 20 patients. SPECT/CT visualized a mean of 2.6 sentinel nodes per patient (range, 1-6). SPECT/CT depicted an additional sentinel node in 16% of the patients and clearly showed the anatomic location of the hot nodes in all patients. The surgical approach was adjusted on the basis of SPECT/CT images in 11 patients (55%). SPECT/CT visualizes more sentinel nodes than conventional images and shows their anatomic location. SPECT/CT is recommended in patients with a melanoma in the head or neck. © 2010 Wiley Periodicals, Inc. Head Neck, 2011.

  4. Thallium-201 SPECT in the diagnosis of head and neck cancer.

    Science.gov (United States)

    Valdés Olmos, R A; Balm, A J; Hilgers, F J; Koops, W; Loftus, B M; Tan, I B; Muller, S H; Hoefnagel, C A; Gregor, R T

    1997-06-01

    The accuracy of SPECT with 201Tl-chloride for the diagnosis of primary tumors, lymph node metastases and recurrences in head and neck cancer was evaluated for clinical applicability. SPECT images, obtained 60 min after administration of 150 MBq 201Tl-chloride, were compared with clinical, CT and/or MRI and histology results. In addition, whole-body images were obtained to detect distant metastases. In 79 patients studied for primary tumors (principally larynix, hypopharynx, oropharynx, nasopharynx and oral cavity), 201Tl SPECT correctly identified 69 of 73 (95% versus 88% for CT/MRI) histologically confirmed malignancies including 63 squamous-cell carcinomas. The method localized four occult naso- and oropharynx carcinomas not seen on CT/MRI and was correctly negative in two patients without tumor and in three of four patients with no confirmed primary tumor in the head and neck. With respect to regional spread, only patients who had cervical lymph node dissection were evaluated, and the findings were recorded per side of the neck. Thallium-201 SPECT correctly identified metastases in 31 of 36 neck dissections with proven lymph node involvement (86%), was correctly negative in nine and false-positive in one. Although the sensitivity of CT/MRI was clearly higher (97%), considerably more false-positive cases affected its accuracy (81% versus 87% for SPECT). In 30 patients investigated for recurrences, 201Tl SPECT correctly identified 27 of 29 microscopically confirmed tumor sites (93%) and was correctly negative in seven. Sensitivity of CT/MRI was lower (76%), and a greater number of false-positives (seven versus three for SPECT) further decreased its accuracy (64% versus 87% for SPECT). Distant metastases were detected in five patients. Thallium-201 SPECT appears to be an accurate method for the diagnosis of head and neck cancer. The method is particularly useful for detection of occult head and neck tumors and for assessing recurrences. It also may be of

  5. Scatter and crosstalk corrections for {sup 99m}Tc/{sup 123}I dual-radionuclide imaging using a CZT SPECT system with pinhole collimators

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Peng [Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 and Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Hutton, Brian F. [Institute of Nuclear Medicine, University College London, London WC1E 6BT, United Kingdom and Centre for Medical Radiation Physics, University of Wollongong, New South Wales 2522 (Australia); Holstensson, Maria [Department of Nuclear Medicine, Karolinska University Hospital, Stockholm 14186 (Sweden); Ljungberg, Michael [Department of Medical Radiation Physics, Lund University, Lund 222 41 (Sweden); Hendrik Pretorius, P. [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); Prasad, Rameshwar; Liu, Chi, E-mail: chi.liu@yale.edu [Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 (United States); Ma, Tianyu; Liu, Yaqiang; Wang, Shi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Thorn, Stephanie L.; Stacy, Mitchel R.; Sinusas, Albert J. [Department of Internal Medicine, Yale Translational Research Imaging Center, Yale University, New Haven, Connecticut 06520 (United States)

    2015-12-15

    Purpose: The energy spectrum for a cadmium zinc telluride (CZT) detector has a low energy tail due to incomplete charge collection and intercrystal scattering. Due to these solid-state detector effects, scatter would be overestimated if the conventional triple-energy window (TEW) method is used for scatter and crosstalk corrections in CZT-based imaging systems. The objective of this work is to develop a scatter and crosstalk correction method for {sup 99m}Tc/{sup 123}I dual-radionuclide imaging for a CZT-based dedicated cardiac SPECT system with pinhole collimators (GE Discovery NM 530c/570c). Methods: A tailing model was developed to account for the low energy tail effects of the CZT detector. The parameters of the model were obtained using {sup 99m}Tc and {sup 123}I point source measurements. A scatter model was defined to characterize the relationship between down-scatter and self-scatter projections. The parameters for this model were obtained from Monte Carlo simulation using SIMIND. The tailing and scatter models were further incorporated into a projection count model, and the primary and self-scatter projections of each radionuclide were determined with a maximum likelihood expectation maximization (MLEM) iterative estimation approach. The extracted scatter and crosstalk projections were then incorporated into MLEM image reconstruction as an additive term in forward projection to obtain scatter- and crosstalk-corrected images. The proposed method was validated using Monte Carlo simulation, line source experiment, anthropomorphic torso phantom studies, and patient studies. The performance of the proposed method was also compared to that obtained with the conventional TEW method. Results: Monte Carlo simulations and line source experiment demonstrated that the TEW method overestimated scatter while their proposed method provided more accurate scatter estimation by considering the low energy tail effect. In the phantom study, improved defect contrasts were

  6. Pinhole Glasses

    Science.gov (United States)

    Colicchia, Giuseppe; Hopf, Martin; Wiesner, Hartmut; Zollman, Dean

    2008-01-01

    Eye aberrations are commonly corrected by lenses that restore vision by altering rays before they pass through the cornea. Some modern promoters claim that pinhole glasses are better than conventional lenses in correcting all kinds of refractive defects such as myopia (nearsighted), hyperopia (farsighted), astigmatisms, and presbyopia. Do pinhole…

  7. A Silicon SPECT System for Molecular Imaging of the Mouse Brain.

    Science.gov (United States)

    Shokouhi, Sepideh; Fritz, Mark A; McDonald, Benjamin S; Durko, Heather L; Furenlid, Lars R; Wilson, Donald W; Peterson, Todd E

    2007-01-01

    We previously demonstrated the feasibility of using silicon double-sided strip detectors (DSSDs) for SPECT imaging of the activity distribution of iodine-125 using a 300-micrometer thick detector. Based on this experience, we now have developed fully customized silicon DSSDs and associated readout electronics with the intent of developing a multi-pinhole SPECT system. Each DSSD has a 60.4 mm × 60.4 mm active area and is 1 mm thick. The strip pitch is 59 micrometers, and the readout of the 1024 strips on each side gives rise to a detector with over one million pixels. Combining four high-resolution DSSDs into a SPECT system offers an unprecedented space-bandwidth product for the imaging of single-photon emitters. The system consists of two camera heads with two silicon detectors stacked one behind the other in each head. The collimator has a focused pinhole system with cylindrical-shaped pinholes that are laser-drilled in a 250 μm tungsten plate. The unique ability to collect projection data at two magnifications simultaneously allows for multiplexed data at high resolution to be combined with lower magnification data with little or no multiplexing. With the current multi-pinhole collimator design, our SPECT system will be capable of offering high spatial resolution, sensitivity and angular sampling for small field-of-view applications, such as molecular imaging of the mouse brain.

  8. Role of SPECT-CT in sentinel lymph node biopsy in patients diagnosed with head and neck melanoma.

    Science.gov (United States)

    López-Rodríguez, E; García-Gómez, F J; Álvarez-Pérez, R M; Martínez-Castillo, R; Borrego-Dorado, I; Fernández-Ortega, P; Zulueta-Dorado, T

    2016-01-01

    Assess the role of SPECT-CT in sentinel lymph node (SLN) biopsy in the accurate anatomical location of the SNL in patients with cutaneous head and neck melanoma. A retrospective study was conducted from February 2010 to June 2013 on 22 consecutive patients with a diagnosis of cutaneous head and neck melanoma (9 female, 13 male), with a mean age of 55 years old and who met the inclusion criteria for SLN biopsy. Patients underwent preoperative scanning after peri-scar injection of (99m)Tc-labeled-nanocolloid. Planar images of the injection-site, whole-body, and SPECT-CT scanning were acquired. Detection rate of SLN reached up to 91% (20/22 patients) by planar lymphoscintigraphy and 95.4% (21/22 patients) by SPECT-CT. SPECT-CT provided an accurate location of SLN in 14/22 patients, enabling to improve the surgical approach (clinical impact: 63.6%). SLN was positive for metastatic cells in 9.1% patients. SPECT-CT provides detailed anatomical SLN location and allows detecting a higher number of SLN than planar lymphoscintigraphy. Routine use of SPECT-CT is recommended in order to optimise the SLN detection and location in patients with head and neck melanoma. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  9. SPECT/CT Improves Detection of Metastatic Sentinel Lymph Nodes in Patients with Head and Neck Melanoma.

    Science.gov (United States)

    Chapman, Brandon C; Gleisner, Ana; Kwak, Jennifer J; Hosokawa, Patrick; Paniccia, Alessandro; Merkow, Justin S; Koo, Phillip J; Gajdos, Csaba; Pearlman, Nathan W; McCarter, Martin D; Kounalakis, Nicole

    2016-08-01

    A positive sentinel lymph node (SLN) is the most important prognostic factor for predicting survival in cutaneous melanoma. This study aimed to evaluate how the addition of single-photon emission computed tomography (SPECT) and computed tomography (CT) to planar lymphoscintigraphy (PL) alters SLN identification, yield, and localization of metastatic nodes in head and neck melanoma. This retrospective review examined patients undergoing SLN biopsy for cutaneous melanoma of the head and neck between July 2003 and December 2015. Patient demographics and pathologic outcomes were compared for patients undergoing SPECT-CT versus PL. A multivariable logistic regression analysis was used to identify factors associated with the identification of a positive SLN. Among 176 patients undergoing SLN biopsy, 91 underwent PL and 85 underwent SPECT-CT and PL. The patients in the SPECT-CT group were older than the PL patients (p = 0.050) but the groups did not differ in gender (p = 0.447), Breslow thickness (p = 0.744), or total number of SLNs identified (p = 0.633). As shown by the multivariate regression analysis, only Breslow thickness [odds ratio (OR) 1.47; 95 % confidence interval (CI) 1.17-1.84] and SPECT-CT (OR 3.58; 95 % CI 1.24-10.4) were associated with a positive SLN. The use of SPECT-CT for patients with head and neck cutaneous melanoma significantly increases the likelihood of retrieving a positive SLN. Long-term follow-up evaluation is needed for further definition of the impact that SPECT-CT has on recurrence and survival.

  10. Digital Pinhole Camera

    Science.gov (United States)

    Lancor, Rachael; Lancor, Brian

    2014-01-01

    In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

  11. Clinical Utility of '9{sup 9m}Tc-HMPAO Brain SPECT Findings in Chronic Head Injury

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Jin ll; Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Lee, Jong Doo; Park, Chang Yoon; Kim, Young Soo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1992-03-15

    Minima deterioration of cerebral perfusion or microanatomical changes were undetectable on conventional Brain CT or MRI. So evaluation of focal functional changes of the brain parenchyme is essential in chronic head injury patients, who did not show focal anatomical changes on these radiological studies. However, the patients who had longstanding neurologic sequelae following head injury, there had been no available imaging modalities for evaluating these patients precisely. Therefore we tried to detect the focal functional changes on the brain parenchyme using {sup 99m}Tc-HMPAO Brain SPECT on the patients of chronic head injuries. Twenty three patients who had suffered from headache, memory dysfunction, personality change and insomnia lasting more than six months following head injury were included in our cases, which showed no anatomical abnormalities on Brain CT or MRI. At first they underwent psychological test whether the symptoms were organic or not. Also we were able to evaluate the cerebral perfusion changes with {sup 99m}Tc-HMPAO Brain SPECT in 22 patients among the 23, which five patients were focal and 17 patients were nonfocally diffuse perfusion changes. Thus we can predict the perfusion changes such as local vascular deterioration or functional defects using {sup 99m}Tc-HMPAO Brain SPECT in the patients who had suffered from post-traumatic sequelae, which changes were undetectable on Brain CT or MRI.

  12. High-resolution single photon planar and spect imaging of brain and neck employing a system of two co-registered opposed gamma imaging heads

    Science.gov (United States)

    Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA

    2011-12-06

    A compact, mobile, dedicated SPECT brain imager that can be easily moved to the patient to provide in-situ imaging, especially when the patient cannot be moved to the Nuclear Medicine imaging center. As a result of the widespread availability of single photon labeled biomarkers, the SPECT brain imager can be used in many locations, including remote locations away from medical centers. The SPECT imager improves the detection of gamma emission from the patient's head and neck area with a large field of view. Two identical lightweight gamma imaging detector heads are mounted to a rotating gantry and precisely mechanically co-registered to each other at 180 degrees. A unique imaging algorithm combines the co-registered images from the detector heads and provides several SPECT tomographic reconstructions of the imaged object thereby improving the diagnostic quality especially in the case of imaging requiring higher spatial resolution and sensitivity at the same time.

  13. Collimator design for a multipinhole brain SPECT insert for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Van Audenhaege, Karen; Van Holen, Roel; Vanhove, Christian; Vandenberghe, Stefaan [Department of Electronics and Information Systems, Ghent University-iMinds Medical IT, MEDISIP-IBiTech, De Pintelaan 185 block B/5, Ghent B-9000 (Belgium)

    2015-11-15

    show sufficient axial sampling (in a Defrise phantom) and a reconstructed resolution of 5.0 mm (in a cold-rod phantom). The authors compared the 24-pinhole setup with a 34-pinhole system (with the same detector radius but a collimator radius of 156.63 mm) and found that 34 pinholes result in better uniformity but a worse reconstruction of the cold-rod phantom. The authors also compared the 24-pinhole system with a clinical triple-head UHR fan beam system based on contrast-to-noise ratio and found that the 24-pinhole setup performs better for the 6 mm hot and the 16 mm cold lesions and worse for the 8 and 10 mm hot lesions. Finally, the authors reconstructed noisy projection data of a Hoffman phantom with a 9 mm cold lesion and found that the lesion was slightly better visible on the multipinhole image compared to the fan beam image. Conclusions: The authors have optimized a stationary multipinhole SPECT insert for MRI and showed the feasibility of doing brain SPECT imaging inside a MRI with an image quality similar to the best clinical SPECT systems available.

  14. Risk stratification for avascular necrosis of the femoral head after internal fixation of femoral neck fractures by post-operative SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sang Won; Oh, Min Young; Yoon, Seok Ho; Kim, Jin Soo; Chang, Jae Suk; Ryu, Jin Sook [Asan Medical CenterUniversity of Ulsan College of Medicine, Seoul (Korea, Republic of); Kim, Ji Wan [Dept. of Orthopedic Surgery, Haeundae Paik Hospital, Inje University, Busan (Korea, Republic of)

    2017-03-15

    Avascular necrosis (AVN) of the femoral head is a major complication after internal fixation of a femoral neck fracture and determines the functional prognosis. We investigated postoperative bone single-photon emission computed tomography/computed tomography (SPECT/CT) for assessing the risk of femoral head AVN. We retrospectively reviewed 53 consecutive patients who underwent bone SPECT/CT within 2 weeks of internal fixation of a femoral neck fracture and follow-up serial hip radiographs over at least 12 months. Nine patients developed femoral head AVN. In 15 patients who showed normal uptake on immediate postoperative SPECT/CT, no AVN occurred, whereas 9 of 38 patients who showed cold defects of the femoral head later developed AVN. The negative predictive value of immediate postoperative SPECT/CT for AVN was 100 %, whereas the positive predictive value was 24 %. Among 38 patients with cold defects, 1 developed AVN 3 months postoperatively. A follow-up bone SPECT/CT was performed in the other 37 patients at 2–10 months postoperatively. The follow-up bone SPECT/CT revealed completely normalized femoral head uptake in 27, partially normalized uptake in 8, and persistent cold defects in 2 patients. AVN developed in 3.7 % (1/27), 62.5 % (5/8), and 100 % (2/2) of each group, respectively. According to the time point of imaging, radiotracer uptake patterns of the femoral head on postoperative bone SPECT/CT indicate the risk of AVN after internal fixation of femoral neck fractures differently. Postoperative bone SPECT/CT may help orthopedic surgeons determine the appropriate follow-up of these patients.

  15. A pinhole gamma camera with optical depth-of-interaction elimination

    NARCIS (Netherlands)

    Korevaar, M.A.N.; Heemskerk, J.W.T.; Beekman, F.J.

    2009-01-01

    The performance of pinhole single photon emission computed tomography (SPECT) depends on the spatial resolution of the gamma-ray detectors used. Pinhole cameras suffer from strong resolution loss due to the varying depth-of-interaction (DOI) of gamma quanta that enter the detector material at an

  16. Wide angle pinhole camera

    Science.gov (United States)

    Franke, J. M.

    1978-01-01

    Hemispherical refracting element gives pinhole camera 180 degree field-of-view without compromising its simplicity and depth-of-field. Refracting element, located just behind pinhole, bends light coming in from sides so that it falls within image area of film. In contrast to earlier pinhole cameras that used water or other transparent fluids to widen field, this model is not subject to leakage and is easily loaded and unloaded with film. Moreover, by selecting glass with different indices of refraction, field at film plane can be widened or reduced.

  17. An investigation of head movement with a view to minimising motion artefact during SPECT and PET imaging of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, H.; Clarke, G.H.; Guy, R. [RMIT, Melbourne, VIC (Australia). Department of Medical Radiations Science; McKay, W.J. [Austin and Repatriation Medical Centre, Heidelberg, VIC (Australia). Department of Nuclear Medicine and Centre for Positron Emission Tomography

    1998-06-01

    Full text: Motion artefact has long been recognised as a major cause of image degradation. Single Photon Emission Computerised Tomography (SPECT) and Positron Emission Tomography (PET) of the brain are playing an important role in the diagnosis and management of several neurological disorders. If these imaging modalities are to contribute fully to medical imaging it is essential that the improved spatial resolution of these systems is not compromised by patient movement. Thirty volunteer subjects have been examined using a simple video technique and the video images were used to classify and measure head movements which may occur during brain imaging. All subjects demonstrated angular movement within the transverse plane or rotation of the head. Angular movement within the sagittal plane or flexion/extension of the neck occurred in 69% of subjects and 72% of subjects exhibited translational movement of the sagittal plane. There was no movement of the coronal plane; nor was there any translational movement of the sagittal plane. These results suggest that when positioning the patient`s head for brain imaging a system of head restraint which minimises rotation of the head should be used if image quality is to be maintained

  18. Make a Pinhole Camera

    Science.gov (United States)

    Fisher, Diane K.; Novati, Alexander

    2009-01-01

    On Earth, using ordinary visible light, one can create a single image of light recorded over time. Of course a movie or video is light recorded over time, but it is a series of instantaneous snapshots, rather than light and time both recorded on the same medium. A pinhole camera, which is simple to make out of ordinary materials and using ordinary…

  19. Theory and state of the art of small animal scintigraphic imaging with single pinhole and multi-hole collimator; Theory et etat de l'art de l'imagerie scintigraphique du petit animal avec collimateur pinhole simple et multi-trous

    Energy Technology Data Exchange (ETDEWEB)

    Israel-Jost, V.; Choquet, Ph.; Blondet, C.; Namer, I.J.; Slim, I.; Elkadri, N.; Constantinesco, A. [Hopital de Hautepierre, Service de Biophysique et Medecine Nucleaire, 67 - Strasbourg (France); Monassier, L. [Institut National de la Sante et de la Recherche Medicale (INSERM U333), 67 - Strasbourg (France); Sonnendrucker, E. [Institut de Recherche Mathematique Avancee de Strasbourg, 67 (France)

    2003-10-01

    In order to get better acquisition conditions in small animal scintigraphic planar or SPECT imaging, we specified the different definitions of spatial resolution which usually appear in the literature and we analysed parameters which act on scintigraphic images resolution and sensitivity using pinhole or multi-pinhole collimation. These theoretical results are related to those obtained by authors who use different collimators (simple pinhole, micro pinhole, multi pinhole and coded aperture) and different detectors (NaI crystal, semi-conductor). Their results are discussed insisting on tomographic reconstruction methods and the way a faithful physical and geometrical modelization can improve final images. (author)

  20. Graphic design of pinhole cameras

    Science.gov (United States)

    Edwards, H. B.; Chu, W. P.

    1979-01-01

    The paper describes a graphic technique for the analysis and optimization of pinhole size and focal length. The technique is based on the use of the transfer function of optical elements described by Scott (1959) to construct the transfer function of a circular pinhole camera. This transfer function is the response of a component or system to a pattern of lines having a sinusoidally varying radiance at varying spatial frequencies. Some specific examples of graphic design are presented.

  1. SPECT assay of radiolabeled monoclonal antibodies. Final performance report, March 1992--November 1995

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1995-12-01

    Research is described in the following areas: development and evaluation quantitatively of reconstruction algorithms with improved compensations for attenuation, scatter, and geometric collimator response; evaluation of single photon emission computed tomography (SPECT) quantification of iodine 123 and astatine 211; and the development and evaluation of SPECT pinhole imaging for low and medium energy photons.

  2. Detection of pulmonary embolism with combined ventilation-perfusion SPECT and low-dose CT: head-to-head comparison with multidetector CT angiography

    DEFF Research Database (Denmark)

    Gutte, Henrik; Mortensen, Jann; Jensen, Claus Verner

    2009-01-01

    The diagnosis of pulmonary embolism (PE) is usually established by a combination of clinical assessment, D-dimer testing, and imaging with either pulmonary ventilation-perfusion (V/Q) scintigraphy or pulmonary multidetector CT (MDCT) angiography. Both V/Q SPECT and MDCT angiography seem to have...

  3. Stereo Pinhole Camera: Assembly and experimental activities

    OpenAIRE

    Santos, Gilmário Barbosa; Departamento de Ciência da Computação, Universidade do Estado de Santa Catarina, Joinville; Cunha, Sidney Pinto; Centro de Tecnologia da Informação Renato Archer, Campinas

    2015-01-01

    This work describes the assembling of a stereo pinhole camera for capturing stereo-pairs of images and proposes experimental activities with it. A pinhole camera can be as sophisticated as you want, or so simple that it could be handcrafted with practically recyclable materials. This paper describes the practical use of the pinhole camera throughout history and currently. Aspects of optics and geometry involved in the building of the stereo pinhole camera are presented with illustrations. Fur...

  4. From Pinholes to Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  5. Combined SPECT/CT improves detection of initial bone invasion and determination of resection margins in squamous cell carcinoma of the head and neck compared to conventional imaging modalities

    Energy Technology Data Exchange (ETDEWEB)

    Kolk, A. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Oral and Maxillofacial Surgery, Munich (Germany); Klinikum rechts der Isar, Technische Universitaet Muenchen, Klinik und Poliklinik fuer Mund-Kiefer und Gesichtschirurgie, Muenchen (Germany); Schuster, T. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Institute of Medical Statistics and Epidemiology, Munich (Germany); Chlebowski, A.; Kesting, M.; Bissinger, O.; Weitz, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Oral and Maxillofacial Surgery, Munich (Germany); Lange, P. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Diagnostic Radiology, Munich (Germany); Scheidhauer, K.; Schwaiger, M.; Dinges, J. [Technische Universitaet Muenchen, Klinikum rechts der Isar, Department of Nuclear Medicine, Munich (Germany)

    2014-07-15

    Knowledge of the presence and extent of bone infiltration is crucial for planning the resection of potential bone-infiltrating squamous cell carcinomas of the head and neck (HNSCC). Routinely, plain-film radiography, multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) are used for preoperative staging, but they show relatively high rates of false-positive and false-negative findings. Scintigraphy with {sup 99m}Tc-bisphosphonate has the ability to show increased metabolic bone activity. If combined with anatomical imaging (e.g. (SPECT)/CT), it facilitates the precise localization of malignant bone lesions. The aim of this study was to analyse the indications and advantages of SPECT/CT compared with standard imaging modalities and histology with regard to specificity and sensitivity A longitudinally evaluated group of 30 patients with biopsy-proven HNSCC adjacent to the mandible underwent {sup 99m}Tc-bisphosphonate SPECT/CT, MRI, MSCT and conventional radiography before partial or rim resection of the mandible was performed. Bone infiltration was first evaluated with plain films, MSCT and MRI. In a second reading, SPECT/CT data were taken into account. The results (region and certainty of bone invasion) were evaluated among the different imaging modalities and finally compared with histological specimens from surgical resection as the standard of reference. For a better evaluation of the hybrid property of SPECT/CT, a retrospectively evaluated group of 20 additional patients with tumour locations similar to those of the longitudinally examined SPECT/CT group underwent SPECT, MSCT and MRI. To assess the influence of dental foci on the specificity of the imaging modalities, all patients were separated into two subgroups depending on the presence or absence of teeth in the area of potential tumour-bone contact. Histologically proven bone infiltration was found in 17 patients (57 %) when analysed by conventional imaging modalities. SPECT/CT data

  6. Detecting near-the-injection-site sentinel nodes in head and neck melanomas with a high-resolution portable gamma camera.

    Science.gov (United States)

    Hellingman, Daan; de Wit-van der Veen, Linda J; Klop, W Martin C; Olmos, Renato A Valdés

    2015-01-01

    In head/neck melanomas, near-the-injection-site sentinel nodes (NIS-SNs) may be missed on planar lymphoscintigraphy and/or SPECT/CT. The aim of the present study is to establish the performance of a portable gamma camera (PGC) to detect NIS-SNs in a simulation phantom set-up, and subsequently in head/neck melanoma patients scheduled for a SN procedure. Five plastic Eppendorf tubes filled with technetium-99m-albumin nanocolloid were used to simulate 4 radiotracer deposit sites, as traditionally injected in melanoma patients, and 1 NIS-SN. A PGC was used with 2 pinhole collimators (2.5 and 4.0 mm). Image acquisition time was 1 minute with the camera positioned at various distances (range 1.5-15.5 cm). Results were compared with conventional lymphoscintigraphy and SPECT/CT acquired with a dual-head gamma camera as well with a gamma probe. Additionally, the same PGC setting was used in a case series of 3 patients with head/neck melanomas. The simulated NIS-SN was differentiated from the injection site at a distance of 3 mm with the 2.5-mm pinhole and at 5 mm with the 4-mm pinhole when the PGC was positioned at 1.5 cm distance. Planar lymphoscintigraphy, SPECT/CT, and the gamma probe depicted the NIS-SN separated from the injection site at distances of 7, 10, and 22 mm, respectively. In all 3 patients, 6 NIS-SNs were depicted with the PGC. A high-resolution PGC, positioned close to the skin, is able to detect SNs at distances of at least 3 mm from the injection site. A further clinical evaluation of this device to establish its added value in reducing false-negative procedures and potential recurrences is necessary.

  7. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Bowsher, James, E-mail: james.bowsher@duke.edu; Giles, William; Yin, Fang-Fang [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Yan, Susu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Roper, Justin [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2014-01-15

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  8. Space Shuttle Pinhole Formation Mechanism Studies

    Science.gov (United States)

    Jacobson, Nathan S.

    1998-01-01

    Pinholes have been observed to form on the wing leading edge of the space shuttle after about 10-15 flights. In this report we expand upon previous observations by Christensen (1) that these pinholes often form along cracks and are associated with a locally zinc-rich area. The zinc appears to come from weathering and peeling paint on the launch structure. Three types of experimental examinations are performed to understand this issue further: (A) Detailed microstructural examination of actual shuttle pinholes (B) Mass spectrometric studies of coupons containing, actual shuttle pinholes and (C) Laboratory furnace studies of ZnO/SiC reactions and ZnO/SiC protected carbon/carbon reaction. On basis of these observations we present a detailed mechanism of pinhole formation due to formation of a corrosive ZnO-Na-2-O-SiO2 ternary glass, which flows into existing cracks and enlarges them.

  9. Gyral high density on CT scan after head injury; [sup 123]I-IMP SPECT and MRI findings in three children

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Takumi; Matsumoto, Kiyoshi (Showa Univ., Tokyo (Japan). School of Medicine); Sakamoto, Tetsuya; Aruga, Tohru

    1994-02-01

    The authors treated three children who had 'gyral high density' on plain CT scans after head injury with acute subdural hematoma. [sup 123]I-IMP SPECT (IMP) and MRI in the chronic stage were performed. All were males, about one year of age, with acute subdural hematoma. CT scan 48 hours after injury showed diffuse low density in the ipsilateral parenchyma with minimum midline shift, and IMP showed decreased activity in the same area. Plain CT scan 1 to 3 weeks after injury showed remarkably high density along the gyri in part of the same area. This area was markedly enhanced on CT with contrast medium and showed decreased blood flow on IMP. This high density area disappeared within 2 months after injury and the area concerned showed brain atrophy. In the chronic stage (after 6 months), only the high density area along the gyri seen in the CT scan showed MRI evidence of ishemia, but there was no definite evidence of hemorrhage. All three children had hemiplegia at the time of discharge. The gyral high density suggests ischemic brain, but the pathophysiological process might be different from that of so-called hemorrhagic infarction. Presumably, it is due to incomplete autoregulation, the incomplete blood-brain barrier and the sensitivity to stimulation of cerebral blood vessels in the brains of infants. The intensity and range of the gyral high density are considered to be important in estimating the future amount of atrophic change in the insulted brain and the resulting sequelae. (author).

  10. PET and SPECT in neurology

    Energy Technology Data Exchange (ETDEWEB)

    Dierckx, Rudi A.J.O. [Groningen University Medical Center (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Ghent Univ. (Belgium). Dept. of Radiology and Nuclear Medicine; Vries, Erik F.J. de; Waarde, Aren van [Groningen University Medical Center (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Otte, Andreas (ed.) [Univ. of Applied Sciences Offenburg (Germany). Faculty of Electrical Engineering and Information Technology

    2014-07-01

    PET and SPECT in Neurology highlights the combined expertise of renowned authors whose dedication to the investigation of neurological disorders through nuclear medicine technology has achieved international recognition. Classical neurodegenerative disorders are discussed as well as cerebrovascular disorders, brain tumors, epilepsy, head trauma, coma, sleeping disorders, and inflammatory and infectious diseases of the CNS. The latest results in nuclear brain imaging are detailed. Most chapters are written jointly by a clinical neurologist and a nuclear medicine specialist to ensure a multidisciplinary approach. This state-of-the-art compendium will be valuable to anybody in the field of neuroscience, from the neurologist and the radiologist/nuclear medicine specialist to the interested general practitioner and geriatrician. It is the second volume of a trilogy on PET and SPECT imaging in the neurosciences, the other volumes covering PET and SPECT in psychiatry and in neurobiological systems.

  11. Myocardial blood flow measurement with a conventional dual-head SPECT/CT with spatiotemporal iterative reconstructions - a clinical feasibility study.

    Science.gov (United States)

    Alhassen, Fares; Nguyen, Nhan; Bains, Sukhkarn; Gould, Robert G; Seo, Youngho; Bacharach, Stephen L; Song, Xiyun; Shao, Lingxiong; Gullberg, Grant T; Aparici, Carina Mari

    2013-01-01

    Cardiac single photon emission computed tomography (SPECT) cameras typically rotate too slowly around a patient to capture changes in the blood pool activity distribution and provide accurate kinetic parameters. A spatiotemporal iterative reconstruction method to overcome these limitations was investigated. Dynamic rest/stress (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) SPECT/CT was performed along with reference standard rest/stress dynamic positron emission tomography (PET/CT) (13)N-NH3 in five patients. The SPECT data were reconstructed using conventional and spatiotemporal iterative reconstruction methods. The spatiotemporal reconstruction yielded improved image quality, defined here as a statistically significant (p<0.01) 50% contrast enhancement. We did not observe a statistically significant difference between the correlations of the conventional and spatiotemporal SPECT myocardial uptake K 1 values with PET K 1 values (r=0.25, 0.88, respectively) (p<0.17). These results indicate the clinical feasibility of quantitative, dynamic SPECT/CT using (99m)Tc-MIBI and warrant further investigation. Spatiotemporal reconstruction clearly provides an advantage over a conventional reconstruction in computing K 1.

  12. [Head to head comparison of dobutamine alone and combined with nitrate stress echocardiography and 99mTc-MIBI/18FDG myocardial SPECT image for diagnosis of viable myocardium in patients with severe left ventricular dysfunction].

    Science.gov (United States)

    Yang, Yue-jin; Yang, Wei-xian; Shi, Rong-fang; Hu, Feng-huan; You, Shi-jie; Tian, Yue-qin; He, Zuo-xiang; Wang, Yan-wu; Ye, Ling; Chen, Ji-lin; Gao, Run-lin; Chen, Zai-jia

    2005-04-01

    This study was sought to compare the sensitivity, specificity and accuracy of (1) dual isotope simultaneous acquisition single-photon emission computed tomography (DISA SPECT) myocardial image with (99m)Tc-sestamibi/(18)F-fluorodeoxyglucose ((99m)Tc-MIBI/(18)FDG); (2) low dose dobutamine alone and combined with Isosorbide Dinitrate (ISDN: Isoket) stress two dimensional echocardiography (2DE) to predict regional movement recovery after revascularization (CRV) in patients with old myocardial infarction (OMI) and severe left ventricular dysfunction. Twenty-six patients (mean age 51 +/- 8 years, male 25, female 1) with OMI and severe left ventricular dysfunction (mean left ventricular ejection fraction, LVEF (38.6% +/- 4.9%) underwent low dose dobutamine 10 microg x kg(-1) x min(-1) (Dob10 microg) and ISDN (286 +/- 31 microg/min) combined with Dob5 microg (ISDN-Dob 5 microg) 2DE and DISA SPECT within one week. In echocardiogram and DISA SPECT images: the left ventricle (LV) was divided into 16 segments. The semi-quantitative scoring system was used for both images. Myocardial viability was defined as an improvement of at least >or= 1 grade in at least two contiguous segments at rest 2DE after CRV. The viable segments detecting rate with stress 2DE and DISA SPECT were compared. Compared with the results of post-CRV, the sensitivity, specificity and accuracy of detecting viable segments of two methods were calculated. Among 272 abnormal segments in 26 patients, 156 (57.4%) segments showed contractile improvement after CRV. The viable segments detecting rate with DISA SPECT was 72.4% (134/254), which was significantly higher than the contractile improved rate after CRV (P 0.05). With DISA SPECT, the sensitivity, specificity and accuracy were 93.7%, 55% and 76.8%, respectively. Compared with DISA SPECT, Dob10 microg 2DE showed similar sensitivity (88.6%), specificity (64.2%) and the accuracy (77.9%). When ISDN combined with Dob5 microg, the sensitivity (91.4%), specificity

  13. A hardware investigation of robotic SPECT for functional and molecular imaging onboard radiation therapy systems

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Susu, E-mail: susu.yan@duke.edu; Tough, MengHeng [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Bowsher, James; Yin, Fang-Fang [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 and Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Cheng, Lin [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2014-11-01

    Purpose: To construct a robotic SPECT system and to demonstrate its capability to image a thorax phantom on a radiation therapy flat-top couch, as a step toward onboard functional and molecular imaging in radiation therapy. Methods: A robotic SPECT imaging system was constructed utilizing a gamma camera detector (Digirad 2020tc) and a robot (KUKA KR150 L110 robot). An imaging study was performed with a phantom (PET CT Phantom{sup TM}), which includes five spheres of 10, 13, 17, 22, and 28 mm diameters. The phantom was placed on a flat-top couch. SPECT projections were acquired either with a parallel-hole collimator or a single-pinhole collimator, both without background in the phantom and with background at 1/10th the sphere activity concentration. The imaging trajectories of parallel-hole and pinhole collimated detectors spanned 180° and 228°, respectively. The pinhole detector viewed an off-centered spherical common volume which encompassed the 28 and 22 mm spheres. The common volume for parallel-hole system was centered at the phantom which encompassed all five spheres in the phantom. The maneuverability of the robotic system was tested by navigating the detector to trace the phantom and flat-top table while avoiding collision and maintaining the closest possible proximity to the common volume. The robot base and tool coordinates were used for image reconstruction. Results: The robotic SPECT system was able to maneuver parallel-hole and pinhole collimated SPECT detectors in close proximity to the phantom, minimizing impact of the flat-top couch on detector radius of rotation. Without background, all five spheres were visible in the reconstructed parallel-hole image, while four spheres, all except the smallest one, were visible in the reconstructed pinhole image. With background, three spheres of 17, 22, and 28 mm diameters were readily observed with the parallel-hole imaging, and the targeted spheres (22 and 28 mm diameters) were readily observed in the

  14. A hardware investigation of robotic SPECT for functional and molecular imaging onboard radiation therapy systems.

    Science.gov (United States)

    Yan, Susu; Bowsher, James; Tough, MengHeng; Cheng, Lin; Yin, Fang-Fang

    2014-11-01

    To construct a robotic SPECT system and to demonstrate its capability to image a thorax phantom on a radiation therapy flat-top couch, as a step toward onboard functional and molecular imaging in radiation therapy. A robotic SPECT imaging system was constructed utilizing a gamma camera detector (Digirad 2020tc) and a robot (KUKA KR150 L110 robot). An imaging study was performed with a phantom (PET CT Phantom(TM)), which includes five spheres of 10, 13, 17, 22, and 28 mm diameters. The phantom was placed on a flat-top couch. SPECT projections were acquired either with a parallel-hole collimator or a single-pinhole collimator, both without background in the phantom and with background at 1/10th the sphere activity concentration. The imaging trajectories of parallel-hole and pinhole collimated detectors spanned 180° and 228°, respectively. The pinhole detector viewed an off-centered spherical common volume which encompassed the 28 and 22 mm spheres. The common volume for parallel-hole system was centered at the phantom which encompassed all five spheres in the phantom. The maneuverability of the robotic system was tested by navigating the detector to trace the phantom and flat-top table while avoiding collision and maintaining the closest possible proximity to the common volume. The robot base and tool coordinates were used for image reconstruction. The robotic SPECT system was able to maneuver parallel-hole and pinhole collimated SPECT detectors in close proximity to the phantom, minimizing impact of the flat-top couch on detector radius of rotation. Without background, all five spheres were visible in the reconstructed parallel-hole image, while four spheres, all except the smallest one, were visible in the reconstructed pinhole image. With background, three spheres of 17, 22, and 28 mm diameters were readily observed with the parallel-hole imaging, and the targeted spheres (22 and 28 mm diameters) were readily observed in the pinhole region-of-interest imaging

  15. Optimizing Pinhole and Parallel Hole Collimation for Scintimammography With Compact Pixellated Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mark F. Smith; Stan Majewski; Andrew G. Weisenberger

    2002-11-01

    The relative resolution and sensitivity advantages of pinhole and parallel hole collimators for planar scintimammography with compact, pixellated gamma detectors were investigated using analytic models. Collimator design was studied as follows. A desired object resolution was specified for a pixellated detector with a given crystal size and intrinsic spatial resolution and for a given object-to- collimator distance. Using analytic formulas, pinhole and parallel hole collimator parameters were calculated that satisfy this object resolution with optimal geometric sensitivity. Analyses were performed for 15 cm x 20 cm field of view detectors with crystal elements 1.0, 2.0 and 3.0 mm on a side and 140 keV incident photons. The sensitivity for a given object resolution was greater for pinhole collimation at smaller distances, as expected. The object distance at which the pinhole and parallel hole sensitivity curves cross each other is important. The crossover distances increased with larger crystal size for a constant object resolution and increased as the desired object resolution decreases for a constant crystal size. For example, for 4 mm object resolution and a pinhole collimator with focal length 13 cm, these distances were 5.5 cm, 6.5 cm and 8 cm for the 1 mm, 2 mm and 3 mm crystal detectors, respectively. The results suggest a strategy of parallel hole collimation for whole breast imaging and pinhole collimation for imaging focal uptake. This could be accomplished with a dual detector system with a different collimator type on each head or a single head system equipped with two collimators and a rapid switching mechanism.

  16. An Evaluation of Pinhole Castration as an Alternative Technique for ...

    African Journals Online (AJOL)

    -thiopental anesthesia. Castrated dogs were closely monitored for up to five days after castration. In 12 days, 278 dogs were castrated. The mean duration for pinhole procedure was 11.4 minutes. Duration of pinhole castration reduced ...

  17. Performance assessment of a preclinical PET scanner with pinhole collimation by comparison to a coincidence-based small-animal PET scanner.

    Science.gov (United States)

    Walker, Matthew D; Goorden, Marlies C; Dinelle, Katherine; Ramakers, Ruud M; Blinder, Stephan; Shirmohammad, Maryam; van der Have, Frans; Beekman, Freek J; Sossi, Vesna

    2014-08-01

    PET imaging of rodents is increasingly used in preclinical research, but its utility is limited by spatial resolution and signal-to-noise ratio of the images. A recently developed preclinical PET system uses a clustered-pinhole collimator, enabling high-resolution, simultaneous imaging of PET and SPECT tracers. Pinhole collimation strongly departs from traditional electronic collimation achieved via coincidence detection in PET. We investigated the potential of such a design by direct comparison to a traditional PET scanner. Two small-animal PET scanners, 1 with electronic collimation and 1 with physical collimation using clustered pinholes, were used to acquire data from Jaszczak (hot rod) and uniform phantoms. Mouse brain imaging using (18)F-FDG PET was performed on each system and compared with quantitative ex vivo autoradiography as a gold standard. Bone imaging using (18)F-NaF allowed comparison of imaging in the mouse body. Images were visually and quantitatively compared using measures of contrast and noise. Pinhole PET resolved the smallest rods (diameter, 0.85 mm) in the Jaszczak phantom, whereas the coincidence system resolved 1.1-mm-diameter rods. Contrast-to-noise ratios were better for pinhole PET when imaging small rods (superior to that on the pinhole system (5%). The high (18)F-FDG uptake in the striatum of the mouse brain was fully resolved using the pinhole system, with contrast to nearby regions equaling that from autoradiography; a lower contrast was found using the coincidence PET system. For short-duration images (low-count), the coincidence system was superior. In the cases for which small regions need to be resolved in scans with reasonably high activity or reasonably long scan times, a first-generation clustered-pinhole system can provide image quality in terms of resolution, contrast, and the contrast-to-noise ratio superior to a traditional PET system. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  18. Prediction of functional recovery after revascularization in patients with chronic ischaemic left ventricular dysfunction : head-to-head comparison between Tc-99m-sestamibi/F-18-FDG DISA SPECT and N-13-ammonia/F-18-FDG PET

    NARCIS (Netherlands)

    Slart, Riemer H. J. A.; Bax, Jeroen J.; van Veldhuisen, Dirk J.; van der Wall, Ernst E.; Irwan, Roy; Sluiter, Wim J.; Dierckx, Rudi A.; de Boer, Jaep; Jager, Pieter L.

    Purpose: F-18-FDG PET is an important modality for myocardial viability assessment in patients with left ventricular (LV) dysfunction. Dual-isotope simultaneous acquisition (DISA) SPECT may be an alternative to PET. The aim of this study was to compare the diagnostic performance of PET and DISA

  19. Serotonin transporters in dopamine transporter imaging: a head-to-head comparison of dopamine transporter SPECT radioligands 123I-FP-CIT and 123I-PE2I

    DEFF Research Database (Denmark)

    Ziebell, Morten; Holm-Hansen, Signe; Thomsen, Gerda

    2010-01-01

    Current SPECT radioligands available for in vivo imaging of the dopamine transporter (DAT) also show affinity for monoamine transporters other than DAT, especially the serotonin transporter (SERT). The effect of this lack of selectivity for in vivo imaging is unknown. In this study, we compared...

  20. SPECT/CT - Technical aspects and optimization possibilities; SPECT/CT - Technische Aspekte und Optimierungsmoeglichkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, W. [Klinikum Passau, Klinik fuer Nuklearmedizin, Passau (Germany)

    2012-07-15

    In contrast to positron emission tomography/computed tomography (PET/CT), the currently available single photon emission computed tomography/computed tomography (SPECT/CT) systems are very heterogeneous. On the side of the gamma cameras, dual-head systems are established, which are not very different from one manufacturer to the other. For the CT component, there are low dose tubes on the one side and flat detector-based cone beam CT and multislice-CT on the other. The CT image data can be used for anatomic correlation of suspicious findings as well as for attenuation correction of SPECT data. Attenuation correction enables on the one hand enhancement of SPECT image quality and on the other hand quantification of the radioactivity concentration becomes possible. Modern iterative reconstruction algorithms allow scatter correction and attenuation correction of SPECT data using the density values from CT. It still has to be shown to what extent attenuation-corrected whole body SPECT/CT studies will be able to improve the sensitivity of scintigraphy studies. As SPECT/CT primarily aims at morphologic correlation and not detection of additional lesions, an attempt should be made to balance the necessary anatomic information and the additional radiation exposure. Besides SPECT-guided CT all technical possibilities for dose reduction should be exhausted. (orig.) [German] Im Gegensatz zur Positronenemissionstomographie/Computertomographie (PET/CT) sind die auf dem Markt angebotenen Single-photon-emission-computed-tomography/CT(SPECT/CT)-Systeme sehr heterogen. Auf der Seite der Gammakameras sind Zweikopfsysteme etabliert, die sich bei den verschiedenen Wettbewerbern nur unwesentlich unterscheiden. Hingegen reicht bei der CT-Komponente die Palette von der einfachen Niedrigdosisroentgenroehre ueber die flachdetektorbasierte Cone-beam-CT-Technologie bis hin zum Mehrzeilenspiral-CT. Die CT-Bilddaten werden dabei zum einen zur anatomischen Korrelation funktionell auffaelliger

  1. SPECT/CT: an update on technological developments and clinical applications.

    Science.gov (United States)

    Ljungberg, Michael; Pretorius, P Hendrik

    2017-01-16

    Functional nuclear medicine imaging with single-photon emission CT (SPECT) in combination with anatomical CT has been commercially available since the beginning of this century. The combination of the two modalities has improved both the sensitivity and specificity of many clinical applications and CT in conjunction with SPECT that allows for spatial overlay of the SPECT data on good anatomy images. Introduction of diagnostic CT units as part of the SPECT/CT system has also potentially allowed for a more cost-efficient use of the equipment. Most of the SPECT systems available are based on the well-known Anger camera principle with NaI(Tl) as a scintillation material, parallel-hole collimators and multiple photomultiplier tubes, which, from the centroid of the scintillation light, determine the position of an event. Recently, solid-state detectors using cadmium-zinc-telluride became available and clinical SPECT cameras employing multiple pinhole collimators have been developed and introduced in the market. However, even if new systems become available with better hardware, the SPECT reconstruction will still be affected by photon attenuation and scatter and collimator response. Compensation for these effects is needed even for qualitative studies to avoid artefacts leading to false positives. This review highlights the recent progress for both new SPECT cameras systems as well as for various data-processing and compensation methods.

  2. Brain SPECT. SPECT in der Gehirndiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Feistel, H. (Erlangen-Nuernberg Univ., Erlangen (Germany). Nuklearmedizinische Klinik mit Poliklinik)

    1991-12-01

    Brain SPECT investigations have gained broad acceptance since the introduction of the lipophilic tracer Tc-99m-HMPAO. Depending on equipment and objectives in different departments, the examinations can be divided into three groups: 1. Under normal conditions and standardised patient preparation the 'rest' SPECT can be performed in every department with a tomographic camera. In cerebrovascular disease there is a demand for determination of either the perfusion reserve in reversible ischemia or prognostic values in completed stroke. In cases of dementia, SPECT may yield useful results according to differential diagnosis. Central cerebral system involvement in immunologic disease may be estimated with higher sensitivity than in conventional brain imaging procedures. In psychiatric diseases there is only a relative indication for brain SPECT, since results during recent years have been contradictory and may be derived only in interventional manner. In brain tumor diagnostics SPECT with Tl-201 possibly permits grading. In inflammatory disease, especially in viral encephalitis, SPECT may be used to obtain early diagnosis. Normal pressure hydrocephalus can be distinguished from other forms of dementia and, consequently, the necessity for shunting surgery can be recognised. 2. In departments equipped for emergency cases an 'acute' SPECT can be performed in illnesses with rapid changing symptoms such as different forms of migraine, transient global amnesia, epileptic seizures (so-called 'ictal SPECT') or urgent forms like trauma. 3. In cooperation with several departments brain SPECT can be practised as an interventional procedure in clinical and in scientific studies. (orig./MG).

  3. Technological Development and Advances in SPECT/CT

    Science.gov (United States)

    Seo, Youngho; Aparici, Carina Mari; Hasegawa, Bruce H

    2010-01-01

    SPECT/CT has emerged over the past decade as a means of correlating anatomical information from CT with functional information from SPECT. The integration of SPECT and CT in a single imaging device facilitates anatomical localization of the radiopharmaceutical to differentiate physiological uptake from that associated with disease and patient-specific attenuation correction to improve the visual quality and quantitative accuracy of the SPECT image. The first clinically available SPECT/CT systems performed emission-transmission imaging using a dual-headed SPECT camera and a low-power x-ray CT sub-system. Newer SPECT/CT systems are available with high-power CT sub-systems suitable for detailed anatomical diagnosis, including CT coronary angiography and coronary calcification that can be correlated with myocardial perfusion measurements. The high-performance CT capabilities also offer the potential to improve compensation of partial volume errors for more accurate quantitation of radionuclide measurement of myocardial blood flow and other physiological processes and for radiation dosimetry for radionuclide therapy. In addition, new SPECT technologies are being developed that significantly improve the detection efficiency and spatial resolution for radionuclide imaging of small organs including the heart, brain, and breast, and therefore may provide new capabilities for SPECT/CT imaging in these important clinical applications. PMID:18396178

  4. SPECT in psychiatry. SPECT in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Barocka, A. (Psychiatrische Klinik und Poliklinik, Erlangen (Germany)); Feistel, H. (Nuklearmedizinische Klinik, Erlangen (Germany)); Ebert, D. (Psychiatrische Klinik und Poliklinik, Erlangen (Germany)); Lungershausen, E. (Psychiatrische Klinik und Poliklinik, Erlangen (Germany))

    1993-08-13

    This review presents Single Photon Emission Computed Tomography (SPECT) as a powerful tool for clinical use and research in psychiatry. Its focus is on regional cerebral blood flow, measured with technetium labelled HMPAO. In addition, first results with brain receptor imaging, concerning dopamin-D[sub 2] and benzodiazepine receptors, are covered. Due to major improvements in image quality, and impressive number of results has been accumulated in the past three years. The authors caution against using SPECT results as markers for disease entities. A finding like 'hypofrontality' is considered typical of a variety of mental disorders. Clearly both, more experience with SPECT and contributions from psychopathology, are needed. (orig.)

  5. Cervical SPECT Camera for Parathyroid Imaging

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-08-31

    Primary hyperparathyroidism characterized by one or more enlarged parathyroid glands has become one of the most common endocrine diseases in the world affecting about 1 per 1000 in the United States. Standard treatment is highly invasive exploratory neck surgery called Parathyroidectomy. The surgery has a notable mortality rate because of the close proximity to vital structures. The move to minimally invasive parathyroidectomy is hampered by the lack of high resolution pre-surgical imaging techniques that can accurately localize the parathyroid with respect to surrounding structures. We propose to develop a dedicated ultra-high resolution (~ 1 mm) and high sensitivity (10x conventional camera) cervical scintigraphic imaging device. It will be based on a multiple pinhole-camera SPECT system comprising a novel solid state CZT detector that offers the required performance. The overall system will be configured to fit around the neck and comfortably image a patient.

  6. Dedicated scanner for laboratory investigations on cone-beam CT/SPECT imaging of the breast

    Energy Technology Data Exchange (ETDEWEB)

    Mettivier, Giovanni, E-mail: mettivier@na.infn.i [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, I-80126 Napoli (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli (Italy); Russo, Paolo, E-mail: russo@na.infn.i [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, I-80126 Napoli (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli (Italy); Cesarelli, Mario; Ospizio, Roberto [Dipartimento di Ingegneria Biomedica, Elettronica e delle Telecomunicazioni, Universita di Napoli Federico II, I-80125 Napoli (Italy); Passeggio, Giuseppe; Roscilli, Lorenzo; Pontoriere, Giuseppe; Rocco, Raffaele [Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, I-80126 Napoli (Italy)

    2011-02-11

    We describe the design, realization and basic tests of a prototype Cone-Beam Breast Computed Tomography (CBBCT) scanner, combined with a SPECT head consisting of a compact pinhole gamma camera based on a photon counting CdTe hybrid pixel detector. The instrument features a 40 {mu}m focal spot X-ray tube, a 50 {mu}m pitch flat panel detector and a 1-mm-thick, 55 {mu}m pitch CdTe pixel detector. Preliminary imaging tests of the separate CT and gamma-ray units are presented showing a resolution in CT of 3.2 mm{sup -1} at a radial distance of 50 mm from the rotation axis and that the 5 and 8 mm hot masses ({sup 99m}Tc labeled with a 15:1 activity ratio with respect to the background) can be detected in planar gamma-ray imaging with a contrast-to-noise ratio of about 4.

  7. A Silicon SPECT System for Molecular Imaging of the Mouse Brain

    OpenAIRE

    Shokouhi, Sepideh; Fritz, Mark A.; McDonald, Benjamin S.; Durko, Heather L.; Furenlid, Lars R.; Wilson, Donald W.; Peterson, Todd E.

    2007-01-01

    We previously demonstrated the feasibility of using silicon double-sided strip detectors (DSSDs) for SPECT imaging of the activity distribution of iodine-125 using a 300-micrometer thick detector. Based on this experience, we now have developed fully customized silicon DSSDs and associated readout electronics with the intent of developing a multi-pinhole SPECT system. Each DSSD has a 60.4 mm × 60.4 mm active area and is 1 mm thick. The strip pitch is 59 micrometers, and the readout of the 102...

  8. Pinhole formation in capacitively coupled external electrode fluorescent lamps

    Science.gov (United States)

    Cho, Guangsup; Lee, Jooyoung; Lee, Deaheung; Koo, Jehuan; Choi, Eunha; Kim, Bongsoo; Lee, Sanghun; Pak, Minsoon; Kang, Junegill; Verboncoeur, John P.

    2004-10-01

    Application of power higher than the optimum operation value to an external electrode fluorescent lamp (EEFL) leads to the formation of pinholes, which subsequently leads to lamp failure. Small holes, called pinholes, are formed through the external electrode and the glass tube when a high voltage with a high power is applied. The phenomenon of pinhole formation has been investigated, including the conditions under which they occur and the characteristics such as size and location on the electrode. Pinhole formation has been analysed and shown to be the insulation layer breakdown of glass in the dielectric barrier discharge of capacitively coupled EEFLs.

  9. Pinhole formation in capacitively coupled external electrode fluorescent lamps

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Guangsup [Department of Electrophysics, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Lee, Jooyoung [Department of Electrophysics, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Lee, Deaheung [Department of Electrophysics, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Koo, Jehuan [Department of Electrophysics, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Choi, Eunha [Department of Electrophysics, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Kim, Bongsoo [Department of Electrical Engineering, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Lee, Sanghun [Department of Electrical Engineering, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Pak, Minsoon [Department of Electrical Engineering, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Kang, Junegill [Department of Electrical Engineering, Kwangwoon University, 447-1, Wallgye-Dong, Nowon-Gu, Seoul 139-701 (Korea, Republic of); Verboncoeur, John P [Department of Nuclear Engineering, University of California, Berkeley, CA 94720-1730 (United States)

    2004-10-21

    Application of power higher than the optimum operation value to an external electrode fluorescent lamp (EEFL) leads to the formation of pinholes, which subsequently leads to lamp failure. Small holes, called pinholes, are formed through the external electrode and the glass tube when a high voltage with a high power is applied. The phenomenon of pinhole formation has been investigated, including the conditions under which they occur and the characteristics such as size and location on the electrode. Pinhole formation has been analysed and shown to be the insulation layer breakdown of glass in the dielectric barrier discharge of capacitively coupled EEFLs.

  10. Quantitatively accurate activity measurements with a dedicated cardiac SPECT camera: Physical phantom experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pourmoghaddas, Amir, E-mail: apour@ottawaheart.ca; Wells, R. Glenn [Physics Department, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Cardiology, The University of Ottawa Heart Institute, Ottawa, Ontario K1Y4W7 (Canada)

    2016-01-15

    Purpose: Recently, there has been increased interest in dedicated cardiac single photon emission computed tomography (SPECT) scanners with pinhole collimation and improved detector technology due to their improved count sensitivity and resolution over traditional parallel-hole cameras. With traditional cameras, energy-based approaches are often used in the clinic for scatter compensation because they are fast and easily implemented. Some of the cardiac cameras use cadmium-zinc-telluride (CZT) detectors which can complicate the use of energy-based scatter correction (SC) due to the low-energy tail—an increased number of unscattered photons detected with reduced energy. Modified energy-based scatter correction methods can be implemented, but their level of accuracy is unclear. In this study, the authors validated by physical phantom experiments the quantitative accuracy and reproducibility of easily implemented correction techniques applied to {sup 99m}Tc myocardial imaging with a CZT-detector-based gamma camera with multiple heads, each with a single-pinhole collimator. Methods: Activity in the cardiac compartment of an Anthropomorphic Torso phantom (Data Spectrum Corporation) was measured through 15 {sup 99m}Tc-SPECT acquisitions. The ratio of activity concentrations in organ compartments resembled a clinical {sup 99m}Tc-sestamibi scan and was kept consistent across all experiments (1.2:1 heart to liver and 1.5:1 heart to lung). Two background activity levels were considered: no activity (cold) and an activity concentration 1/10th of the heart (hot). A plastic “lesion” was placed inside of the septal wall of the myocardial insert to simulate the presence of a region without tracer uptake and contrast in this lesion was calculated for all images. The true net activity in each compartment was measured with a dose calibrator (CRC-25R, Capintec, Inc.). A 10 min SPECT image was acquired using a dedicated cardiac camera with CZT detectors (Discovery NM530c, GE

  11. Exploring performance of neutron guide systems using pinhole beam extraction

    Energy Technology Data Exchange (ETDEWEB)

    Bertelsen, Mads, E-mail: mads.bertelsen@gmail.com [Nanoscience Center and eScience Center, Niels Bohr Institute, University of Copenhagen (Denmark); ESS Design Update Program (Denmark); Jacobsen, Henrik; Bengaard Hansen, Ursula [Nanoscience Center and eScience Center, Niels Bohr Institute, University of Copenhagen (Denmark); ESS Design Update Program (Denmark); Hoffmann Carlsen, Henrik [Nanoscience Center and eScience Center, Niels Bohr Institute, University of Copenhagen (Denmark); Lefmann, Kim [Nanoscience Center and eScience Center, Niels Bohr Institute, University of Copenhagen (Denmark); ESS Design Update Program (Denmark)

    2013-11-21

    We perform an optimization of pinhole neutron guide systems under systematically varying conditions. It is investigated how neutron guide systems consisting of a parabolic feeder inside the biological shielding followed by a pinhole and an elliptical guide perform with different pinhole sizes and divergence requirements. We have clarified in which situations such a guide system is a viable choice and when the parabolic feeder is necessary in terms of neutron transport. The advantage of this design is the reduction of background from fast thermal neutrons compared to a system without a pinhole, hence the smallest possible pinhole is of interest. It is found that instruments with divergence requirements of ±1.0° will have excellent neutron transport with a 3×3 cm{sup 2} pinhole, while lower divergence requirements of ±0.5° can do with a smaller pinhole of 2×2 cm{sup 2}. The feeder effectively reduces the necessary pinhole size, and is especially beneficial for short instruments. In addition to these qualities, a feeder will often smoothen the divergence profile, mostly for longer instruments.

  12. The timing of bone SPECT to predict osteonecrosis after internal fixation of femur neck fractures.

    Science.gov (United States)

    Kim, Ji Wan; Ryu, Jin-Sook; Baek, Sora; Byun, Seong-Eun; Chang, Jae Suk

    2017-05-01

    Bone SPECT can be used after a femur neck fracture to assess the circulation of the femoral head in the immediate postoperative period because the blood supply is one of the major factors affecting bone uptake of radiotracer on bone scintigraphy. The purpose of our present study was to investigate whether osteonecrosis of the femoral head (OFH) after internal fixation of femoral neck fracture could be predicted by early and late bone SPECT. This retrospective cohort study enrolled 44 patients (33 women; mean age, 66.9 years) who underwent surgical fixation for femoral neck fractures. Early and late bone SPECT images were obtained within 2 weeks postoperatively and at 3 months postoperatively. Patients were followed up for a minimum of 24 months (average, 34 months). OFH developed in 9 out of 44 patients but no patient showed nonunion. Seventeen patients with normal femoral head uptake on early bone SPECT were healed. Of 27 patients with decreased femoral head uptake on early bone SPECT, 2 patients developed OFH on radiography before 3 months postoperatively, 18 patients recovered to normal uptake on the late SPECT, and the remaining 7 patients still showed decreased uptake on the late SPECT at 3 months postoperatively. All of these 7 cases finally developed OFH on radiography. Bone SPECT can reliably predict the possibility of OFH with after femoral neck fracture at least 3 months after surgery, while early bone SPECT showed low specificity. Clinical. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  13. Proton pinhole imaging on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Zylstra, A. B., E-mail: zylstra@lanl.gov [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Park, H.-S.; Ross, J. S.; Higginson, D. P.; Huntington, C.; Pollock, B.; Remington, B.; Rinderknecht, H. G.; Ryutov, D.; Turnbull, D.; Wilks, S. C. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Fiuza, F. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Séguin, F. H. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2016-11-15

    Pinhole imaging of large (mm scale) carbon-deuterium (CD) plasmas by proton self-emission has been used for the first time to study the microphysics of shock formation, which is of astrophysical relevance. The 3 MeV deuterium-deuterium (DD) fusion proton self-emission from these plasmas is imaged using a novel pinhole imaging system, with up to five different 1 mm diameter pinholes positioned 25 cm from target-chamber center. CR39 is used as the detector medium, positioned at 100 cm distance from the pinhole for a magnification of 4 ×. A Wiener deconvolution algorithm is numerically demonstrated and used to interpret the images. When the spatial morphology is known, this algorithm accurately reproduces the size of features larger than about half the pinhole diameter. For these astrophysical plasma experiments on the National Ignition Facility, this provides a strong constraint on simulation modeling of the experiment.

  14. A pinhole camera for ultrahigh-intensity laser plasma experiments

    Science.gov (United States)

    Wang, C.; An, H. H.; Xiong, J.; Fang, Z. H.; Wang, Y. W.; Zhang, Z.; Hua, N.; Sun, J. R.; Wang, W.

    2017-11-01

    A pinhole camera is an important instrument for the detection of radiation in laser plasmas. It can monitor the laser focus directly and assist in the analysis of the experimental data. However, conventional pinhole cameras are difficult to use when the target is irradiated by an ultrahigh-power laser because of the high background of hard X-ray emission generated in the laser/target region. Therefore, an improved pinhole camera has been developed that uses a grazing-incidence mirror that enables soft X-ray imaging while avoiding the effect of hard X-ray from hot dense plasmas.

  15. SPECT imaging of D{sub 2} dopamine receptors and endogenous dopamine release in mice

    Energy Technology Data Exchange (ETDEWEB)

    Jongen, Cynthia [University Medical Center Utrecht, Image Sciences Institute, Q0S.459, P.O. Box 85500, Utrecht (Netherlands); Bruin, Kora de; Booij, Jan [University of Amsterdam, Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Beekman, Freek [University Medical Center Utrecht, Image Sciences Institute, Q0S.459, P.O. Box 85500, Utrecht (Netherlands); University Medical Center Utrecht, Department of Neuroscience and Pharmacology, Utrecht (Netherlands); Technical University Delft, Department R3, Section Radiation, Detection and Matter, Delft (Netherlands)

    2008-09-15

    The dopamine D{sub 2} receptor (D2R) is important in the mediation of addiction. [{sup 123}I]iodobenzamide (IBZM), a SPECT ligand for the D2R, has been used for in vivo studies of D2R availability in humans, monkeys, and rats. Although mouse models are important in the study of addiction, [{sup 123}I]IBZM has not been used in mice SPECT studies. This study evaluates the use of [{sup 123}I]IBZM for measuring D2R availability in mice. Pharmacokinetics of [{sup 123}I]IBZM in mice were studied with pinhole SPECT imaging after intravenous (i.v.) injection of [{sup 123}I]IBZM (20, 40, and 70 MBq). In addition, the ability to measure the release of endogenous dopamine after amphetamine administration with [{sup 123}I]IBZM SPECT was investigated. Thirdly, i.v. administration, the standard route of administration, and intraperitoneal (i.p.) administration of [{sup 123}I]IBZM were compared. Specific binding of [{sup 123}I]IBZM within the mouse striatum could be clearly visualized with SPECT. Peak specific striatal binding ratios were reached around 90 min post-injection. After amphetamine administration, the specific binding ratios of [{sup 123}I]IBZM decreased significantly (-27.2%; n=6; p=0.046). Intravenous administration of [{sup 123}I]IBZM led to significantly higher specific binding than i.p. administration of the same dose. However, we found that i.v. administration of a dose of 70 MBq [{sup 123}I]IBZM might result in acute ethanol intoxication because ethanol is used as a preparative aid for the routine production of [{sup 123}I]IBZM. Imaging of D2R availability and endogenous dopamine release in mice is feasible using [{sup 123}I]IBZM single pinhole SPECT. Using commercially produced [{sup 123}I]IBZM, a dose of 40 MBq injected i.v. can be recommended. (orig.)

  16. Diffraction phase microscopy realized with an automatic digital pinhole

    Science.gov (United States)

    Zheng, Cheng; Zhou, Renjie; Kuang, Cuifang; Zhao, Guangyuan; Zhang, Zhimin; Liu, Xu

    2017-12-01

    We report a novel approach to diffraction phase microscopy (DPM) with automatic pinhole alignment. The pinhole, which serves as a spatial low-pass filter to generate a uniform reference beam, is made out of a liquid crystal display (LCD) device that allows for electrical control. We have made DPM more accessible to users, while maintaining high phase measurement sensitivity and accuracy, through exploring low cost optical components and replacing the tedious pinhole alignment process with an automatic pinhole optical alignment procedure. Due to its flexibility in modifying the size and shape, this LCD device serves as a universal filter, requiring no future replacement. Moreover, a graphic user interface for real-time phase imaging has been also developed by using a USB CMOS camera. Experimental results of height maps of beads sample and live red blood cells (RBCs) dynamics are also presented, making this system ready for broad adaption to biological imaging and material metrology.

  17. Research On The Measure Method Of Oblique Pinhole Parameters

    Directory of Open Access Journals (Sweden)

    Ma Yu-Zhen

    2016-01-01

    Full Text Available There are many special advantages in measuring the diameter of blind and deep holes with a capacitive probe, there are still some challenges for the measurement of a oblique pinhole parameters because the measuring device is inconvenient to stretch into the oblique pinhole exactly. A five-dimensional measurement system was adopted in the paper which included a capacitive sensor probe and a three-coordinate measuring machine to accomplish the measurement for oblique pinholes. With the help of the three-dimensional coordinates measured from the pinhole axis, we put forward a comprehensive method of combining the projection method and the least squares method together for fitting spatial straight line to obtain the optimal equation of the spacial axis. Finally, a reliable and entire measurement system was set up.

  18. Pinhole Viewing Strengthens the Hollow-Face Illusion.

    Science.gov (United States)

    Koessler, Trent; Hill, Harold

    2015-08-01

    A hollow (concave) mask appears convex when viewed from beyond a certain distance even when viewed stereoscopically-this is the hollow-face illusion. At close viewing distances, the same mask is seen as hollow even when disparity information is eliminated by monocular viewing. A potential source of nonpictorial, monocular information that favors a veridical percept at close distances is accommodation in conjunction with focus blur. In this article, we used pinhole viewing to minimize this potential source of information and test whether it affects whether a hollow mask is seen as veridical (concave) or illusory (convex). Since monocular viewing also facilitates the illusory (convex) percept, it was included in the design both as a comparison and to test whether any effect of accommodation depends on vergence. Pinhole viewing was found favor the illusory percept, and its effect was at least as large as, and added to, that of monocular viewing. A control experiment using tinted glasses that attenuate illumination at least as much as the pinholes did not strengthen the illusion ruling out explanations in terms of reduced luminance. For pinhole viewing, there was no difference between monocular and binocular conditions. The results are interpreted as evidence that focus driven depth information affects perceived three-dimensional shape at close distances even when other sources of depth information are available. The lack of a difference between monocular and binocular pinhole viewing suggests that, by disrupting accommodation, pinholes may also interfere with linked vergence cues to depth.

  19. Pinhole Viewing Strengthens the Hollow-Face Illusion

    Directory of Open Access Journals (Sweden)

    Trent Koessler

    2015-08-01

    Full Text Available A hollow (concave mask appears convex when viewed from beyond a certain distance even when viewed stereoscopically—this is the hollow-face illusion. At close viewing distances, the same mask is seen as hollow even when disparity information is eliminated by monocular viewing. A potential source of nonpictorial, monocular information that favors a veridical percept at close distances is accommodation in conjunction with focus blur. In this article, we used pinhole viewing to minimize this potential source of information and test whether it affects whether a hollow mask is seen as veridical (concave or illusory (convex. Since monocular viewing also facilitates the illusory (convex percept, it was included in the design both as a comparison and to test whether any effect of accommodation depends on vergence. Pinhole viewing was found favor the illusory percept, and its effect was at least as large as, and added to, that of monocular viewing. A control experiment using tinted glasses that attenuate illumination at least as much as the pinholes did not strengthen the illusion ruling out explanations in terms of reduced luminance. For pinhole viewing, there was no difference between monocular and binocular conditions. The results are interpreted as evidence that focus driven depth information affects perceived three-dimensional shape at close distances even when other sources of depth information are available. The lack of a difference between monocular and binocular pinhole viewing suggests that, by disrupting accommodation, pinholes may also interfere with linked vergence cues to depth.

  20. SPECT in epilepsies; SPECT bei Epilepsien

    Energy Technology Data Exchange (ETDEWEB)

    Stefan, H. [Neurologische Klinik, Univ. Erlangen-Nuernberg, Zentrum Epilepsie Erlangen (Germany)

    1997-06-01

    Registration of regional cerebral blood flow provides important new data for the investigation of pathophysiological processes in epilepsies. Further to the registration of perfusions, receptor studies are employed for the differentiation of localisation in focal epilepsies. For ultimative issues interictal registrations are supplemented by ictal recordings during the epileptic seizure. The combination of SPECT and electrophysiological registration can contribute to analysis of propagation of focal epileptic activity. (orig.) [Deutsch] Die Messung der regionalen Hirndurchblutung liefert wichtige neue Erkenntnis zur Untersuchung pathophysiologischer Ablaeufe bei Epilepsien. Ergaenzend zur Registrierung der Perfusion koennen Rezeptor-Studien zur Differenzierung der Lokalisation fokaler Epilepsien beitragen. Interiktale Registrierungen werden fuer letztere Fragestellung durch iktuale Messungen waehrend des epileptischen Anfalls ergaenzt. Die Kombination von SPECT und elektrophysiologischen Registrierungen kann zur Analyse der Propagation fokaler epileptischer Aktivitaet beitragen. (orig.)

  1. Left ventricular function in response to dipyridamole stress: head-to-head comparison between {sup 82}Rubidium PET and {sup 99m}Tc-sestamibi SPECT ECG-gated myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giorgi, Maria Clementina; Meneghetti, Jose Claudio; Soares, Jose; Izaki, Marisa; Falcao, Andrea; Imada, Rodrigo; Chalela, William; Oliveira, Marco Antonio de; Nomura, Cesar [Department of Radiology and Nuclear Medicine and Molecular Imaging Service - Heart Institute of the University of Sao Paulo Medical School, Sao Paulo (Brazil); Verberne, Hein J. [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, P.O. Box 22700, Amsterdam (Netherlands)

    2017-05-15

    Myocardial perfusion imaging (MPI) with {sup 99m}Tc-sestamibi (sestamibi) SPECT and rubidium-82 ({sup 82}Rb) PET both allow for combined assessment of perfusion and left ventricular (LV) function. We sought to compare parameters of LV function obtained with both methods using a single dipyridamole stress dose. A group of 221 consecutive patients (65.2 ± 10.4 years, 52.9% male) underwent consecutive sestamibi and {sup 82}Rb MPI after a single dipyridamole stress dose. Sestamibi and {sup 82}Rb summed rest (SRS), stress (SSS) and difference (SDS) scores, and LV end-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were compared. Bland-Altman analysis showed that with increasing ESV and EDV the difference between the two perfusion tracers increased both at rest and post-stress. The mean difference in EDV and ESV between the two perfusion tracers at rest could both be independently explained by the {sup 82}Rb SDS and the sestamibi SRS. The combined models explained approximately 30% of the variation in these volumes between the two perfusion tracers (R{sup 2} = 0.261, p = 0.005; R{sup 2} = 0.296, p < 0.001, for EDV and ESV respectively). However, the mean difference in LVEF between sestamibi and {sup 82}Rb showed no significant trend post-stress (R{sup 2} = 0.001, p = 0.70) and only a modest linear increase with increasing LVEF values at rest (R{sup 2} = 0.032, p = 0.009). Differences in left ventricular volumes between sestamibi and {sup 82}Rb MPI increase with increasing volumes. However, these differences did only marginally affect LVEF between sestamibi and {sup 82}Rb. In clinical practice these results should be taken into account when comparing functional derived parameters between sestamibi and {sup 82}Rb MPI. (orig.)

  2. Comparison of Objective and Subjective Changes Induced by Multiple-Pinhole Glasses and Single-Pinhole Glasses

    OpenAIRE

    Kim, Won Soo; Park, In Ki; Park, Young Kee; Chun, Yeoun Sook

    2017-01-01

    Multiple-pinhole (MPH) glasses are currently sold in many countries with unproven advertisements; however, their objective and subjective effects have not been investigated. Therefore, to investigate the effects of MPH glasses excluding the single-pinhole (SPH) effect, we compared the visual functional changes, reading speed, and ocular discomfort after reading caused by MPH and SPH glasses. Healthy 36 participants with a mean age of 33.1 years underwent examinations of pupil size, visual acu...

  3. Comparison of Objective and Subjective Changes Induced by Multiple-Pinhole Glasses and Single-Pinhole Glasses.

    Science.gov (United States)

    Kim, Won Soo; Park, In Ki; Park, Young Kee; Chun, Yeoun Sook

    2017-05-01

    Multiple-pinhole (MPH) glasses are currently sold in many countries with unproven advertisements; however, their objective and subjective effects have not been investigated. Therefore, to investigate the effects of MPH glasses excluding the single-pinhole (SPH) effect, we compared the visual functional changes, reading speed, and ocular discomfort after reading caused by MPH and SPH glasses. Healthy 36 participants with a mean age of 33.1 years underwent examinations of pupil size, visual acuity (VA), depth of focus (DOF), and near point accommodation (NPA); tests for visual field (VF), contrast sensitivity (CS), stereopsis, and reading speed; and a survey of ocular discomfort after reading. Both types of pinhole glasses enlarged pupil diameter and improved VA, DOF, and NPA. However, CS, stereopsis, and VF parameters deteriorated. In comparison with SPH glasses, MPH glasses induced smaller pupil dilation (5.3 and 5.9 mm, P pinhole glasses was significantly slower than baseline; SPH glasses showed the slowest reading speed. Both types of glasses caused significant ocular discomfort after reading compared with baseline, and symptoms were worst with MPH glasses. In conclusion, both types of pinhole glasses had positive effects due to the pinhole effect; however, they had negative effects on VF, CS, stereopsis, reading speed, and ocular discomfort. In spite of the increased luminance and preserved peripheral VF with MPHs, these glasses caused more severe ocular discomfort than SPH glasses. © 2017 The Korean Academy of Medical Sciences.

  4. Quantitative analysis of functional changes caused by pinhole glasses.

    Science.gov (United States)

    Kim, Won Soo; Park, In Ki; Chun, Yeoun Sook

    2014-08-12

    To quantify the visual functional changes caused by pinhole glasses. Healthy subjects underwent ophthalmic examinations including uncorrected distance visual acuity (UDVA) and corrected near visual acuity (CNVA), pupil size, depth of focus (DOF), accommodative amplitude, visual field (VF) test, contrast sensitivity (CS), and stereopsis. Subjects underwent the same examinations while wearing pinhole glasses 1 week later. Forty-eight eyes of 48 subjects (24 male and 24 female) with a mean age of 35.5±6.7 years and a mean spherical equivalent of -2.4±3.3 diopters (D) were enrolled. The pinhole glasses significantly improved UDVA and CNVA (logMAR) from 0.44±0.46 and 0.26±0.40 to 0.19±0.25 and 0.14±0.22, respectively. The pinhole glasses markedly enlarged pupils from 3.6±0.5 mm photopic size to 6.0±0.5 mm, very close to the mesopic size of 6.2±0.6 mm. Mean DOF and accommodative amplitude also significantly increased by approximately 50%, while VF featured a general reduction of sensitivity. Mean deviation (MD) significantly decreased from -0.48±1.57 to -4.22±1.66 dB, and visual field index (VFI) decreased from 99.4±0.7% to 98.4±1.3%. The CS decreased significantly at all four spatial frequencies, and stereopsis deteriorated with pinhole glasses. The pinhole glasses improved visual acuity, DOF, and accommodative amplitude; however, they resulted in decreased visual quality including general reduction of VF sensitivity, CS, and stereopsis. Therefore, particular attention is needed when wearing pinhole glasses while driving, playing sports, or working with instruments. (ClinicalTrials.gov number, NCT02111356.). Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  5. Visualization of brainstem perfusion using a high spatial resolution SPECT system.

    Science.gov (United States)

    Dierckx, R; Dobbeleir, A; Vandevivere, J; Abts, H; DeDeyn, P P

    1992-05-01

    The authors explored the high spatial resolution of a three-head rotating SPECT system, equipped with lead super-fine fanbeam collimator. The brainstem was high-lighted in a three-dimensional reconstruction, showing perfusion small structures such as mesencephalon, pons, and medulla oblongata. The visualization of brainstem perfusion sets new landmarks in functional neuroimaging and, moreover, was obtained with a commercially available three-head SPECT system.

  6. Simulation of HyperSPECT: a high-resolution small-animal system with in-line x-ray optics.

    Science.gov (United States)

    Tibbelin, Sandra; Nillius, Peter; Danielsson, Mats

    2012-03-21

    SPECT has become an important tool in pre-clinical applications. Small-animal imaging systems based on the use of one or more pinhole collimators now reach sub-half-mm resolution but unfortunately suffer from a compromise between sensitivity and resolution due to the pinhole collimators. We propose a small-animal SPECT system based not on pinholes but on in-line x-ray optics, which is rare in medical imaging systems for nuclear medicine. The x-ray lenses are optimized for 27 keV for low-energy imaging with iodine-125. We believe that this new system, HyperSPECT, can simultaneously improve on sensitivity and resolution compared to today's state-of-the-art systems. A full three-dimensional simulation of the system has been performed including the prism-array lenses, pre- and post-collimators and scintillator-based detector. Images of capillary phantoms have been reconstructed using an iterative image reconstruction method. Sensitivity was uniformly 0.37% throughout the 1 cm diameter spherical field of view and rod sizes of around 100 μm diameter were distinguishable in the images of simulated capillary phantoms. These results indicate an increase in resolution by a factor of 5 during a simultaneous increase in sensitivity by a factor of 2 compared to the current state-of-the-art small-animal SPECT systems. © 2012 Institute of Physics and Engineering in Medicine

  7. Applications of cerebral SPECT

    Energy Technology Data Exchange (ETDEWEB)

    McArthur, C., E-mail: claire.mcarthur@nhs.net [Department of Neuroradiology, Institute of Neurological Sciences, Glasgow (United Kingdom); Jampana, R.; Patterson, J.; Hadley, D. [Department of Neuroradiology, Institute of Neurological Sciences, Glasgow (United Kingdom)

    2011-07-15

    Single-photon emission computed tomography (SPECT) can provide three-dimensional functional images of the brain following the injection of one of a series of radiopharmaceuticals that crosses the blood-brain barrier and distributes according to cerebral perfusion, neurotransmitter, or cell density. Applications include differentiating between the dementias, evaluating cerebrovascular disease, preoperative localization of epileptogenic foci, diagnosing movement disorders, and evaluation of intracerebral tumours, while also proving a useful research tool. Unlike positronemission tomography (PET), SPECT imaging is widely available and can be performed in any department that has access to a rotating gamma camera. The purpose of this review is to demonstrate the utility of cerebral SPECT and increase awareness of its role in the investigation of neurological and psychiatric disorders.

  8. Development in Belgium of pinhole tomo-scintigraphy and of its applications to human and to small animals; Developpement en Belgique de la tomoscintigraphie stenopeique et de ses applications a l'homme et au petit animal

    Energy Technology Data Exchange (ETDEWEB)

    Seret, A. [Liege Univ., Institut de Physique, Imagerie Medicale Experimentale (Belgium)

    2006-06-15

    In Belgium, several researchers have been highly active in developing pinhole tomo-scintigraphy and have sometimes made a pioneer work. Their contributions concern as well the methodology of the technique as its applications to human and small animals. Reconstruction algorithms, of analytic and iterative type, have been developed and validated. They can reconstruct data obtained along circular, half-circular and non-circular acquisition orbits, the camera head being eventually tilted. A very performing method has been elaborated to determine the seven geometric parameters of the acquisition that are needed for an optimal reconstruction. The use of pinhole tomo-scintigraphy for thyroid exploration seems to be born in Belgium and a few validation studies were conducted in the country. Potentials of pinhole tomography application to parathyroid or bone scintigraphy have also been considered. Finally, some research groups are using pinhole tomo-scintigraphy for small animal studies. (author)

  9. Pinhole induced efficiency variation in perovskite solar cells

    Science.gov (United States)

    Agarwal, Sumanshu; Nair, Pradeep R.

    2017-10-01

    Process induced efficiency variation is a major concern for all thin film solar cells, including the emerging perovskite based solar cells. In this article, we address the effect of pinholes or process induced surface coverage aspects on the efficiency of such solar cells through detailed numerical simulations. Interestingly, we find that the pinhole size distribution affects the short circuit current and open circuit voltage in contrasting manners. Specifically, while the JS C is heavily dependent on the pinhole size distribution, surprisingly, the VO C seems to be only nominally affected by it. Further, our simulations also indicate that, with appropriate interface engineering, it is indeed possible to design a nanostructured device with efficiencies comparable to those of ideal planar structures. Additionally, we propose a simple technique based on terminal I-V characteristics to estimate the surface coverage in perovskite solar cells.

  10. Comparison of Objective and Subjective Changes Induced by Multiple-Pinhole Glasses and Single-Pinhole Glasses

    Science.gov (United States)

    2017-01-01

    Multiple-pinhole (MPH) glasses are currently sold in many countries with unproven advertisements; however, their objective and subjective effects have not been investigated. Therefore, to investigate the effects of MPH glasses excluding the single-pinhole (SPH) effect, we compared the visual functional changes, reading speed, and ocular discomfort after reading caused by MPH and SPH glasses. Healthy 36 participants with a mean age of 33.1 years underwent examinations of pupil size, visual acuity (VA), depth of focus (DOF), and near point accommodation (NPA); tests for visual field (VF), contrast sensitivity (CS), stereopsis, and reading speed; and a survey of ocular discomfort after reading. Both types of pinhole glasses enlarged pupil diameter and improved VA, DOF, and NPA. However, CS, stereopsis, and VF parameters deteriorated. In comparison with SPH glasses, MPH glasses induced smaller pupil dilation (5.3 and 5.9 mm, P SPH glasses showed the slowest reading speed. Both types of glasses caused significant ocular discomfort after reading compared with baseline, and symptoms were worst with MPH glasses. In conclusion, both types of pinhole glasses had positive effects due to the pinhole effect; however, they had negative effects on VF, CS, stereopsis, reading speed, and ocular discomfort. In spite of the increased luminance and preserved peripheral VF with MPHs, these glasses caused more severe ocular discomfort than SPH glasses. This clinical trial was registered at www.ClinicalTrials.gov (Identifier: NCT02572544). PMID:28378561

  11. FLUORESCENT X-RAY IMAGING WITH PINHOLE CAMERA

    Directory of Open Access Journals (Sweden)

    Yu. I. Dudchik

    2016-01-01

    Full Text Available Pinhole camera is one of X-ray optics devices. The pinhole camera is used for obtaining the image of synchrotron and laboratory sources, and also as a lens in a method of X-ray fluorescent microscopy. This method allows to obtain information on a spatial distribution of various chemical elements to the areas of several square centimeters with spatial resolution at the level of 50–100 μm. As a rule energy-dispersive two-dimensional CCD cameras are used for imaging. Such cameras are expensive devices and have low sensitivity for X-rays with energy of photons higher than 8 keV. Therefore it is perspective to use for X-ray fluorescent microscopy more effective CCD cameras with a scintillator layer. The purpose of this work consists in development of the device for imaging with secondary fluorescent X-rays by using pinhole as a lens and CCD camera for registration of the X-ray image. The device for obtaining the image of objects in secondary X-rays is developed. The device consists of an X-ray tube, pinhole and CCD camera. The object of research was irradiated with radiation from the X-ray tube and emits secondary X-rays. 100-microns pinhole was used for formation of the image of the object at an entrance window of the CCD camera. Images of a number of the iron springs differing in the sizes are received. It is established that the spatial resolution of the device is about 200 μm at an exposition of 60 s. It is possible to improve permission of the device by increasing in an exposition, optimization imaging conditions and reduction of the pinhole size. 

  12. First imaging result with an ultrahigh resolution stationary MR compatible SPECT system.

    Science.gov (United States)

    Cai, L; Shen, Z M; Zhang, J C; Chen, C T; Meng, L J

    2012-01-01

    In this paper, we will present the design and preliminary performance of an ultrahigh resolution stationary MR compatible SPECT (MRC-SPECT) system that is developed in our lab. The MRC-SPECT system is based on the second-generation energy-resolved photon-counting (ERPC) CdTe detectors and there are several key features associated with this system. Firstly, up to a total of twenty ERPC detectors will be assembled as a very compact ring, which provides an adequate angular sampling capability and a relatively high detection efficiency. The detectors are supported on a gantry made of high strength polyamide structure constructed using 3-D printing. This compact system can be directly operated inside an MR scanner. The detector module used in this system offers an intrinsic resolution of 350μm and an excellent energy resolution of around 3~4kev. Each ERPC detector module consists of four pixelated CdTe detectors with a total dimension of 4.5cm×2.25cm. Secondly, a die-cast platinum pinhole inserts and cast lead apertures are developed for this stationary SPECT system. Four 300/500μm diameter pinholes are used for each detector and all pinholes are mounted around a casted cylinder lead aperture tube. The inner diameter of the lead aperture tube is 6cm and the lead tube thickness is 16mm. The opposite detectors are placed 15.6cm apart and the magnification factor of this SPECT system is about 1.2. Thirdly, a comprehensive charge collection model inside strong magnetic field has been developed to account for the magnetic field induced distortion in the SPECT image. This model can accurately predict the detector's energy and spatial response to gamma ray incident events and then help to compensate for the event position recording error due to the strong magnetic field. In this development, we have made an effort to minimize the amount of magnetic materials in the system to alleviate potential interference to magnetic field inhomogeneity.

  13. SPECT imaging of myocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Shulkin, B.L.; Wahl, R.L.

    1987-11-01

    Gallium-67 citrate has been useful in providing scintigraphic evidence for pericarditis and myocarditis. However, the differentiation between pericardial and myocardial localization is difficult with planar images alone. SPECT can be valuable in making these distinctions, and a case of myocarditis is presented in which uptake of Gallium is shown to lie within the heart, correlating with the histologic proof.

  14. Prediction of functional recovery after revascularization in patients with chronic ischaemic left ventricular dysfunction: head-to-head comparison between 99mTc-sestamibi/18F-FDG DISA SPECT and 13N-ammonia/ 18F-FDG PET.

    Science.gov (United States)

    Slart, Riemer H J A; Bax, Jeroen J; van Veldhuisen, Dirk J; van der Wall, Ernst E; Irwan, Roy; Sluiter, Wim J; Dierckx, Rudi A; de Boer, Jaep; Jager, Pieter L

    2006-06-01

    (18)F-FDG PET is an important modality for myocardial viability assessment in patients with left ventricular (LV) dysfunction. Dual-isotope simultaneous acquisition (DISA) SPECT may be an alternative to PET. The aim of this study was to compare the diagnostic performance of PET and DISA SPECT for the prediction of improvement in regional and global LV function as well as LV reverse remodelling after revascularization. Patients (n=47) with chronic coronary artery disease and LV dysfunction underwent DISA SPECT (with (99m)Tc-sestamibi and (18)F-FDG) and PET (with (13)N-ammonia and (18)F-FDG) on the same day to assess viability. All patients underwent revascularization and recovery of function was derived from serial magnetic resonance imaging studies. Of 264 revascularized, dysfunctional segments, 143 (54%) improved in function. For prediction of improvement in regional LV function, PET and DISA SPECT had similar sensitivity (90% versus 89%, NS) and specificity (86% versus 86%, NS). For prediction of improvement in global LV function, sensitivity was 83% for DISA SPECT and 86% for PET (p=NS), whereas both modalities had a specificity of 100%. Finally, sensitivity and specificity for the prediction of LV reverse remodelling were also similar for DISA SPECT and PET. In patients undergoing revascularization, DISA SPECT and PET predict the improvement in regional and global LV function and LV remodelling equally well post revascularization.

  15. Spect in epilepsy; SPECT bei Anfallsleiden

    Energy Technology Data Exchange (ETDEWEB)

    Feistel, H. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Weis, M. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Michalik, K. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Schueler, P. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Platsch, G. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Stefan, H. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Wolf, F. [Nuklearmedizinische Klinik mit Poliklinik und Neurologische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany)

    1997-06-01

    In the Federal Republic of Germany it is assumed that about 80 000 patients suffer from a focal form of epilepsy which can not be sufficiently controlled with medication. As potential candidates for surgery, these patients undergo stepwise monitoring procedure in which the epileptic focus is located by means of increasingly invasive methods. In Erlangen the periictal SPECT is performed, whereby the perfusion tracer is injected after onset (ictal SPECT), immediately after cessation of the seizure (postictal scan) or between the seizures (interictal scan). To administer the tracer strongly in ictal or postictal state a close functional cooperation between the neurology and nuclear medicine department must be arranged. Injection inside the monitoring unit must be attuned to federal antiradiation precaution law. In temporal lobe epilepsy, different injection-times demonstrate a large area of hyperperfusion after ictal onset, which refines in the first two postictal minutes to the generating focus together with a decreased parietal blood flow pattern. Later, the entire temporal lobe epilepsy an early tracer injection within 40 seconds has to be achieved, otherwise an ictal propagation into distant brain areas, possibly contralateral, may occur. Extratemporal epilepsy is often linked to trauma or congenital malformations, and is difficult to categorize. In difficult cases with equivocal results, efforts can be undertaken by means of receptor scintigraphy with, for example, iomazenil, to localize the focus as a cold lesion caused by neuronal loss. (orig.) [Deutsch] In der Bundesrepublik Deutschland leiden nach vorsichtigen Schaetzungen ca. 80 000 Patienten an einer fokalen Epilepsieform, die mit Medikamenten nur unzureichend kontrolliert werden kann. Als potentielle Kandidaten fuer einen epilepsiechirurgischen Eingriff werden sie einem intensiven Monitoringverfahren unterzogen, in dem stufenweise nach dem Grad der Invasivitaet gesteigert, verschiedene Moeglichkeiten zu

  16. CdZnTe strip detector SPECT imaging with a slit collimator.

    Science.gov (United States)

    Zheng, Gengsheng L; Gagnon, Daniel

    2004-06-07

    In this paper, we propose a CdZnTe rotating and spinning gamma camera attached with a slit collimator. This imaging system acquires convergent planar integrals of a radioactive distribution. Two analytical image reconstruction algorithms are proposed. Preliminary phantom studies show that our small CdZnTe camera with a slit collimator outperforms a larger NaI(Tl) camera with a pinhole collimator in terms of spatial resolution in the reconstructed images. The main application of this system is small animal SPECT imaging.

  17. Tc-99m RBC SPECT in hepatic cavernous hemangioma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung Hoon; Park, Chan H.; Yoon, Seok Nam; Hwang, Kyung Hoon [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    2001-07-01

    Hepatic cavernous hemangioma (HCH) is the most common benign hepatic tumor which is detected incidentally during ultrasonography (US) done at health check-up and computed tomography (CT) done for evaluation of metastasis. The aim of the study is to evaluate retrospectively the accuracy of the modality in the diagnosis of HCH at our institution. 229 patients underwent Tc-99m RBC liver SPECT from Nov 16, 1994 to Sep 24, 2001. There were 127 males and 103 females. Their ages ranges from 82 to 17 years with a mean age of 45.8 years. Twenty millicuries of Tc-99m RBCs autologously labeled were injected. SPECT was done in 2-3 hours after the tracer administration and several hours delayed scan was also obtained in some patients. SPECT was performed with low energy high resolution collimators and triple-head gamma camera (MultiSPECT, Siemens medical systems, Inc., Hoffman Estate, III. USA). SPECT was evaluated visually and results were compared with US, CT, MRI, and clinical follow-up. Of the 156 patients a total of 210 hemangiomas were found in RBC liver SPECT. With regard to the distribution of the lesions, 113 cases revealed single; 43 cases depicted multiple HCHs, with 164 in the right lobe and 46 in the left lobe. The size of lesions ranges from 0.9 to 10 cm. Regarding the size of the lesions on radiographic image, 11 were less than 1cm, 144 were 1 to 4 cm, and the others were more than 4 cm in diameter. RBC liver SPECT is none-invasive and very useful method in the diagnosis of hepatic hemangioma in patients with sonographic and computed tomographic suspicion, if the size is more than 1 cm in diameter. The method is used often for confirmation of HCH in our institution.

  18. Light intensity and SNR improvement for high-resolution optical imaging via time multiplexed pinhole arrays.

    Science.gov (United States)

    Schwarz, Ariel; Shemer, Amir; Zalevsky, Zeev

    2014-07-10

    In this paper, we present a novel method for pinhole optics with variable pinhole arrays. The imaging system is based on a time multiplexing method using variable and moving pinhole arrays. The improved resolution and signal-to-noise ratio are achieved with improved light intensity in the same exposure time, compared with that of a one-pinhole system. This new configuration preserves the advantages of pinhole optics while solving the resolution limitation problem and the long exposure time of such systems. The system also can be used as an addition to several existing optical systems, which use visible and invisible light and x-ray systems.

  19. Implementation of angular response function modeling in SPECT simulations with GATE

    Energy Technology Data Exchange (ETDEWEB)

    Descourt, P; Visvikis, D [INSERM, U650, LaTIM, IFR SclnBioS, Universite de Brest, CHU Brest, Brest, F-29200 (France); Carlier, T; Bardies, M [CRCNA INSERM U892, Nantes (France); Du, Y; Song, X; Frey, E C; Tsui, B M W [Department of Radiology, J Hopkins University, Baltimore, MD (United States); Buvat, I, E-mail: dimitris@univ-brest.f [IMNC-UMR 8165 CNRS Universites Paris 7 et Paris 11, Orsay (France)

    2010-05-07

    Among Monte Carlo simulation codes in medical imaging, the GATE simulation platform is widely used today given its flexibility and accuracy, despite long run times, which in SPECT simulations are mostly spent in tracking photons through the collimators. In this work, a tabulated model of the collimator/detector response was implemented within the GATE framework to significantly reduce the simulation times in SPECT. This implementation uses the angular response function (ARF) model. The performance of the implemented ARF approach has been compared to standard SPECT GATE simulations in terms of the ARF tables' accuracy, overall SPECT system performance and run times. Considering the simulation of the Siemens Symbia T SPECT system using high-energy collimators, differences of less than 1% were measured between the ARF-based and the standard GATE-based simulations, while considering the same noise level in the projections, acceleration factors of up to 180 were obtained when simulating a planar 364 keV source seen with the same SPECT system. The ARF-based and the standard GATE simulation results also agreed very well when considering a four-head SPECT simulation of a realistic Jaszczak phantom filled with iodine-131, with a resulting acceleration factor of 100. In conclusion, the implementation of an ARF-based model of collimator/detector response for SPECT simulations within GATE significantly reduces the simulation run times without compromising accuracy. (note)

  20. Myocardial Infarction Area Quantification using High-Resolution SPECT Images in Rats

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luciano Fonseca Lemos de [Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Mejia, Jorge [Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP (Brazil); Carvalho, Eduardo Elias Vieira de; Lataro, Renata Maria; Frassetto, Sarita Nasbine [Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Fazan, Rubens Jr.; Salgado, Hélio Cesar [Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Galvis-Alonso, Orfa Yineth [Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP (Brazil); Simões, Marcus Vinícius, E-mail: msimoes@fmrp.usp.br [Divisão de Cardiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2013-07-15

    Imaging techniques enable in vivo sequential assessment of the morphology and function of animal organs in experimental models. We developed a device for high-resolution single photon emission computed tomography (SPECT) imaging based on an adapted pinhole collimator. To determine the accuracy of this system for quantification of myocardial infarct area in rats. Thirteen male Wistar rats (250 g) underwent experimental myocardial infarction by occlusion of the left coronary artery. After 4 weeks, SPECT images were acquired 1.5 hours after intravenous injection of 555 MBq of 99mTc-Sestamibi. The tomographic reconstruction was performed by using specially developed software based on the Maximum Likelihood algorithm. The analysis of the data included the correlation between the area of perfusion defects detected by scintigraphy and extent of myocardial fibrosis assessed by histology. The images showed a high target organ/background ratio with adequate visualization of the left ventricular walls and cavity. All animals presenting infarction areas were correctly identified by the perfusion images. There was no difference of the infarct area as measured by SPECT (21.1 ± 21.2%) and by histology (21.7 ± 22.0%; p=0.45). There was a strong correlation between individual values of the area of infarction measured by these two methods. The developed system presented adequate spatial resolution and high accuracy for the detection and quantification of myocardial infarction areas, consisting in a low cost and versatile option for high-resolution SPECT imaging of small rodents.

  1. Plasma sheath effects on ion collection by a pinhole

    Science.gov (United States)

    Herr, Joel L.; Snyder, David B.

    1993-01-01

    This work presents tables to assist in the evaluation of pinhole collection effects on spacecraft. These tables summarize results of a computer model which tracks particle trajectories through a simplified electric field in the plasma sheath. A technique is proposed to account for plasma sheath effects in the application of these results and scaling rules are proposed to apply the calculations to specific situations. This model is compared to ion current measurements obtained by another worker, and the agreement is very good.

  2. Emission computerized myocardial tomography with the 7-pinhole collimator

    Energy Technology Data Exchange (ETDEWEB)

    Sochor, H.; Pachinger, O.; Ogris, E.; Probst, P.; Joskowicz, G.; Kaindl, F. (Vienna Univ. (Austria). Kardiologische Klinik)

    1983-01-01

    89 patients (78 with coronary artery disease, 11 normals) were studied comparatively with Tl-201 planar myocardial scintigraphy and 7-pinhole emission tomography with a mobile gamma-camera. In 46 patients stress studies were performed, the other studies were performed as resting protocols. In 13 patients a correlation of scintigraphically determined infarct size calculated from the Tl-201 tomograms with CK and CK-MB values (maximum values) in the acute infarction period was performed. 17 patients having undergone intracoronary streptolysis were studied to investigate the effect of this intervention. In patients without previous myocardial infarction (n=35) sensitivity of 7-pinhole tomography was significantly superior over planar reading of images (83% for qualitative evaluation, 91% for quantitative analysis). In patients with previous myocardial infarction (n=26) comparative sensitivities were not significantly different, although slightly higher, neverthelesss the fraction of questionable findings was reduced from 9 to 4%, furthermore in 31% an additional information concerning size or localization could be obtained from the tomograms. Predictive diagnostic accuracy was highest for quantitative 7-pinhole tomography (91%) but not significantly different from qualitative tomography but higher than for planar imaging. Specificities of all methods were comparable. In patients during the acute phase of myocardial infarction a significant correlation (r = 0.76 for CK, r = 0.78 for CK-MB, p < 0.01) was obtained with enzymatic markers of infarct size. In the group after intracoronary streptolysis 7-pinhole tomography was able to demonstrate a quantitative reduction of thallium infarct size in patients after successful lysis (23.5% vs 48.7%, p < 0.01).

  3. Evaluation of Pinhole castration as an alternative technique for goat ...

    African Journals Online (AJOL)

    Les animaux ont été surveillés quotidiennement à travers des examens cliniques de stress et d'un dosage du cortisol plasmatique. L'efficacité de la méthode a été évaluée par l'étude des caractéristiques séminales et des changements morphologiques de testicules. Les boucs qui ont subi la castration pinhole ont montré ...

  4. Pinhole Viewing Strengthens the Hollow-Face Illusion

    OpenAIRE

    Koessler, Trent; Hill, Harold

    2015-01-01

    A hollow (concave) mask appears convex when viewed from beyond a certain distance even when viewed stereoscopically—this is the hollow-face illusion. At close viewing distances, the same mask is seen as hollow even when disparity information is eliminated by monocular viewing. A potential source of nonpictorial, monocular information that favors a veridical percept at close distances is accommodation in conjunction with focus blur. In this article, we used pinhole viewing to minimize this pot...

  5. Pinhole castration technique: an alternative to orchiectomy in stray dogs.

    Science.gov (United States)

    Baba, M A; Fazili, M R; Athar, H; Mir, M S; Moulvi, B A; Khan, I

    2013-02-01

    The study evaluates a pinhole castration technique in male stray dogs. Animals (n=18) were randomly allotted to 2 groups: group I (n=12, pinhole castration) and group II (n=6, sham control). Percutaneous (in situ) spermatic cord ligation was performed under xylazine-ketamine anesthesia in all animals of group I. Scrotal and the testicular dimensions and testicular volume were measured on day 28 followed by bilateral orchiectomy in both the groups. Significantly lower readings were obtained from animals of group I when compared with pre-ligation readings as well as the corresponding readings from group II animals. In ligated animals volume of testicles showed a reduction by 40.57%. Histopathological examination of testicles revealed degeneration and atrophy in Group I animals. On the whole pinhole castration was found effective, minimally invasive, cheap, simple and a quick technique for male dog sterilization with potential for adoption in large-scale animal birth control programs. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Assessment of grass root effects on soil piping in sandy soils using the pinhole test

    Science.gov (United States)

    Bernatek-Jakiel, Anita; Vannoppen, Wouter; Poesen, Jean

    2017-10-01

    Soil piping is an important land degradation process that occurs in a wide range of environments. Despite an increasing number of studies on this type of subsurface erosion, the impact of vegetation on piping erosion is still unclear. It can be hypothesized that vegetation, and in particular plant roots, may reduce piping susceptibility of soils because roots of vegetation also control concentrated flow erosion rates or shallow mass movements. Therefore, this paper aims to assess the impact of grass roots on piping erosion susceptibility of a sandy soil. The pinhole test was used as it provides quantitative data on pipeflow discharge, sediment concentration and sediment discharge. Tests were conducted at different hydraulic heads (i.e., 50 mm, 180 mm, 380 mm and 1020 mm). Results showed that the hydraulic head was positively correlated with pipeflow discharge, sediment concentration and sediment discharge, while the presence of grass roots (expressed as root density) was negatively correlated with these pipeflow characteristics. Smaller sediment concentrations and sediment discharges were observed in root-permeated samples compared to root-free samples. When root density exceeds 0.5 kg m- 3, piping erosion rates decreased by 50% compared to root-free soil samples. Moreover, if grass roots are present, the positive correlation between hydraulic head and both sediment discharge and sediment concentration is less pronounced, demonstrating that grass roots become more effective in reducing piping erosion rates at larger hydraulic heads. Overall, this study demonstrates that grass roots are quite efficient in reducing piping erosion rates in sandy soils, even at high hydraulic head (> 1 m). As such, grass roots may therefore be used to efficiently control piping erosion rates in topsoils.

  7. TH-C-17A-06: A Hardware Implementation and Evaluation of Robotic SPECT: Toward Molecular Imaging Onboard Radiation Therapy Machines

    Energy Technology Data Exchange (ETDEWEB)

    Yan, S; Touch, M [Duke University Medical Physics Graduate Program, Durham, NC (United States); Bowsher, J; Yin, F [Duke University Medical Physics Graduate Program, Durham, NC (United States); Duke University Medical Center, Durham, NC (United States); Cheng, L [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Purpose: To construct a robotic SPECT system and demonstrate its capability to image a thorax phantom on a radiation therapy flat-top couch. The system has potential for on-board functional and molecular imaging in radiation therapy. Methods: A robotic SPECT imaging system was developed utilizing a Digirad 2020tc detector and a KUKA KR150-L110 robot. An imaging study was performed with the PET CT Phantom, which includes 5 spheres: 10, 13, 17, 22 and 28 mm in diameter. Sphere-tobackground concentration ratio was 6:1 of Tc99m. The phantom was placed on a flat-top couch. SPECT projections were acquired with a parallel-hole collimator and a single pinhole collimator. The robotic system navigated the detector tracing the flat-top table to maintain the closest possible proximity to the phantom. For image reconstruction, detector trajectories were described by six parameters: radius-of-rotation, x and z detector shifts, and detector rotation θ, tilt ϕ and twist γ. These six parameters were obtained from the robotic system by calibrating the robot base and tool coordinates. Results: The robotic SPECT system was able to maneuver parallel-hole and pinhole collimated SPECT detectors in close proximity to the phantom, minimizing impact of the flat-top couch on detector-to-COR (center-ofrotation) distance. In acquisitions with background at 1/6th sphere activity concentration, photopeak contamination was heavy, yet the 17, 22, and 28 mm diameter spheres were readily observed with the parallel hole imaging, and the single, targeted sphere (28 mm diameter) was readily observed in the pinhole region-of-interest (ROI) imaging. Conclusion: Onboard SPECT could be achieved by a robot maneuvering a SPECT detector about patients in position for radiation therapy on a flat-top couch. The robot inherent coordinate frame could be an effective means to estimate detector pose for use in SPECT image reconstruction. PHS/NIH/NCI grant R21-CA156390-01A1.

  8. Usefulness of {sup 99m}Tc-HMPAO-SPECT in evaluation of bacterial meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Kentaro; Ando, Hiroshi; Sueyoshi, Keiko; Matsuyuki, Makado; Hashimoto, Nobuo; Ono, Eiichiro; Katsuragi, Makoto [St. Maria Hospital, Kurume, Fukuoka (Japan)

    1997-03-01

    {sup 99m}Tc-HMPAO SPECT was performed to detect the periodical changes of blood flow distribution in 6 infants (average age 5.5 months) with bacterial meningitis and was compared with findings by CT and MRI imaging, by DQ (developmental quotient) and by neurological examinations. SPECT was done with Shimadzu HEADTOME SET 70 for 20 min at 5 min after intravenous administration of {sup 99m}Tc-HMPAO (111 MBq) at the stage of 16-26 days (SPECT I) after hospitalization, of 39-105 days (II) and/or of 138-197 days (III). The region of interest was set in both cerebellar hemispheres to calculate the mean pixel count c1 and in other 16 areas for the count c2. SPECT image was evaluated together with c2/c1 ratios. Head CT was performed at hospitalization or at the period around the SPECT I, and head MRI, at 39-183 days. At 3-5 months after crisis, evaluation was done for DQ and neurological signs. Periodical brain SPECT was found useful for the precise evaluation of bacterial meningitis and for prediction of its prognosis. (K.H.)

  9. Radiopharmaceuticals for SPECT cancer detection

    Science.gov (United States)

    Chernov, V. I.; Medvedeva, A. A.; Zelchan, R. V.; Sinilkin, I. G.; Stasyuk, E. S.; Larionova, L. A.; Slonimskaya, E. M.; Choynzonov, E. L.

    2016-08-01

    The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with 199Tl and 99mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. A total of 220 patients were included into the study: 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and 100 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). No abnormal 199Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of 199Tl SPECT. In the breast cancer patients, the increased 199Tl uptake in the breast was visualized in 94.8% patients, 99mTc-MIBI—in 93.4% patients. The increased 199Tl uptake in axillary lymph nodes was detected in 60% patients, and 99mTc-MIBI—in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, the sensitivity of SPECT with 199Tl and 99mTc-MIBI was 95%. The 199Tl SPECT sensitivity in identification of regional lymph node metastases in the patients with laryngeal/hypopharyngeal cancer was 75% and the 99mTc-MIBI SPECT sensitivity was 17%. The data obtained showed that SPECT with 199Tl and 99mTc-MIBI can be used as one of the additional imaging methods in detection of tumors.

  10. Experimental evaluation of niobium film pinholes [for LEP cavities

    CERN Document Server

    Chiggiato, P; Benvenuti, Cristoforo; Malabaila, M

    1999-01-01

    To assess the quality of vacuum-deposited films, well-defined areas of free-hanging thin film may be obtained by chemically dissolving the substrate on a fraction of its surface. A global evaluation of the thin film pinholes is then possible by measuring the gas conductance across the film. To do so, copper discs clamped between Con-Flat flanges have been used to separate a chamber filled with helium gas from another chamber where the helium throughput was measured. This method has been used to compare films produced under dust-free and dusty conditions, of various surface roughnesses and at different deposition incidence angles.

  11. High-Damage-Threshold Pinhole for Glass Fusion Laser Applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumit, N.A.; Letzring, S.A.; Johnson, R.P.

    1998-06-07

    We are investigating methods to fabricate high-damage-threshold spatial-filter pinholes that might not be susceptible to plasma closure for relatively high energies and long pulses. These are based on the observation that grazing-incidence reflection from glass can withstand in excess of 5 kJ/cm{sup 2} (normal to the beam) without plasma formation. The high damage threshold results from both the cos q spreading of the energy across the surface and the reflection of a large fraction of the energy from the surface, thereby greatly reducing the field strength within the medium.

  12. A SPECT Scanner for Rodent Imaging Based on Small-Area Gamma Cameras

    Science.gov (United States)

    Lage, Eduardo; Villena, José L.; Tapias, Gustavo; Martinez, Naira P.; Soto-Montenegro, Maria L.; Abella, Mónica; Sisniega, Alejandro; Pino, Francisco; Ros, Domènec; Pavia, Javier; Desco, Manuel; Vaquero, Juan J.

    2010-10-01

    We developed a cost-effective SPECT scanner prototype (rSPECT) for in vivo imaging of rodents based on small-area gamma cameras. Each detector consists of a position-sensitive photomultiplier tube (PS-PMT) coupled to a 30 x 30 Nal(Tl) scintillator array and electronics attached to the PS-PMT sockets for adapting the detector signals to an in-house developed data acquisition system. The detector components are enclosed in a lead-shielded case with a receptacle to insert the collimators. System performance was assessed using 99mTc for a high-resolution parallel-hole collimator, and for a 0.75-mm pinhole collimator with a 60° aperture angle and a 42-mm collimator length. The energy resolution is about 10.7% of the photopeak energy. The overall system sensitivity is about 3 cps/μCi/detector and planar spatial resolution ranges from 2.4 mm at 1 cm source-to-collimator distance to 4.1 mm at 4.5 cm with parallel-hole collimators. With pinhole collimators planar spatial resolution ranges from 1.2 mm at 1 cm source-to-collimator distance to 2.4 mm at 4.5 cm; sensitivity at these distances ranges from 2.8 to 0.5 cps/μCi/detector. Tomographic hot-rod phantom images are presented together with images of bone, myocardium and brain of living rodents to demonstrate the feasibility of preclinical small-animal studies with the rSPECT.

  13. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S. [Oak Ridge National Laboratory; Endres, Christopher J. [Johns Hopkins, Baltimore; Foss, Catherine A. [Johns Hopkins, Baltimore; Nimmagadda, Sridhar [Johns Hopkins, Baltimore; Jung, Hyeyun [Johns Hopkins, Baltimore; Goddard, James S. [Oak Ridge National Laboratory; Lee, Seung Joon [JLAB; McKisson, John [JLAB; Smith, Mark F. [University of Maryland; Stolin, Alexander V. [West Virginia University; Weisenberger, Andrew G. [JLAB; Pomper, Martin G. [Johns Hopkins, Baltimore

    2013-06-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a ^99mTc-pertechnetate phantom, ^99mTc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand ^123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of ^123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  14. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S [ORNL; Endres, Christopher [Johns Hopkins University; Foss, Catherine [Johns Hopkins University; Nimmagadda, Sridhar [Johns Hopkins University; Jung, Hyeyun [Johns Hopkins University; Goddard Jr, James Samuel [ORNL; Lee, Seung Joon [Jefferson Lab; McKisson, John [Jefferson Lab; Smith, Mark F. [University of Maryland School of Medicine, The, Baltimore, MD; Stolin, Alexander [West Virginia University, Morgantown; Weisenberger, Andrew G. [Jefferson Lab; Pomper, Martin [Johns Hopkins University

    2013-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  15. The yield of SPECT/CT for anatomical lymphatic mapping in patients with melanoma.

    Science.gov (United States)

    van der Ploeg, Iris M C; Valdés Olmos, Renato A; Kroon, Bin B R; Wouters, Michael W J M; van den Brekel, Michiel W M; Vogel, Wouter V; Hoefnagel, Cornelis A; Nieweg, Omgo E

    2009-06-01

    The hybrid single-photon emission computed tomography camera with integrated CT (SPECT/CT) fuses tomographic lymphoscintigrams with anatomical CT data. SPECT/CT shows the exact anatomical location of a sentinel node and may detect additional drainage. The purpose of this study was to explore its potential in patients with melanoma. We studied 85 patients with melanoma with conventional lymphoscintigrams that were difficult to interpret (51 patients), that showed an unusual drainage pattern (33 patients), or with nonvisualization (1 patient). Forty-one patients had melanoma on an extremity, 31 on the trunk, and 14 in the head and neck region. SPECT/CT was performed following late conventional imaging without reinjection of the radiopharmaceutical. Conventional imaging suggested 214 sentinel nodes in 84 of the 85 patients (99%). SPECT/CT showed these same nodes and 12 extra sentinel nodes in seven patients (8%). Ten of these additional nodes were harvested, of which three nodes of two patients harbored metastases. There was a clear advantage of SPECT/CT in 30 patients (35%), resulting in a different incision in 17 patients, an incision at another site in 8, and an extra incision in 5 patients. The value was questionable in 19 patients (22%) in whom sentinel nodes were more clearly visualized by SPECT/CT, although the incision remained unchanged. There was no additional value of SPECT/CT in 36 patients (42%). SPECT/CT detects additional drainage and shows the exact anatomical location of sentinel nodes in patients with inconclusive conventional lymphoscintigrams. SPECT/CT facilitates surgical exploration in difficult cases and may improve staging.

  16. Development of a combined microSPECT/CT system for small animal imaging

    Science.gov (United States)

    Sun, Mingshan

    Modern advances in the biomedical sciences have placed increased attention on small animals such as mice and rats as models of human biology and disease in biological research and pharmaceutical development. Their small size and fast breeding rate, their physiologic similarity to human, and, more importantly, the availability of sophisticated genetic manipulations, all have made mice and rats the laboratory mammals of choice in these experimental studies. However, the increased use of small animals in biomedical research also calls for new instruments that can measure the anatomic and metabolic information noninvasively with adequate spatial resolution and measurement sensitivity to facilitate these studies. This dissertation describes the engineering development of a combined single photon emission computed tomography (SPECT) and X-ray computed tomography (CT) system dedicated for small animals imaging. The system aims to obtain both the anatomic and metabolic images with submillimeter spatial resolution in a way that the data can be correlated to provide improved image quality and to offer more complete biological evaluation for biomedical studies involving small animals. The project requires development of complete microSPECT and microCT subsystems. Both subsystems are configured with a shared gantry and animal bed with integrated instrumentation for data acquisition and system control. The microCT employs a microfocus X-ray tube and a CCD-based detector for low noise, high resolution imaging. The microSPECT utilizes three semiconductor detectors coupled with pinhole collimators. A significant contribution of this dissertation project is the development of iterative algorithms with geometrical compensation that allows radionuclide images to be reconstructed at submillimeter spatial resolution, but with significantly higher detection efficiency than conventional methods. Both subsystems are capable of helical scans, offering lengthened field of view and improved

  17. Impact of 111In-DTPA-octreotide SPECT/CT fusion images in the management of neuroendocrine tumours.

    Science.gov (United States)

    Castaldi, P; Rufini, V; Treglia, G; Bruno, I; Perotti, G; Stifano, G; Barbaro, B; Giordano, A

    2008-10-01

    Somatostatin receptor scintigraphy with [(111)In]-diethylene triamine pentaacetate acid (DTPA)-octreotide is an accurate method for detecting neuroendocrine tumours (NETs) but often does not provide clear anatomical localisation of lesions. The aim of this study was to assess the clinical usefulness of anatomical-functional image fusion. Fifty-four patients with known or suspected NET were included in the study. Planar and single-photon-emission computed tomography (SPECT) imaging was performed using a dual-head gamma camera equipped with an integrated X-ray transmission system, and the images were first interpreted alone by two nuclear medicine physicians and then compared with SPECT/CT fusion images together with a radiologist. The improvement provided by SPECT/CT in the interpretation of SPECT data alone and any modification in patient management were recorded. Fusion images improved SPECT interpretation in 23 cases, providing precise anatomical localisation of increased tracer uptake in 20 cases and disease exclusion in sites of physiological uptake in 5. In 10 patients, SPECT/CT allowed definition of the functional significance of lesions detected by diagnostic CT. SPECT/CT data modified clinical management in 14 cases by changing the diagnostic approach in 8 and the therapeutic modality in 6. Our study demonstrates that image fusion is clearly superior to SPECT alone, allowing precise localisation of lesions and reducing false-positive results.

  18. SPECT in Focal Epilepsies

    Directory of Open Access Journals (Sweden)

    Roderick Duncan

    2000-01-01

    Full Text Available Brain perfusion changes during seizures were first observed in the 1930s. Single Photon Emission Computed Tomography (SPECT was developed in the 1970s, and tracers suitable for the imaging of regional cerebral perfusion (rCP became available in the 1980s. The method was first used to study rCP in the interictal phase, and this showed areas of low perfusion in a proportion of cases, mainly in patients with temporal lobe epilepsies. However, the trapping paradigm of tracers such as hexamethyl propyleneamine oxime (HMPAO provided a practicable method of studying changes in rCP during seizures, and a literature was established in the late 1980s and early 1990s showing a typical sequence of changes during and after seizures of mesial temporal lobe origin; the ictal phase was associated with large increases in perfusion throughout the temporal lobe, with first the lateral, then the mesial temporal lobe becoming hypoperfused in the postictal phase. Activation and inhibition of other structures, such as the basal ganglia and frontal cortex, were also seen. Studies of seizures originating elsewhere in the brain have shown a variety of patterns of change, according to the structures involved. These changes have been used practically to aid the process of localisation of the epileptogenic zone so that epilepsy surgery can be planned.

  19. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    Science.gov (United States)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  20. [Bony pathologies of the metacarpophalangeal joints in early rheumatoid arthritis: comparison of MRI and high-resolution SPECT].

    Science.gov (United States)

    Scherer, A; Wirrwar, A; Mattes-György, K; Blondin, D; Reichelt, D; Müller, H-W; Schneider, M; Mödder, U; Ostendorf, B

    2009-09-01

    Comparison of MRI with a newly developed high-resolution multi-pinhole single photon emission computed tomography (MPH-SPECT) regarding the detection of bony pathologies of the metacarpophalangeal (MCP) joints in patients with early rheumatoid arthritis (ERA). The clinically dominant hand of 15 patients with ERA (disease duration 6 months) was examined using MRI and MPH-SPECT. The evaluation of MRI was achieved according to RAMRIS criteria and for the MPH SPECT regarding pathological tracer uptake and distribution. Image fusions of MRI and MPH-SPECT were provided and the two methods were compared. In MRI 12 of 15 patients showed arthritic joint pathologies, while 8 patients exhibited soft tissue and bony changes. 4 patients had only soft tissue inflammation (synovitis) with a normal bone signal. In MPH-SPECT 10 of 15 patients showed pathologically increased bone metabolism. The fusion images presented a high agreement of the pathological changes in both methods, while areas with increased bone metabolism were not only present in the case of erosions, but also in the case of bone edema. In 2 patients increased bone metabolism was detectable in areas of MR tomographic normal bone, while a clear surrounding synovitis was present in each case here. The comparison of MPH-SPECT with MRI proves that the latter is a sensitive procedure for the detection of bony pathologies of MCP joints in ERA. A normal bone signal in MRI does not exclude early changes in bone metabolism in cases of severe synovialitis. Georg Thieme Verlag KG Stuttgart, New York.

  1. Organ volume estimation using SPECT

    CERN Document Server

    Zaidi, H

    1996-01-01

    Knowledge of in vivo thyroid volume has both diagnostic and therapeutic importance and could lead to a more precise quantification of absolute activity contained in the thyroid gland. In order to improve single-photon emission computed tomography (SPECT) quantitation, attenuation correction was performed according to Chang's algorithm. The dual-window method was used for scatter subtraction. We used a Monte Carlo simulation of the SPECT system to accurately determine the scatter multiplier factor k. Volume estimation using SPECT was performed by summing up the volume elements (voxels) lying within the contour of the object, determined by a fixed threshold and the gray level histogram (GLH) method. Thyroid phantom and patient studies were performed and the influence of 1) fixed thresholding, 2) automatic thresholding, 3) attenuation, 4) scatter, and 5) reconstruction filter were investigated. This study shows that accurate volume estimation of the thyroid gland is feasible when accurate corrections are perform...

  2. Radiopharmaceuticals for SPECT cancer detection

    Energy Technology Data Exchange (ETDEWEB)

    Chernov, V. I., E-mail: chernov@oncology.tomsk.ru; Medvedeva, A. A., E-mail: tickayaAA@oncology.tomsk.ru; Zelchan, R. V., E-mail: r.zelchan@yandex.ru; Sinilkin, I. G., E-mail: sinilkinig@oncology.tomsk.ru [Tomsk Cancer Research Institute, Kooperativny Street 5, Tomsk, 634050 (Russian Federation); Tomsk Polytechnic University, Lenin Avenue 30, Tomsk, 634050 (Russian Federation); Stasyuk, E. S.; Larionova, L. A. [Tomsk Polytechnic University, Lenin Avenue 30, Tomsk, 634050 (Russian Federation); Slonimskaya, E. M.; Choynzonov, E. L. [Tomsk Cancer Research Institute, Kooperativny Street 5, Tomsk, 634050 (Russian Federation)

    2016-08-02

    The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with {sup 199}Tl and {sup 99}mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. A total of 220 patients were included into the study: 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and 100 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). No abnormal {sup 199}Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of {sup 199}Tl SPECT. In the breast cancer patients, the increased {sup 199}Tl uptake in the breast was visualized in 94.8% patients, {sup 99m}Tc-MIBI—in 93.4% patients. The increased {sup 199}Tl uptake in axillary lymph nodes was detected in 60% patients, and {sup 99m}Tc-MIBI—in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, the sensitivity of SPECT with {sup 199}Tl and {sup 99m}Tc-MIBI was 95%. The {sup 199}Tl SPECT sensitivity in identification of regional lymph node metastases in the patients with laryngeal/hypopharyngeal cancer was 75% and the {sup 99m}Tc-MIBI SPECT sensitivity was 17%. The data obtained showed that SPECT with {sup 199}Tl and {sup 99m}Tc-MIBI can be used as one of the additional imaging methods in detection of tumors.

  3. Size measurement of the thyroid gland on a magnified pinhole thyroid scan using an ultrasonic device measuring distance from the pinhole to the thyroid gland.

    Science.gov (United States)

    Ahn, Byeong-Cheol; Ahn, Gilhwan; Kim, Do-Hoon; Kim, Kyoung Dong; Jeong, Shin Young; Lee, Sang-Woo; Lee, Jaetae

    2015-02-01

    Pinhole has been used for magnification of gamma camera images and is valuable for imaging of small organs, such as thyroid; however, size of the organ cannot be measured on the image due to variable degree of magnification by distance between the pinhole and the organ. The aim of this study was to develop a true size measuring system (TSM system) on magnified pinhole thyroid scan using an ultrasonic sensor. An ultrasonic device capable of measuring the distance from the pinhole to the skin overlying the thyroid gland was manufactured using a ~40 kHz piezoelectric-transducer-based sensor, and its accuracy was tested. An interface program was developed and fused with the ultrasonic device for development of the TSM system. Accuracy of the TSM system for measuring size was tested with phantom images and 35 thyroid scans. The ultrasonic device accurately measured the distance from the pinhole to the skin over the thyroid gland and the measured values were highly reproducible (6 cm; 6.02 ± 0.04 cm, 8 cm; 8.00 ± 0.05 cm, 10 cm; 10.00 ± 0.05 cm). Distance on the phantom image corrected by the TSM system was almost the same as the true distance. Size of the thyroid on the pinhole image was larger (+67.3 to 103.1 %) than the true thyroid size on the parallel-hole image and the magnification decreased by increase of the distance between the pinhole and the skin over the thyroid gland. However, size of the thyroid obtained using the TSM system was almost equal (-2.1 to +3.6 %) to the true thyroid size on the parallel-hole image. We developed the TSM system for magnified pinhole images using a distance measuring ultrasonic sensor. Size of the thyroid on the magnified pinhole image obtained using the system was almost the same as the true thyroid size. The TSM system can be applied to obtain accurate size of the thyroid gland or lesions in the thyroid gland on pinhole thyroid scan.

  4. Final Report: A CdZnTe detector for MRI-compatible SPECT Systems

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Ling-Jian

    2012-12-27

    The key objective of this project is to develop the enabling technology for future MRI-compatible nuclear (e.g. SPECT) imaging system, and to demonstrate the feasibility of performing simultaneous MR and SPECT imaging studies of the same object. During the past three years, we have developed (a) a MRI-compatible ultrahigh resolution gamma ray detector and associated readout electronics, (b) a theoretical approach for modeling the effect of strong magnetic field on SPECT image quality, and (c) a maximum-likelihood (ML) based reconstruction routine with correction for the MR-induced distortion. With this support, we have also constructed a four-head MR-compatible SPECT system and tested the system inside a 3-T clinical MR-scanner located on UI campus. The experimental results obtained with this system have clearly demonstrated that sub-500um spatial resolution can be achieved with a SPECT system operated inside a 3-T MRI scanner. During the past three years, we have accomplished most of the major objectives outlined in the original proposal. These research efforts have laid out a solid foundation the development of future MR-compatible SPECT systems for both pre-clinical and clinical imaging applications.

  5. Collar Osteophytes Mimicking Osteonecrosis in Planar Bone Scintigraphy and Usefulness of SPECT/CT Images.

    Science.gov (United States)

    Juang, Jr-Jian; Chen, Yi-Hsing; Tsai, Shih-Chuan; Lin, Wan-Yu

    2017-03-01

    The use of prednisolone is one major risk factor for osteonecrosis in patients with systemic lupus erythematosus. Bone scintigraphy can be a diagnostic tool for early diagnosis. We present a case who had collar osteophytes at the bilateral femoral heads, which mimicked osteonecrosis in the planar bone scintigram. An SPECT/CT scan avoided this pitfall and increased the diagnostic accuracy for osteonecrosis.

  6. Invisible Base Electrode Coordinates Approximation for Simultaneous SPECT and EEG Data Visualization

    Directory of Open Access Journals (Sweden)

    Kowalczyk L.

    2014-04-01

    Full Text Available This work was performed as part of a larger research concerning the feasibility of improving the localization of epileptic foci, as compared to the standard SPECT examination, by applying the technique of EEG mapping. The presented study extends our previous work on the development of a method for superposition of SPECT images and EEG 3D maps when these two examinations are performed simultaneously. Due to the lack of anatomical data in SPECT images it is a much more difficult task than in the case of MRI/EEG study where electrodes are visible in morphological images. Using the appropriate dose of radioisotope we mark five base electrodes to make them visible in the SPECT image and then approximate the coordinates of the remaining electrodes using properties of the 10-20 electrode placement system and the proposed nine-ellipses model. This allows computing a sequence of 3D EEG maps spanning on all electrodes. It happens, however, that not all five base electrodes can be reliably identified in SPECT data. The aim of the current study was to develop a method for determining the coordinates of base electrode(s missing in the SPECT image. The algorithm for coordinates approximation has been developed and was tested on data collected for three subjects with all visible electrodes. To increase the accuracy of the approximation we used head surface models. Freely available model from Oostenveld research based on data from SPM package and our own model based on data from our EEG/SPECT studies were used. For data collected in four cases with one electrode not visible we compared the invisible base electrode coordinates approximation for Oostenveld and our models. The results vary depending on the missing electrode placement, but application of the realistic head model significantly increases the accuracy of the approximation.

  7. PET and SPECT in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Dierckx, Rudi A.J.O. [University Medical Center Groningen (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Ghent Univ. (Belgium); Otte, Andreas [Univ. of Applied Sciences Offenburg (Germany). Faculty of Electrical Engineering and Information Technology; Vries, Erik F.J. de; Waarde, Aren van (eds.) [University Medical Center Groningen (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging

    2014-09-01

    Covers classical psychiatric disorders as well as other subjects such as suicide, sleep, eating disorders, and autism. Emphasis on a multidisciplinary approach. Written by internationally acclaimed experts. PET and SPECT in Psychiatry showcases the combined expertise of renowned authors whose dedication to the investigation of psychiatric disease through nuclear medicine technology has achieved international recognition. The classical psychiatric disorders as well as other subjects - such as suicide, sleep, eating disorders, and autism - are discussed and the latest results in functional neuroimaging are detailed. Most chapters are written jointly by a clinical psychiatrist and a nuclear medicine expert to ensure a multidisciplinary approach. This state of the art compendium will be valuable to all who have an interest in the field of neuroscience, from the psychiatrist and the radiologist/nuclear medicine specialist to the interested general practitioner and cognitive psychologist. It is the first volume of a trilogy on PET and SPECT imaging in the neurosciences; other volumes will focus on PET and SPECT in neurology and PET and SPECT of neurobiological systems.

  8. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

    Paulson, O B; Lassen, N A

    1997-01-01

    PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series...

  9. Performance of the dynamic single photon emission computed tomography (dSPECT) method for decreasing or increasing activity changes

    Science.gov (United States)

    Celler, A.; Farncombe, T.; Bever, C.; Noll, D.; Maeght, J.; Harrop, R.; Lyster, D.

    2000-12-01

    Radionuclide imaging is now widely used whenever functional information is required. We present a new approach to dynamic SPECT imaging (dSPECT method) that uses a single slow rotation of a conventional camera and allows us to reconstruct a series of 3D images corresponding to the radiotracer distribution in the body at various times. Using simulations of various camera configurations and acquisition protocols, we have shown that this method is able to reconstruct washout half-lives with an accuracy greater than 90% when used with triple-head SPECT cameras. Accuracy decreases when using fewer camera heads, but dual-head geometries still give an accuracy greater than 80% for short and 90% for long half-lives and about 50-75% for single-head systems. Dynamic phantom experiments have yielded similar results. Presence of attenuation and background activity does not affect the accuracy of the dSPECT reconstructions. In all situations investigated satisfactory dynamic images were produced. A preliminary normal volunteer study measuring renal function was performed. The reconstructed dynamic images may be presented as a three-dimensional movie showing movement of the tracer through the kidneys and the measurement of the regional renal function can be performed. The time-activity curves determined from this dSPECT data are very similar to those obtained from dynamic planar scans.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  11. Robin Hood caught in Wonderland: brain SPECT findings.

    Science.gov (United States)

    Morland, David; Wolff, Valérie; Dietemann, Jean-Louis; Marescaux, Christian; Namer, Izzie Jacques

    2013-12-01

    We present the case of a 53-year-old woman presenting several episodes of body image distortions, ground deformation illusions, and problems assessing distance in the orthostatic position corresponding to the Alice in Wonderland syndrome. No symptoms were reported when sitting or lying down. She had uncontrolled hypertension, hyperglycemia, hypercholesterolemia, and a history of head trauma. Her condition had been diagnosed with left internal carotid artery dissection 2 years earlier. Brain SPECT with 99mTc-ECD performed after i.v. injection of the radiotracer in supine and in standing positions showed hypoperfusion in the healthy contralateral frontoparietal operculum (Robin Hood syndrome), deteriorating when standing up.

  12. Multi-pinhole fluorescent x-ray computed tomography for molecular imaging

    National Research Council Canada - National Science Library

    Tenta Sasaya; Naoki Sunaguchi; Kazuyuki Hyodo; Tsutomu Zeniya; Tetsuya Yuasa

    2017-01-01

    We propose a multi-pinhole fluorescent x-ray computed tomography (mp-FXCT) technique for preclinical molecular imaging that can provide the complete data necessary to produce 3-D tomographic images during anaesthesia...

  13. Reference Range of Functional Data of Gated Myocardial Perfusion SPECT by Quantitative Gated SPECT of Cedars-Sinai and 4D-MSPECT of Michigan University

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Kim, Moo Hyun; Kim, Young Dae [College of Medicine, Univ. of Donga, Pusan (Korea, Republic of)

    2003-07-01

    Various programs have been developed for gating of myocardial perfusion SPECT. Among the those program, the most popular program is the Quantitative Gated SPECT (QGS)? developed by Cedars-Sinai hospital and most recently released program is 4D-MSPECT? developed by university of Michigan. It is important to know the reference range of the functional data of gated myocardial perfusion SPECT because it is necessary to determine abnormality of individual patient and echocardiographic data is different from those of gated SPECT. Tc-99m MIBI gated myocardial perfusion SPECT image was reconstructed by dual head gamma camera (Siemens, BCAM, esoft) as routine procedure and analyzed using QGS? and 4D-MSPECT? program. All patients (M: F=9: 18, Age 69{+-}9 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded: previous angina or MI history, ECG change with Q wave or ST-T change, diabetes melitius, hypercholesterolemia, typical chest pain, hypertension and cardiomyopathy. Pre-test likelihood of all patients was low. (1) In stress gated SPECT by QGS?, EDV was 73{+-}25 ml, ESV 25{+-}14 ml, EF 67{+-}11 % and area of first frame of gating 106.4{+-}21cm{sup 2}. In rest gated SPECT, EDV was 76{+-}26 ml, ESV 27{+-}15 ml, EF 66{+-}12 and area of first frame of gating 108{+-}20cm{sup 2}. (2) In stress gated SPECT by 4D-MSPECT?, EDV was 76{+-}28 ml, ESV 23{+-}16 ml, EF 72{+-}11 %, mass 115{+-}24 g and ungated volume 42{+-}15 ml. In rest gated SPECT, EDV was 75{+-}27 ml, ESV 23{+-}12 ml, EF 71{+-}9%, mass 113{+-}25g and ungate dvolume 42{+-}15 ml, (3) s-EDV, s-EF, r-ESV and r-EF were significantly different between QGS? and 4D-MSPECT? (each p=0.016, p<0.001. p=0.003 and p=0.001). We determined the normal reference range of functional parameters by QGS? and 4D-MSPECT? program to diagnose individually the abnormality of patients. And the reference ranges have to adopted to be patients by each specific gating program.

  14. Effect of the Substrate Cleaning Process on Pinhole Formation in Sputtered CdTe Films

    Science.gov (United States)

    Camacho-Espinosa, E.; Oliva-Avilés, A. I.; Oliva, A. I.

    2017-08-01

    Seven cleaning methods for glass substrates were proposed and their role on pinhole formation of deposited CdTe films was examined. AFM micrographs of the cleaned substrates show the presence of surface particles after cleaning. RMS-roughness of the cleaned glass substrates is associated with the remaining particles at the surface after the cleaning processes. CdTe thin films deposited by the sputtering technique onto the cleaned substrates were analyzed to evaluate the pinhole formation. Parameters such as the occupied area, size, and circularity of the formed pinholes in the CdTe thin films were investigated by microscopy technique through image processing software. Some illustrative 2.5-D images of the pinholes in CdTe films were obtained for each cleaning method. For all the investigated cleaning methods, the mean pinhole diameters ranged from 30 to 55 μm. Correlations between the pinhole formation and the cleaning method were observed, which highlight the importance of the cleaning process selection.

  15. [Brain SPECT in Lewy body dementia].

    Science.gov (United States)

    Farid, Karim; Volpe-Gillot, Lisette; Caillat-Vigneron, Nadine

    2011-06-01

    Dementia of Lewy bodies (DLB) is the second cause of degenerative dementia. There is many clinical presentation of the disease. Brain single photon computed tomography (SPECT) is a simple way to investigate routinely the cerebral blood flow. On cerebral perfusion SPECT, DLB is accompanied by diffuse cortical hypoperfusion predominantly at the posterior cortex and may affect the associative and primary visual areas in relation to neuronal loss or dysfunction. DLB patients have striatal hypofixation on cerebral neurotranmission SPECT-DaTSCAN(®), related with dopaminergic loss. Brain SPECT is useful in the differential diagnosis between DLB and other dementia. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. Preliminary experience with thallous chloride T1 201-labeled single-photon emission computed tomography scanning in head and neck cancer

    NARCIS (Netherlands)

    Gregor, R. T.; Valdés-Olmos, R.; Koops, W.; Balm, A. J.; Hilgers, F. J.; Hoefnagel, C. A.

    1996-01-01

    To test the feasibility of single-photon emission computed tomography (SPECT) scanning with the use of thallous chloride T1 201 in patients with head and neck cancer and to decide its possible applications to improve the diagnosis and staging of head and neck cancer. Findings from SPECT with the use

  17. SPECT of aged backache patients

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Shigehiko; Nishikimi, Junzo; Mizuno, Naokado; Watanabe, Kentaro; Kondo, Masaki; Ozaki, Satoshi; Urasaki, Tetsuya; Muro, Toshiyuki [Prefectural Tajimi Hospital, Gifu (Japan)

    1995-12-01

    Single photon emission computed tomography (SPECT) using {sup 99m}Tc-HMDP was performed on 53 middle-aged or elderly patients (male 20, female, 33; age range, 40-80 years old) with lumbago, i.e., 25 patients with lumbar spondylosis, 15 with lumbar degenerative spondylolisthesis, 4 with spondylolytic spondylolisthesis, 3 with compression fracture, 3 with pulurent spondylitis, 2 with spondylous osteoporosis, and 1 with spinal osteodesmosis. {sup 99m}Tc-HMDP (740 MBq) was intravenously injected and regular SPECT was performed at 3 hours. Gamma camera was performed for about 10 seconds with 5deg intervals, and 36 steps (180deg) of collection was completed after about 6 minutes. The radioisotope accumulation, the presence or absence of sthenia, and its site were evaluated. Forty-seven (88.7%) patients showed excessive accumulation, i.e., 40 (75.5%) in peripheral vertebral osteophyte, 31 (58.5%) in vertebral articulations, and 10 (18.9%) in whole vertebral body. Significantly increased bilateral excessive accumulation was admitted in the vertebral articulations of sliding disc in degenerative spondylolisthesis. SPECT is considered useful in understanding the pathophysiology of degenerative lumber diseases. (S.Y.).

  18. Comparison of brain perfusion SPECT abnormalities with anatomical imaging in mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Majid Asadi

    2007-02-01

    Full Text Available Background: Trauma is the most common cause of morbidity and mortality in industrialized countries and also in Iran. Anatomical imaging (AI CT and MRI is helpful in the diagnosis of acute traumatic complications however it is not efficient in the diagnosis of disabling injury syndrome. In contrast, brain perfusion SPECT (Single Photon Emission Computed Tomography can be more useful for evaluation of microvascular structure. This study was designed to compare these two diagnostic methods. Methods: A total of 50 patients who had been suffering from traumatic brain injury for more than 1 year, and were followed as mild traumatic brain injury group according to “the Brain Injury Interdisciplinary Special Interest Group of the Ameri can Congress of Rehabilitation Medicine” criteria, were examined by brain perfusion SPECT and AI. The common anatomical classification of the lobes of brain was used. Results: The male to female ratio was 3:2. The mean age was 32.32±11.8 years and mean post-traumatic time was 1.48±0.65 years. The most common symptoms were headache (60%, agusia (36% and anosmia (32%. Among 400 examined brain lobes in this study, brain perfusion SPECT revealed remarkable abnormality in 76 lobes (19%, but AI determined abnormalities in 38 lobes (9.5% therefore, SPECT was twice sensitive than AI in mild traumatic brain injury (P<0.001. The correlation between SPECT and AI findings was 84%. SPECT was more sensitive than AI in demonstrating brain abnormalities in frontal lobe it was more obvious in the male group however, there was no significant difference between more and less than 30 years old groups. Conclusion: According to the findings of this study, we recommend using brain perfusion SPECT for all patients with chronic complications of head trauma, particularly those who have signs and symptoms of hypofrontalism, even though with some abnormalities in AI.

  19. Feasibility of Stereo-Infrared Tracking to Monitor Patient Motion During Cardiac SPECT Imaging.

    Science.gov (United States)

    Beach, Richard D; Pretorius, P Hendrik; Boening, Guido; Bruyant, Philippe P; Feng, Bing; Fulton, Roger R; Gennert, Michael A; Nadella, Suman; King, Michael A

    2004-10-01

    Patient motion during cardiac SPECT imaging can cause diagnostic imaging artifacts. We investigated the feasibility of monitoring patient motion using the Polaris motion-tracking system. This system uses passive infrared reflection from small spheres to provide real-time position data with vendor stated 0.35 mm accuracy and 0.2 mm repeatability. In our configuration, the Polaris system views through the SPECT gantry toward the patient's head. List-mode event data was temporally synchronized with motion-tracking data utilizing a modified LabVIEW virtual instrument that we have employed in previous optical motion-tracking investigations. Calibration of SPECT to Polaris coordinates was achieved by determining the transformation matrix necessary to align the position of four reflecting spheres as seen by Polaris, with the location of Tc-99m activity placed inside the sphere mounts as determined in SPECT reconstructions. We have successfully tracked targets placed on volunteers in simulated imaging positions on the table of our SPECT system. We obtained excellent correlation (R(2) > 0.998) between the change in location of the targets as measured by our SPECT system and the Polaris. We have also obtained excellent agreement between the recordings of the respiratory motion of four targets attached to an elastic band wrapped around the abdomen of volunteers and from a pneumatic bellows. We used the axial motion of point sources as determined by the Polaris to correct the motion in SPECT image acquisitions yielding virtually identical point source FWHM and FWTM values, and profiled maximum heart wall counts of cardiac phantom images, compared to the reconstructions with no motion.

  20. The current status of SPECT or SPECT/CT in South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Ik Dong; Choi, Eun Kyung; Chung, Yong An [Dept. of Radiology, Incheon Saint Mary' s HospitalThe Catholic University of Korea, Incheon (Korea, Republic of)

    2017-06-15

    The first step to nuclear medicine in Korea started with introduction of the gamma camera in 1969. Although planar images with the gamma camera give important functional information, they have the limitations that result from 2-dimensional images. Single-photon emission computed tomography (SPECT) due to its 3-dimensional image acquisition is superior to earlier planar gamma imaging in image resolution and diagnostic accuracy. As demand for a hybrid functional and anatomical imaging device has increased, integrated SPECT/CT systems have been used. In Korea, SPECT/CT was for the first time installed in 2003. SPECT/CT can eliminate many possible pitfalls on SPECT-alone images, making better attenuation correction and thereby improving image quality. Therefore, SPECT/CT is clinically preferred in many hospitals in various aspects. More recently, additional SPECT/CT images taken from the region with equivocal uptake on planar images have been helpful in making precise interpretation as part of their clinical workup in postoperative thyroid cancer patients. SPECT and SPECT/CT have various advantages, but its clinical application has gradually decreased in recent few years. While some researchers investigated the myocardial blood flow with cardiac PET using F-18 FDG or N-13 ammonia, myocardial perfusion SPECT is, at present, the radionuclide imaging study of choice for the risk stratification and guiding therapy in the coronary artery disease patients in Korea. New diagnostic radiopharmaceuticals for AD have received increasing attention; nevertheless, brain SPECT will remain the most reliable modality evaluating cerebral perfusion.

  1. Formation of Leading-Edge Pinholes in the Space Shuttle Wings Investigated

    Science.gov (United States)

    Jacobson, Nathan S.

    2000-01-01

    The space shuttle wing leading edge and nose cap are composed of a carbon/carbon composite that is protected by silicon carbide. The coefficient of thermal expansion mismatch leads to cracks in the silicon carbide. The outer coating of the silicon carbide is a sodium-silicate-based glass that becomes fluid at the shuttles high reentry temperatures and fills these cracks. Small pinholes roughly 0.1 mm in diameter have been observed on these materials after 12 or more flights. These pinholes have been investigated by researchers at the NASA Johnson Space Center, Rockwell International, the Boeing Company, Lockheed Martin Corporation, and the NASA Glenn Research Center at Lewis Field to determine the possible sources and the extent of damage. A typical pinhole is illustrated in the photomicrographs. These pinholes are found primarily on the wing leading edges and not on the nose cap, which is covered when the orbiter is on the launch pad. The pinholes are generally associated with a bead of zincrich glass. Examination of the orbiter and launch structure indicates that weathering paint on the launch structure leads to deposits of zinc-containing paint flakes on the wing leading edge. These may become embedded in the crevices of the wing leading edge and form the observed zinc-rich glass. Laboratory experiments indicate that zinc oxide reacts vigorously with the glass coating on the silicon carbide. Thus, it is likely that this is the reaction that leads to pinhole formation (Christensen, S.V.: Reinforced Carbon/Carbon Pin Hole Formation Through Zinc Oxide Attack. Rockwell International Internal Letter, RDW 96 057, May 1996). Cross-sectional examination of pinholes suggests that they are enlarged thermal expansion mismatch cracks. This is illustrated in the photomicrographs. A careful microstructural analysis indicates that the pinhole walls consist of layers of zinc-containing glass. Thus, pinholes are likely formed by zinc oxide particles lodging in crevices and

  2. SPECT assay of radiolabeled monoclonal antibodies. Progress report, September 1, 1992--August 24, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1993-08-20

    The overall goal of this project is to improve the effectiveness of single photon emission computed tomography (SPECT) to image and quantify radiolabeled monoclonal antibodies. During the past year, we have made significant progress toward this goal, and this report summarizes that work. Our efforts have been mainly directed along three fronts. First, we have developed and tested new reconstruction methods including three-dimensional iterative algorithms that model non-uniform attenuation and distance-dependent detector response. Both fan beam and parallel beam collimator geometries have been modeled and novel ways of improving the efficiency of the computationally intensive methods have been introduced. Second, an ultra-high resolution, small field-of-view pinhole collimator has been constructed and evaluated. Reconstructed spatial resolution of 1 to 3 mm (FWHM) has been achieved in phantom scans with a useful field-of-view of 9 to 10 cm. Finally, we have investigated the ability of SPECT to image and quantify astatine-211 distributions. Reconstructed images of phantom data demonstrated quantitative accuracy to within 10% with proper attenuation and scatter compensation.

  3. Clinical applications of SPECT-CT

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadzadehfar, Hojjat; Biersack, Hans-Juergen (eds.) [University Hospital Bonn (Germany). Dept. of Nuclear Medicine

    2014-06-01

    Covers the full spectrum of clinical applications of SPECT/CT in diagnosis of benign and malignant diseases. Includes chapters on the use of SPECT/CT for dosimetry and for therapy planning. Completely up to date. Many helpful illustrations. SPECT/CT cameras have considerably improved diagnostic accuracy in recent years. Such cameras allow direct correlation of anatomic and functional information, resulting in better localization and definition of scintigraphic findings. In addition to this anatomic referencing, CT coregistration provides superior quantification of radiotracer uptake based on the attenuation correction capabilities of CT. Useful applications of SPECT/CT have been identified not only in oncology but also in other specialties such as orthopedics and cardiology. This book covers the full spectrum of clinical applications of SPECT/CT in diagnosis and therapy planning of benign and malignant diseases. Opening chapters discuss the technology and physics of SPECT/CT and its use for dosimetry. The role of SPECT/CT in the imaging of a range of pathologic conditions is then addressed in detail. Applications covered include, among others, imaging of the thyroid, bone, and lungs, imaging of neuroendocrine tumors, cardiac scintigraphy, and sentinel node scintigraphy. Individual chapters are also devoted to therapy planning in selective internal radiation therapy of liver tumors and bremsstrahlung SPECT/CT. Readers will find this book to be an essential and up-to-date source of information on this invaluable hybrid imaging technique.

  4. SPECT/CT and pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, Jann [Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); The Faroese National Hospital, Department of Medicine, Torshavn (Faroe Islands); Gutte, Henrik [Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Herlev Hospital, Copenhagen University Hospital, Department of Radiology, Copenhagen (Denmark); University of Copenhagen, Cluster for Molecular Imaging, Faculty of Health Sciences, Copenhagen (Denmark)

    2014-05-15

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume coverage per rotation and faster rotation. Furthermore, the dual energy CT technique is a promising modality that can provide functional imaging in combination with anatomical information. Newer high-end CT scanners and SPECT systems are able to visualize smaller subsegmental emboli. However, consensus is lacking regarding the clinical impact and treatment. In the present review, SPECT and SPECT in combination with low-dose CT, CTPA and dual energy CT are discussed in the context of diagnosing PE. (orig.)

  5. Analytically based photon scatter modeling for a multipinhole cardiac SPECT camera.

    Science.gov (United States)

    Pourmoghaddas, Amir; Wells, R Glenn

    2016-11-01

    Dedicated cardiac SPECT scanners have improved performance over standard gamma cameras allowing reductions in acquisition times and/or injected activity. One approach to improving performance has been to use pinhole collimators, but this can cause position-dependent variations in attenuation, sensitivity, and spatial resolution. CT attenuation correction (AC) and an accurate system model can compensate for many of these effects; however, scatter correction (SC) remains an outstanding issue. In addition, in cameras using cadmium-zinc-telluride-based detectors, a large portion of unscattered photons is detected with reduced energy (low-energy tail). Consequently, application of energy-based SC approaches in these cameras leads to a higher increase in noise than with standard cameras due to the subtraction of true counts detected in the low-energy tail. Model-based approaches with parallel-hole collimator systems accurately calculate scatter based on the physics of photon interactions in the patient and camera and generate lower-noise estimates of scatter than energy-based SC. In this study, the accuracy of a model-based SC method was assessed using physical phantom studies on the GE-Discovery NM530c and its performance was compared to a dual energy window (DEW)-SC method. The analytical photon distribution (APD) method was used to calculate the distribution of probabilities that emitted photons will scatter in the surrounding scattering medium and be subsequently detected. APD scatter calculations for (99m)Tc-SPECT (140 ± 14 keV) were validated with point-source measurements and 15 anthropomorphic cardiac-torso phantom experiments and varying levels of extra-cardiac activity causing scatter inside the heart. The activity inserted into the myocardial compartment of the phantom was first measured using a dose calibrator. CT images were acquired on an Infinia Hawkeye (GE Healthcare) SPECT/CT and coregistered with emission data for AC. For comparison, DEW scatter

  6. A restraint-free small animal SPECT imaging system with motion tracking

    Energy Technology Data Exchange (ETDEWEB)

    Weisenberger, A.G.; Gleason, S.S.; Goddard, J.; Kross, B.; Majewski, S.; Meikle, S.R.; Paulus, M.J.; Pomper, M.; Popov, V.; Smith, M.F.; Welch, B.L.; Wojcik, R.

    2005-06-01

    We report on an approach toward the development of a high-resolution single photon emission computed tomography (SPECT) system to image the biodistribution of radiolabeled tracers such as Tc-99m and I-125 in unrestrained/unanesthetized mice. An infrared (IR)-based position tracking apparatus has been developed and integrated into a SPECT gantry. The tracking system is designed to measure the spatial position of a mouse's head at a rate of 10-15 frames per second with submillimeter accuracy. The high-resolution, gamma imaging detectors are based on pixellated NaI(Tl) crystal scintillator arrays, position-sensitive photomultiplier tubes, and novel readout circuitry requiring fewer analog-digital converter (ADC) channels while retaining high spatial resolution. Two SPECT gamma camera detector heads based upon position-sensitive photomultiplier tubes have been built and installed onto the gantry. The IR landmark-based pose measurement and tracking system is under development to provide animal position data during a SPECT scan. The animal position and orientation data acquired by the tracking system will be used for motion correction during the tomographic image reconstruction.

  7. Pinhole diffraction holography for fabrication of high-resolution Fresnel zone plates.

    Science.gov (United States)

    Sarkar, Sankha S; Solak, Harun H; David, Christian; van der Veen, J Friso

    2014-01-27

    Fresnel zone plates (FZPs) play an essential role in high spatial resolution x-ray imaging and analysis of materials in many fields. These diffractive lenses are commonly made by serial writing techniques such as electron beam or focused ion beam lithography. Here we show that pinhole diffraction holography has potential to generate FZP patterns that are free from aberrations and imperfections that may be present in alternative fabrication techniques. In this presented method, FZPs are fabricated by recording interference pattern of a spherical wave generated by diffraction through a pinhole, illuminated with coherent plane wave at extreme ultraviolet (EUV) wavelength. Fundamental and practical issues involved in formation and recording of the interference pattern are considered. It is found that resolution of the produced FZP is directly related to the diameter of the pinhole used and the pinhole size cannot be made arbitrarily small as the transmission of EUV or x-ray light through small pinholes diminishes due to poor refractive index contrast found between materials in these spectral ranges. We also find that the practical restrictions on exposure time due to the light intensity available from current sources directly imposes a limit on the number of zones that can be printed with this method. Therefore a trade-off between the resolution and the FZP diameter exists. Overall, we find that this method can be used to fabricate aberration free FZPs down to a resolution of about 10 nm.

  8. The potential of the pinhole as a visual aid in the developing world

    Directory of Open Access Journals (Sweden)

    Antony S. Carlson

    2016-03-01

    Full Text Available Purpose: Providing vision correction in communities where healthcare facilities are unavailable is problematic. Here, we explore the possibility of using pinholes as near visual aids in the developing world.Method: Uncompensated (without the pinhole proximal visual acuities (VAs were measured and recorded for one eye of 45 presbyopic subjects over the age of 50 years in photopic (250 lux and scotopic (20 lux conditions. The proximal VAs were then repeated while the subjects looked through nine different pinholes.Results: The VAs varied with the diameter of each pinhole. A comparative measure was devised to determine the relative performance of different diameter pinholes as a near visual aid. The results suggest an improvement of more than 40% in VA in about 67% of subjects in good lighting conditions and about 60% in poorer lighting conditions.Conclusion: By creating more awareness that there are other ways of improving vision that cost almost nothing, visual impairment can be reduced until spectacles become available.

  9. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

    Paulson, O B; Lassen, N A

    1997-01-01

    PET (positron emission tomography) and SPECT (single photon emission computed tomography) are isotopic methods in which the distribution is registered of radiolabelled tracers given in such small amounts that they are without effect on the organism or the organism's disposal of them. Thus, a series...... of important biological processes in the intact organism can be studied. The methods have been used in many disciplines but in particular for neurobiological research on the brain--e.g., the brain's regional blood circulation and mapping of the brain's functional structure. The methods have also been used...

  10. HIGH-ENERGY X-RAY PINHOLE CAMERA FOR HIGH-RESOLUTION ELECTRON BEAM SIZE MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Morgan, J.; Lee, S.H.; Shang, H.

    2017-03-25

    The Advanced Photon Source (APS) is developing a multi-bend achromat (MBA) lattice based storage ring as the next major upgrade, featuring a 20-fold reduction in emittance. Combining the reduction of beta functions, the electron beam sizes at bend magnet sources may be reduced to reach 5 – 10 µm for 10% vertical coupling. The x-ray pinhole camera currently used for beam size monitoring will not be adequate for the new task. By increasing the operating photon energy to 120 – 200 keV, the pinhole camera’s resolution is expected to reach below 4 µm. The peak height of the pinhole image will be used to monitor relative changes of the beam sizes and enable the feedback control of the emittance. We present the simulation and the design of a beam size monitor for the APS storage ring.

  11. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies.

    Science.gov (United States)

    Winant, Celeste D; Aparici, Carina Mari; Zelnik, Yuval R; Reutter, Bryan W; Sitek, Arkadiusz; Bacharach, Stephen L; Gullberg, Grant T

    2012-01-21

    spatiotemporal maximum-likelihood expectation-maximization (4D ML-EM) reconstructions gave more accurate reconstructions than did standard frame-by-frame static 3D ML-EM reconstructions. The SPECT/P results showed that 4D ML-EM reconstruction gave higher and more accurate estimates of K(1) than did 3D ML-EM, yielding anywhere from a 44% underestimation to 24% overestimation for the three patients. The SPECT/D results showed that 4D ML-EM reconstruction gave an overestimation of 28% and 3D ML-EM gave an underestimation of 1% for K(1). For the patient study the 4D ML-EM reconstruction provided continuous images as a function of time of the concentration in both ventricular cavities and myocardium during the 2 min infusion. It is demonstrated that a 2 min infusion with a two-headed SPECT system rotating 180° every 54 s can produce measurements of blood pool and myocardial TACs, though the SPECT simulation studies showed that one must sample at least every 30 s to capture a 1 min infusion input function.

  12. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    Science.gov (United States)

    Winant, Celeste D.; Aparici, Carina Mari; Zelnik, Yuval R.; Reutter, Bryan W.; Sitek, Arkadiusz; Bacharach, Stephen L.; Gullberg, Grant T.

    2012-01-01

    -likelihood expectation-maximization (4D ML-EM) reconstructions gave more accurate reconstructions than did standard frame-by-frame static 3D ML-EM reconstructions. The SPECT/P results showed that 4D ML-EM reconstruction gave higher and more accurate estimates of K1 than did 3D ML-EM, yielding anywhere from a 44% underestimation to 24% overestimation for the three patients. The SPECT/D results showed that 4D ML-EM reconstruction gave an overestimation of 28% and 3D ML-EM gave an underestimation of 1% for K1. For the patient study the 4D ML-EM reconstruction provided continuous images as a function of time of the concentration in both ventricular cavities and myocardium during the 2 min infusion. It is demonstrated that a 2 min infusion with a two-headed SPECT system rotating 180° every 54 s can produce measurements of blood pool and myocardial TACs, though the SPECT simulation studies showed that one must sample at least every 30 s to capture a 1 min infusion input function.

  13. SPECT in the diagnosis of hepatic hemangioma

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, J.C.; Van Heertum, R.L.; Yudd, A.P.

    1985-05-01

    Tc99m labeled red blood cell blood flow and delayed static blood pool imaging is widely accepted as a reliable, accurate method for the diagnosis of hepatic hemangiomata. The purpose of this study is to assess the relative value of SPECT blood pool imaging in the evaluation of hepatic hemangionata. A total of 68 patients, including 21 patients with proven hepatic cavernous hemangiomas, were studied using both planar and SPECT imaging techniques. All patients underwent multi-phase evaluation which included a hepatic flow study, immediate planar images of the liver, followed by a 360/sup 0/ tomographic (SPECT) study and subsequent 60 minute delayed static planar hepatic blood pool images. All 21 patients with proven hepatic hemangiomas had a positive SPECT exam and 17 of the 21 (81%) patients had a positive planar exam. In the 21 patients, there were a total of 36 hemangiomas ranging in size from .7 cm to 13 cm. The SPECT imaging technique correctly identified all 36 lesions (100%) where as planar imaging detected 25 of the 36 lesions (69.4%). In all the remaining patients (10-normal, 17-metastatic disease, 12-hepatocellular disease, 6-hepatoma, 2-liver cysts), both the planar and SPECT imaging techniques were interpreted as showing no evidence of focal sequestration of red blood cells. SPECT hepatic blood pool imaging represents an improvement in the evaluation of hepatic hemangioma as a result of a reduction in imaging time (less than thirty minutes), improved spatial resolution and greater overall accuracy.

  14. System calibration and image reconstruction for a new small-animal SPECT system

    Science.gov (United States)

    Chen, Yi-Chun

    A novel small-animal SPECT imager, FastSPECT II, was recently developed at the Center for Gamma-Ray Imaging. FastSPECT II consists of two rings of eight modular scintillation cameras and list-mode data-acquisition electronics that enable stationary and dynamic imaging studies. The instrument is equipped with exchangeable aperture assemblies and adjustable camera positions for selections of magnifications, pinhole sizes, and fields of view (FOVs). The purpose of SPECT imaging is to recover the radiotracer distribution in the object from the measured image data. Accurate knowledge of the imaging system matrix (referred to as H) is essential for image reconstruction. To assure that all of the system physics is contained in the matrix, experimental calibration methods for the individual cameras and the whole imaging system were developed and carefully performed. The average spatial resolution over the FOV of FastSPECT II in its low-magnification (2.4X) configuration is around 2.4 mm, computed from the Fourier crosstalk matrix. The system sensitivity measured with a 99mTc point source at the center of the FOV is about 267 cps/MBq. The system detectability was evaluated by computing the ideal-observer performance on SKE/BKE (signal-known-exactly/background-known-exactly) detection tasks. To reduce the system-calibration time and achieve finer reconstruction grids, two schemes for interpolating H were implemented and compared: these are centroid interpolation with Gaussian fitting and Fourier interpolation. Reconstructed phantom and mouse-cardiac images demonstrated the effectiveness of the H-matrix interpolation. Tomographic reconstruction can be formulated as a linear inverse problem and solved using statistical-estimation techniques. Several iterative reconstruction algorithms were introduced, including maximum-likelihood expectation-maximization (ML-EM) and its ordered-subsets (OS) version, and some least-squares (LS) and weighted-least-squares (WLS) algorithms such

  15. Evaluation of MR perfusion abnormalities in organophosphorus poisoning and its correlation with SPECT

    Directory of Open Access Journals (Sweden)

    K Uday Bhanu

    2017-01-01

    Full Text Available Aim: Acute organophosphate (OP pesticide poisoning causes substantial morbidity and mortality worldwide. Many imaging modalities, such as computerized tomography (CT, magnetic resonance imaging (MRI, and single photon emission computed tomography (SPECT of the brain, have been used for quantitative assessment of the acute brain insult caused by acute OP poisoning. Perfusion defects on SPECT in acutely poisoned patients with OPs have been described, however, MR perfusion abnormalities have not been described in the literature. MR perfusion Imaging has the advantage of having higher spatial resolution, no radiation, and better availability. Materials and Methods: In this prospective study, 20 patients who ingested OP compounds were included. All the patients underwent brain SPECT on a dual head SPECT gamma camera and MRI brain on a 1.5T MR system. Neurocognitive tests were performed for all patients. Results: SPECT showed perfusion defects in 7 patients and total number of perfusion defects were 29. On MR perfusion, based on the cut-off values of normalized cerebral blood volume (nCBV ratios and normalized cerebral blood flow (nCBF ratios, the total number of patients showing perfusion defects were 6 and 8; and the total number of perfusion defects were 29 and 45, respectively. There was significant difference of the nCBV ratios and nCBF ratios between the control group (n = 20 and positive patients group (n = 6 and n = 8, respectively (P > 0.05. All the defects seen on SPECT were well appreciated on nCBF maps (MRI perfusion suggestive of 100% correlation. Conclusion: MR perfusion imaging can be used as an effective modality for evaluation in acute OP poisoning.

  16. Repeat thallium-201 SPECT in cerebral lymphoma.

    Science.gov (United States)

    Borggreve, F; Dierckx, R A; Crols, R; Mathijs, R; Appel, B; Vandevivere, J; Mariën, P; Martin, J J; De Deyn, P P

    1993-01-01

    The authors report on the contribution of Thallium-201 brain SPECT in the diagnosis and follow-up of a non-immunosuppressed patient, presenting with primary cerebral lymphoma. The tumoral process was at first not diagnosed on CT-scan, but Thallium-201 SPECT suggested a tumoral invasion. During corticosteroid treatment the tumor volume on CT-scan decreased, while on Thallium-201 SPECT there was an enhancement of the accumulation and an increasing tumor to non-tumor ratio. These scintigraphical findings more closely reflected the clinical course and the postmortem results.

  17. Crossed cerebellar hyperperfusion in brain perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Jinnouchi, Seishi; Nagamachi, Shigeki; Nishii, Ryuuichi; Futami, Shigemi; Tamura, Shozo [Miyazaki Medical Coll., Kiyotake (Japan); Kawai, Keiichi

    2000-10-01

    Crossed cerebellar diaschisis is a well-known brain SPECT finding in stroke patients. Few reports, however, have described supratentorial and contralateral cerebellar hyperperfusion (crossed cerebellar hyperperfusion, CCH). We assessed the incidence of CCH in 33 patients with cerebral hyperperfusion. Brain SPECT showed CCH in five patients out of 20 epilepsy and three of 13 patients with acute encephalitis. These eight patients with CCH had recent epileptic attack. CCH was found in ECD SPECT as well as HM-PAO. The contralateral cerebellar activity correlated with the cerebral activity in patients with CCH. CCH would have a relation with supratentrial hyperfunction in epilepsy and acute encephalitis. (author)

  18. SemiSPECT: A Small-animal Imaging System Based on Eight CdZnTe Pixel Detectors.

    Science.gov (United States)

    Peterson, Todd E; Kim, Hyunki; Crawford, Michael J; Gershman, Benjamin M; Hunter, William C J; Barber, H Bradford; Furenlid, Lars R; Wilson, Donald W; Woolfenden, James M; Barrett, Harrison H

    We have constructed a SPECT system for small animals that utilizes eight CdZnTe pixel detectors. The eight detectors are arranged in a single octagonal ring, where each views the object to be imaged through a single pinhole. Additional projections are obtained via rotation of the animal. Each CdZnTe detector is approximately 2 mm in thickness and is patterned on one surface into a 64×64 array of pixels with 380 micron pitch. We have designed an electronic readout system capable of collecting data from the eight detectors in listmode. In this scheme each event entry for a gamma-ray hit includes the pulse height of the pixel with the largest signal and the pulse height for each of its eight nearest neighbors. We present details of the overall design, the electronics, and system performance.

  19. Single Photon Emission Computed Tomography (SPECT)

    Science.gov (United States)

    ... comfortable shoes if you will have an exercise stress test. What happens during cardiac SPECT? A doctor and nuclear medicine technologist usually perform the scan in a hospital or clinic using special equipment. The technician will ...

  20. SPECT assay of radiolabeled monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1992-02-01

    The long-term goal of this research project is to develop methods to improve the utility of single photon emission computed tomography (SPECI) to quantify the biodistribution of monoclonal antibodies (MoAbs) labeled with clinically relevant radionuclides ({sup 123}I, {sup 131}I, and {sup 111}In) and with another radionuclide,{sup 211}At, recently used in therapy. We describe here our progress in developing quantitative SPECT methodology for {sup 111}In and {sup 123}I. We have focused our recent research thrusts on the following aspects of SPECT: (1) The development of improved SPECT hardware, such as improved acquisition geometries. (2) The development of better reconstruction methods that provide accurate compensation for the physical factors that affect SPECT quantification. (3) The application of carefully designed simulations and experiments to validate our hardware and software approaches.

  1. Hypoglycaemic hemiplegia: a repeat SPECT study.

    Science.gov (United States)

    Shintani, S; Tsuruoka, S; Shiigai, T

    1993-01-01

    During a hypoglycaemic right hemiplegia induced by a deliberate overdose of oral hypoglycaemics, brain CT and angiography revealed no abnormalities. SPECTs made one day and six days later showed relative hypoperfusion in the left hemisphere. Repeat SPECT study suggested that the left hemisphere was more vulnerable than the right in the cerebral blood perfusion. This vulnerability might provoke the right hemiplegia in a critical condition, such as severe hypoglycaemia. Images PMID:8509788

  2. Brain SPECT imaging in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Krausz, Y.; Yaffe, S.; Atlan, H. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Medical Biophysics and Nuclear Medicine); Cohen, D. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Radiology); Konstantini, S. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Neurosurgery); Meiner, Z. (Hadassah Univ. Hospital, Jerusalem (Israel). Dept. of Neurology)

    1991-06-01

    Temporal lobe epilepsy is diagnosed by clinical symptoms and signs and by localization of an epileptogenic focus. A brain SPECT study of two patients with temporal lobe epilepsy, using {sup 99m}Tc-HMPAO, was used to demonstrate a perfusion abnormality in the temporal lobe, while brain CT and MRI were non-contributory. The electroencephalogram, though abnormal, did not localize the diseased area. The potential role of the SPECT study in diagnosis and localization of temporal lobe epilepsy is discussed. (orig.).

  3. The application of SPECT/CT in the sentinel lymph node diagnostic; Der Einsatz von SPECT/CT bei der Waechterlymphknotendiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Forstner, C. von [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Klinik fuer Nuklearmedizin

    2011-03-15

    Sentinel lymph node (SLN) visualisation by means of scintigraphy is gaining increasing importance in different operative disciplines. This method is an established part of clinical routine procedures and clinical guidelines in the treatment of breast cancer and of malign melanoma. SLN imaging is being increasingly used also in carcinoma of prostate, vulva carcinoma and in neoplasm of the head and neck region. When the localisation of the SLN with the help of planar scintigraphy is not certain or in case of uncommon lymphatic drainage the use of SPECT/CT might be useful for the exact anatomical localisation of SLN and of secondary lymph nodes. This diagnostic measure enables a differentiated stage adapted operation to the benefit of the patients involved. The underlying study is a summary of the actual situation of SLN diagnostics using SPECT/CT in different tumours. (orig.)

  4. SPECT assay of radiolabeled monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1992-02-01

    The accurate determination of the biodistribution of radiolabeled monoclonal antibodies (MoAbs) is important for calculation of dosimetry and evaluation of pharmacokinetic variables such as antibody dose and route of administration. The hypothesis of this application is that the biodistribution of radiolabeled monoclonal antibodies (MoAbs) can be quantitatively determined using single photon emission computed tomography (SPECT). The major thrusts during the third year include the continued development and evaluation of improved 3D SPECT acquisition and reconstruction approaches to improve quantitative imaging of radiolabeled monoclonal antibodies (MoAbs), and the implementation and evaluation of algorithms to register serial SPECT image data sets, or to register 3D SPECT images with 3D image data sets acquired from positron emission tomography (PEI) and magnetic resonance images (MRI). The research has involved the investigation of statistical models and iterative reconstruction algorithms that accurately account for the physical characteristics of the SPECT acquisition system. It is our belief that SPECT quantification can be improved by accurately modeling the physical processes such as attenuation, scatter, geometric collimator response, and other factors that affect the measured projection data.

  5. Reflections on Using Pinhole Photography as a Pedagogical and Methodological Tool with Adolescents in Wild Nature

    Science.gov (United States)

    Socha, Teresa; Potter, Tom; Potter, Stephanie; Jickling, Bob

    2016-01-01

    This paper shares our experiences using pinhole photography with adolescents as both a pedagogical tool to support and deepen adolescent experiences in wild nature, and as a visual methodological tool to elucidate their experiences. Reflecting on a journey that explored the nature-based experiences of two adolescents on a family canoe trip in…

  6. From the Pinhole Camera to the Shape of a Lens: The Camera-Obscura Reloaded

    Science.gov (United States)

    Ziegler, Max; Priemer, Burkhard

    2015-01-01

    We demonstrate how the form of a plano-convex lens and a derivation of the thin lens equation can be understood through simple physical considerations. The basic principle is the extension of the pinhole camera using additional holes. The resulting images are brought into coincidence through the deflection of light with an arrangement of prisms.…

  7. SPECT/CT diagnostics for skeletal infections; SPECT/CT-Infektdiagnostik am Skelett

    Energy Technology Data Exchange (ETDEWEB)

    Klaeser, B.; Spanjol, M.; Krause, T. [Inselspital Bern, Universitaetsklinik fuer Nuklearmedizin, Bern (Switzerland)

    2012-07-15

    Skeletal infections are often a diagnostic and clinical challenge. Nuclear imaging modalities used in the diagnostic workup of acute and chronic skeletal infections include three-phase bone scintigraphy and scintigraphy with labelled leucocytes. The introduction of hybrid technologies, such as single photon emission computed tomography/computed tomography (SPECT/CT) has dramatically changed nuclear medical imaging of infections. In general SPECT/CT leads to a considerably more accurate diagnosis than planar or SPECT imaging. Given the integrated acquisition of metabolic, functional and morphological information, SPECT/CT has increased in particular the specificity of three-phase skeletal scanning and scintigraphy with labeled leucocytes. (orig.) [German] Knoecherne Infekte stellen nicht selten eine diagnostische und klinische Herausforderung dar. Nuklearmedizinische Standardverfahren fuer die Diagnostik akuter und chronischer Knocheninfekte sind die Mehrphasenskelettszintigraphie und die Infektszintigraphie mit markierten Leukozyten. Die Einfuehrung von Hybridtechnologien wie der SPECT/CT hat die nuklearmedizinische Infektbildgebung tiefgreifend veraendert. Die SPECT/CT erlaubt bei der Frage nach Knocheninfekten insgesamt eine wesentlich genauere Beurteilung als planare Aufnahmen und SPECT. Die integrierte Akquisition von metabolischer, funktioneller und topographisch-morphologischer Information mit SPECT/CT steigerte insbesondere die Spezifitaet der Mehrphasenskelettszintigraphie und der Infektszintigraphie mit markierten Leukozyten. (orig.)

  8. Design and development of a high resolution animal SPECT scanner dedicated for rat and mouse imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sajedi, Salar; Zeraatkar, Navid [Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Moji, Vahideh; Farahani, Mohammad Hossein [Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Parto Negar Persia Co, Tehran (Iran, Islamic Republic of); Sarkar, Saeed [Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Arabi, Hossein [Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Teymoorian, Behnoosh [Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Parto Negar Persia Co, Tehran (Iran, Islamic Republic of); Ghafarian, Pardis [Chronic Respiratory Disease Research Center, NRITLD, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); PET/CT and Cyclotron Center, Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Rahmim, Arman [Department of Radiology, Johns Hopkins University, Baltimore, MD (United States); Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD (United States); Reza Ay, Mohammad, E-mail: mohammadreza_ay@sina.tums.ac.ir [Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-03-21

    A dedicated small-animal SPECT system, HiReSPECT, was designed and developed to provide a high resolution molecular imaging modality in response to growing research demands. HiReSPECT is a dual-head system mounted on a rotating gantry. The detection system is based on pixelated CsI(Na) scintillator crystals coupled to two Hamamatsu H8500 Position Sensitive Photomultiplier Tubes in each head. Also, a high resolution parallel-hole collimator is applied to every head. The dimensions of each head are 50 mm×100 mm, enabling sufficient transaxial and axial fields-of-view (TFOV and AFOV), respectively, for coverage of the entire mouse in single-bed position imaging. However, a 50 mm TFOV is not sufficient for transaxial coverage of rats. To address this, each head can be rotated by 90 degrees in order to align the larger dimension of the heads with the short body axis, allowing tomographic data acquisition for rats. An innovative non-linear recursive filter was used for signal processing/detection. Resolution recovery was also embedded in the modified Maximum-Likelihood Expectation Maximization (MLEM) image reconstruction code to compensate for Collimator-Detector Response (CDR). Moreover, an innovative interpolation algorithm was developed to speed up the reconstruction code. The planar spatial resolution at the head surface and the image spatial resolutions were 1.7 mm and 1.2–1.6 mm, respectively. The measurements followed by post-processing showed that the observed count rate at 20% count loss is about 42 kcps. The system sensitivity at the collimator surface for heads 1 and 2 were 1.32 cps/µCi and 1.25 cps/µCi, respectively. The corresponding values were 1.18 cps/µCi and 1.02 cps/µCi at 8 cm distance from the collimator surfaces. In addition, whole-body scans of mice demonstrated appropriate imaging capability of the HiReSPECT.

  9. Improved Benefit of SPECT/CT Compared to SPECT Alone for the Accurate Localization of Endocrine and Neuroendocrine Tumors

    Directory of Open Access Journals (Sweden)

    Gonca G. Bural

    2012-12-01

    Full Text Available Objective: To assess the clinical utility of SPECT/ CT in subjects with endocrine and neuroendocrine tumors compared to SPECT alone. Material and Methods: 48 subjects (31 women;17 men; mean age 54±11 with clinical suspicion or diagnosis of endocrine and neuroendocrine tumor had 50 SPECT/CT scans (32 Tc-99m MIBI, 5 post treatment I-131, 8 In-111 Pentetreotide, and 5 I-123 MIBG. SPECT alone findings were compared to SPECT/CT and to pathology or radiological follow up. Results: From the 32 Tc-99m MIBI scans, SPECT accurately localized the lesion in 22 positive subjects while SPECT/CT did in 31 subjects. Parathyroid lesions not seen on SPECT alone were smaller than 10 mm. In five post treatment I-131 scans, SPECT alone neither characterized, nor localized any lesions accurately. SPECT/CT revealed 3 benign etiologies, a metastatic lymph node, and one equivocal lesion. In 8 In-111 Pentetreotide scans, SPECT alone could not localize primary or metastatic lesions in 6 subjects all of which were localized with SPECT/CT. In five I-123 MIBG scans, SPECT alone could not detect a 1.1 cm adrenal lesion or correctly characterize normal physiologic adrenal uptake in consecutive scans of the same patient with prior history of adrenelectomy, all of which were correctly localized and characterized with SPECT/CT. Conclusion: SPECT/CT is superior to SPECT alone in the assessment of endocrine and neuroendocrine tumors. It is better in lesion localization and lesion characterization leading to a decrease in the number of equivocal findings. SPECT/CT should be included in the clinical work up of all patients with diagnosis or suspicion of endocrine and neuroendocrine tumors. (MIRT 2012;21:91-96

  10. A quantitative reconstruction software suite for SPECT imaging

    Science.gov (United States)

    Namías, Mauro; Jeraj, Robert

    2017-11-01

    Quantitative Single Photon Emission Tomography (SPECT) imaging allows for measurement of activity concentrations of a given radiotracer in vivo. Although SPECT has usually been perceived as non-quantitative by the medical community, the introduction of accurate CT based attenuation correction and scatter correction from hybrid SPECT/CT scanners has enabled SPECT systems to be as quantitative as Positron Emission Tomography (PET) systems. We implemented a software suite to reconstruct quantitative SPECT images from hybrid or dedicated SPECT systems with a separate CT scanner. Attenuation, scatter and collimator response corrections were included in an Ordered Subset Expectation Maximization (OSEM) algorithm. A novel scatter fraction estimation technique was introduced. The SPECT/CT system was calibrated with a cylindrical phantom and quantitative accuracy was assessed with an anthropomorphic phantom and a NEMA/IEC image quality phantom. Accurate activity measurements were achieved at an organ level. This software suite helps increasing quantitative accuracy of SPECT scanners.

  11. Utility of combined high-resolution bone SPECT and MRI for the identification of rheumatoid arthritis patients with high-risk for erosive progression

    Energy Technology Data Exchange (ETDEWEB)

    Buchbender, Christian, E-mail: christian.buchbender@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Sewerin, Philipp, E-mail: philipp.sewerin@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Rheumatology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Mattes-György, Katalin, E-mail: katalin.mattes@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Nuclear Medicine, Moorenstr. 5, D-40225 Dusseldorf (Germany); Miese, Falk, E-mail: falk.miese@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Wittsack, Hans-Joerg, E-mail: hans-joerg.wittsack@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Specker, Christof, E-mail: c.specker@kliniken-essen-sued.de [Department of Rheumatology and Clinical Immunology, Kliniken Essen-Sud, Propsteistrasse 2, D-45239 Essen (Germany); Antoch, Gerald, E-mail: antoch@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Müller, Hans-Wilhelm, E-mail: HansW.Mueller@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Nuclear Medicine, Moorenstr. 5, D-40225 Dusseldorf (Germany); Schneider, Matthias, E-mail: matthias.schneider@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Rheumatology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Scherer, Axel, E-mail: scherer@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstr. 5, D-40225 Dusseldorf (Germany); Ostendorf, Benedikt, E-mail: ostendorf@med.uni-duesseldorf.de [Univ Dusseldorf, Medical Faculty, Department of Rheumatology, Moorenstr. 5, D-40225 Dusseldorf (Germany)

    2013-02-15

    Objectives: To evaluate the utility of sequentially acquired, post hoc fused, magnetic resonance imaging (MRI) and multi-pinhole single photon emission computed tomography (MPH-SPECT) with technetium-99m-labeled disphosphonates (Tc99m-DPD) for the identification of finger joints with later erosive progression in early rheumatoid arthritis (ERA) patients. Methods: Ten consecutive ERA patients prospectively underwent MPH-SPECT and MRI of metacarpophalangeal (MCP) joints prior to and after 6 months methotrexate therapy. Tc99m-DPD uptake was measured at proximal and distal MCP sites using regional analysis. The course of joint pathologies was scored according to the Rheumatoid Arthritis MRI Score (RAMRIS) criteria. Results: The frequency of increased Tc99m-DPD uptake, synovitis and bone marrow edemadecreased under MTX therapy; but the number of bone erosions increased. Joints with progressive and new erosions on follow-up had a higher baseline Tc99m-DPD uptake (2.64 ± 1.23 vs. 1.43 ± 0.91) (p = 0.02). Conclusions: Joints with erosive progression are characterized by an early increased Tc99m-DPD uptake, even in absence of MRI bone pathologies. Tc99m-DPD MPH-SPECT might thus be of additional value to morphological MRI for the identification of RA patients with a high risk for erosive progression.

  12. Dosimetry estimation of SPECT/CT for iodine 123-labeled metaiodobenzylguanidine in children

    Directory of Open Access Journals (Sweden)

    Aida Mhiri

    2015-09-01

    Full Text Available Purpose: To evaluate the additional radiation exposure in terms of effective dose incurred by patients in the CT (computed tomography portion of 123I-MIBG (123II-metaiodobenzylguanidine study with SPECT/CT (Single photon emission computed tomography associated to computed tomography in some pediatric patients of our department. Methods: Data from 123II-MIBG scans comprising 50 children were presented in this study. The contribution of total effective dose imparted by the nuclear tracer and patient's age was calculated. Effective dose from the CT portion of the examination is also estimated.SPECT acquisitions were performed with a dual-headed SPECT unit with an integrated 2-slice CT scanner (Symbia T E-Cam, Siemens Medical Systems, Erlangen, Germany. The CT acquisition were performed using a tube current modulation system (Care Dose 4D. Parameters used were: tube current of 30 - 60 mAs, slice thickness of 3-5 mm, and tube voltage of 110 kV. Results: Our results show that SPECT dosimetry depends on administered activity and patient’s age and weight. For CT scan, effective dose is affected by tube current (mA, tube potential (kVp, rotation speed, pitch, slice thickness, patient mass, and the exact volume of the patient that is being imaged. Conclusion: For children, 123II-MIBG study with SPECT/CT should be performed using the lowest available voltage and current. A sensible choice of these two parameters used can significantly reduce radiation dose, without any compromise in the quality of the diagnostic information.

  13. Measurements with Pinhole and Coded Aperture Gamma-Ray Imaging Systems

    Energy Technology Data Exchange (ETDEWEB)

    Raffo-Caiado, Ana Claudia [ORNL; Solodov, Alexander A [ORNL; Abdul-Jabbar, Najeb M [ORNL; Hayward, Jason P [ORNL; Ziock, Klaus-Peter [ORNL

    2010-01-01

    From a safeguards perspective, gamma-ray imaging has the potential to reduce manpower and cost for effectively locating and monitoring special nuclear material. The purpose of this project was to investigate the performance of pinhole and coded aperture gamma-ray imaging systems at Oak Ridge National Laboratory (ORNL). With the aid of the European Commission Joint Research Centre (JRC), radiometric data will be combined with scans from a three-dimensional design information verification (3D-DIV) system. Measurements were performed at the ORNL Safeguards Laboratory using sources that model holdup in radiological facilities. They showed that for situations with moderate amounts of solid or dense U sources, the coded aperture was able to predict source location and geometry within ~7% of actual values while the pinhole gave a broad representation of source distributions

  14. "Planaltina in the Hole of Aluminum": production and consumption of pinhole photographs

    Directory of Open Access Journals (Sweden)

    Juliana Soares Mendes

    2015-08-01

    Full Text Available This article analyzes a photographic exhibition consisting of 15 images created by pinhole technique, which stimulates a critical thinking about photojournalism practice and consumption. The exhibition in the internet (www.fosfoto.com and at the Artistic and Historic Museum of Planaltina (Brazilian Federal District happened in May 2009. Participants were asked to interpret the photographs and rewrite temporary captions. The 1.860 proposed captions indicates the public’s interest to participate, discuss and interpret the pictures.

  15. The effect of pinholes of different sizes on visual acuity under different refracting states and ambient lighting conditions*

    Directory of Open Access Journals (Sweden)

    N. Abdul

    2009-12-01

    Full Text Available Purpose: The purpose of this pilot study was to investigate the effect of different size pinholes on visual acuity (VA at near (0.4 m while various factors were altered. The alterations made involved accommodation and illumination.Method: Four subjects were selected and their ages ranged from 7 to 14 years. Subjective refractions were performed and then near visual acuities were measured at 0.4 m under two different lighting conditions (460 lux and 1 lux by adding stigmatic (or spherical lenses of positive and negative powers in front of pinholes of diameters 1.5 mm and 2 mm.Results: The results showed that there was an improvement in VA in most, however, the size of the pinhole played a minor role. Low illumination did have a drastic effect on our results not only by decreasing the amount of lenses used for near that gave more positive results, but also when the pinhole was placed in front of the subjects. According to Borish, the pinhole does improve VA by a straight forward process of elimination produced by spherical aberrations of the eye. However, this did not seem to be the case in this study under conditions of low illumination.Conclusion: The pinhole effect offers improvement in VA at near by reducing the amount of blupresented to the retina. This study showed that alsubjects had an improvement in VA of at least twolines in high illumination. Pinhole size did not alte the results sufficiently thus suggesting that a pinhole, no matter the size, should increase the VA. However this was not the case when illumination was decreased.

  16. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics

    Science.gov (United States)

    Rácz, R.; Biri, S.; Pálinkás, J.; Mascali, D.; Castro, G.; Caliri, C.; Romano, F. P.; Gammino, S.

    2016-02-01

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  17. System geometry optimization for molecular breast tomosynthesis with focusing multi-pinhole collimators

    Science.gov (United States)

    van Roosmalen, Jarno; Beekman, Freek J.; Goorden, Marlies C.

    2018-01-01

    Imaging of 99mTc-labelled tracers is gaining popularity for detecting breast tumours. Recently, we proposed a novel design for molecular breast tomosynthesis (MBT) based on two sliding focusing multi-pinhole collimators that scan a modestly compressed breast. Simulation studies indicate that MBT has the potential to improve the tumour-to-background contrast-to-noise ratio significantly over state-of-the-art planar molecular breast imaging. The aim of the present paper is to optimize the collimator-detector geometry of MBT. Using analytical models, we first optimized sensitivity at different fixed system resolutions (ranging from 5 to 12 mm) by tuning the pinhole diameters and the distance between breast and detector for a whole series of automatically generated multi-pinhole designs. We evaluated both MBT with a conventional continuous crystal detector with 3.2 mm intrinsic resolution and with a pixelated detector with 1.6 mm pixels. Subsequently, full system simulations of a breast phantom containing several lesions were performed for the optimized geometry at each system resolution for both types of detector. From these simulations, we found that tumour-to-background contrast-to-noise ratio was highest for systems in the 7 mm–10 mm system resolution range over which it hardly varied. No significant differences between the two detector types were found.

  18. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Rácz, R., E-mail: rracz@atomki.hu; Biri, S.; Pálinkás, J. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Mascali, D.; Castro, G.; Caliri, C.; Gammino, S. [Instituto Nazionale di Fisica Nucleare—Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Romano, F. P. [Instituto Nazionale di Fisica Nucleare—Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy)

    2016-02-15

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  19. Reduction in camera-specific variability in [(123)I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings

    DEFF Research Database (Denmark)

    Buchert, Ralph; Kluge, Andreas; Tossici-Bolt, Livia

    2016-01-01

    of [(123)I]FP-CIT recruited at six centres, 70 aged between 20 and 82 years were included. SPECT images were reconstructed using the QSPECT software package which provides fully automated detection of the outer contour of the head, camera-specific correction for scatter and septal penetration...

  20. SPECT in psychiatry; Die Bedeutung der Hirn-SPECT in der Psychiatrie

    Energy Technology Data Exchange (ETDEWEB)

    Kasper, S. [Universitaetsklinik fuer Psychiatrie, Wien (Austria); Gruenwald, F. [Bonn Univ. (Germany). Klinik fuer Nuklearmedizin; Danos, P. [Psychiatrische Universitaetsklinik, Bonn (Germany); Walter, H. [Universitaetsklinik fuer Psychiatrie, Wien (Austria); Klemm, E. [Bonn Univ. (Germany). Klinik fuer Nuklearmedizin; Bruecke, T. [Universitaetsklinik fuer Neurologie, Wien (Austria); Podreka, I. [Universitaetsklinik fuer Neurologie, Wien (Austria); Biersack, H.J. [Bonn Univ. (Germany). Klinik fuer Nuklearmedizin

    1994-10-01

    In the last fifteen years different attempts have been undertaken to understand the biological basis of major psychiatric disorders. One important tool to determine patterns of brain dysfunction is single emission computed tomography (SPECT). Whereas SPECT investigations are already a valuable diagnostic instrument for the diagnosis of dementia of the Alzheimer Type (DAT) there have not been consistent findings that can be referred to as specific for any other particular psychiatric diagnostic entity. Nevertheless, SPECT studies have been able to demonstrate evidence of brain dysfunction in patients with schizophrenia, depression, anxiety disorders, and substance abuse in which other methods showed no clear abnormality of brain function. Our manuscript reviews the data which are currently available in the literature and stresses the need for further studies, especially for prediction and monitoring psychiatric treatment modalities. (orig.) [Deutsch] In den vergangenen 15 Jahren wurde durch verschiedene methodologische Ansaetze versucht, die biologischen Ursachen psychiatrischer Erkrankungen naeher zu erforschen. Als eine bedeutende Methode hat sich dabei die Single-Photonen-Emissions-Computertomographie (SPECT) herausgestellt. Waehrend die SPECT-Untersuchungen bereits Eingang in die Routinediagnostik bei Demenzen vom Alzheimer-Typ gefunden haben, konnten fuer weitere psychiatrische Erkrankungen noch keine eindeutigen Befunde etabliert werden. Mit der SPECT-Methode ist es jedoch gelungen, funktionelle Veraenderungen des Gehirns von psychiatrischen Erkrankungen darzustellen, wie z.B. Schizophrenie, Depression, Angsterkrankungen bzw. Substanzmissbrauch. In Forschungsprotokollen wird durch die SPECT-Methode versucht, abzuklaeren, inwieweit es moeglich ist, innerhalb der Erkrankungsentitaeten psychiatrischer Erkrankungen oder auch diese uebergreifend eine Subklassifizierung zu finden und evtl. Gehirnsysteme ausfindig zu machen, die mit einer spezifischen

  1. Basic design and simulation of a SPECT microscope for in vivo stem cell imaging

    Science.gov (United States)

    Moats, Rex A.; Tang, Yang; Hugg, James W.; Meier, Dirk; Koos, David; Hartsough, Neal E.; Patt, Bradley E.; Wagenaar, Douglas J.

    2011-03-01

    The need to understand the behavior of individual stem cells at the various stages of their differentiation and to assess the resulting reparative action in pre-clinical model systems, which typically involves laboratory animals, provides the motivation for imaging of stem cells in vivo at high resolution. Our initial focus is to image cells and cellular events at single cell resolution in vivo in shallow tissues (few mm of intervening tissue) in laboratory mice and rates. In order to accomplish this goal we are building a SPECT-based microscope. We based our design on earlier theoretical work with near-field coded apertures and have adjusted the components of the system to meet the real-world demands of instrument construction and of animal imaging. Our instrumental design possesses a reasonable trade-off between field-of-view, sensitivity, and contrast performance (photon penetration). A layered gold aperture containing 100 pinholes and intended for use in coded aperture imaging application has been designed and constructed. A silicon detector connected to a TimePix readout from the CERN collaborative group was selected for use in our prototype microscope because of its ultra-high spatial and energy resolution capabilities. The combination of the source, aperture, and detector has been modeled and the coded aperture reconstruction of simulated sources is presented in this work.

  2. A micro-SPECT imaging pilot study of myocardial perfusion in mice; Etude pilote de la perfusion myocardique chez la souris par micro-imagerie TEMP

    Energy Technology Data Exchange (ETDEWEB)

    Constantinesco, A.; Choquet, P.; Israel-Jost, V. [Hopital de Hautepierre, Service de Biophysique et Medecine Nucleaire, 67 - Strasbourg (France); Israel-Jost, V.; Sonnendrucker, E. [Institut de Recherche Mathematique Avancee de Strasbourg, 67 (France); Monassier, L. [Institut National de la Sante et de la Recherche Medicale (INSERM U333), 67 - Strasbourg (France); Elfertak, L. [Institut Clinique de la Souris (ICS), 67 - Illkirch (France)

    2004-04-01

    Objective: demonstrate the feasibility of micro-SPECT for myocardial perfusion imaging in mice. Methods: a micro-SPECT dedicated camera with a field of view of 17 cm x 17 cm, a 1,5 mm pinhole with a focal distance of 12 cm was used. An infra millimetric linear phantom permitted to measure the planar and tomographic FWHM. Two normal adult mice were studied under gaseous anaesthesia (isoflurane 1,5%) and after IV administration of 0,1 mL of {sup 99m}Tc-Sestamibi (350 MBq) in one case and {sup 201}Tl (64 MBq) in the other case. In the two cases, 48 projections of 1 mn over 180 deg C in a 64 x 64 image format with a radius of rotation of 2,5 cm were used with a 20% window centered on the photoelectric peak of 99mTc or the 71 KeV of {sup 201}Tl. Tomographic reconstruction was done with a specific ART cone beam algorithm. Results: phantoms FWHM were respectively 1.6 mm and 1.5 mm in planar and tomographic modes with a reconstructed field of view of 26 mm and 1 mm when the reconstructed field of view was 10 mm. Micro-SPECT perfusion images using a reconstructed voxel volume of 0.064 mm{sup 3} of the mice myocardium were obtained with a better anatomical resolution with Sestamibi than thallium. Conclusion: this pilot study demonstrate the potential of micro-SPECT imaging for mice nuclear cardiology. (author)

  3. SPECT and PET in Eating Disorders

    NARCIS (Netherlands)

    van Waarde, Aren; Audenaert, Kurt; Busatto, Geraldo F.; Buchpiguel, Carlos; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; de Vries, Erik FJ; van Waarde, Aren; den Boer, Johan A

    2014-01-01

    Medical imaging techniques like PET and SPECT have been applied for investigation of brain function in anorexia and bulimia nervosa. Regional abnormalities have been detected in cerebral blood flow, glucose metabolism, the availability of several neurotransmitter receptors (serotonin 1A and 2A,

  4. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas ov...

  5. PET and SPECT of neurobiological systems

    Energy Technology Data Exchange (ETDEWEB)

    Dierckx, Rudi A.J.O. [Groningen Univ. (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging; Gent Univ. (Belgium). Dept. of Nuclear Medicine; Otte, Andreas [Univ. of Applied Sciences, Offenburg (Germany). Faculty of Electrical Engineering and Information Technology; Vries, Erik F.J. de; Waarde, Aren van (eds.) [Groningen Univ. (Netherlands). Dept. of Nuclear Medicine and Molecular Imaging

    2014-04-01

    Addresses a variety of aspects of neurotransmission in the brain. Details the latest results in probe development. Emphasis on a multidisciplinary approach. Written by internationally acclaimed experts. PET and SPECT of Neurobiological Systems combines the expertise of renowned authors whose dedication to the development of novel probes and techniques for the investigation of neurobiological systems has achieved international recognition. Various aspects of neurotransmission in the brain are discussed, such as visualization and quantification of (more than 20 different) neuroreceptors, neuroinflammatory markers, transporters, and enzymes as well as neurotransmitter synthesis, ?-amyloid deposition, cerebral blood flow, and the metabolic rate of glucose. The latest results in probe development are also detailed. Most chapters are written jointly by radiochemists and nuclear medicine specialists to ensure a multidisciplinary approach. This state of the art compendium will be valuable to anyone in the field of clinical or preclinical neuroscience, from the radiochemist and radiologist/nuclear medicine specialist to the interested neurobiologist and general practitioner. It is the second volume of a trilogy on PET and SPECT imaging in the neurosciences. Other volumes focus on PET and SPECT in psychiatry and PET and SPECT in neurology''.

  6. Chilaiditi's syndrome demonstrated by SPECT/CT

    Directory of Open Access Journals (Sweden)

    Nalini S Perumal

    2009-11-01

    Full Text Available Purpose: Chilaiditi’s syndrome is a rare condition commonly diagnosed as an incidental radiological finding. The aim of this report is to show the role of SPECT-CT in this syndrome and state the functional and anatomical role of this hybrid imaging modality. Materials and Methods: A case report. Results: A 49-year-old female patient was referred for gallium-67 citrate for a possible granulomatous myositis and underwent SPECT-CT of the abdomen to assess the area of decreased gallium uptake on planar images of the liver. The combined SPECT and CT modality demonstrated findings consistent with the clinical evidence of Chilaiditi’s syndrome. The anatomical part of this hybrid modality made it easier to evaluate the area of gallium lack of uptake which was due to air in the colon. Conclusion: This case does not only show the role of SPECT-CT in this syndrome but also suggest that the use of such modality should be considered whenever available in the evaluation of patients in whom the localization of active disease becomes imperative.

  7. SPECT/CT and pulmonary embolism

    DEFF Research Database (Denmark)

    Mortensen, Jann; Borgwardt, Henrik Gutte

    2014-01-01

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar...

  8. SPECT/CT imaging in children with papillary thyroid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hwa-Young; Gelfand, Michael J.; Sharp, Susan E. [Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States)

    2011-08-15

    SPECT/CT improves localization of single photon-emitting radiopharmaceuticals. To determine the utility of SPECT/CT in children with papillary thyroid carcinoma. 20 SPECT/CT and planar studies were reviewed in 13 children with papillary thyroid carcinoma after total thyroidectomy. Seven studies used I-123 and 13 used I-131, after elevating TSH by T4 deprivation or intramuscular thyrotropin alfa. Eight children had one study and five children had two to four studies. Studies were performed at initial post-total thyroidectomy evaluation, follow-up and after I-131 treatment doses. SPECT/CT was performed with a diagnostic-quality CT unit in 13 studies and a localization-only CT unit in 7. Stimulated thyroglobulin was measured (except in 2 cases with anti-thyroglobulin antibodies). In 13 studies, neck activity was present but poorly localized on planar imaging; all foci of uptake were precisely localized by SPECT/CT. Two additional foci of neck uptake were found on SPECT/CT. SPECT/CT differentiated high neck uptake from facial activity. In six studies (four children), neck uptake was identified as benign by SPECT/CT (three thyroglossal duct remnants, one skin contamination, two by precise anatomical CT localization). In two children, SPECT/CT supported a decision not to treat with I-131. When SPECT/CT was unable to identify focal uptake as benign, stimulated thyroglobulin measurements were valuable. In three of 13 studies with neck uptake, SPECT/CT provided no useful additional information. SPECT/CT precisely localizes neck iodine uptake. In small numbers of patients, treatment is affected. SPECT/CT should be used when available in thyroid carcinoma patients. (orig.)

  9. Iodine-123 iodobenzofuran (I-123 IBF) SPECT in patients with parkinsonism

    Energy Technology Data Exchange (ETDEWEB)

    Nakabeppu, Yoshiaki; Nakajo, Masayuki; Mitsuda, Mitsuru; Tsuchimochi, Shinsaku; Tani, Atsushi; Osame, Mitsuhiro [Kagoshima Univ. (Japan). Faculty of Medicine

    1999-12-01

    Iodine-123 benzofuran (I-123 IBF) is a dopaminergic antagonist which is suitable for SPECT imaging of D2 receptors. The purpose of this study is to evaluate the potential usefulness of semi-quantitative parameters obtained from brain SPECT data of I-123 IBF for differential diagnosis in patients with parkinsonism (PN). Subjects were 10 patients with PN: 2 patients with striato-nigral degeneration (SND), 5 patients with Parkinson's disease (PD), 2 patients with progressive supranuclear palsy (PSP) and one patient with olivo-ponto-cerebellar atrophy (OPCA). The data were acquired with a triple-head gamma camera at 2 hours after intravenous injection of 167 MBq of I-123 IBF. Transverse images were reconstructed by means of filtered backprojection, and attenuation correction was performed by Chang's method ({mu}=0.08). The basal ganglia-to-frontal cortex ratio (GFR) and the basal ganglia-to-occipital cortex ratio (GOR) on slices of 5 different thicknesses were calculated. The GFR and GOR were lower in the SND group than in the other disease groups in all slices with different thicknesses (7.2 mm, 14.4 mm, 21.6 mm, 28.8 mm and 43.2 mm). The semiquantitative parameters (GFR and GOR) obtained from brain SPECT data at 2 hours after intravenous injection of I-123 IBF may be useful for differential diagnosis in patients with PN. (author)

  10. Clinical significance of brain SPECT abnormalities of thalami and cerebellum in cerebral palsy with normal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Park, C. H.; Lim, S. Y.; Lee, I. Y.; Kim, O. H.; Bai, M. S.; Kim, S. J.; Yoon, S. N.; Cho, C. W. [College of Medicine, Ajou Univ., Suwon (Korea, Republic of)

    1997-07-01

    The cerebral palsy(CP) encephalopathies are often of uncertain etiology and various functional image findings comparing with anatomical image findings have been reported. However, only a few have mentioned its clinical implications. The purpose of our report is to compare clinical severity and functional SPECT abnormalities of thalami and cerebellum in CP patients with normal MRI. Thirty six CP patients with bilateral spastic palsy who had normal MRI and brain SPECT were studied from July 1996 to September 1997. The patients' age at the time of SPECT was 22.84{+-}17.69 months. The patients were divided into two groups according to motor quotient(MQ); moderate defect (>50MQ : n=27 MQ=22.78{+-}10.36), mild defect (<50MQ : n=9, MQ=66.11{+-}13.87). The degree of rCBF decrease between the two groups was evaluated by {chi}{sup 2} test. Brain SPECT was performed following IV administration of 0.05-0.1 mCi/kg (minimum 2.0 mCi) of Tc-99m ECD and chloral hydrate sedation (50-80 mg/kg p.o) using a triple head system (MS 3, Siemens). Interpretation of brain SPECT was visual analysis: severe decrease is defined when the defect is moderate to marked and mild decrease in rCBF as mild. Seven of 36 (19.4%) showed unilateral or bilateral moderate decrease in rCBF in thalami, 20(55.6%) showed mild decrease, and 9(25.0%) showed no decreased rCBF. All 7 who had moderate thalamic defect reveled moderate motor defect clinically. Ten of 36(27.9%) revealed unilateral or bilateral moderate rCBF defect, 23 (63.9%) depicted mild defect, and 3(8.3%) showed no defect. Sixteen with moderate thalamic rCBF defect showed moderate motor defect in 15 patients. There was statistically significant (p=0.02605) relationship between rCBF defect and motor defect in our CP patients. In conclusion, brain SPECT appears sensitive, non-invasive tool in the evaluation as well as in the prognostication of bilateral spastic cerebral palsy patients and deserves further study using larger number of patients.

  11. Differential diagnosis of trampoline fracture from osteomyelitis by bone scan with pinhole collimator.

    Science.gov (United States)

    Gauthé, Mathieu; Mestas, Danielle; Canavese, Federico; Samba, Antoine; Cachin, Florent

    2014-02-01

    A 2-year-old girl with recent history of trampoline fall presented to the A&E Department for complete functional impairment of the left lower extremity and fever. Blood examination revealed an inflammatory syndrome, while plain radiographs were normal. As magnetic resonance imaging was unavailable, a bone scintigraphy was performed. While standard acquisition found an intense uptake focused on the left proximal tibial metaphysis whose appearance was suggestive of acute hematogenous osteomyelitis, complementary acquisition with the pinhole collimator demonstrated that this abnormal uptake was clearly distinct from the cartilage growth plate. One month follow-up radiographs showed a fracture that confirmed the diagnosis of trampoline fracture.

  12. Lens-free and portable quantitative phase microscope using a dual-pinhole aperture

    Directory of Open Access Journals (Sweden)

    Lu Yujie

    2015-01-01

    Full Text Available This paper presents a lens-free and portable quantitative phase microscope. This microscope employs a concise off-axis set-up where a dual-pinhole aperture is utilized to generate the reference wave and the object wave. As no lenses or beamsplitters are used in this microscope, the total size of this microscope is only slightly larger than a smart phone, and the cost of this microscope except for the digital camera is about 3000 RMB. Even with such small size and low cost, this microscope possesses a lateral resolution of ~ 1:7μm and an axial accuracy of tens of nanometers.

  13. Statistical parametric mapping of Tc-99m HMPAO SPECT cerebral perfusion in the normal elderly

    Energy Technology Data Exchange (ETDEWEB)

    Turlakow, A.; Scott, A.M.; Berlangieri, S.U.; Sonkila, C.; Wardill, T.D.; Crowley, K.; Abbott, D.; Egan, G.F.; McKay, W.J.; Hughes, A. [Austin and Repatriation Medical Centre, Heidelberg, VIC (Australia). Departments of Nuclear Medicine and Centre for PET Neurology and Clinical Neuropsychology

    1998-06-01

    Full text: The clinical value of Tc-99m HMPAO SPECT cerebral blood flow studies in cognitive and neuropsychiatric disorders has been well described. Currently, interpretation of these studies relies on qualitative or semi- quantitative techniques. The aim of our study is to generate statistical measures of regional cerebral perfusion in the normal elderly using statistical parametric mapping (Friston et al, Wellcome Department of Cognitive Neurology, London, UK) in order to facilitate the objective analysis of cerebral blood flow studies in patient groups. A cohort of 20 healthy, elderly volunteers, aged 68 to 81 years, was prospectively selected on the basis of normal physical examination and neuropsychological testing. Subjects with risk factors, or a history of cognitive impairment were excluded from our study group. All volunteers underwent SPECT cerebral blood flow imaging, 30 minutes following the administration of 370 MBq Tc-99m HMPAO, on a Trionix Triad XLT triple-headed scanner (Trionix Research Laboratory Twinsburg, OH) using high resolution, fan-beam collimators resulting in a system resolution of 10 mm full width at half-maximum (FWHM). The SPECT cerebral blood flow studies were analysed using statistical parametric mapping (SPM) software specifically developed for the routine statistical analysis of functional neuroimaging data. The SPECT images were coregistered with each individual`s T1-weighted MR volume brain scan and spatially normalized to standardised Talairach space. Using SPM, these data were analyzed for differences in interhemispheric regional cerebral blood flow. Significant asymmetry of cerebral perfusion was detected in the pre-central gyrus at the 95th percentile. In conclusion, the interpretation of cerebral blood flow studies in the elderly should take into account the statistically significant asymmetry in interhemispheric pre-central cortical blood flow. In the future, clinical studies will be compared to statistical data sets in age

  14. Neural constraints on eye motion in human eye-head saccades.

    Science.gov (United States)

    Misslisch, H; Tweed, D; Vilis, T

    1998-02-01

    We examined two ways in which the neural control system for eye-head saccades constrains the motion of the eye in the head. The first constraint involves Listing's law, which holds ocular torsion at zero during head-fixed saccades. During eye-head saccades, does this law govern the eye's motion in space or in the head? Our subjects, instructed to saccade between space-fixed targets with the head held still in different positions, systematically violated Listing's law of the eye in space in a way that approximately, but not perfectly, preserved Listing's law of the eye in head. This finding implies that the brain does not compute desired eye position based on the desired gaze direction alone but also considers head position. The second constraint we studied was saturation, the process where desired-eye-position commands in the brain are "clipped" to keep them within an effective oculomotor range (EOMR), which is smaller than the mechanical range of eye motion. We studied the adaptability of the EOMR by asking subjects to make head-only saccades. As predicted by current eye-head models, subjects failed to hold their eyes still in their orbits. Unexpectedly, though, the range of eye-in-head motion in the horizontal-vertical plane was on average 31% smaller in area than during normal eye-head saccades, suggesting that the EOMR had been reduced by effort of will. Larger reductions were possible with altered visual input: when subjects donned pinhole glasses, the EOMR immediately shrank by 80%. But even with its reduced EOMR, the eye still moved into the "blind" region beyond the pinhole aperture during eye-head saccades. Then, as the head movement brought the saccade target toward the pinhole, the eyes reversed their motion, anticipating or roughly matching the target's motion even though it was still outside the pinhole and therefore invisible. This finding shows that the backward rotation of the eye is timed by internal computations, not by vision. When subjects wore

  15. Functional neuroimaging in epilepsy: FDG-PET and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kun; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2003-02-01

    Finding epileptogenic zone is the most important step for the successful epilepsy surgery. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and single photon emission computed tomography (SPECT) can be used in the localization of epileptogenic foci. In medial temporal lobe epilepsy, the diagnostic sensitivity of FDG-PET and ictal SPECT is excellent. However, detection of hippocampal sclerosis by MRI is so certain that use of FDG-PET and ictal SPECT in medial temporal lobe epilepsy is limited for some occasions. In neocortical epilepsy, the sensitivities of FDG-PET or ictal SPECT are fair. However, FDG-PET and ictal SPECT can have a crucial role in the localization of epileptogenic foci for non-lesional neocortical epilepsy. Interpretation of FDG-PET has been recently advanced by voxel-based analysis and automatic volume of interest analysis based on a population template. Both analytical methods can aid the objective diagnosis of epileptogenic foci. lctal SPECT was analyzed using subtraction methods and voxel-based analysis. Rapidity of injection of tracers, ictal EEG findings during injection of tracer, and repeated ictal SPECT were important technical issues of ictal SPECT. SPECT can also be used in the evaluation of validity of Wada test.

  16. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over...... radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  17. SPECT/CT in pediatric patient management

    Energy Technology Data Exchange (ETDEWEB)

    Nadel, Helen R. [British Columbia Children' s Hospital, University of British Columbia, Pediatric Radiologist and Nuclear Medicine Physician, Division of Nuclear Medicine Department of Radiology, Vancouver, British Columbia (Canada)

    2014-05-15

    Hybrid SPECT/CT imaging is becoming the standard of care in pediatric imaging. Indications are mainly for oncologic imaging including mIBG scintigraphy for neuroblastoma and I-123 post surgical imaging of children with thyroid carcinoma, bone scintigraphy for back pain, children referred from sports medicine and neurodevelopmentally delayed children presenting with pain symptoms. The studies provide improved diagnostic accuracy, and oncologic imaging that includes optimized CT as part of the SPECT/CT study may decrease the number of studies and sedation procedures an individual child may need. The studies, however, must be tailored on an individual basis as the addition of the CT study can increase exposure to the child and should only be performed after appropriate justification and with adherence to optimized low dose pediatric protocols. (orig.)

  18. SPECT Molecular Imaging in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2012-01-01

    Full Text Available Parkinson's disease (PD is a common disorder, and the diagnosis of Parkinson's disease is clinical and relies on the presence of characteristic motor symptoms. The accuracy of the clinical diagnosis of PD is still limited. Functional neuroimaging using SPECT technique is helpful in patients with first signs of parkinsonism. The changes detected may reflect the disease process itself and/or compensatory responses to the disease, or they may arise in association with disease- and/or treatment-related complications. This paper addresses the value of SPECT in early differential diagnosis of PD and its potential as a sensitive tool to assess the pathophysiology and progression, as well as the therapeutic efficacy of PD.

  19. Fuzzy segmentation approach for quantitative SPECT

    Science.gov (United States)

    Schmitt, Thomas; Freyer, Richard; Oehme, Liane; Andreeff, Michael; Franke, Wolf-Gunter

    1998-06-01

    The determination of objective numerical criteria from nuclear medicine image data renders it possible to plan and control therapies, to compare inter- and intra-individual studies as well as time course studies and to facilitate the dominating visual interpretation of scintigrams. SPECT performs real 3D functional imaging of radionuclide distributions. The basic numerical value is the functional volume of a certain region. The volume is one prerequisite for activity measurement, but the value itself is of diagnostic importance, too. For determining the region boundaries several segmentation approaches are commonly used which are generally based on interactive ROI drawing, thresholding or edge detection methods. The image quality properties of SPECT render the segmentation process more difficult in any case. We propose an alternative segmentation approach where the crisp decision `object: yes or not' is substituted by a fuzzy boundary model `object: more or less'.

  20. Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, J. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Reis, M.A. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Miranda, A.C.C. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Batista, I.R. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Barboza, M.R.F.; Shih, M.C. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Fu, G. [GE Global Research, Schenectady, NY (United States); Chen, C.T. [Department of Radiology, University of Chicago, Chicago, IL (United States); Meng, L.J. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana-Champaign, IL (United States); Bressan, R.A. [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil); Laboratório Interdisciplinar de Neurociências Clínicas, Departamento de Psiquiatria, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Amaro, E. Jr [Hospital Israelita Albert Einstein, Instituto do Cérebro, São Paulo, SP (Brazil)

    2013-11-06

    The single photon emission microscope (SPEM) is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT) images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl)] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD). Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s{sup -1}·MBq{sup -1} were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging {sup 99m}Tc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using {sup 99m}Tc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

  1. Performance assessment of the single photon emission microscope: high spatial resolution SPECT imaging of small animal organs

    Directory of Open Access Journals (Sweden)

    J. Mejia

    2013-11-01

    Full Text Available The single photon emission microscope (SPEM is an instrument developed to obtain high spatial resolution single photon emission computed tomography (SPECT images of small structures inside the mouse brain. SPEM consists of two independent imaging devices, which combine a multipinhole collimator, a high-resolution, thallium-doped cesium iodide [CsI(Tl] columnar scintillator, a demagnifying/intensifier tube, and an electron-multiplying charge-coupling device (CCD. Collimators have 300- and 450-µm diameter pinholes on tungsten slabs, in hexagonal arrays of 19 and 7 holes. Projection data are acquired in a photon-counting strategy, where CCD frames are stored at 50 frames per second, with a radius of rotation of 35 mm and magnification factor of one. The image reconstruction software tool is based on the maximum likelihood algorithm. Our aim was to evaluate the spatial resolution and sensitivity attainable with the seven-pinhole imaging device, together with the linearity for quantification on the tomographic images, and to test the instrument in obtaining tomographic images of different mouse organs. A spatial resolution better than 500 µm and a sensitivity of 21.6 counts·s-1·MBq-1 were reached, as well as a correlation coefficient between activity and intensity better than 0.99, when imaging 99mTc sources. Images of the thyroid, heart, lungs, and bones of mice were registered using 99mTc-labeled radiopharmaceuticals in times appropriate for routine preclinical experimentation of <1 h per projection data set. Detailed experimental protocols and images of the aforementioned organs are shown. We plan to extend the instrument's field of view to fix larger animals and to combine data from both detectors to reduce the acquisition time or applied activity.

  2. ENVISION, developing SPECT imaging for particle therapy

    CERN Multimedia

    2013-01-01

    Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. ENVISION aims at developing medical imaging tools to improve the dose delivery to the patient, to ensure a safer and more effective treatment. The animation illustrates the use of Single Photon Emission Computed Tomography (SPECT) for monitoring the dose during treatment. Produced by: CERN KT/Life Sciences and ENVISION Project Management: Manuela Cirilli 3D animation: Jeroen Huijben, Nymus3d

  3. PET and SPECT imaging in veterinary medicine.

    Science.gov (United States)

    LeBlanc, Amy K; Peremans, Kathelijne

    2014-01-01

    Veterinarians have gained increasing access to positron emission tomography (PET and PET/CT) imaging facilities, allowing them to use this powerful molecular imaging technique for clinical and research applications. SPECT is currently being used more in Europe than in the United States and has been shown to be useful in veterinary oncology and in the evaluation of orthopedic diseases. SPECT brain perfusion and receptor imaging is used to investigate behavioral disorders in animals that have interesting similarities to human psychiatric disorders. This article provides an overview of the potential applications of PET and SPECT. The use of commercially available and investigational PET radiopharmaceuticals in the management of veterinary disease has been discussed. To date, most of the work in this field has utilized the commercially available PET tracer, (18)F-fluorodeoxyglucose for oncologic imaging. Normal biodistribution studies in several companion animal species (cats, dogs, and birds) have been published to assist in lesion detection and interpretation for veterinary radiologists and clinicians. Studies evaluating other (18)F-labeled tracers for research applications are underway at several institutions and companion animal models of human diseases are being increasingly recognized for their value in biomarker and therapy development. Although PET and SPECT technologies are in their infancy for clinical veterinary medicine, increasing access to and interest in these applications and other molecular imaging techniques has led to a greater knowledge and collective body of expertise for veterinarians worldwide. Initiation and fostering of physician-veterinarian collaborations are key components to the forward movement of this field. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Staging of moyamoya disease by perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo [Kyushu Univ., Fukuoka (Japan). Hospital; Matsushima, Toshio; Fukui, Masashi

    2001-04-01

    Staging of moyamoya disease, based on angiography and PET have already been established. The authors have established staging of moyamoya disease based on perfusion SPECT, that can be summarized as follows: Stage I, no abnormality is seen at rest or after acetazolamide loading; Stage II, no abnormality is seen at rest, however, a decreased response (blood flow increase rate: <15%) is seen to acetazolamide loading (a, a decreased response is seen only in the frontal lobe; b, a decreased response is seen in regions other than the frontal lobe; and c, a decreased response is seen throughout the cerebrum); Stage III, localized decrease in blood flow (blood flow decrease compared with peripheral tissue: {>=}15%) and marked decrease in response to acetazolamide (blood flow increase rate: <5%) are seen at rest. In Stage III, CT and MRI show no abnormal findings or only mild lesions of the white matter; and Stage IV, multiple decreases in blood flow are seen at rest, and CT and MRI reveal infarctions and severe atrophy at the same sites. The above staging does not require determination of cerebral blood flow, and thus it can be used in children, in whom cerebral blood flow determination is difficult. The authors performed 99m-Tc ECD perfusion SPECT in 25 patients with moyamoya disease for the staging, and compared staging based on angiography with staging based on perfusion SPECT. The results did not show a correlation between the 2 staging methods. A problem inherent in the staging of moyamoya disease based on perfusion SPECT is that the relationship between cerebral blood flow and cerebral radioactivity concentrations may differ depending on the drug used to determine cerebral blood flow. Thus, although the present staging system does not depend on any specific radioactive drug to determine cerebral blood flow, further investigation is necessary to identify a more appropriate drug than those in current use. (K.H.)

  5. Accelerated GPU based SPECT Monte Carlo simulations.

    Science.gov (United States)

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-07

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: (99m) Tc, (111)In and (131)I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational

  6. Loss of the six3/6 controlling pathways might have resulted in pinhole-eye evolution in Nautilus.

    Science.gov (United States)

    Ogura, Atsushi; Yoshida, Masa-aki; Moritaki, Takeya; Okuda, Yuki; Sese, Jun; Shimizu, Kentaro K; Sousounis, Konstantinos; Tsonis, Panagiotis A

    2013-01-01

    Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor to Nautilus or squid are almost the same. Although most upstream eye development controlling genes were expressed in both species, six3/6 that are required for lens formation in vertebrates was not expressed in Nautilus. Furthermore, many downstream target genes of six3/6 including crystallin genes and other lens protein related genes were not expressed in Nautilus. As six3/6 and its controlling pathways are widely conserved among molluscs other than Nautilus, the present data suggest that deregulation of the six3/6 pathway led to the pinhole eye evolution in Nautilus.

  7. SPECT and PET Imaging of Meningiomas

    Directory of Open Access Journals (Sweden)

    Varvara Valotassiou

    2012-01-01

    Full Text Available Meningiomas arise from the meningothelial cells of the arachnoid membranes. They are the most common primary intracranial neoplasms and represent about 20% of all intracranial tumors. They are usually diagnosed after the third decade of life and they are more frequent in women than in men. According to the World Health Organization (WHO criteria, meningiomas can be classified into grade I meningiomas, which are benign, grade II (atypical and grade III (anaplastic meningiomas, which have a much more aggressive clinical behaviour. Computed Tomography (CT and Magnetic Resonance Imaging (MRI are routinely used in the diagnostic workup of patients with meningiomas. Molecular Nuclear Medicine Imaging with Single Photon Emission Computed Tomography (SPECT and Positron Emission Tomography (PET could provide complementary information to CT and MRI. Various SPECT and PET tracers may provide information about cellular processes and biological characteristics of meningiomas. Therefore, SPECT and PET imaging could be used for the preoperative noninvasive diagnosis and differential diagnosis of meningiomas, prediction of tumor grade and tumor recurrence, response to treatment, target volume delineation for radiation therapy planning, and distinction between residual or recurrent tumour from scar tissue.

  8. Neuropharmacological studies with SPECT in neuropsychiatric disorders

    Energy Technology Data Exchange (ETDEWEB)

    Heinz, Andreas; Jones, Douglas W.; Raedler, Thomas; Coppola, Richard; Knable, Michael B.; Weinberger, Daniel R. E-mail: weinberd@intra.nimh.nih.gov

    2000-10-01

    The last decade saw a rapid development of single photon emission computed tomography (SPECT) from a tool to assess cerebral blood flow to the study of specific neurotransmitter systems. Because of the relatively long half-life of SPECT radioisotopes, it is practical to measure the availability of neuroreceptors and transporters in conditions approaching equilibrium. The cost-efficiency of SPECT allowed studies in relatively large samples of patients with various neuropsychiatric disorders. We have applied this approach in studies of dopaminergic, serotonergic, and muscarinergic neurotransmission in patients with dementia, extrapyramidal disorders, schizophrenia, and alcoholism. No simple associations were observed between a single defect in one neurotransmitter system and a certain neuropsychiatric disease. Instead, complex dysfunction of several neurotransmitter systems in multiple, partially connected brain circuits have been implicated. Treatment effects also have been characterized. Microdialysis and neurotransmitter depletion studies showed that most radioligands and endogenous neurotransmitters compete for binding at receptors and transporters. Future research directions include the assessment of endogenous neurotransmitter concentrations measured by depletion studies and of genetic effects on neuroreceptor and transporter expression.

  9. The Amnioscope Strikes Back as a Useful Device for Pinhole Amniotomy in the Management of Polyhydramnios

    Science.gov (United States)

    Koyama, Shinsuke; Tomimatsu, Takuji; Kanagawa, Takeshi; Tsutsui, Tateki; Kimura, Tadashi

    2011-01-01

    Polyhydramnios is associated with many serious maternal complications such as placental abruption or cord prolapse at rupture of membranes, uterine dysfunction at delivery, and postpartum hemorrhage. When considering uterine dysfunction caused by overstretched uterine muscles, active artificial amniotomy for more efficient labor seems to be a preferred obstetric management, but the potential adverse complications make obstetricians hesitate to perform this procedure. In such a challenging situation, a new strategy is required. We recently performed pinhole artificial amniotomy using an amnioscope in four women with polyhydramnios, not only to accelerate of labor but also to more slowly and safely reduce amniotic fluid volume. We had no complications using this procedure, and all women were able to have a vaginal delivery without postpartum hemorrhage and neonatal asphyxia. Pinhole artificial amniotomy using an amnioscope may be more convenient and safer than conventional artificial amniotomy. The significance of the amnioscope has been practically nil in modern obstetric management. In this pilot clinical study, we identified a new value for the amnioscope as a promising device for safer amniotomy in women with polyhydramnios. PMID:23705096

  10. The Amnioscope Strikes Back as a Useful Device for Pinhole Amniotomy in the Management of Polyhydramnios

    Directory of Open Access Journals (Sweden)

    Shinsuke Koyama

    2011-12-01

    Full Text Available Polyhydramnios is associated with many serious maternal complications such as placental abruption or cord prolapse at rupture of membranes, uterine dysfunction at delivery, and postpartum hemorrhage. When considering uterine dysfunction caused by overstretched uterine muscles, active artificial amniotomy for more efficient labor seems to be a preferred obstetric management, but the potential adverse complications make obstetricians hesitate to perform this procedure. In such a challenging situation, a new strategy is required. We recently performed pinhole artificial amniotomy using an amnioscope in four women with polyhydramnios, not only to accelerate of labor but also to more slowly and safely reduce amniotic fluid volume. We had no complications using this procedure, and all women were able to have a vaginal delivery without postpartum hemorrhage and neonatal asphyxia. Pinhole artificial amniotomy using an amnioscope may be more convenient and safer than conventional artificial amniotomy. The significance of the amnioscope has been practically nil in modern obstetric management. In this pilot clinical study, we identified a new value for the amnioscope as a promising device for safer amniotomy in women with polyhydramnios.

  11. SPECT and PET imaging in epilepsia; SPECT und PET in der Diagnostik von Epilepsien

    Energy Technology Data Exchange (ETDEWEB)

    Landvogt, C. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2007-09-15

    In preoperative localisation of epileptogenic foci, nuclear medicine diagnostics plays a crucial role. FDG-PET is used as first line diagnostics. In case of inconsistent MRI, EEG and FDG-PET findings, {sup 11}C-Flumazenil-PET or ictal and interictal perfusion-SPECT should be performed. Other than FDG, Flumazenil can help to identify the extend of the region, which should be resected. To enhance sensitivity and specificity, further data analysis using voxelbased statistical analyses or SISCOM (substraction ictal SPECT coregistered MRI) should be performed.

  12. Experimental measurements of the plasma sheath around pinhole defects in a simulated high-voltage solar array

    Science.gov (United States)

    Gabriel, S. B.; Garner, C.; Kitamura, S.

    1983-01-01

    An emissive Langmuir probe was used to measure the potentials within the plasma sheath developed around a hole in a simulated solar array at voltages between 50 and 450 V. The hole sizes were larger than actual pinhole defects; the plasma density was in the 10,000 per cu cm range, which is considerably lower than the density of 1,000,000 per cu cm found at low-earth-orbit altitudes. Despite these inadequacies in the simulation, the experiments indicate that this type of probe is a useful diagnostic technique for investigating the plasma sheaths developing around pinhole defects.

  13. Pinhole-type two-dimensional ultra-small-angle X-ray scattering on the micrometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Hiroyuki, E-mail: h-kishimoto.az@srigroup.co.jp [Sumitomo Rubber Industries Ltd, 2-1-1 Tsutsui, Chuo, Kobe, Hyogo 651-0071 (Japan); The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Shinohara, Yuya, E-mail: h-kishimoto.az@srigroup.co.jp [The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan); Suzuki, Yoshio; Takeuchi, Akihisa; Yagi, Naoto [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Amemiya, Yoshiyuki [The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

    2013-11-02

    A pinhole-type ultra-small-angle X-ray scattering set-up that enlarges the accessible q-range to 0.25 µm{sup −1} is described. A pinhole-type two-dimensional ultra-small-angle X-ray scattering set-up at a so-called medium-length beamline at SPring-8 is reported. A long sample-to-detector distance, 160.5 m, can be used at this beamline and a small-angle resolution of 0.25 µm{sup −1} was thereby achieved at an X-ray energy of 8 keV.

  14. Usefulness of hybrid SPECT/CT for the {sup 99m}Tc-HMPAO-labeled leukocyte scintigraphy in a case of cranial osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Bruni, Chiara; Padovano, Federico; Travascio, Laura; Schillaci, Orazio; Simonetti, Giovanni [University of Rome Tor Vergata, Rome (Italy). Dept. of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy]. E-mail: chiarabruni79@hotmail.com

    2008-12-15

    Cranial osteomyelitis is a potentially fatal lesion. White blood cell scanning (WBC) with {sup 99m}Tc-hexamethylpropylene amine oxime (HMPAO) has proven highly sensitive and specific in the diagnosis and follow-up of patients with suspected osteomyelitis. In this report we show the usefulness of SPECT and transmission CT performed simultaneously using a hybrid imaging device for the functional anatomic mapping of soft tissue and cranial bone infections. {sup 99m}Tc-HMPAO-labeled leukocytes scintigraphy was performed on an elderly diabetic man with an intracranial mass lesion and with suspected temporal bone infection. Planar scans were acquired 30 min, 4 h, and 24 h after injection. SPECT/CT was obtained 6 h after tracer injection, using a dual-head camera coupled with a low-power X-ray tube. The scintigraphic results were matched with the results of surgery and of clinical follow-up. The planar images alone were true-positives for abscess in this patient. SPECT/CT improves the accuracy of {sup 99m}Tc- HMPAO scintigraphy especially in discriminating between soft-tissue and bone involvement. In fact, SPECT/CT also showed temporal bone osteomyelitis. This result indicates that SPECT/CT performed using a hybrid device can improve imaging with {sup 99m}Tc-HMPAO-labeled leukocytes in patients with suspected osteomyelitis by providing accurate anatomic localization and precise definition of the extent of infection. (author)

  15. A portable gamma-camera for intraoperative detection of sentinel nodes in the head and neck region

    NARCIS (Netherlands)

    Vermeeren, Lenka; Valdés Olmos, Renato A.; Klop, W. Martin C.; Balm, Alfons J. M.; van den Brekel, Michiel W. M.

    2010-01-01

    We introduced and evaluated a portable gamma-camera for intraoperative visualization of sentinel nodes in the head and neck region. METHODS: Planar lymphoscintigraphy and SPECT/CT were performed after peritumoral injection of (99m)Tc-nanocolloid in 25 patients (head and neck melanoma or oral cavity

  16. Electric Field Reconstruction in the Image Plane of a High-Contrast Coronagraph Using a Set of Pinholes Around the Lyot Plane

    Science.gov (United States)

    Giveon, Amir; Kern, Brian; Shaklan, Stuart; Wallace, Kent; Noecker, Charley

    2012-01-01

    The pair-wise estimation has been used now on various testbeds with different coronagraphs with the best contrast results to date. Pinholes estimate has been implemented and ready to be tested in closed loop correction. Pinholes estimate offers an independent method. We hope to improve the calibration process to gain better estimates.

  17. Ictal cerebral perfusion patterns in partial epilepsy: SPECT subtraction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyang Woon; Hong, Seung Bong; Tae, Woo Suk; Kim, Sang Eun; Seo, Dae Won; Jeong, Seung Cheol; Yi, Ji Young; Hong, Seung Chyul [Sungkyunkwan Univ. School of Medicine, Seoul (Korea, Republic of)

    2000-06-01

    To investigate the various ictal perfusion patterns and find the relationships between clinical factors and different perfusion patterns. Interictal and ictal SPECT and SPECT subtraction were performed in 61 patients with partial epilepsy. Both positive images showing ictal hyperperfusion and negative images revealing ictal hypoperfusion were obtained by SPECT subtraction. The ictal perfusion patterns of subtracted SPECT were classified into focal hyperperfusion, hyperperfusion-plus, combined hyperperfusion-hypoperfusion, and focal hypoperfusion only. The concordance rates with epileptic focus were 91.8% in combined analysis of ictal hyperperfusion and hypoperfusion images of subtracted SPECT, 85.2% in hyperperfusion images only of subtracted SPECT, and 68.9% in conventional ictal SPECT analysis. Ictal hypoperfusion occurred less frequently in temporal lobe epilepsy (TLE) than extratemporal lobe epilepsy. Mesial temporal hyperperfusion alone was seen only in mesial TLE while lateral temporal hyperperfusion alone was observed only in neocortical TLE. Hippocampal sclerosis had much lower incidence of ictal hypoperfusion than any other pathology. Some patients showed ictal hypoperfusion at epileptic focus with ictal hyperperfusion in the neighboring brain regions where ictal discharges propagated. Hypoperfusion as well as hyperperfusion in ictal SPECT should be considered for localizing epileptic focus. Although the mechanism of ictal hypoperfusion could be an intra-ictal early exhaustion of seizure focus or a steal phenomenon by the propagation of ictal discharges to adjacent brain areas, further study is needed to elucidate it.

  18. Evaluation of parathyroid imaging methods with {sup 99m}Tc-MIBI. The comparison of planar images obtained using a pinhole collimator and a parallel-hole collimator

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Hirofumi; Iwasaki, Ryuichiro; Hashimoto, Jun; Nakamura, Kayoko; Kunieda, Etsuo; Sanmiya, Toshikazu; Kubo, Atsushi [Keio Univ., Tokyo (Japan). School of Medicine; Ogawa, Koichi; Inagaki, Kazutoshi

    1999-07-01

    Parathyroid scintigraphy with {sup 99m}Tc-MIBI was performed using two kinds of collimators, namely, a pinhole one and a parallel-hole one, to evaluate which one was more suitable for the detection of hyperfunctioning parathyroid lesions. In the studies using {sup 99m}Tc source, the pinhole collimator showed better efficiency and spatial resolution in the distance where the parathyroid scan are actually performed. In the phantom study, the nodular activities modeling parathyroid lesions were visualized better on the images obtained using the pinhole collimator. In clinical studies for 30 patients suspicious of hyperparathyroidism, hyperfunctioning parathyroid nodules were better detected when the pinhole collimator was used. In conclusion, the pinhole collimator was thought to be more suitable for parathyroid scintigraphy with {sup 99m}Tc-MIBI than the parallel-hole collimator. (author)

  19. (99m)Tc-labelled nanosystem as tumour imaging agent for SPECT and SPECT/CT modalities.

    Science.gov (United States)

    Polyák, András; Hajdu, István; Bodnár, Magdolna; Trencsényi, György; Pöstényi, Zita; Haász, Veronika; Jánoki, Gergely; Jánoki, Győző A; Balogh, Lajos; Borbély, János

    2013-06-05

    We report the synthesis, in vitro and in vivo investigation of folate-targeted, biocompatible, biodegradable self-assembled nanoparticles radiolabelled with (99m)Tc, as potential new SPECT or SPECT/CT imaging agent. Nanoparticles with hydrodynamic size in the range of 75-200 nm were prepared by self-assembly of chitosan and folated poly-γ-glutamic acid, and then radiolabelled with (99m)Tc. The nanoparticles target tumour cells overexpressing folate receptors and internalize specifically into them to realize early tumour diagnosis detected by SPECT and SPECT/CT modalities. Rat hepatocellular carcinoma cells were used as model system. Cell specificity and tumour targeting efficacy of these nanosystems were investigated in vitro, and in vivo using SPECT and fusion nanoSPECT/CT imaging. In vitro results showed that the radiolabeled nanosystem was efficiently internalized by tumour cells. Whole-body biodistribution of the new radiolabelled, folate-targeted nanoparticles revealed higher uptake in the tumorous kidney compared to the non-tumorous contralateral side. Uptake by the lungs and thyroids was negligible, which confirmed the stability of the nanoparticles in vivo. In vivo SPECT and SPECT/CT imaging visually reinforced the uptake results and were in accordance with the biodistribution data: the new nanoparticles as a targeted contrast agent improve tumour targeting and are able to detect folate-receptor-overexpressing tumours in animal models with enhanced contrast. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. The effect of CT-based attenuation correction on the automatic perfusion score of myocardial perfusion imaging using a dedicated cardiac solid-state CZT SPECT/CT.

    Science.gov (United States)

    Kennedy, John A; Brodov, Yafim; Weinstein, Adam L; Israel, Ora; Frenkel, Alex

    2017-05-01

    Data regarding cardiac cadmium-zinc-telluride (CZT)-specific augmented databases and their impact on CT-based attenuation correction (AC) perfusion scores in myocardial perfusion imaging (MPI) were obtained on a multiple-pinhole CZT SPECT/CT. Summed stress (SSS) and rest scores (SRS) were measured using automated software in three independent patient groups: group 1 (n = 80) underwent MPI on both CZT and conventional sodium iodide (NaI) devices, group 2 (n = 80) with low coronary artery disease likelihood and normal MPI provided reference CZT databases; and group 3 (n = 152) served to compare AC and non-AC (NAC) scores on CZT. Group 1 CZT and NaI scores gave a significant 1:1 linear correlation for CZT scores referenced to the custom database vs NaI scores referenced to the default database, but these were not concordant when CZT scores were referenced to the default database. AC significantly decreased average SSS and SRS in men vs NAC, 4.29 ± 6.30 vs 5.37 ± 7.26 (P < 0.001) and 2.37 ± 4.72 vs 3.13 ± 5.85 (P < 0.001), but not in women, 2.28 ± 3.42 vs 2.28 ± 3.08 (p NS) and 0.46 ± 1.51 vs 0.61 ± 1.86, (p NS), respectively. Specifically designed databases for solid-state CZT cardiac SPECT provide accurate quantitation of perfusion scores concordant with those previously validated for conventional SPECT. AC and NAC CZT scores differed significantly, especially in men.

  1. Dynamic Growth of Pinhole-Free Conformal CH3NH3PbI3 Film for Perovskite Solar Cells.

    Science.gov (United States)

    Li, Bo; Tian, Jianjun; Guo, Lixue; Fei, Chengbin; Shen, Ting; Qu, Xuanhui; Cao, Guozhong

    2016-02-01

    Two-step dipping is one of the popular low temperature solution methods to prepare organic-inorganic halide perovskite (CH3NH3PbI3) films for solar cells. However, pinholes in perovskite films fabricated by the static growth method (SGM) result in low power conversion efficiency (PCE) in the resulting solar cells. In this work, the static dipping process is changed into a dynamic dipping process by controlled stirring PbI2 substrates in CH3NH3I isopropanol solution. The dynamic growth method (DGM) produces more nuclei and decreases the pinholes during the nucleation and growth of perovskite crystals. The compact perovskite films with free pinholes are obtained by DGM, which present that the big perovskite particles with a size of 350 nm are surrounded by small perovskite particles with a size of 50 nm. The surface coverage of the perovskite film is up to nearly 100%. Such high quality perovskite film not only eliminated pinholes, resulting in reduced charge recombination of the solar cells, but also improves the light harvesting efficiency. As a result, the PCE of the perovskite solar cells is increased from 11% for SGM to 13% for DGM.

  2. Use of simulation to optimize the pinhole diameter and mask thickness for an x-ray backscatter imaging system

    Science.gov (United States)

    Vella, A.; Munoz, Andre; Healy, Matthew J. F.; Lane, David; Lockley, D.

    2017-08-01

    The PENELOPE Monte Carlo simulation code was used to determine the optimum thickness and aperture diameter of a pinhole mask for X-ray backscatter imaging in a security application. The mask material needs to be thick enough to absorb most X-rays, and the pinhole must be wide enough for sufficient field of view whilst narrow enough for sufficient image spatial resolution. The model consisted of a fixed geometry test object, various masks with and without pinholes, and a 1040 x 1340 pixels' area detector inside a lead lined camera housing. The photon energy distribution incident upon masks was flat up to selected energy limits. This artificial source was used to avoid the optimisation being specific to any particular X-ray source technology. The pixelated detector was modelled by digitising the surface area represented by the PENELOPE phase space file and integrating the energies of the photons impacting within each pixel; a MATLAB code was written for this. The image contrast, signal to background ratio, spatial resolution, and collimation effect were calculated at the simulated detector as a function of pinhole diameter and various thicknesses of mask made of tungsten, tungsten/epoxy composite or bismuth alloy. A process of elimination was applied to identify suitable masks for a viable X-ray backscattering security application.

  3. The impact of system matrix dimension on small FOV SPECT reconstruction with truncated projections

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Chung, E-mail: Chung.Chan@yale.edu, E-mail: Chi.Liu@yale.edu; Wu, Jing; Liu, Chi, E-mail: Chung.Chan@yale.edu, E-mail: Chi.Liu@yale.edu [Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 (United States); Dey, Joyoni [Department of Physics and Astronomy, Medical Physics Program, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Grobshtein, Yariv [GE Healthcare, Haifa 30200 (Israel); Liu, Yi-Hwa; Lampert, Rachel [Department of Internal Medicine, Yale University, New Haven, Connecticut 06520 (United States); Sinusas, Albert J. [Department of Diagnostic Radiology, Yale University, New Haven, Connecticut 06520 and Department of Internal Medicine, Yale University, New Haven, Connecticut 06520 (United States)

    2016-01-15

    Purpose: A dedicated cardiac hybrid single photon emission computed tomography (SPECT)/CT scanner that uses cadmium zinc telluride detectors and multiple pinhole collimators for stationary acquisition offers many advantages. However, the impact of the reconstruction system matrix (SM) dimension on the reconstructed image quality from truncated projections and 19 angular samples acquired on this scanner has not been extensively investigated. In this study, the authors aimed to investigate the impact of the dimensions of SM and the use of body contour derived from adjunctive CT imaging as an object support in reconstruction on this scanner, in relation to background extracardiac activity. Methods: The authors first simulated a generic SPECT/CT system to image four NCAT phantoms with various levels of extracardiac activity and compared the reconstructions using SM in different dimensions and with/without body contour as a support for quantitative evaluations. The authors then compared the reconstructions of 18 patient studies, which were acquired on a GE Discovery NM570c scanner following injection of different radiotracers, including {sup 99m}Tc-Tetrofosmin and {sup 123}I-mIBG, comparing the scanner’s default SM that incompletely covers the body with a large SM that incorporates a patient specific full body contour. Results: The simulation studies showed that the reconstructions using a SM that only partially covers the body yielded artifacts on the edge of the field of view (FOV), overestimation of activity and increased nonuniformity in the blood pool for the phantoms with higher relative levels of extracardiac activity. However, the impact on the quantitative accuracy in the high activity region, such as the myocardium, was subtle. On the other hand, an excessively large SM that enclosed the entire body alleviated the artifacts and reduced overestimation in the blood pool, but yielded slight underestimation in myocardium and defect regions. The reconstruction

  4. Pinhole cameras as sensors for atomic oxygen in orbit: Application to attitude determination of the LDEF

    Science.gov (United States)

    Peters, Palmer N.; Gregory, John C.

    1992-01-01

    Images produced by pinhole cameras using film sensitive to atomic oxygen provide information on the ratio of spacecraft orbital velocity to the most probable thermal speed of oxygen atoms, provided the spacecraft orientation is maintained stable relative to the orbital direction. Alternatively, information on the spacecraft attitude relative to the orbital velocity can be obtained, provided that corrections are properly made for thermal spreading and a corotating atmosphere. The Long Duration Exposure Facility (LDEF) orientation, uncorrected for a corotating atmosphere, was determined to be yawed 8.0 +/- 0.4 degrees from its nominal attitude, with an estimated +/- 0.35 degree oscillation in yaw. The integrated effect of inclined orbit and corotating atmosphere produces an apparent oscillation in the observed yaw direction, suggesting that the LDEF attitude measurement will indicate even better stability when corrected for a corotating atmosphere. The measured thermal spreading is consistent with major exposure occurring during high solar activity, which occurred late during the LDEF mission.

  5. Fabricating Pinhole-Free YSZ Sub-Microthin Films by Magnetron Sputtering for Micro-SOFCs

    Directory of Open Access Journals (Sweden)

    T. Hill

    2011-01-01

    Full Text Available Submicron thin yttria stabilized zirconia (YSZ films were prepared on a variety of substrates with different surface morphologies by magnetron sputtering followed by thermal oxidation. Pinholes were observed in the films deposited on nanoporous alumina substrates. Initial dense Y/Zr films developed nanocracks after thermal oxidation on smooth Si wafer substrates. At optimal sputtering and oxidation conditions, smooth and crack/pore-free films were achieved on Si wafer substrates. The thin YSZ films exhibited fully ionic conduction with ionic conductivities, and activation energy corroborated well with the values from commercial YSZ plates. The thin YSZ films can be utilized in Solid Oxide Fuel Cells (SOFCs for intermediate temperature operations.

  6. Evaluation of Tl-201 SPECT imaging findings in prostate cancer

    Directory of Open Access Journals (Sweden)

    Sinem Ozyurt

    2015-07-01

    Full Text Available Objectives: To compare with histopathological findings the findings of prostate cancer imaging by SPECT method using Tl-201 as a tumor seeking agent. Methods: The study comprised 59 patients (age range 51-79 years, mean age 65.3 ± 6.8 years who were planned to have transrectal ultrasonography (TRUS-guided biopsies due to suspicion of prostate cancer between April 2011 and September 2011. Early planar, late planar and SPECT images were obtained for all patients. Scintigraphic evaluation was made in relation to uptake presence and patterns in the visual assessment and to Tumor/Background (T/Bg ratios for both planar and SPECT images in the quantitative assessment. Histopathological findings were compatible with benign etiology in 36 (61% patients and malign etiology in 23 (39% patients. Additionally, comparisons were made to evaluate the relationships between uptake patterns,total PSA values and Gleason scores. Results: A statistically significant difference was found between the benign and malignant groups in terms of uptake in planar and SPECT images and T/Bg ratios and PSA values. No statistically significant difference was found between uptake patterns of planar and SPECT images and Gleason scores in the malignant group. Conclusions: SPECT images were superior to planar images in the comparative assessment. Tl-201 SPECT imaging can provide an additional contribution to clinical practice in the diagnosis of prostate cancer and it can be used in selected patients.

  7. Juvenile spondylolysis: a comparative analysis of CT, SPECT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R.S.D. [Royal Liverpool University Hospital, Department of Radiology, Liverpool (United Kingdom); Grainger, A.J. [Leeds General Infirmary, Department of Radiology, Leeds (United Kingdom); Hide, I.G. [Freeman Hospital, Department of Radiology, Newcastle upon Tyne (United Kingdom); Papastefanou, S. [James Cook University Hospital, Department Radiology, Middlesbrough (United Kingdom); Greenough, C.G. [James Cook University Hospital, Department of Trauma and Orthopaedics, Middlesbrough (United Kingdom)

    2005-02-01

    To evaluate whether MRI correlates with CT and SPECT imaging for the diagnosis of juvenile spondylolysis, and to determine whether MRI can be used as an exclusive image modality. Juveniles and young adults with a history of extension low back pain were evaluated by MRI, CT and SPECT imaging. All images were reviewed blindly. Correlative analyses included CT vs MRI for morphological grading and SPECT vs MRI for functional grading. Finally, an overall grading system compared MRI vs CT and SPECT combined. Statistical analysis was performed using the kappa statistic. Seventy-two patients (mean age 16 years) were recruited. Forty pars defects were identified in 22 patients (31%), of which 25 were chronic non-union, five acute complete defects and ten acute incomplete fractures. Kappa scores demonstrated a high level of agreement for all comparative analyses. MRI vs SPECT (kappa: 0.794), MRI vs CT (kappa: 0.829) and MRI vs CT/SPECT (kappa: 0.786). The main causes of discrepancy were between MRI and SPECT for the diagnosis of stress reaction in the absence of overt fracture, and distinguishing incomplete fractures from intact pars or complete defects. MRI can be used as an effective and reliable first-line image modality for diagnosis of juvenile spondylolysis. However, localised CT is recommended as a supplementary examination in selected cases as a baseline for assessment of healing and for evaluation of indeterminate cases. (orig.)

  8. Innovative reconstruction algorithms in cardiac SPECT scintigraphy.

    Science.gov (United States)

    Zoccarato, O

    2012-06-01

    The recent entry into the market of some advanced iterative reconstruction algorithms (IA) optimized for bone and cardiac studies has raised a great interest among specialists in nuclear medicine. In particular, myocardial perfusion studies have received a significant boost thanks to the superior quality of images obtained with these new reconstruction methods. Differently from the filtered back-projection (FBP), the basic principles of the iterative reconstruction techniques are less known; unclear is the way by which the iterative methods are able to include compensations for the main degradation phenomena in SPECT imaging. Aim of this review is to provide a simple introduction to the iterative solution of the tomographic problem by using its matricial representation. This paper will also provide simple graphical examples of how phenomena such as attenuation and depth dependent resolution can be modelled in the projection operator. The main degrading factors in cardiac SPECT images will be retrieved along with some indication of the effectiveness of the corrections adopted. This step makes clear the noteworthy qualitative improvement obtained with these advanced algorithms. A brief summary of the main features of the most widespread new iterative reconstruction algorithms will be presented. The majority of manufacturers emphasize the reduction of acquisition times allowed by these innovative algorithms. Finally, because of the awareness of the increasing exposure of the population due to the increasing number of imaging studies with ionizing radiation, the use of these advanced algorithms to achieve a simultaneous reduction in patient dose and acquisition time will be also shown.

  9. Combined SPECT and Multidetector CT for Prostate Cancer Evaluations.

    Science.gov (United States)

    Aparici, Carina Mari; Carlson, David; Nguyen, Nhan; Hawkins, Randall A; Seo, Youngho

    2012-01-01

    (111)In-capromab pendetide is an imaging probe for noninvasive detection of prostate cancer dissemination, and can be difficult to interpret because of low photon statistics resulting in noisy images with limited anatomical precision. We examined if a 16-slice multidetector computed tomography (MDCT) combined with single photon emission computed tomography (SPECT) could increase the impact on the clinical management and improve confidence in SPECT image interpretations in comparison to a relatively low-mA (limited resolution) CT. 17 scans were reviewed from a SPECT combined with low-mA CT scanner; 21 scans were reviewed from a SPECT combined with 16-slice MDCT scanner. Reports of the clinical interpretations from the imaging studies, additional examinations performed by referring physicians as a follow-up to the imaging results, and long-term clinical and laboratory follow-ups were used to define confidence of the SPECT/CT readings and impact of the readings on the patient management. The impact was defined as: the occurrence of the (111)In-capromab pendetide interpretation resulted in additional imaging studies or biopsies. MDCT improved the quality and confidence in the characterization of small lymph nodes with or without uptake of (111)In-capromab pendetide. The increased confidence with MDCT in SPECT/CT readings was evident in all cases reviewed in this study, and the impact on the clinical management was higher (8 out of 21) using SPECT/MDCT than the impact using SPECT combined with low-mA CT (2 out of 17). The dual-modality SPECT/CT provides a quantifiable benefit when MDCT is used instead of low-mA CT, particularly for prostate cancer evaluations using (111)In-capromab pendetide.

  10. Sequential SPECT/CT imaging starting with stress SPECT in patients with left bundle branch block suspected for coronary artery disease.

    Science.gov (United States)

    Engbers, Elsemiek M; Timmer, Jorik R; Mouden, Mohamed; Knollema, Siert; Jager, Pieter L; Ottervanger, Jan Paul

    2017-01-01

    To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, pbundle branch block patients have abnormal stress-first SPECT. • Coronary CT excluded obstructive CAD in many LBBB patients with abnormal SPECT. • Stress-first SPECT imaging is not the optimal imaging protocol in LBBB patients. • In LBBB patients imaging with initial coronary CT may be more appropriate.

  11. Very low-activity stress/high-activity rest, single-day myocardial perfusion SPECT with a conventional sodium iodide camera and wide beam reconstruction processing.

    Science.gov (United States)

    DePuey, E Gordon; Ata, Pashmina; Wray, Rick; Friedman, Marvin

    2012-10-01

    A stress (S)/rest (R) 1-day Tc-99m sestamibi protocol is logistically advantageous and facilitates stress-only imaging. However, with conventional 370 MBq (10 mCi) S activity and subsequent 1,110-1,295 MBq (30-35 mCi) R activity there is a risk of S-to-R "shine-through" and underestimation of defect reversibility. New software methods cope with lower counting statistics and should allow for both a reduced S activity and also less likelihood of S-to-R "shine-through." 102 prospective patients [49 men, 53 women; mean weight 178 ± 41 lbs (range 98-265 lbs); chest 41.5″ ± 4.0″ (range 32″-52″)] received 192.4 + 18.5 MBq (5.2 ± 0.5 mCi) Tc-99m sestamibi S (25 exercise, 77 regadenoson) activity followed in 30-40 minutes by "full-time" (12 minutes) two-headed NaI camera S SPECT. Immediately thereafter, a 16-minute S SPECT acquisition was also performed in 37/102 patients. Then at 60-80 minute post-S all patients received 1328.3 + 129.5 MBq (35.9 ± 3.5 mCi) Tc-99m sestamibi, and "half-time" (7.5 minutes) R SPECT was acquired. All tomograms were processed with wide beam reconstruction (WBR, UltraSPECT Ltd.) software. A time-adjusted R/S myocardial count density ratio (MCDR) was calculated using automated software. S SPECT quality was visually graded (poor, fair, good, excellent) based upon myocardial definition, cavity contrast, RV visualization, and noise. For comparison, the S/R MCDR was calculated in 581 consecutive patients undergoing a conventional 370 MBq R/1110 MBq S (10 mCi R/30 mCi S) protocol. S SPECT was normal in 44 patients (43%). Image quality was good-excellent in 93 (91%) patients with 12-minute S SPECT. Also in 37 (98%) patients with 16-minute S SPECT, quality was good-excellent. In patients with >42″ chests 12-minute S SPECT quality worsened with increasing chest circumference, manifested by myocardial "blurring." Image quality improved by ≥1 grade in the 12/37 patients (32%) also undergoing 16-minute S SPECT. The time- and decay

  12. Incremental value of (99m)Tc-HYNIC-TOC SPECT/CT over whole-body planar scintigraphy and SPECT in patients with neuroendocrine tumours.

    Science.gov (United States)

    Trogrlic, Mate; Težak, Stanko

    2017-06-12

    The aim of this study was to evaluate the additional value of (99m)Tc-HYNIC-TOC SPECT/CT over planar whole-body (WB) scintigraphy and SPECT alone in the detection and accurate localisation of neuroendocrine tumour (NET) lesions. This study included 65 patients with a definitive histological diagnosis of NET prior to scintigraphy. Planar WB scintigraphy, SPECT, and SPECT/CT images were acquired at 4 h post-administration of 670 MBq (99m)Tc-HYNIC-TOC. Additional SPECT images at 10 min after tracer administration were also acquired. Clinical and imaging follow-up findings were considered as the reference standards (minimum follow-up period, 15 months). Patient and lesion-based analyses of the efficacies of the imaging modalities were performed. While 38 patients exhibited metastasis of NETs, 27 presented no evidence of metastasis. Upon patient-based analysis, the sensitivity and specificity of SPECT/CT were found to be 88.9 and 79.3 %, respectively. The diagnostic accuracies of WB scintigraphy, 4h-SPECT, and SPECT/CT were 72.3, 73.8, and 84.6 %, respectively. The area under curve (AUC) value for SPECT/CT (0.84) was the highest, followed by those for 4h-SPECT (0.75) and WB scintigraphy (0.74). The accuracy and AUC values of SPECT/CT were significantly better compared to those of WB scintigraphy (p < 0.001), 10 min-SPECT (p < 0.001), and 4 h-SPECT (p = 0.001). The findings of SPECT/CT led to the change in treatment plan of 11 patients (16.9 %). The sensitivity and diagnostic accuracy of SPECT/CT in the evaluation of NET lesions outperforms planar WB imaging or SPECT alone.

  13. SU-F-J-08: Quantitative SPECT Imaging of Ra-223 in a Phantom

    Energy Technology Data Exchange (ETDEWEB)

    Yue, J; Hobbs, R; Sgouros, G; Frey, E [Johns Hopkins University Baltimore, MD (United States)

    2016-06-15

    Purpose: Ra-223 therapy of prostate cancer bone metastases is being used to treat patients routinely. However, the absorbed dose distribution at the macroscopic and microscopic scales remains elusive, due to the inability to image the small activities injected. Accurate activity quantification through imaging is essential to calculate the absorbed dose in organs and sub-units in radiopharmaceutical therapy, enabling personalized absorbed dose-based treatment planning methodologies and more effective and optimal treatments. Methods: A 22 cm diameter by 20 cm long cylindrical phantom, containing a 3.52 cm diameter sphere, was used. A total of 2.01 MBq of Ra-223 was placed in the phantom with 177.6 kBq in the sphere. Images were acquired on a dual-head Siemens Symbia T16 gamma camera using three 20% full-width energy windows and centered at 84, 154, and 269 keV (120 projections, 360° rotation, 45 s per view). We have implemented reconstruction of Ra-223 SPECT projections using OS-EM (up to 20 iterations of 10 subsets) with compensation for attenuation using CT-based attenuation maps, collimator-detector response (CDR) (including septal penetration, scatter and Pb x-ray modeling), and scatter in the patient using the effective source scatter estimation (ESSE) method. The CDR functions and scatter kernels required for ESSE were computed using the SIMIND MC simulation code. All Ra-223 photon emissions as well as gamma rays from the daughters Rn-219 and Bi-211 were modeled. Results: The sensitivity of the camera in the three combined windows was 107.3 cps/MBq. The visual quality of the SPECT images was reasonably good and the activity in the sphere was 27% smaller than the true activity. This underestimation is likely due to partial volume effect. Conclusion: Absolute quantitative Ra-223 SPECT imaging is achievable with careful attention to compensate for image degrading factors and system calibration.

  14. Visual evaluation of I-123-betamethyliodophenylpentadecanoic acid (BMIPP) myocardial SPECT findings in hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Bunko, Hisashi; Tonami, Norihisa; Hisada, Kinichi (Kanazawa Univ. (Japan). School of Medicine)

    1993-03-01

    I-123-betamethyliodophenylpentadecanoic acid (BMIPP) is a branched fatty acid analogue for the imaging of myocardial metabolism. Seventeen patients with hypertrophic cardiomyopathy (HCM) and 17 patients with ischemic or valvular heart diseases (non-HCMs) were studied to evaluate the characteristic findings of the BMIPP myocardial images in HCM. Early (20 min) and delayed (3 hr) images were obtained after intravenous injection of 111 MBq of BMIPP with 3-headed SPECT. Tl-201 myocardial SPECT was also obtained within a week of BMIPP SPECT. Regional myocardial uptake of BMIPP relative to Tl-201 and its serial change from early to delayed images were visually evaluated in patient basis as well as segmental basis. Decreased uptake of BMIPP in HCM was frequently seen in anterior, septal, apical and inferior wall. Relatively decreased myocardial uptake of BMIPP (type H+B) was seen in 14 patients (82%) of HCM which was significantly higher than non-HCMs (12%, p<0.001). Number of segments with type H+B was higher in HCM than non-HCMs (mean: 4.59 vs 0.53, p<0.001). This relative decrease of BMIPP uptake was frequently seen in hypertrophied segments of HCM (71%, p<0.01). Serial decrease of regional BMIPP uptake was also frequently seen in HCM especially in hypertrophied myocardium than non-HCMs (76% vs 41%, p<0.01). This was concordant with segmental analysis (mean: 3.41 vs 1.06, p<0.01). Significant decrease in BMIPP image quality in HCM was concordant with higher frequency of serial decrease of BMIPP in HCM. In conclusion, HCM patients frequently showed abnormality of BMIPP uptake and retention which indicated the presence of metabolic abnormality in hypertrophied myocardium. (author).

  15. Is SPECT or CT Based Attenuation Correction More Quantitatively Accurate for Dedicated Breast SPECT Acquired with Non-Traditional Trajectories?

    Science.gov (United States)

    Perez, Kristy L.; Mann, Steve D.; Pachon, Jan H.; Madhav, Priti; Tornai, Martin P.

    2015-01-01

    Attenuation correction is necessary for SPECT quantification. There are a variety of methods to create attenuation maps. For dedicated breast SPECT imaging, it is unclear if either SPECT- or CT-based attenuation map would provide the most accurate quantification and whether or not segmenting the different tissue types will have an effect on the qunatification. For these experiments, 99mTc diluted in methanol and water was filled into geometric and anthropomorphic breast phantoms and was imaged with a dedicated dual-modality SPECT-CT scanner. SPECT images were collected using a compact CZT camera with various 3D acquisitions including vertical and 30° tilted parallel beam, and complex sinusoidal trajectories. CT images were acquired using a quasi-monochromatic x-ray source and CsI(T1) flat panel digital detector in a half-cone beam geometry. Measured scatter correction for SPECT and CT were implemented. To compare photon attenuation correction in the reconstructed SPECT images, various volumetric attenuation matrices were derived from 1) uniform SPECT, 2) uniform CT, and 3) segmented CT, populated with different attenuation coefficient values. Comparisons between attenuation masks using phantoms consisting of materials with different attenuation values show that at 140 keV the differences in the attenuation between materials do not affect the quantification as much as the size and alignment of the attenuation map. The CT-based attenuation maps give quantitative values 30% below the actual value, but are consistent. While the SPECT-based attenuation maps can provide within 10% accurate quantitative values, but are less consistent. PMID:25999683

  16. Using Rose's metal alloy as a pinhole collimator material in preclinical small-animal imaging: a Monte Carlo evaluation.

    Science.gov (United States)

    Peterson, Mikael; Strand, Sven-Erik; Ljungberg, Michael

    2015-04-01

    Pinhole collimation is the most common method of high-resolution preclinical single photon emission computed tomography imaging. The collimators are usually constructed from dense materials with high atomic numbers, such as gold and platinum, which are expensive and not always flexible in the fabrication step. In this work, the authors have investigated the properties of a fusible alloy called Rose's metal and its potential in pinhole preclinical imaging. When compared to current standard pinhole materials such as gold and platinum, Rose's metal has a lower density and a relatively low effective atomic number. However, it is inexpensive, has a low melting point, and does not contract when solidifying. Once cast, the piece can be machined with high precision. The aim of this study was to evaluate the imaging properties for Rose's metal and compare them with those of standard materials. After validating their Monte Carlo code by comparing its results with published data and the results from analytical calculations, they investigated different pinhole geometries by varying the collimator material, acceptance angle, aperture diameter, and photon incident angle. The penetration-to-scatter and penetration-to-total component ratios, sensitivity, and the spatial resolution were determined for gold, tungsten, and Rose's metal for two radionuclides, (99)Tc(m) and (125)I. The Rose's metal pinhole-imaging simulations show higher penetration/total and scatter/total ratios. For example, the penetration/total is 50% for gold and 75% for Rose's metal when simulating (99)Tc(m) with a 0.3 mm aperture diameter and a 60° acceptance angle. However, the degradation in spatial resolution remained below 10% relative to the spatial resolution for gold for acceptance angles below 40° and aperture diameters larger than 0.5 mm. Extra penetration and scatter associated with Rose's metal contribute to degradation in the spatial resolution, but this degradation is not always substantial. The

  17. An innovative multimodality approach for sentinel node mapping and biopsy in head and neck malignancies

    NARCIS (Netherlands)

    Borbón-Arce, M.; Brouwer, O. R.; van den Berg, N. S.; Mathéron, H.; Klop, W. M. C.; Balm, A. J. M.; van Leeuwen, F. W. B.; Valdés-Olmos, R. A.

    2014-01-01

    Purpose: Recent innovations such as preoperative SPECT/CT, intraoperative imaging using portable devices and a hybrid tracer were evaluated in a multimodality approach for sentinel node (SN) mapping and biopsy in head and neck malignancies. Material and methods: The evaluation included 25

  18. SPECT/CT in the Diagnosis of Skull Base Osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Damle, Nishikant Avinash; Kumar, Rakesh; Kumar, Praveen; Jaganthan, Sriram; Patnecha, Manish; Bal, Chandrasekhar; Bandopadhyaya, Gurupad; Malhotra, Arun [All India Institute of Medical Sciences, New Delhi (India)

    2011-09-15

    Skull base osteomyelitis is a potentially fatal disease. We demonstrate here the utility of SPECT/CT in diagnosing this entity, which was not obvious on a planar bone scan. A {sup 99mT}c MDP bone scan with SPECT/CT was carried out on a patient with clinically suspected skull base osteomyelitis. Findings were correlated with contrast enhanced CT (CECT) and MRI. Planar images were equivocal, but SPECT/CT showed intense uptake in the body of sphenoid and petrous temporal bone as well as the atlas corresponding to irregular bone destruction on CT and MRI. These findings indicate that SPECT/CT may have an additional role beyond planar imaging in the detection of skull base osteomyelitis.

  19. The value of SPECT/CT in carpal boss

    Energy Technology Data Exchange (ETDEWEB)

    Bhure, Ujwal; Huellner, Martin W.; Gruenig, Hannes; Zander, Andrea; Sol Perez Lago, Maria del; Strobel, Klaus [Cantonal Hospital Lucerne, Nuclear Medicine and Radiology, Lucerne (Switzerland); Hug, Urs [Cantonal Hospital Lucerne, Department of Hand and Plastic Surgery, Lucerne (Switzerland)

    2015-11-15

    To assess the value of SPECT/CT in patients with carpal boss (CB). In 24 wrists with CB (18 right-sided, 6 left-sided) in 21 patients, planar images and SPECT/CT images were obtained. Three patients had bilateral CB. The grade of uptake (0 absent, 1 low, 2 moderate, 3 high) on planar imaging and SPECT/CT was assessed and compared with CT findings, clinical symptoms and follow-up findings. CB affected carpometacarpal joint II in 4 wrists, carpometacarpal joint III in 17 wrists and both carpometacarpal joints II and III in 3 wrists. Of the 24 CB, 12 (50 %) were active (i.e. increased radionuclide uptake) on planar images and 18 (75 %) on SPECT/CT images. Of the 17 symptomatic CB, 10 (59 %) were active on planar images and 14 (82 %) were active (mean grade 1.9, range 1 - 3) on SPECT/CT images. Of the 7 asymptomatic CB, 2 were active on planar images and 4 were active (mean grade 1.25, range 1 - 2) on SPECT/CT images. CT alone showed CB in all patients and an accessory ossicle (os styloideum) in 8 wrists. MR imaging was available in 7 patients and positive for CB in 5 (sensitivity 71 %). Plain radiographs were available in 17 patients and positive in 10 (59 %). Therapeutic infiltration of the CB was performed in 9 patients, and resection of the CB in 7 patients. SPECT/CT provides important morphological and metabolic information for the clinical assessment of CB, but because SPECT/CT tends to overestimate the clinical importance of CB, we recommend that planar images should still be obtained. (orig.)

  20. Efficacy of (99m)Tc-EDDA/HYNIC-TOC SPECT/CT scintigraphy in Graves' ophthalmopathy.

    Science.gov (United States)

    Zhao, Rong; Wang, Jiang; Deng, Jinglan; Yang, Weidong; Wang, Jing

    2012-01-01

    The aim of this study was to investigate the predictive role of the orbital somatostatin receptor scintigraphy with (99m)Tc-EDDA/HYNIC-TOC ((99m)Tc-TOC) to detect clinical stage of Graves' ophthalmopathy and the response to corticosteroid therapy. The subjects of the experiment were 46 patients with Graves' ophthalmopathy (GO) and four volunteers without eye disease or GO as the normal group (NG). Single photon emission computed tomography (SPECT), computed tomography (CT) and the left and right lateral position planar imaging of the heads of the all subjects were obtained 4 h after the intravenous injection of 555 MBq of (99m)Tc-TOC. The (99m)Tc-TOC SPECT/CT was repeated 3 months later. 35 (35/46) patients were received corticosteroid therapy (prednisolone, 10 mg po tid ) for 3 months, however, the other 11 patients as control groups did not receive any treatment. The treatment effect was evaluated both by the orbital (99m)Tc-TOC uptake and NOSPECS. A significant decrease in the O/OC ratio was observed in 22 GO patients between pre- and post-treatment (1.64 ± 0.13 vs. 1.21 ± 0.09, P TOC scintigraphy is a feasible technique to estimate the Graves' ophthalmopathy activity and predict the response to subsequent corticosteroid therapy in GO patients. The technique could be a useful tool for physicians not familiar with CAS determination.

  1. Evaluation of the therapeutic effect of hyperbaric oxygenation and erythropoietin in the treatment of chronic heart failure using myocardial perfusion scintigraphy G-SPECT

    Directory of Open Access Journals (Sweden)

    Baškot Branislav

    2009-01-01

    Full Text Available Background. The most important predictors of longterm survival in patients with cardiac ischemic disease are left ventricular ejection fraction, left ventricular volumes, infarction size, presence and extent of residual myocardial ischemia. One of the most important recent developments in single photon emission computed tomography (SPECT myocardial perfusion imaging is the ability to acquire these studies in conjunction with electrocardiogram (ECG gating (G-SPECT. The ability to asses radionuclide myocardial perfusion and function with ECG G-SPECT imaging has revolutionized this field of nuclear cardiology. Study with G-SPECT development algorithms permits to quantify measures of left ventricular (LV volume, ejection fraction (LVEF and even regional myocardial wall motion and thickening. The American Society of Nuclear Cardiology (ASNC in its position paper from March 1999 recommends the routine incorporation of G-SPECT during cardiac perfusion scintigraphy. Case report. We presented a 70-year-old male with ischemic heart disease (dilatative, cardiomyopathy and absolute arrhythmia. He was few times hospitally treated by medicamentous therapy with no evidence of improvement. After hospital treatment, we included hyperbaric oxygenation (HBO and erythropoietin injections. Hyperbaric oxygenation was carried out in a monoplace hyperbaric chamber, BLK S-303, by a graduated protocol for patients with severe heart insufficiency, totally 15 treatments. Recombinant erythropoietin beta (RecormonR F. Hoffmann-La Roche was applied deeply subcutaneously, every second day from 2 000 IU to totally 16 000 IU. Before the therapy G-SPECT study was performed with 99m technetium-MIBI, and we obtained the functional parameters and perfusion of the left ventricle to follow-up the therapy effects. The study was performed by an ADAC-VERTEX PLUS-EPIC two-head gamma camera with dedicated quantitatively algorithm Auto-QUANT. The results of LVEF were 15%, with severity

  2. PET/SPECT imaging: From carotid vulnerability to brain viability

    Energy Technology Data Exchange (ETDEWEB)

    Meerwaldt, Robbert [Department of Surgery, Isala Clinics, Zwolle (Netherlands); Slart, Riemer H.J.A. [Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen (Netherlands); Dam, Gooitzen M. van [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands); Luijckx, Gert-Jan [Department of Neurology, University Medical Center Groningen, Groningen (Netherlands); Tio, Rene A. [Department of Cardiology, University Medical Center Groningen, Groningen (Netherlands); Zeebregts, Clark J. [Department of Surgery, University Medical Center Groningen, Groningen (Netherlands)], E-mail: czeebregts@hotmail.com

    2010-04-15

    Background: Current key issues in ischemic stroke are related to carotid plaque vulnerability, brain viability, and timing of intervention. The treatment of ischemic stroke has evolved into urgent active interventions, as 'time is brain'. Functional imaging such as positron emission tomography (PET)/single photon emission computed tomography (SPECT) could improve selection of patients with a vulnerable plaque and evaluation of brain viability in ischemic stroke. Objective: To describe the current applications of PET and SPECT as a diagnostic tool in relation to ischemic stroke. Methods: A literature search using PubMed identified articles. Manual cross-referencing was also performed. Results: Several papers, all observational studies, identified PET/SPECT to be used as a tool to monitor systemic atheroma modifying treatment and to select high-risk patients for surgery regardless of the degree of luminal stenosis in carotid lesions. Furthermore, PET/SPECT is able to quantify the penumbra region during ischemic stroke and in this way may identify those patients who may benefit from timely intervention. Discussion: Functional imaging modalities such as PET/SPECT may become important tools for risk-assessment and evaluation of treatment strategies in carotid plaque vulnerability and brain viability. Prospective clinical studies are needed to evaluate the diagnostic accuracy of PET/SPECT.

  3. The Neuroactivation of Cognitive Processes Investigated with SPECT

    Directory of Open Access Journals (Sweden)

    Daniela Montaldi

    2000-01-01

    Full Text Available The last ten years have seen the development and expansion of an exciting new field of neuroscientific research; functional mapping of the human brain. Whilst many of the questions addressed by this area of research could be answered using SPECT, relatively few SPECT activation studies of this kind have been carried out. The present paper combines an evaluation of SPECT procedures used for neuroactivation studies, and their comparison with other imaging modalities (i.e., PET and fMRI, with a review of SPECT neuroactivation studies that yield information concerning normal brain function with a particular emphasis on the brain activations produced by memory processing. The paper aims to describe and counter common misunderstandings regarding potential limitations of the SPECT technique, to explain and illustrate which SPECT procedures best fulfill the requirements of a neuroactivation study, and how best to obtain information about normal brain function (whether using normal healthy subjects or patients and finally to highlight SPECT’s potential future role in the functional mapping of the human brain.

  4. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay ...

  5. Pinhole cameras as sensors for atomic oxygen in orbit; application to attitude determination of the LDEF

    Science.gov (United States)

    Peters, Palmer N.; Gregory, John C.

    1991-01-01

    Images produced by pinhole cameras using film sensitive to atomic oxygen provide information on the ratio of spacecraft orbital velocity to the most probable thermal speed of oxygen atoms, provided the spacecraft orientation is maintained stable relative to the orbital direction. Alternatively, as it is described, information on the spacecraft attitude relative to the orbital velocity can be obtained, provided that corrections are properly made for thermal spreading and a co-rotating atmosphere. The LDEF orientation, uncorrected for a co-rotating atmosphere, was determined to be yawed 8.0 minus/plus 0.4 deg from its nominal attitude, with an estimated minus/plus 0.35 deg oscillation in yaw. The integrated effect of inclined orbit and co-rotating atmosphere produces an apparent oscillation in the observed yaw direction, suggesting that the LDEF attitude measurement will indicate even better stability when corrected for a co-rotating atmosphere. The measured thermal spreading is consistent with major exposure occurring during high solar activity, which occurred late during the LDEF mission.

  6. Initial operation of the tangential x-ray pinhole camera system for KSTAR plasma

    Science.gov (United States)

    Jang, Siwon; Lee, S. G.; Moon, M. K.; Lim, C. H.; Lee, S. H.; Choe, Wonho; Kstar Team; Korea Advanced Institute Of Science; Technology Team; National Fusion Research Institute Collaboration; Korea Atomic Energy Research Institute Collaboration

    2011-10-01

    The tangential soft x-ray pinhole camera (TXPC), which is a fast, two-dimensional (2-D), soft x-ray imaging system with a toroidal view, has been developed for studying MHD activities and transport in KSTAR plasmas. It consists of 50x50 channels multi-wire proportional counter (MWPC) filled with a gas mixture of 78% Kr, 20% C2H6, and 2% CF4 at atmospheric pressure. It can measure 2-D x-ray emissivity with a high and controllable intrinsic gain (> 104) , high spatial ( 100 kHz) resolution with a 100 MHz DAQ system. They can assist analysis of plasma profile, MHD modes, localization and effects of auxiliary heating and transport phenomena from core to edge. Also, the TXPC employs a duplex multi-wire proportional x-ray (DMPX) detector that combines two MWPCs in series. It will provide simultaneous measurements of plasma x-ray emission in two spectral ranges using the first MWPC as an absorber filter for the second one. The signals of the first and the second MWPC allow providing the fast 2-D measurement of the plasma electron temperature. The TXPC system is installed on KSTAR in 2011, and initial plasma data and an assessment of the system performance are presented.

  7. Ion pinhole imaging diagnostics on fast ion source in femtosecond laser plasma of cluster targets.

    Science.gov (United States)

    Makarov, Sergey; Pikuz, Sergey; Faenov, Anatoly; Pikuz, Tatiana; Fukuda, Yuji; Skobelev, Igor; Zhvaniya, Irina; Varzar, Sergey; Kando, Masaki; Kodama, Ryousuke

    2017-07-10

    The spatial configuration of the ion source generated under femtosecond laser interaction with clusters is investigated. While intense laser pulses (36 fs, 60 mJ, intensity of 4 × 1017 W/cm2) propagated in CO2 cluster (~0.22 μm in diameter) media, the shape of the obtained plasma ion source was registered for the first time by means of pinhole imaging method. The remarkable decrease in fast ion yield in the vicinity of the assumed best laser focus near the gas cluster jet axis is observed. Such observed anisotropy of the ion source is suggested to originate from the influence of the laser prepulse destroying clusters in advance to the arrival of the main pulse. The assumption is confirmed by optical shadowgraphy images of the plasma channel and is important for further development of an efficient laser-plasma-based fast ion source. Following the observed geometry of the ion source, the laser intensity limit allowing to accelerate ions to ~100 keV energy range was estimated.

  8. Novel energy resolving x-ray pinhole camera on Alcator C-Moda)

    Science.gov (United States)

    Pablant, N. A.; Delgado-Aparicio, L.; Bitter, M.; Brandstetter, S.; Eikenberry, E.; Ellis, R.; Hill, K. W.; Hofer, P.; Schneebeli, M.

    2012-10-01

    A new energy resolving x-ray pinhole camera has been recently installed on Alcator C-Mod. This diagnostic is capable of 1D or 2D imaging with a spatial resolution of ≈1 cm, an energy resolution of ≈1 keV in the range of 3.5-15 keV and a maximum time resolution of 5 ms. A novel use of a Pilatus 2 hybrid-pixel x-ray detector [P. Kraft et al., J. Synchrotron Rad. 16, 368 (2009), 10.1107/S0909049509009911] is employed in which the lower energy threshold of individual pixels is adjusted, allowing regions of a single detector to be sensitive to different x-ray energy ranges. Development of this new detector calibration technique was done as a collaboration between PPPL and Dectris Ltd. The calibration procedure is described, and the energy resolution of the detector is characterized. Initial data from this installation on Alcator C-Mod is presented. This diagnostic provides line-integrated measurements of impurity emission which can be used to determine impurity concentrations as well as the electron energy distribution.

  9. Approximately 800-nm-Thick Pinhole-Free Perovskite Films via Facile Solvent Retarding Process for Efficient Planar Solar Cells.

    Science.gov (United States)

    Yuan, Zhongcheng; Yang, Yingguo; Wu, Zhongwei; Bai, Sai; Xu, Weidong; Song, Tao; Gao, Xingyu; Gao, Feng; Sun, Baoquan

    2016-12-21

    Device performance of organometal halide perovskite solar cells significantly depends on the quality and thickness of perovskite absorber films. However, conventional deposition methods often generate pinholes within ∼300 nm-thick perovskite films, which are detrimental to the large area device manufacture. Here we demonstrated a simple solvent retarding process to deposit uniform pinhole free perovskite films with thicknesses up to ∼800 nm. Solvent evaporation during the retarding process facilitated the components separation in the mixed halide perovskite precursors, and hence the final films exhibited pinhole free morphology and large grain sizes. In addition, the increased precursor concentration after solvent-retarding process led to thick perovskite films. Based on the uniform and thick perovskite films prepared by this convenient process, a champion device efficiency up to 16.8% was achieved. We believe that this simple deposition procedure for high quality perovskite films around micrometer thickness has a great potential in the application of large area perovskite solar cells and other optoelectronic devices.

  10. Importance of SPECT/CT for resolving diseases of the jaw; Stellenwert der SPECT/CT zur Abklaerung von Kiefererkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, K.; Huellner, M.W.; Bolouri, C.; Veit-Haibach, P.; Sol Perez-Lago, M. del [Luzerner Kantonsspital, Institut fuer Nuklearmedizin und Roentgendiagnostik, Luzern (Switzerland); Merwald, M.; Kuttenberger, J. [Luzerner Kantonsspital, Klinik fuer Mund-, Kiefer- und Gesichtschirurgie, Luzern (Switzerland)

    2012-07-15

    Diseases of the jaw, such as osteomyelitis, condylar hyperactivity and tumors need adequate imaging to evaluate the extension and activity for therapy planning. Conventional planar scintigraphy, orthopantomography, computed tomography (CT) and magnetic resonance imaging (MRI) can be used for the evaluation of jaw diseases. Single photon emission computed tomography/computed tomography (SPECT/CT) provides metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals. The SPECT/CT is superior to planar scintigraphy alone, CT and orthopantomography in the evaluation of the extension and activity of osteomyelitis and jaw tumors. In our hospital SPECT/CT has replaced the other imaging modalities in the evaluation of osteomyelitis and condylar hyperactivity. If available SPECT/CT should be performed for the evaluation of osteomyelitis of the jaw. (orig.) [German] Kiefererkrankungen wie Osteomyelitis, kondylaere Hyperaktivitaet und Kiefertumoren benoetigen eine exakte bildgebende Abklaerung, um die Therapie adaequat planen zu koennen. Die klassische planare Skelettszintigraphie, Orthopantomographie, CT und MRT koennen zur Abklaerung von Kiefererkrankungen eingesetzt werden. Die ''single photon emission computed tomography''/CT (SPECT/CT) bietet metabolische und morphologische Informationen in einem Untersuchungsgang und ist zunehmend in groesseren Kliniken verfuegbar. Die SPECT/CT ist zur Beurteilung der Ausbreitung und Aktivitaet einer Osteomyelitis und von Kiefertumoren der planaren Szintigraphie alleine, der CT und der Orthopantomographie ueberlegen. In unserer Klinik hat die SPECT/CT die bisherigen Verfahren zur Beurteilung der Kieferosteomyelitis und kondylaeren Hyperaktivitaet abgeloest. Sofern verfuegbar, sollte zur Abklaerung einer Kieferosteomyelitis die SPECT/CT eingesetzt werden. (orig.)

  11. Sequential SPECT/CT imaging starting with stress SPECT in patients with left bundle branch block suspected for coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Engbers, Elsemiek M.; Mouden, Mohamed [Isala, Department of Cardiology, Zwolle (Netherlands); Isala, Department of Nuclear Medicine, Zwolle (Netherlands); Timmer, Jorik R.; Ottervanger, Jan Paul [Isala, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Jager, Pieter L. [Isala, Department of Nuclear Medicine, Zwolle (Netherlands)

    2017-01-15

    To investigate the impact of left bundle branch block (LBBB) on sequential single photon emission computed tomography (SPECT)/ CT imaging starting with stress-first SPECT. Consecutive symptomatic low- to intermediate-risk patients without a history of coronary artery disease (CAD) referred for SPECT/CT were included from an observational registry. If stress SPECT was abnormal, additional rest SPECT and, if feasible, coronary CT angiography (CCTA) were acquired. Of the 5,018 patients, 218 (4.3 %) demonstrated LBBB. Patients with LBBB were slightly older than patients without LBBB (65±12 vs. 61±11 years, p<0.001). Stress SPECT was more frequently abnormal in patients with LBBB (82 % vs. 46 %, p<0.001). After reviewing stress and rest images, SPECT was normal in 43 % of the patients with LBBB, compared to 77 % of the patients without LBBB (p<0.001). Sixty-four of the 124 patients with LBBB and abnormal stress-rest SPECT underwent CCTA (52 %), which could exclude obstructive CAD in 46 of the patients (72 %). Sequential SPECT/CT imaging starting with stress SPECT is not the optimal imaging protocol in patients with LBBB, as the majority of these patients have potentially false-positive stress SPECT. First-line testing using CCTA may be more appropriate in low- to intermediate-risk patients with LBBB. (orig.)

  12. Preclinical imaging characteristics and quantification of Platinum-195m SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Aalbersberg, E.A.; Wit-van der Veen, B.J. de; Vegt, E.; Vogel, Wouter V. [The Netherlands Cancer Institute (NKI-AVL), Department of Nuclear Medicine, Amsterdam (Netherlands); Zwaagstra, O.; Codee-van der Schilden, K. [Nuclear Research and Consultancy Group (NRG), Petten (Netherlands)

    2017-08-15

    In vivo biodistribution imaging of platinum-based compounds may allow better patient selection for treatment with chemo(radio)therapy. Radiolabeling with Platinum-195m ({sup 195m}Pt) allows SPECT imaging, without altering the chemical structure or biological activity of the compound. We have assessed the feasibility of {sup 195m}Pt SPECT imaging in mice, with the aim to determine the image quality and accuracy of quantification for current preclinical imaging equipment. Enriched (>96%) {sup 194}Pt was irradiated in the High Flux Reactor (HFR) in Petten, The Netherlands (NRG). A 0.05 M HCl {sup 195m}Pt-solution with a specific activity of 33 MBq/mg was obtained. Image quality was assessed for the NanoSPECT/CT (Bioscan Inc., Washington DC, USA) and U-SPECT{sup +}/CT (MILabs BV, Utrecht, the Netherlands) scanners. A radioactivity-filled rod phantom (rod diameter 0.85-1.7 mm) filled with 1 MBq {sup 195m}Pt was scanned with different acquisition durations (10-120 min). Four healthy mice were injected intravenously with 3-4 MBq {sup 195m}Pt. Mouse images were acquired with the NanoSPECT for 120 min at 0, 2, 4, or 24 h after injection. Organs were delineated to quantify {sup 195m}Pt concentrations. Immediately after scanning, the mice were sacrificed, and the platinum concentration was determined in organs using a gamma counter and graphite furnace - atomic absorption spectroscopy (GF-AAS) as reference standards. A 30-min acquisition of the phantom provided visually adequate image quality for both scanners. The smallest visible rods were 0.95 mm in diameter on the NanoSPECT and 0.85 mm in diameter on the U-SPECT{sup +}. The image quality in mice was visually adequate. Uptake was seen in the kidneys with excretion to the bladder, and in the liver, blood, and intestine. No uptake was seen in the brain. The Spearman correlation between SPECT and gamma counter was 0.92, between SPECT and GF-AAS it was 0.84, and between GF-AAS and gamma counter it was0.97 (all p < 0

  13. Inverse Modelling to Obtain Head Movement Controller Signal

    Science.gov (United States)

    Kim, W. S.; Lee, S. H.; Hannaford, B.; Stark, L.

    1984-01-01

    Experimentally obtained dynamics of time-optimal, horizontal head rotations have previously been simulated by a sixth order, nonlinear model driven by rectangular control signals. Electromyography (EMG) recordings have spects which differ in detail from the theoretical rectangular pulsed control signal. Control signals for time-optimal as well as sub-optimal horizontal head rotations were obtained by means of an inverse modelling procedures. With experimentally measured dynamical data serving as the input, this procedure inverts the model to produce the neurological control signals driving muscles and plant. The relationships between these controller signals, and EMG records should contribute to the understanding of the neurological control of movements.

  14. Radiotracers for SPECT imaging. Current scenario and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Adak, S.; Vijaya Raj, K.K.; Mandal, S. [GE Healthcare Medical Diagnostics, John F. Welch Technology Center, Bangalore (India).; Bhalla, R.; Pickett, R.; Luthra, S.K. [GE Healthcare Medical Diagnostics, The Grove Centre, Amersham (United Kingdom)

    2012-07-01

    Single photon emission computed tomography (SPECT) has been the cornerstone of nuclear medicine and today it is widely used to detect molecular changes in cardiovascular, neurological and oncological diseases. While SPECT has been available since the 1980s, advances in instrumentation hardware, software and the availability of new radiotracers that are creating a revival in SPECT imaging are reviewed in this paper. The biggest change in the last decade has been the fusion of CT with SPECT, which has improved attenuation correction and image quality. Advances in collimator design, replacement of sodium iodide crystals in the detectors with cadmium zinc telluride (CZT) detectors as well as advances in software and reconstruction algorithms have all helped to retain SPECT as a much needed and used technology. Today, a wide spectrum of radiotracers is available for use in cardiovascular, neurology and oncology applications. The development of several radiotracers for neurological disorders is briefly described in this review, including [{sup 123}I]FP-CIT (DaTSCAN trademark) available for Parkinson's disease. In cardiology, while technetium-99m labeled tetrofosmin and technetium-99m labeled sestamibi have been well known for myocardial perfusion imaging, we describe a recently completed multicenter clinical study on the use of [{sup 123}I]mIBG (AdreView trademark) for imaging in chronic heart failure patients. For oncology, while bone scanning has been prevalent, newer radiotracers that target cancer mechanisms are being developed. Technetium-99m labeled RGD peptides have been reported in the literature that can be used for imaging angiogenesis, while technetium-99m labeled duramycin has been used to image apoptosis. While PET/CT is considered to be the more advanced technology particularly for oncology applications, SPECT continues to be the modality of choice and the workhorse in many hospitals and nuclear medicine centers. The cost of SPECT instruments also

  15. Proceedings of clinical SPECT (single photon emission computed tomography) symposium

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which demand awareness and attention in order to make SPECT operational in clinical practice. These include selection of equipment, details of uniformity correction, utilization of phantoms for equipment acceptance and quality assurance, the major aspect of algorithms, an understanding of filtered back projection and appropriate choice of filters and an awareness of the most commonly generated artifacts and how to recognize them. With respect to the acquisition and interpretation of organ images, the faculty will present information on the major aspects of hepatic, brain, cardiac, skeletal, and immunologic imaging techniques. Individual papers are processed separately for the data base. (TEM)

  16. Effects of scatter and attenuation correction on quantitative assessment of regional cerebral blood flow with SPECT.

    Science.gov (United States)

    Iida, H; Narita, Y; Kado, H; Kashikura, A; Sugawara, S; Shoji, Y; Kinoshita, T; Ogawa, T; Eberl, S

    1998-01-01

    Appropriate corrections for scatter and attenuation correction are prerequisites for quantitative SPECT studies. However, in most cerebral SPECT studies, uniform attenuation in the head is assumed, and scatter is usually neglected. This study evaluated the effect of attenuation correction and scatter correction on quantitative values and image contrast. Studies were performed in six normal volunteers (ages 22-26 yr) following intravenous 123I-IMP administration using a rotating, dual-head gamma camera. A transmission scan was acquired with a 99mTc rod source (74 MBq) placed at the focus of a symmetrical fanbeam collimator. Data were reconstructed using two attenuation coefficient (mu) maps: quantitative mu map from the transmission scan and a uniform mu map generated by edge detection of the reconstructed images. Narrow and broad beam mu values were used with and without scatter correction, respectively. Scatter was corrected with transmission-dependent convolution subtraction and triple-energy window techniques. Quantitative rCBF images were calculated by the previously validated IMP-autoradiographic technique, and they were compared with those obtained by (15)O-water and PET. SPECT and PET images were registered to MRI studies, and rCBF values were compared in 39 ROIs selected on MRI. Clear differences were observed in rCBF images between the measured and constant mu maps in the lower slices due to the airways and in the higher slices due to increased skull attenuation. However, differences were white matter regions by 10%-20% after scatter correction, increasing gray-to-white ratio to be close to that of PET measurement. The rCBF values from the two scatter correction were not significantly different, but the triple-energy window technique suffered from increased noise. After scatter correction, rCBF values were in good agreement with those measured by PET. This study shows little loss in accuracy results from assuming uniform mu map. However, scatter correction

  17. Pinhole X-ray Fluorescence Imaging of Gadolinium Nanoparticles: A Preliminary Monte Carlo Study

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seong Moon; Sung, Won Mo; Ye, Sung Joon [Seoul National University, Seoul (Korea, Republic of)

    2014-10-15

    X-ray fluorescence imaging is a modality for the element-specific imaging of a subject through analysis of characteristic x-rays produced by exploiting the interaction of high atomic number elements and incoming x-rays. Previous studies have utilized a polychromatic x-ray source to investigate the production of in vivo x-ray fluorescence images for the assessment of concentrations and locations of gold nanoparticles. However, previous efforts have so far been unable to detect low concentrations, such as 0.001% gold by weight, which is an expected concentration accumulated in tumors. We examined the feasibility of a monochromatic synchrotron x-rays implementation of pinhole x-ray fluorescence imaging by Monte Carlo simulations using MCNP5. In the current study, gadolinium (Gd) nanoparticles, which have been widely used as a contrast agent in magnetic resonance imaging and also as a dose enhancer in radiation therapy, were chosen for tumor targeting. Since a monochromatic x-ray source is used, the increased x-ray fluorescence signals allow the detection of low concentrations of Gd. Two different monochromatic x-ray beam energies, 50.5 keV near the Kedge energy (i.e., 50.207 keV) of Gd and 55 keV, were compared by their respective imaging results. Using Monte Carlo simulations the feasibility of imaging low concentrations of Gd nanoparticles (e.g., 0.001 wt%) with x-ray fluorescence using monochromatic synchrotron x-rays of two different energies was shown. In the case of imaging a single Gd column inserted in the center of a water phantom, the fluorescence signals from 0.05 wt% and 0.1 wt% Gd columns irradiated with a 50.5 keV photon beam were higher than those irradiated with 55 keV. Below 0.05 wt% region no significant differences were found.

  18. Usefulness of CT based SPECT Fusion Image in the lung Disease : Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hoon Hee; Lyu, Kwang Yeul [Dept. of Radiological Technology, Shingu University, Seoul (Korea, Republic of); Kim, Tae Hyung [Dept. of Radiological Science, Kangwon National University, Samcheok (Korea, Republic of); Shin, Ji Yun [Dept. of Biomedical Engineering, Cheongju National University, Cheongju (Korea, Republic of)

    2012-03-15

    Recently, SPECT/CT system has been applied to many diseases, however, the application is not extensively applied at pulmonary disease. Especially, in case that, the pulmonary embolisms suspect at the CT images, SPECT is performed. For the accurate diagnosis, SPECT/CT tests are subsequently undergoing. However, without SPECT/CT, there are some limitations to apply these procedures. With SPECT/CT, although, most of the examination performed after CT. Moreover, such a test procedures generate unnecessary dual irradiation problem to the patient. In this study, we evaluated the amount of unnecessary irradiation, and the usefulness of fusion images of pulmonary disease, which independently acquired from SPECT and CT. Using NEMA PhantomTM (NU2-2001), SPECT and CT scan were performed for fusion images. From June 2011 to September 2010, 10 patients who didn't have other personal history, except lung disease were selected (male: 7, female: 3, mean age: 65.3{+-}12.7). In both clinical patient and phantom data, the fusion images scored higher than SPECT and CT images. The fusion images, which is combined with pulmonary vessel images from CT and functional images from SPECT, can increase the detection possibility in detecting pulmonary embolism in the resin of lung parenchyma. It is sure that performing SPECT and CT in integral SPECT/CT system were better. However, we believe this protocol can give more informative data to have more accurate diagnosis in the hospital without integral SPECT/CT system.

  19. The clinical utility of brain SPECT imaging in process addictions.

    Science.gov (United States)

    Amen, Daniel G; Willeumier, Kristen; Johnson, Robert

    2012-01-01

    Brain SPECT imaging is a nuclear medicine study that uses isotopes bound to neurospecific pharmaceuticals to evaluate regional cerebral blood flow (rCBF) and indirectly metabolic activity. With current available technology and knowledge SPECT has the potential to add important clinical information to benefit patient care in many different areas of a substance abuse practice, including in the area of process addictions. This article explores the ways brain SPECT has the potential to be useful to clinicians in helping to understand and direct treatment for complex cases of obesity and sexual addictions. Areas where SPECT can add value include helping clinicians ask betterquestions, helping them in making more complete diagnoses, evaluating underlying brain systems pathology, decreasing stigma and increasing compliance, and visualizing effectiveness via follow-up evaluations. In particular, SPECT can help in identifying and assessing the issue of brain trauma and toxicity in process addictions, which may be significant contributing factors in treatment failure. Three illustrative case histories will be given.

  20. Performance Evaluation of a Bedside Cardiac SPECT System

    Science.gov (United States)

    Studenski, Matthew T.; Gilland, David R.; Parker, Jason G.; Hammond, B.; Majewski, Stan; Weisenberger, Andrew G.; Popov, Vladimir

    2009-06-01

    This paper reports on the initial performance evaluation of a bedside cardiac PET/SPECT system. The system was designed to move within a hospital to image critically-ill patients, for example, those in intensive care unit (ICU) or emergency room settings, who cannot easily be transported to a conventional SPECT or PET facility. The system uses two compact (25 cm times 25 cm) detectors with pixilated NaI crystals and position sensitive PMTs. The performance is evaluated for both 140 keV (Tc-99m) and 511 keV (F-18) emitters with the system operating in single photon counting (SPECT) mode. The imaging performance metrics for both 140 keV and 511 keV included intrinsic energy resolution, spatial resolution (intrinsic, system, and reconstructed SPECT), detection sensitivity, count rate capability, and uniformity. Results demonstrated an intrinsic energy resolution of 31% at 140 keV and 23% at 511 keV, a planar intrinsic spatial resolution of 5.6 mm full width half-maximum (FWHM) at 140 keV and 6.3 mm FWHM at 511 keV, and a sensitivity of 4.15 countsmiddotmuCi-1 ldr s-1 at 140 keV and 0.67 counts ldr muCi-1 ldr s-1 at 511 keV. To further the study, a SPECT acquisition using a dynamic cardiac phantom was performed, and the resulting reconstructed images are presented.

  1. Mapping of treatment-induced apoptosis in normal structures: {sup 99m}Tc-Hynic-rh-annexin V SPECT and CT image fusion

    Energy Technology Data Exchange (ETDEWEB)

    Kartachova, Marina S.; Valdes Olmos, Renato A. [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, CX Amsterdam (Netherlands); Haas, Rick L.M.; Hoebers, Frank J.P.; Herk, Marcel van; Verheij, Marcel [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Radiotherapy, Amsterdam (Netherlands); Brekel, Michiel W. van den [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Head and Neck Oncology and Surgery, Amsterdam (Netherlands); Zandwijk, Nico van [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Thoracic Oncology, Amsterdam (Netherlands)

    2006-08-15

    The purpose of this study was to map treatment-induced {sup 99m}Tc-Hynic-rh-annexin V uptake in normal tissues using co-registration of SPECT and CT. Nineteen patients (11 male, 8 female, mean age 57 years) with various malignant tumours (12 lymphomas, four non-small cell lung cancers and three head and neck squamous cell carcinomas) underwent {sup 99m}Tc-Hynic-rh-annexin V scintigraphy and CT before and within 48 h after the start of anticancer therapy. SPECT and CT were performed separately, with the patient in a reproducible position. Volume-based automated and manual methods were used to match functional and anatomical data. SPECT/CT co-registration was used to evaluate treatment-induced changes in the normal structures. A significant radiation field-related increase in early post-treatment {sup 99m}Tc-Hynic-rh-annexin V uptake in salivary glands and bone marrow was detected in eight of nine patients. Radiation field-related increase in bone marrow activity above the baseline value was detected in all 13 irradiated patients. A minimal, symmetrical increase in activity in the salivary glands was detected after the initial course of platinum-based chemotherapy, and a diffuse prominent increase in {sup 99m}Tc-Hynic-rh-annexin V in the bone marrow was detected in all cases. Precise delineation between the tumour and normal tissue tracer accumulation was accomplished in all cases using SPECT/CT co-registered volumes, enhanced by the ''colourwash'' technique. Mapping of early treatment-related changes in annexin V uptake by SPECT/CT co-registration permits accurate evaluation of tracer distribution in normal structures and precise delineation from tumour uptake. The associations between tracer distribution in the normal tissues and treatment regimen found in this study may contribute to the evaluation of dose-effect relations in various treatment schedules. (orig.)

  2. A limitation of the split-dose method for evaluating rCBF changes using {sup 99m}Tc-ECD and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Odano, Ikuo; Takahashi, Makoto; Noguchi, Eikichi; Ohtaki, Hiro; Shibaki, Mitsurou; Kasahara, Tosifumi; Hatano, Masayoshi [Niigata Univ. (Japan). School of Medicine; Ohkubo, Masaki

    1997-05-01

    The purpose of the study is to validate the split-dose method corrected with dose ratio of {sup 99m}Tc-ECD for brain perfusion scan. A dose of 600 MBq of {sup 99m}Tc-ECD was divided into two with various dose ratios from 1 : 1 to 1 : 4, and injected to eleven patients with various cerebral diseases. A lesser dose of {sup 99m}Tc-ECD was injected under a control state for the first SPECT scan, and 15 min SPECT scan was performed 10 min after injection with a triple-head high resolution gamma camera. After the scan, the other dose of {sup 99m}Tc-ECD was injected under the same control state and the second SPECT scan was performed as same as above. A ratio of the activity of the first scan to the net activity of the second scan corrected by dose ratio, defined as K, was measured in brain regions of each subject. Expected value of K was 1, but the value was distributed with large variations in each subject. The mean % error of the K value was 10.4{+-}4.9%. Hence it is considered that activity changes by more than 20% from the control values should be required to detect a significant rCBF change in an activation SPECT study. Then, we proposed a new method in which the activity of both two SPECT scans was normalized by cerebellar or occipital activity and compared. The ratio obtained by the proposed method came closer to 1 with less variations and with less mean % error in comparison with those of K value obtained by the dose-correction method. Although the proposed method has a limitation in the use of an activation study loaded with Diamox, it may be useful to evaluate an alteration of rCBF in the study such as postural testing or finger-moving test. (author)

  3. 123I-FP-CIT brain SPECT (DaTSCAN imaging in the diagnosis of patients with movement disorders: First results

    Directory of Open Access Journals (Sweden)

    Jauković Ljiljana

    2012-01-01

    Full Text Available Background/Aim. 123I-FP-CIT brain single-photon emission computed tomography (SPECT, DaTSCAN imaging, offers a possibility to study structural and biochemical integrity of presinaptic dopaminergic neurotransmitter system. The aim of this study was to evaluate the usefulness of 123I-FP-CIT brain SPECT scintigraphy in patients with extrapyramidal diseases. Methods. Fifteen patients (8 males and 7 females, aged 26-81 years, presenting with extrapyramidal symptoms entered the study. Out of them, 7 patients were diagnosed with definite clinical form of idiopathic Parkinson’s disease (PD or clinical probable for PD clinical stage 2-4 using the Hoehn&Yahr scale (H&Y; 6 patients were with atypical parkinsonism (AP, 1 patient with essential, and 1 with psychogenic tremor. SPECT was performed 180 min after injection of 185 MBq 123IFP- CIT using a dual head Gamma camera. Sixty four one minutes’ frames were acquired using a noncircular rotation mode into a 128 × 128 image matrix. Transverse slices were reconstructed using a 0.6 order Butterworth filter. Visual interpretation was based on striatal uptake, left to right asymmetry and substructures most affected. The ratio of binding for the entire striatum, caudate and putamen to nonspecific binding in occipital cortex was calculated. SPECT findings were categorized as normal and abnormal (incipient, moderate and severe presinaptic deficit. Results. 123I-FP-CIT uptake was reduced in the striatum of 6/7 patients with PD and 5/6 patients with AP. Two patients with PD and AP showed a negative finding. The remaining 2 negative results were obtained in the patients diagnosed with essential tremor and psychogenic tremor. The mean striato-occipital ratio (SDR of the most affected side was lower in the patients with PD. Conclusion. Our first results confirm the usefulness of 123I-FPCIT brain SPECT in differential diagnosis of extrapyramidal diseases.

  4. Head Lice

    Science.gov (United States)

    ... 1044-1047. Canyon, DV, Speare R, et al . “Spatial and kinetic factors for the transfer of head ... for children. Natural products can give parents false sense of safety If using a natural product or ...

  5. The Effect of Electromagnetic Field Generated by a Mobile Phone on the Performance of a SPECT Scanner: A Quantitative Study.

    Science.gov (United States)

    Pashazadeh, Ali Mahmoud; Dehkordi, Forough Jafarian; Tanha, Kaveh; Assadi, Majid

    2015-07-01

    The aim of the current attempt was quantitative investigation of the electromagnetic interference (EMI) of a mobile phone with the function of a SPECT gamma camera during data acquisition. We tested the effect of a mobile phone, in both ringing mode and standby mode, on one SPECT gamma camera during scanning a cylindrical phantom containing 5.4 mCi (99m)Tc. The experiment was performed for different distances of 10, 12, 14, 16, 18, 20, 25, and 30 cm between mobile phone and head of the scanner, and for different head angles of 0, 30, 60, 90, 120, 150, and 180 degrees. A RF-EMF meter measured strength of electromagnetic field throughout the study. Statistically significant decrease in count number was considered to be electromagnetic interference. There was significant reduction in the recorded counts during ringing of the mobile phone in all studied distances. For gamma camera, fixed at a distance, there was no uniform pattern of reduction of the counts at different angles between two operation modes of the mobile phone. A mobile phone, at close distance, can be a sensible source of electromagnetic field, disturbing the normal function of a gamma camera.

  6. Characteristic findings of exercise ECG test, perfusion SPECT and coronary angiography in patients with exercise induced myocardial stunning

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byeong Cheol; Seo, Ji Hyoung; Bae, Jin Ho; Jeong, Shin Young; Park, Hun Sik; Lee, Jae Tae; Chae, Shung Chull; Lee, Kyu Bo [School of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of)

    2004-06-01

    Transient wall motion abnormality and contractile dysfunction of the left ventricle (LV) can be observed in patients with coronary artery disease due to post-stress myocardial stunning. To understand clinical characteristics of stress induced LV dysfunction, we have compared the findings of exercise stress test, myocardial perfusion SPECT and coronary angiography between subjects with and without post-stress LV dysfunction. Among subjects who underwent exercise stress test, myocardial perfusion SPECT and coronary angiography within a month of interval, we enrolled 36 patients with post-stress LV ejection fraction (LVEF) was {>=}5% lower than rest (stunning group) and 16 patients with difference of post-stress and rest LVEF was lesser than 1% (non-stunning group) for this study. Treadmill exercise stress gated myocardial perfusion SPECT was performed with dual head SPECT camera using 740 MBq Tc-99m MIBI and coronary angiography was also performed by conventional Judkins method. Stunning group had a significantly higher incidence of hypercholesterolemia than non-stunning group(45.5 vs 7.1%, p=0.01). Stunning group also had higher incidence of diabetes mellitus and lower incidence of hypertension, but these were not statistically significant. Stunning group had larger and more severe perfusion defect in stress perfusion myocardial SPECT than non-stunning group(extent 18.2 vs 9.2%, p=0.029; severity 13.5 vs 6.9, p=0.040). Stunning group also had higher degree of reversibility of perfusion defect, higher incidence of positive exercise stress test and higher incidence of having severe stenosis(80{approx}99%) in coronary angiography than non-stunning group, but these were not statistically significant. In stunning group, all of 4 patients without perfusion defect had significant coronary artery stenosis and had received revascularization treatment. Patients with post-stress LV dysfunction had larger and more severe perfusion defect and severe coronary artery stenosis than

  7. Clinical Significance of Brain SPECT in Zipeprol Abusers

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Dai Ok; Kim, Jae Phil; Kim, Deog Yoon; Yang, Hyung In; Koh, Eun Mi; Kim, Kwang Won; Choi, Young Kil [Kyung Hee University College of Medicine, Seoul (Korea, Republic of)

    1993-03-15

    Drug abuse is widespread in worldwide and has been associated with neurologic complication. Zipeprol is one of drugs which been abused for psychological satisfaction in some adolescents. This agent is non-opioid antitussive agent, which is not legally considered as being capable of creating dependence or abuse liability at therapeutic serum levels. But it has been reported that acute or chronic overdose create neurologic complication such as convulsion as well as dependence. Recently we experienced six zipeprol abusers who admitted due to convulsion and variable neurologic symptoms. The aim of our study was to determine the role of Tc-99m- HMPAO brain SPECT in those patients. EEG and brain CT showed no abnormal finding, but brain SPECT showed focal or multiple perfusion abnormalities in frontal, parietal, occipital cortex, basal ganglia, thalamus and especially at temporal cortex. These results suggest that brain SPECT may be a useful diagnostic tool to evaluate the cerebral dysfunction induced by zipeprol abuse.

  8. 3D quantitative analysis of brain SPECT images

    Science.gov (United States)

    Loncaric, Sven; Ceskovic, Ivan; Petrovic, Ratimir; Loncaric, Srecko

    2001-07-01

    The main purpose of this work is to develop a computer-based technique for quantitative analysis of 3-D brain images obtained by single photon emission computed tomography (SPECT). In particular, the volume and location of ischemic lesion and penumbra is important for early diagnosis and treatment of infracted regions of the brain. SPECT imaging is typically used as diagnostic tool to assess the size and location of the ischemic lesion. The segmentation method presented in this paper utilizes a 3-D deformable model in order to determine size and location of the regions of interest. The evolution of the model is computed using a level-set implementation of the algorithm. In addition to 3-D deformable model the method utilizes edge detection and region growing for realization of a pre-processing. Initial experimental results have shown that the method is useful for SPECT image analysis.

  9. Iodine-123-iodo-lisuride SPECT in Parkinson's disease.

    Science.gov (United States)

    Cordes, M; Hierholzer, J; Schelosky, L; Schrag, A; Richter, W S; Eichstädt, H; Schulze, P E; Poewe, W; Felix, R

    1996-01-01

    Recently, [123I]iodo-lisuride was synthesized for possible applications in SPECT studies. The purpose of this investigation was to compare the striatal binding and kinetics of this radioligand in patients with Parkinson's disease and normal controls. Six patients with Parkinson's disease and three normal controls were examined. After intravenous injection of 111 MBq [123I]iodo-lisuride, sequential SPECT examinations at 20, 40, 80 and 120 min were performed. For each SPECT series the basal ganglia-to-cerebellum ratio of tracer accumulation was calculated. In one patient a repeat SPECT examination was undertaken under identical conditions to test the reproducibility of the procedure. In two other patients a second SPECT examination was performed after injection of cold lisuride as a receptor saturation study. In addition, the time course of the radioactivity was measured in the plasma and red blood cells in each individual. In both patients and controls, the highest tracer accumulation was found within the striatum. The basal ganglia-to-cerebellum ratio was 1.182 and 1.303 at 20 min, 1.353 and 1.450 at 40 min, 1.490 and 1.533 at 80 min, 1.550 and 1.583 at 120 min for patients and controls, respectively, which was not statistically different. In the saturation study, 50 micrograms and 100 micrograms cold lisuride led to a 28% and 33% reduction, respectively, of the basal ganglia-to-cerebellum ratio at 120 min. The ligand showed a rapid decline in plasma and red blood cells. The percent injected dose per liter was calculated to be 1.6 and 0.9, respectively, for plasma and red blood cells at 20 min. Iodine-123-iodo-lisuride SPECT seems useful for imaging intact striatal dopamine D2 receptors in patients with Parkinson's disease and may provide clinically relevant information for quantitative assessment of the availability and integrity of dopamine D2 receptors.

  10. Direct asymmetry measurement of temperature and density spatial distributions in inertial confinement fusion plasmas from pinhole space-resolved spectra

    CERN Document Server

    Nagayama, T; Florido, R; Mayes, D; Tommasini, R; Koch, J A; Delettrez, J A; Regan, S P; Smalyuk, V A

    2014-01-01

    Two-dimensional space-resolved temperature and density images of an inertial confinement fusion (ICF) implosion core have been diagnosed for the first time. Argon-doped, direct-drive ICF experiments were performed at the Omega Laser Facility and a collection of two-dimensional space-resolved spectra were obtained from an array of gated, spectrally resolved pinhole images recorded by a multi-monochromatic x-ray imager. Detailed spectral analysis revealed asymmetries of the core not just in shape and size but in the temperature and density spatial distributions, thus characterizing the core with an unprecedented level of detail.

  11. Visual Acuity Testing Using Autorefraction or Pinhole Occluder as Compared with a Manual Protocol Refraction in Individuals with Diabetes

    Science.gov (United States)

    Sun, Jennifer K.; Aiello, Lloyd Paul; Cavallerano, Jerry D.; Stockman, Margaret; Miller, Kellee M.; Qin, Haijing; Beck, Roy W.; Glassman, Adam R.

    2010-01-01

    Purpose To compare visual acuity (VA) scores obtained after autorefraction or using a pinhole occluder to scores obtained after refraction according to a standard clinical research protocol. Design Prospective, comparative case series Participants One hundred and ten study participants (209 eyes) with diabetes mellitus and a broad range of diabetic retinopathy severity and visual acuity (VA). Methods VA was measured after autorefraction by a Topcon KR-8000 autorefractor as well as after a Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction. The order of testing was randomized and examiners were masked to the source of each refraction. A second VA measurement, utilizing an identical DRCR.net manual refraction, was made in a subset of eyes (N = 144, 69%) in order to establish test-retest variability for comparison purposes. All eyes underwent VA testing using a pinhole occluder. Main Outcome Measures Best corrected VA as measured by the Electronic Early Treatment Diabetic Retinopathy Study Visual Acuity Test© (E-ETDRS). Results In all eyes, the median E-ETDRS VA letter score (EVA) obtained after manual refraction (MR-EVA) was 69 (Snellen equivalent 20/40), ranging from 4 to 93 (20/800 to 20/16). The median MR-EVA was slightly better than the median EVA obtained after autorefraction (AR-EVA), with a median difference (AR-EVA – MR-EVA) of −1 letter (25th, 75th percentiles: −4, 2 letters). The absolute difference between AR-EVA and MR-EVA was similar to the test-retest variability of MR-EVA alone. In contrast, MR-EVA was better than EVA obtained using a pinhole occluder (PH-EVA), (median PH-EVA – MR-EVA: −4 letters [−9, 0]), and had significantly less test-retest variability (Prefraction (median difference: +0.25 Diopters [0, +0.63 Diopters]). Conclusions Given the substantial time and effort required for training and certification of study protocol refractionists, and the similarity between AR-EVA and MR-EVA, further

  12. Visual acuity testing using autorefraction or pinhole occluder compared with a manual protocol refraction in individuals with diabetes.

    Science.gov (United States)

    Sun, Jennifer K; Aiello, Lloyd Paul; Cavallerano, Jerry D; Stockman, Margaret; Miller, Kellee M; Qin, Haijing; Beck, Roy W; Glassman, Adam R

    2011-03-01

    To compare visual acuity (VA) scores obtained after autorefraction or using a pinhole occluder to scores obtained after refraction according to a standard clinical research protocol. Prospective, comparative case series. One hundred ten study participants (209 eyes) with diabetes mellitus and a broad range of diabetic retinopathy severity and VA. We measured VA after autorefraction by a Topcon KR-8000 autorefractor as well as after a Diabetic Retinopathy Clinical Research Network (DRCR.net) protocol manual refraction. The order of testing was randomized and examiners were masked to the source of each refraction. A second VA measurement, utilizing an identical DRCR.net manual refraction, was made in a subset of eyes (n = 144; 69%) to establish test-retest variability for comparison purposes. All eyes underwent VA testing using a pinhole occluder. Best corrected VA as measured by the Electronic Early Treatment Diabetic Retinopathy Study Visual Acuity Test (E-ETDRS). In all eyes, the median E-ETDRS VA letter score (EVA) obtained after manual refraction (MR-EVA) was 69 (Snellen equivalent 20/40), ranging from 4 to 93 (20/800 to 20/16). The median MR-EVA was slightly better than the median EVA obtained after autorefraction (AR-EVA), with a median difference (AR-EVA - MR-EVA) of -1 letter (25th, 75th percentiles, -4, 2 letters). The absolute difference between AR-EVA and MR-EVA was similar to the test-retest variability of MR-EVA alone. In contrast, MR-EVA was better than EVA obtained using a pinhole occluder (PH-EVA; median PH-EVA - MR-EVA, -4 letters [-9, 0]), and had significantly less test-retest variability (Prefraction (median difference, +0.25 diopters [0, +0.63]). Given the substantial time and effort required for training and certification of study protocol refractionists, and the similarity between AR-EVA and MR-EVA, further evaluation of autorefraction, but not pinhole occluder testing, as an alternative to the current clinical research gold standard of ETDRS

  13. Pinhole camera for study of atmospheric UV flashes as a source of background in the TUS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, E. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); BUAP, Puebla (Mexico); Khrenov, B.; Panasyuk, M.I. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation); Martinez, O., E-mail: omartin@fcfm.buap.m [BUAP, Puebla (Mexico); Salazar, H. [BUAP, Puebla (Mexico); Garipov, G.; Klimov, P. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation)

    2011-05-21

    The pinhole camera design fulfills the requirements of FOV, compactness , reliability, and attached to a fast position sensitive detector PSD will allow us to obtain 2d-images, as proposed in the future space mission TUS (tracking ultraviolet system) . In this work we propose a device based in this optical design, to evaluate the possibility to detect ultra high energy cosmic ray fluorescence, Cherenkov signals and other fast luminous phenomena from the space , as transient luminous events, traces of micro-meteorites and human activities.

  14. SPECT deadtime count loss correction using monitor source method

    Directory of Open Access Journals (Sweden)

    Wendy Siman

    2014-03-01

    Full Text Available Purpose: Deadtime-count-loss (DTloss correction using monitor source (MS requires: 1 uniform fractional DTloss across FOV, 2 high statistics MS images both with & without the object. The aims are validating condition 1 and developing a practical protocol that satisfies conditions 2 with minimal additional study duration.Methods and Materials: SPECT images of non-uniform phantoms (4GBq 99mTc along with MS (20MBq 99mTc attached to each detector were acquired multiple times over 48 hours in photopeak and scatter energy window (EW using Siemens-SymbiaS and GE-D670. Planar images of the MS alone were acquired. Photopeak counts for the MS ROIs were > 100kcts. Fractional DTloss uniformity across the FOV was evaluated by correlating count rates in different ROIs on projection images at different DTloss levels. The correction factor for each SPECT projection at every time point was calculated as the ratio of time-corrected MS count rates with & without the phantom.The DTloss-corrected projections for each SPECT acquisition were decay corrected to one time point. The correction accuracy was assessed against DTloss estimated by paralyzable model. The accuracy of projection-based DTloss correction for SPECT was evaluated. A method to model projection DTloss based on a subset of measured projection DTloss was investigated. The relation of DTloss between photopeak and scatter EW was explored.Results: The fractional DTloss was uniform across the FOV (r > 0.99, validating condition 1. The MS method was accurate to > 99% for planar and SPECT. Measured DTloss from 3-to-5 projections/detector may be used to estimate DTloss with accuracy > 98% for all SPECT projections by modeling DTloss with measured projection rate. The correction factor in photopeak and scatter EW are equivalent with > 99% agreement.Conclusion: MS method can accurately correct planar and SPECT DTloss. Sparse sampling of the projection DTloss allows acquiring MS counts with high statistics with

  15. Determination of left ventricular mass through SPECT imaging

    Science.gov (United States)

    Zárate-Morales, A.; Rodríguez-Villafuerte, M.; Martínez-Rodríguez, F.; Arévila-Ceballos, N.

    1998-08-01

    An edge detection algorithm has been applied to estimate left ventricular (LV) mass from single photon emission computed tomography (SPECT) thallium-201 images. The algorithm was validated using SPECT images of a phantom. The algorithm was applied to 20 patient studies from the Hospital de Cardiologia, Centro Médico Nacional Siglo XXI. Left ventricular masses derived from the stress and redistribution studies were highly correlated (r=0.96). The average LV masses obtained were 162±37 g and 169±34 g in the redistribution and stress studies, respectively.

  16. Femoral chondrosarcoma discovered by SPECT-T.D.M. osseous scintigraphy; Chondrosarcome femoral decouvert par scintigraphie osseuse SPECT-TDM

    Energy Technology Data Exchange (ETDEWEB)

    Bourahla, K.; Nguyen, L.; Rolling, P.; Schott, A.; Di Salvo, R. [CLCC Paul-Strauss, Strasbourg, (France)

    2009-05-15

    Objectives: the SPECT/T.D.M. imaging can allow a quick diagnosis direction by the concomitant exploitation of scintigraphy data and morphological data brought by the T.D.M.. We present the case of a chondrosarcoma diagnosed in nuclear medicine thanks to the exploitation of the data supplied by the SPECT/T.D.M. that allowed to direct rapidly the later explorations while reducing the time of the patient coverage. Conclusions: A knowledge of the most characteristic morphological data allows to give some diagnosis at first sight during the scintigraphy explorations coupled SPECT/T.D.M. and this in the interest of the patient by reducing his coverage while including the nuclear doctor more broadly in some diagnosis approaches previously remote from his reach. (N.C.)

  17. Feasibility of one-eighth time gated myocardial perfusion SPECT functional imaging using IQ-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Caobelli, Federico; Thackeray, James T.; Bengel, Frank M. [Medizinische Hochschule Hannover, Klinik fuer Nuklearmedizin, Hannover (Germany); Soffientini, Alberto; Pizzocaro, Claudio; Guerra, Ugo Paolo [Fondazione Poliambulanza, Department of Nuclear Medicine, Brescia (Italy)

    2015-11-15

    IQ-SPECT, an add-on to general purpose cameras based on multifocal collimation, can reduce myocardial perfusion imaging (MPI) acquisition times to one-fourth that of standard procedures (to 12 s/view). In a phantom study, a reduction of the acquisition time to one-eighth of the standard time (to 6 s/view) was demonstrated as feasible. It remains unclear whether such a reduction could be extended to clinical practice. Fifty patients with suspected or diagnosed CAD underwent a 2-day stress-rest {sup 99m}Tc-sestamibi MPI protocol. Two consecutive SPECT acquisitions (6 and 12 s/view) were performed. Electrocardiogram-gated images were reconstructed with and without attenuation correction (AC). Polar maps were generated and visually scored by two blinded observers for image quality and perfusion in 17 segments. Global and regional summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were determined. Left ventricular volumes and ejection fraction were calculated based on automated contour detection. Image quality was scored higher with the 12 s/view acquisition, both with and without AC. Summed scores were statistically comparable between the 6 s/view and the 12 s/view acquisition, both globally and in individual coronary territories (e.g. in images with AC, SSS were 6.6 ± 8.3 and 6.2 ± 8.2 with 6 s and 12 s/view, respectively, p = 0.10; SRS were 3.9 ± 5.6 and 3.5 ± 5.3, respectively, p = 0.19; and SDS were 2.8 ± 5.7 and 2.6 ± 5.7, respectively, p = 0.59). Both acquisitions allowed MPI-based diagnosis of CAD in 25 of the 50 patients (with AC). Calculated end-diastolic volume (EDV) and end-systolic volume (ESV) were modestly higher with the 6 s/view acquisition than with the 12 s/view acquisition (EDV +4.8 ml at rest and +3.7 ml after stress, p = 0.003; ESV +4.1 ml at rest and +2.6 ml after stress, p = 0.01), whereas the ejection fraction did not differ (-1.2 % at rest, p = 0.20, and -0.9 % after stress, p = 0.27). Image quality and

  18. HMPAO-SPECT during epileptic seizures: Early and late images. Fruehe und spaete HMPAO-SPECT waehrend eines epileptischen Anfalls

    Energy Technology Data Exchange (ETDEWEB)

    Overbeck, B.; Gruenwald, F.; Bockisch, A.; Biersack, H.J. (Bonn Univ. (Germany, F.R.). Klinik fuer Nuklearmedizin); Reinke, U. (Bonn Univ. (Germany, F.R.). Nervenklinik/Epileptologie); Gratz, K.F. (Medizinische Hochschule Hannover (Germany, F.R.). Abt. Nuklearmedizin und Spezielle Biophysik)

    1990-11-01

    For presurgical evaluation of epilepsy a 44-year old patient with complex-partial seizures underwent HMPAO-SPECT. The morphology of the seizures, the MRI-scan, psychometry and ictal as well as interictal EEGs showed a left temporal origin of the seizures. Early images were obtained 20 min and late images 24 h following injection. On both scans a marked hyperperfusion was observed in the left temporal area. A crossed cerebellar diaschisis was also seen on both SPECTs. It could be shown that during ictal examinations there is no bloodflow-dependent wash-out from brain tissue. (orig.).

  19. Robust, fully automatic delineation of the head contour by stereotactical normalization for attenuation correction according to Chang in dopamine transporter scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Catharina; Brenner, Winfried; Buchert, Ralph [Charite - Universitaetsmedizin Berlin, Department of Nuclear Medicine, Berlin (Germany); Kurth, Jens; Schwarzenboeck, Sarah; Krause, Bernd J. [Universitaetsmedizin Rostock, Department of Nuclear Medicine, Rostock (Germany); Seese, Anita; Steinhoff, Karen; Sabri, Osama; Hesse, Swen [Universitaetsklinikum Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Umland-Seidler, Bert [GE Healthcare Buchler GmbH and Co. KG, Munich (Germany)

    2015-09-15

    Chang's method, the most widely used attenuation correction (AC) in brain single-photon emission computed tomography (SPECT), requires delineation of the outer contour of the head. Manual and automatic threshold-based methods are prone to errors due to variability of tracer uptake in the scalp. The present study proposes a new method for fully automated delineation of the head based on stereotactical normalization. The method was validated for SPECT with I-123-ioflupane. The new method was compared to threshold-based delineation in 62 unselected patients who had received I-123-ioflupane SPECT at one of 3 centres. The impact on diagnostic power was tested for semi-quantitative analysis and visual reading of the SPECT images (six independent readers). The two delineation methods produced highly consistent semi-quantitative results. This was confirmed by receiver operating characteristic analyses in which the putamen specific-to-background ratio achieved highest area under the curve with negligible effect of the delineation method: 0.935 versus 0.938 for stereotactical normalization and threshold-based delineation, respectively. Visual interpretation of DVR images was also not affected by the delineation method. Delineation of the head contour by stereotactical normalization appears useful for Chang AC in I-123-ioflupane SPECT. It is robust and does not require user interaction. (orig.)

  20. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  1. Small hepatocellular carcinomas in chronic liver disease: Detection with SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, M.; Hirasa, M.; Takakuwa, H.; Ibuki, Y.; Fujimi, K.; Miyamura, M.; Tomita, S.; Komori, H.; Todo, A.; Kitaura, Y.

    1986-06-01

    Single-photon emission computed tomography (SPECT) performed using a rotating gamma camera was compared with ..cap alpha../sub 1/-fetoprotein (AFP) assay, conventional liver scintigraphy, ultrasound (US) imaging, computed tomography (CT), and selective celiac angiography in 40 patients with a total of 50 small hepatocellular carcinomas (HCCs;<5 cm). The detection rates of US and CT were determined on an initial screening study and on a second, more precisely focused study. The detection rate of small HCCs by the various modalities was as follows: AFP, 13%; liver scintigraphy, 36%; SPECT, 72%; initial screening US, 80%; second, more precise US studies, 94%; initial screening CT, 64%; second, more precise CT study, 82%; angiography, 88%. Although SPECT was inferior to the initial screening US examination in detecting HCCs less than 2 cm in size, its sensitivity was identical to that of the initial screening US study for detecting HCCs of 2-5 cm. The combination of SPECT and US was an excellent method for the early detection of HCCs, yielding a detection rate of 94%.

  2. Diagnosis of lung embolism by V / Q scintigraphy. Pt. 2. SPECT and SPECT-CT for pulmonary diagnostic in nuclear medicine; V / Q-Szintigrafie zur Diagnostik der Lungenembolie. T. 2. SPECT und SPECT-CT in der nuklearmedizinischen Lungendiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Krause, T. [Universitaetsklinik fuer Nuklearmedizin, Bern (Switzerland). Inselspital

    2008-12-15

    Imaging of the pulmonary ventilation and perfusion by using SPECT proved to be a useful development of this examination. At first this article gives a brief overview of the technical aspects followed by a discussion of clinical questions regarding pulmonary embolism, preoperative assessment of postoperative lung function as well as radioaerosol deposition and clearance. (orig.)

  3. Tc-99m HMPAO brain SPECT scanning in Munchausen syndrome.

    Science.gov (United States)

    Mountz, J M; Parker, P E; Liu, H G; Bentley, T W; Lill, D W; Deutsch, G

    1996-01-01

    Regional cerebral blood flow was studied in a patient with Munchausen syndrome using high resolution Tc-99m HMPAO SPECT. The scan demonstrated marked hyperperfusion of the right hemithalamus. The cranial CT scan was normal. The abnormal right hemithalamic blood flow is discussed in relation to the hypothesized neuropathy of this disorder. Images Figure 1 Figure 2 Figure 3 PMID:8580117

  4. SPECT and PET in Late-Life Depression

    NARCIS (Netherlands)

    Vieira, Tiago S; Oude Voshaar, Richard; De Deyn, Peter; Dierckx, Rudi; van Waarde, Aren; Dierckx, Rudi AJO; Otte, Andreas; de Vries, Erik FJ; van Waarde, Aren; den Boer, Johan A

    2014-01-01

    Late-life late onset depression (i.e., depression with an age of onset above 60 yrs) appears to differ from depression with early onset in its association with cerebral small vessel disease, beta-amyloid and tau deposition, and neurodegenerative processes. Multimodality imaging (SPECT, PET, MRI)

  5. Thallium-201 accumulation in cerebral candidiasis: Unexpected finding on SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Tonami, N.; Matsuda, H.; Ooba, H.; Yokoyama, K.; Hisada, K.; Ikeda, K.; Yamashita, J. (Kanazawa Univ. (Japan))

    1990-06-01

    The authors present an unexpected finding of Tl-201 uptake in the intracerebral lesions due to candidiasis. SPECT demonstrated the extent of the lesions and a high target-to-background ratio. The regions where abnormal Tl-201 accumulation was seen were nearly consistent with CT scans of those enhanced by a contrast agent. After treatment, most of the abnormal Tl-201 accumulation disappeared.

  6. Cerebral fat embolism studied with MRI and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, E. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey)); Namer, I.J. (Inst. of Biophysics, Faculty of Medicine, Louis Pasteur Univ., Strasbourg (France)); Saribas, O. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey)); Aras, T. (Dept. of Nuclear Medicine, Hacettepe Univ. School of Medicine Ankara (Turkey)); Tan, E. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey)); Bekdik, C. (Dept. of Nuclear Medicine, Hacettepe Univ. School of Medicine Ankara (Turkey)); Zileli, T. (Dept. of Neurology, Hacettepe Univ. School of Medicine, Ankara (Turkey))

    1993-03-01

    In a patient with fat embolism to the brain CT showed no abnormality. MRI performed after recovery from coma, when the patient had aphasia and quadriparesis, demonstrated multiple high signal abnormalities in the white matter on both T1- and T2-weighted images. HMPAO-SPECT showed left-sided hypoperfusion which resolved in parallel with clinical improvement 1 month later. (orig.)

  7. Eating epilepsy: phenotype, MRI, SPECT and video-EEG observations.

    Science.gov (United States)

    Patel, M; Satishchandra, P; Saini, J; Bharath, R D; Sinha, S

    2013-11-01

    Eating epilepsy is one of the rare forms of reflex epilepsy precipitated by eating. Previous studies have demonstrated lesions due to variable aetiology involving the temporolimbic and suprasylvian regions. To study anatomical correlates of reflex eating epilepsy using multimodality investigations (MR imaging, video-EEG and SPECT). Six patients (M:F=3:3; mean age: 20.7±4.9 years) with eating epilepsy were subjected to MRI of brain, video-EEG studies and SPECT scan. These were correlated with phenotypic presentations. Among the five patients with ictal recording of eating epilepsy during video-EEG, semiology was characterized by behavioural arrest followed by either flexion or extension of trunk and neck and two patients had speech arrest and four had salivation from angle of mouth. Another patient had EEG changes during "thought about eating". Four patients had perisylvian frontal lobe lesions and one had high frontal lesion on MRI. Ictal EEG (n=6) showed ictal rhythmic slowing/fast activity in parieto-temporal (n=2) or fronto-temporal (n=4) regions with subsequent secondary generalization in three. Ictal and interictal SPECT imaging showed changes in frontal lobe (n=1), anterior temporal lobe (n=1), and parieto-insular region (n=1) suggesting it to be seizure onset zone. Three of four patients with structural lesions in MRI had concordant ictal EEG and ictal SPECT changes. Lesions near the perisylvian region might play a major role in eating epilepsy. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. SPECT bone scintigraphy of medial collateral ligament/meniscus injury

    Energy Technology Data Exchange (ETDEWEB)

    Micallef, L.; Larcos, G. [Westmead Medical Imaging, Westmead, NSW (Australia)

    1998-06-01

    Full text: Acute or chronic knee pain is common amongst athletic persons. MRI is generally regarded as the best test, but is not widely available and may lack specificity in meniscal tears and cruciate injury. Bone scan with SPECT is an appealing alternative since it is relatively cheap and easily obtained. Further, a number of investigators have published data indicating sensitivity and specificity exceeding 85%. The purpose of the study is to determine typical scintigraphic findings in medial collateral ligament or medial meniscus injury. We present a small group of patients with acute knee trauma in whom arthroscopy and/or clinical follow-up indicated medial collateral ligament injury. Bone scans were undertaken after 900-1000 MBq of {sup 99m}Tc-MDP with immediate blood pool, delayed planar images and SPECT acquired on a Picker Prism 2000. SPECT was obtained with high resolution collimators and 20 sec/stop for 180 deg each. SPECT images showed focal radiopharmaceutical accumulation in the medial proximal tibial shaft and medial femoral condyle, corresponding to the superficial layer of the medial collateral ligament (best seen on coronal images). Disruption of the deep layer and/or medial meniscus can be suspected with abnormal uptake in part or all of the meniscus (best seen on transverse images). We conclude that acute/chronic medial collateral ligament injury can be detected on bone scintigraphy with abnormal uptake at the predicted anatomic site of attachment

  9. Brain SPECT findings in long-term inhalant abuse.

    Science.gov (United States)

    Küçük, N O; Kiliç, E O; Ibis, E; Aysev, A; Gençoglu, E A; Aras, G; Soylu, A; Erbay, G

    2000-08-01

    This study evaluates brain perfusion in long-term inhalant abusers of toluene, acetone, benzene and derivatives. Ten patients in the age range 16-18 years (mean, 17.3+/-0.67 years), who had been inhalant dependent for a mean period of 48.3+/-6.2 months, but who had stopped using inhalants for 1-11 months (mean, 5.4+/-2.1 months), and ten controls (mean age, 17.3+/-0.67 years) were included in the study. Psychiatric tests, biochemical tests and Tc-99m-hexamethylpropyleneamine oxime (Tc-99m-HMPAO) brain single photon emission computed tomography (SPECT) were performed on all patients. Brain SPECT images were evaluated qualitatively and quantitatively. The mean IQ level was found to be 84 (by psychological tests). Brain SPECT showed non-homogeneous Tc-99m-HMPAO uptake and hypoperfusion areas in all patients (five left temporal, one right temporal, two left temporal plus bilateral parietooccipital, one biparietal and one left temporoparietal). Seven patients had hyperperfused foci (unifocal in five patients and multifocal in two patients). Six hyperperfused foci were in a parietal and one in a temporoparietal location. This study suggests that inhalant dependents exhibit serious abnormalities in brain SPECT images, including hypo-hyperperfusion foci and non-homogeneous uptake of the radiopharmaceutical. A further study with a larger number of patients and long-term follow-up may help to reach a more specific conclusion.

  10. Affordable CZT SPECT with dose-time minimization (Conference Presentation)

    Science.gov (United States)

    Hugg, James W.; Harris, Brian W.; Radley, Ian

    2017-03-01

    PURPOSE Pixelated CdZnTe (CZT) detector arrays are used in molecular imaging applications that can enable precision medicine, including small-animal SPECT, cardiac SPECT, molecular breast imaging (MBI), and general purpose SPECT. The interplay of gamma camera, collimator, gantry motion, and image reconstruction determines image quality and dose-time-FOV tradeoffs. Both dose and exam time can be minimized without compromising diagnostic content. METHODS Integration of pixelated CZT detectors with advanced ASICs and readout electronics improves system performance. Because historically CZT was expensive, the first clinical applications were limited to small FOV. Radiation doses were initially high and exam times long. Advances have significantly improved efficiency of CZT-based molecular imaging systems and the cost has steadily declined. We have built a general purpose SPECT system using our 40 cm x 53 cm CZT gamma camera with 2 mm pixel pitch and characterized system performance. RESULTS Compared to NaI scintillator gamma cameras: intrinsic spatial resolution improved from 3.8 mm to 2.0 mm; energy resolution improved from 9.8% to medicine applications.

  11. Multimodal imaging analysis of single-photon emission computed tomography and magnetic resonance tomography for improving diagnosis of Parkinson's disease; Multimodale SPECT- und MRT-Bilddatenanalyse zur Verbesserung der Diagnostik des idiopathischen Parkinson-Syndroms

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, H.; Georgi, P. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Mueller, U.; Waechter, T.; Murai, T. [Max-Planck-Inst. fuer Neuropsychologische Forschung, Leipzig (Germany); Slomka, P. [Universitaet West-Ontario, London (Canada). Abt. fuer Nuklearmedizin; Dannenberg, C.; Kahn, T. [Leipzig Univ. (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie

    2000-10-01

    Parkinson's disease (PD) is characterized by a degeneration of nigrostriated dopaminergic neurons, which can be imaged with {sup 123}I-labeled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl) tropane ([{sup 123}I]{beta}-CIT) and single-photon emission computed tomography (SPECT). However, the quality of the region of interest (ROI) technique used for quantitative analysis of SPECT data is compromised by limited anatomical information in the images. We investigated whether the diagnosis of PD can be improved by combining the use of SPECT images with morphological image data from magnetic resonance imaging (MRI)/computed tomography (CT). We examined 27 patients (8 men, 19 women; aged 55{+-}13 years) with PD (Hoehn and Yahr stage 2.1{+-}0.8) by high-resolution [{sup 123}I]{beta}-CIT SPECT (185-200 MBq, Ceraspect camera). SPECT images were analyzed both by a unimodal technique (ROIs defined directly within the SPECT studies) and a multimodal technique (ROIs defined within individual MRI/CT studies and transferred to the corresponding interactively coregistered SPECT studies). [{sup 123}I]{beta}-CIT binding ratios (cerebellum as reference), which were obtained for heads of caudate nuclei (CA), putamina (PU), and global striatal structures were compared with clinical parameters. Differences between contra- and ipsilateral (related to symptom dominance) striatal [{sup 123}I]{beta}-CIT binding ratios proved to be larger in the multimodal ROI technique than in the unimodal approach (e.g., for PU: 1.2*** vs. 0.7**). Binding ratios obtained by the unimodal ROI technique were significantly correlated with those of the multimodal technique (e.g., for CA: y=0.97x+2.8; r=0.70; P<0.001). Concerning the correlations between SPECT data and clinical parameters, the significance levels in the multimodal ROI technique exceeded those of the unimodal technique, for example, for the correlation between CA and the UPDRS{sub com} subscore (r=-0.49* vs. -0.32). These results show that the

  12. Partial volume correction in SPECT reconstruction with OSEM

    Science.gov (United States)

    Erlandsson, Kjell; Thomas, Ben; Dickson, John; Hutton, Brian F.

    2011-08-01

    SPECT images suffer from poor spatial resolution, which leads to partial volume effects due to cross-talk between different anatomical regions. By utilising high-resolution structural images (CT or MRI) it is possible to compensate for these effects. Traditional partial volume correction (PVC) methods suffer from various limitations, such as correcting a single region only, returning only regional mean values, or assuming a stationary point spread function (PSF). We recently presented a novel method in which PVC was combined with the reconstruction process in order to take into account the distance dependent PSF in SPECT, which was based on filtered backprojection (FBP) reconstruction. We now present a new method based on the iterative OSEM algorithm, which has advantageous noise properties compared to FBP. We have applied this method to a series of 10 brain SPECT studies performed on healthy volunteers using the DATSCAN tracer. T1-weighted MRI images were co-registered to the SPECT data and segmented into 33 anatomical regions. The SPECT data were reconstructed using OSEM, and PVC was applied in the projection domain at each iteration. The correction factors were calculated by forward projection of a piece-wise constant image, generated from the segmented MRI. Images were also reconstructed using FBP and standard OSEM with and without resolution recovery (RR) for comparison. The images were evaluated in terms of striatal contrast and regional variability (CoV). The mean striatal contrast obtained with OSEM, OSEM-RR and OSEM-PVC relative to FBP were 1.04, 1.42 and 1.53, respectively, and the mean striatal CoV values are 1.05, 1.53, 1.07. Both OSEM-RR and OSEM-PVC results in images with significantly higher contrast as compared to FBP or OSEM, but OSEM-PVC avoids the increased regional variability of OSEM-RR due to improved structural definition.

  13. Advanced reconstruction of attenuation maps using SPECT emission data only

    Science.gov (United States)

    Salomon, André; Goedicke, Andreas; Aach, Til

    2009-02-01

    Today, attenuation corrected SPECT, typically performed using CT or Gadolinium line source based transmission scans, is more and more becoming standard in many medical applications. Moreover, the information about the material density distribution provided by these scans is key for other artifact compensation approaches in advanced SPECT reconstruction. Major drawbacks of these approaches are the additional patient radiation and hardware/maintenance costs as well as the additional workflow effort, e.g. if the CT scans are not performed on a hybrid scanner. It has been investigated in the past, whether it is possible to recover this structural information solely from the SPECT scan data. However, the investigated methods often result in noticeable image artifacts due to cross-dependences between attenuation and activity distribution estimation. With the simultaneous reconstruction method presented in this paper, we aim to effectively prevent these typical cross-talk artifacts using a-priori known atlas information of a human body. At first, an initial 3D shape model is coarsely registered to the SPECT data using anatomical landmarks and each organ structure within the model is identified with its typical attenuation coefficient. During the iterative reconstruction based on a modified ML-EM scheme, the algorithm simultaneously adapts both, the local activity estimation and the 3D shape model in order to improve the overall consistency between measured and estimated sinogram data. By explicitly avoiding topology modifications resulting in a non-anatomical state, we ensure that the estimated attenuation map remains realistic. Several tests with simulated as well as real patient SPECT data were performed to test the proposed algorithm, which demonstrated reliable convergence behaviour in both cases. Comparing the achieved results with available reference data, an overall good agreement for both cold as well as hot activity regions could be observed (mean deviation: -5.98%).

  14. Co-57 SPECT, Tc-99m-ECD SPECT, MRI and neuropsychological testing in senile dementia of the Alzheimer type

    NARCIS (Netherlands)

    Versijpt, J; Decoo, D; Van Laere, KJR; Achten, E; Audenaert, K; D'Asseler, Y; Slegers, G; Dierckx, RA; Korf, J

    Inflammatory mechanisms contribute to the pathophysiology of senile dementia of the Alzheimer type (sDAT). Previous studies have shown that Co-57 Single photon emission computed tomography (SPECT) is able to visualize inflammatory lesions, probably by means of the final common pathway of Ca2+

  15. Pre-evaluation study in SPECT images using a phantom; Avaliacao do pre processamento das projecoes em SPECT com phantom fisico

    Energy Technology Data Exchange (ETDEWEB)

    Rebelo, Marina de Sa; Furuie, Sergio Shiguemi [Sao Paulo Univ., SP (Brazil). Instituto do Coracao. Div. de Informatica; Abe, Rubens [Sao Paulo Univ., SP (Brazil). Instituto do Coracao. Servico de Radioisotopos; Moura, Lincoln [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Hospital das Clinicas

    1996-12-31

    An alternative solution for the reconstruction of SPECT images using a Poisson Noise Model is presented. The proposed algorithm was applied on a real phantom and compared to the standard clinical procedures. Results have shown that the proposed method improves the quality of the SPECT images 3 refs.

  16. Activity concentration measurements using a conjugate gradient (Siemens xSPECT) reconstruction algorithm in SPECT/CT.

    Science.gov (United States)

    Armstrong, Ian S; Hoffmann, Sandra A

    2016-11-01

    The interest in quantitative single photon emission computer tomography (SPECT) shows potential in a number of clinical applications and now several vendors are providing software and hardware solutions to allow 'SUV-SPECT' to mirror metrics used in PET imaging. This brief technical report assesses the accuracy of activity concentration measurements using a new algorithm 'xSPECT' from Siemens Healthcare. SPECT/CT data were acquired from a uniform cylinder with 5, 10, 15 and 20 s/projection and NEMA image quality phantom with 25 s/projection. The NEMA phantom had hot spheres filled with an 8 : 1 activity concentration relative to the background compartment. Reconstructions were performed using parameters defined by manufacturer presets available with the algorithm. The accuracy of activity concentration measurements was assessed. A dose calibrator-camera cross-calibration factor (CCF) was derived from the uniform phantom data. In uniform phantom images, a positive bias was observed, ranging from ∼6% in the lower count images to ∼4% in the higher-count images. On the basis of the higher-count data, a CCF of 0.96 was derived. As expected, considerable negative bias was measured in the NEMA spheres using region mean values whereas positive bias was measured in the four largest NEMA spheres. Nonmonotonically increasing recovery curves for the hot spheres suggested the presence of Gibbs edge enhancement from resolution modelling. Sufficiently accurate activity concentration measurements can easily be measured on images reconstructed with the xSPECT algorithm without a CCF. However, the use of a CCF is likely to improve accuracy further. A manual conversion of voxel values into SUV should be possible, provided that the patient weight, injected activity and time between injection and imaging are all known accurately.

  17. A methodology for generating normal and pathological brain perfusion SPECT images for evaluation of MRI/SPECT fusion methods: application in epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Grova, C [Laboratoire IDM, Faculte de Medecine, Universite de Rennes 1, Rennes (France); Jannin, P [Laboratoire IDM, Faculte de Medecine, Universite de Rennes 1, Rennes (France); Biraben, A [Laboratoire IDM, Faculte de Medecine, Universite de Rennes 1, Rennes (France); Buvat, I [INSERM U494, CHU Pitie Salpetriere, Paris (France); Benali, H [INSERM U494, CHU Pitie Salpetriere, Paris (France); Bernard, A M [Service de Medecine Nucleaire, Centre Eugene Marquis, Rennes (France); Scarabin, J M [Laboratoire IDM, Faculte de Medecine, Universite de Rennes 1, Rennes (France); Gibaud, B [Laboratoire IDM, Faculte de Medecine, Universite de Rennes 1, Rennes (France)

    2003-12-21

    Quantitative evaluation of brain MRI/SPECT fusion methods for normal and in particular pathological datasets is difficult, due to the frequent lack of relevant ground truth. We propose a methodology to generate MRI and SPECT datasets dedicated to the evaluation of MRI/SPECT fusion methods and illustrate the method when dealing with ictal SPECT. The method consists in generating normal or pathological SPECT data perfectly aligned with a high-resolution 3D T1-weighted MRI using realistic Monte Carlo simulations that closely reproduce the response of a SPECT imaging system. Anatomical input data for the SPECT simulations are obtained from this 3D T1-weighted MRI, while functional input data result from an inter-individual analysis of anatomically standardized SPECT data. The method makes it possible to control the 'brain perfusion' function by proposing a theoretical model of brain perfusion from measurements performed on real SPECT images. Our method provides an absolute gold standard for assessing MRI/SPECT registration method accuracy since, by construction, the SPECT data are perfectly registered with the MRI data. The proposed methodology has been applied to create a theoretical model of normal brain perfusion and ictal brain perfusion characteristic of mesial temporal lobe epilepsy. To approach realistic and unbiased perfusion models, real SPECT data were corrected for uniform attenuation, scatter and partial volume effect. An anatomic standardization was used to account for anatomic variability between subjects. Realistic simulations of normal and ictal SPECT deduced from these perfusion models are presented. The comparison of real and simulated SPECT images showed relative differences in regional activity concentration of less than 20% in most anatomical structures, for both normal and ictal data, suggesting realistic models of perfusion distributions for evaluation purposes. Inter-hemispheric asymmetry coefficients measured on simulated data were

  18. A combined static-dynamic single-dose imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT.

    Science.gov (United States)

    Sciammarella, Maria; Shrestha, Uttam M; Seo, Youngho; Gullberg, Grant T; Botvinick, Elias H

    2017-08-03

    SPECT myocardial perfusion imaging (MPI) is a clinical mainstay that is typically performed with static imaging protocols and visually or semi-quantitatively assessed for perfusion defects based upon the relative intensity of myocardial regions. Dynamic cardiac SPECT presents a new imaging technique based on time-varying information of radiotracer distribution, which permits the evaluation of regional myocardial blood flow (MBF) and coronary flow reserve (CFR). In this work, a preliminary feasibility study was conducted in a small patient sample designed to implement a unique combined static-dynamic single-dose one-day visit imaging protocol to compare quantitative dynamic SPECT with static conventional SPECT for improving the diagnosis of coronary artery disease (CAD). Fifteen patients (11 males, four females, mean age 71 ± 9 years) were enrolled for a combined dynamic and static SPECT (Infinia Hawkeye 4, GE Healthcare) imaging protocol with a single dose of 99mTc-tetrofosmin administered at rest and a single dose administered at stress in a one-day visit. Out of 15 patients, eleven had selective coronary angiography (SCA), 8 within 6 months and the rest within 24 months of SPECT imaging, without intervening symptoms or interventions. The extent and severity of perfusion defects in each myocardial region was graded visually. Dynamically acquired data were also used to estimate the MBF and CFR. Both visually graded images and estimated CFR were tested against SCA as a reference to evaluate the validity of the methods. Overall, conventional static SPECT was normal in ten patients and abnormal in five patients, dynamic SPECT was normal in 12 patients and abnormal in three patients, and CFR from dynamic SPECT was normal in nine patients and abnormal in six patients. Among those 11 patients with SCA, conventional SPECT was normal in 5, 3 with documented CAD on SCA with an overall accuracy of 64%, sensitivity of 40% and specificity of 83%. Dynamic SPECT image

  19. Feasibility of one-eighth time gated myocardial perfusion SPECT functional imaging using IQ-SPECT.

    Science.gov (United States)

    Caobelli, Federico; Thackeray, James T; Soffientini, Alberto; Bengel, Frank M; Pizzocaro, Claudio; Guerra, Ugo Paolo

    2015-11-01

    IQ-SPECT, an add-on to general purpose cameras based on multifocal collimation, can reduce myocardial perfusion imaging (MPI) acquisition times to one-fourth that of standard procedures (to 12 s/view). In a phantom study, a reduction of the acquisition time to one-eighth of the standard time (to 6 s/view) was demonstrated as feasible. It remains unclear whether such a reduction could be extended to clinical practice. Fifty patients with suspected or diagnosed CAD underwent a 2-day stress-rest (99m)Tc-sestamibi MPI protocol. Two consecutive SPECT acquisitions (6 and 12 s/view) were performed. Electrocardiogram-gated images were reconstructed with and without attenuation correction (AC). Polar maps were generated and visually scored by two blinded observers for image quality and perfusion in 17 segments. Global and regional summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS) were determined. Left ventricular volumes and ejection fraction were calculated based on automated contour detection. Image quality was scored higher with the 12 s/view acquisition, both with and without AC. Summed scores were statistically comparable between the 6 s/view and the 12 s/view acquisition, both globally and in individual coronary territories (e.g. in images with AC, SSS were 6.6 ± 8.3 and 6.2 ± 8.2 with 6 s and 12 s/view, respectively, p = 0.10; SRS were 3.9 ± 5.6 and 3.5 ± 5.3, respectively, p = 0.19; and SDS were 2.8 ± 5.7 and 2.6 ± 5.7, respectively, p = 0.59). Both acquisitions allowed MPI-based diagnosis of CAD in 25 of the 50 patients (with AC). Calculated end-diastolic volume (EDV) and end-systolic volume (ESV) were modestly higher with the 6 s/view acquisition than with the 12 s/view acquisition (EDV +4.8 ml at rest and +3.7 ml after stress, p = 0.003; ESV +4.1 ml at rest and +2.6 ml after stress, p = 0.01), whereas the ejection fraction did not differ (-1.2 % at rest, p = 0.20, and -0

  20. Receptor mapping in psychiatric patients with SPECT; Rezeptor-SPECT-Untersuchungen bei psychiatrischen Patienten

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, S. [Mainz Univ. (Germany). Psychiatrische Klinik

    1997-06-01

    This paper summarizes some data of our studies with the single-photon-emission-computerized tomography (SPECT), focussing on the dopamine-D2- and the benzodiazepine receptor mapping. Benzodiazepine receptors: Central benzodiazepine receptors (BZr) can be visualized with iomazenil which is an analogue of the benzodiazepine antagonist flumazenil, labeled with 123-iodine. Since the involvement of the BZr system is discussed in the pathogenesis of anxiety and depression, patients with these disorders were investigated. A third study investigated the BZr-occupancy during benzodiazepine treatment (lorazepam). Results: (a) Patients with panic disorders had lower iomazenil uptake values compared to epileptic patients. (b) Depressed patients showed a positive correlation between severity of illness and frontal uptake. (c) BZr occupancy during lorazepam treatment was measurable, but not associated with lorazepam plasma levels. Dopamine-D2-receptors: With 123-I-iodobenzamide (IBZM), and iodine-labeled dopamine receptor ligand, the D2 receptor density can be measured by a semiquantitative approach (striatum/frontal cortex=ST/FC). Therefore, we investigated the D2-receptor occupancy during treatment with typical and atypical neuroleptics in relationship to dosages (normalized with different formulas of chlorpromazine equivalents), side effects, and prolactin plasma levels. Results: Dependent on the selected formula for chlorpromazine equivalents, the ST/FC ratio was correlated with dosages. Side effects and prolactin plasma levels showed a negative association with lower ST/FC ratios. (orig.) [Deutsch] Der Beitrag soll einen Ueberblick ueber verschiedene eigene Studien geben, die die Darstellung von Dopamin-D2- und Benzodiazepinrezeptoren mit der Single-Photon-Emissions-Computertomographie (SPECT) untersuchten. Benzodiazepinrezeptoren: Jomazenil, der mit 123-Jod markierte Benzodiazepinantagonist Flumazenil, ermoeglicht die Darstellung der zentralen Benzodiazepinrezeptoren (BZr

  1. Gated pinhole camera imaging of the high-energy ions emitted by a discharge produced Sn plasma for extreme ultraviolet generation

    NARCIS (Netherlands)

    Gielissen, K.; Sidelnikov, Y.; Glushkov, D.; Soer, W.A.; Banine V.Y.; Van der Mullen, J.J.A.M.

    2010-01-01

    The origin and nature of the high-energy ions emitted by a dischargeproduced plasma source are studied using gated pinhole camera imaging. Time-of-flight analysis in combination with Faraday cup measurements enables characterization of the high-velocity component of theionic debris. The use of an

  2. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... contraception], Safety, Self-harm) interview is a feasible way of exploring health risk behaviors and resilience. OBJECTIVE: The purpose of this study was to evaluate how often HEADS topics were addressed according to young patients and staff in pediatric and adult outpatient clinics. METHODS: We conducted...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...

  3. Simultaneous usage of pinhole and penumbral apertures for imaging small scale neutron sources from inertial confinement fusion experiments.

    Science.gov (United States)

    Guler, N; Volegov, P; Danly, C R; Grim, G P; Merrill, F E; Wilde, C H

    2012-10-01

    Inertial confinement fusion experiments at the National Ignition Facility are designed to understand the basic principles of creating self-sustaining fusion reactions by laser driven compression of deuterium-tritium (DT) filled cryogenic plastic capsules. The neutron imaging diagnostic provides information on the distribution of the central fusion reaction region and the surrounding DT fuel by observing neutron images in two different energy bands for primary (13-17 MeV) and down-scattered (6-12 MeV) neutrons. From this, the final shape and size of the compressed capsule can be estimated and the symmetry of the compression can be inferred. These experiments provide small sources with high yield neutron flux. An aperture design that includes an array of pinholes and penumbral apertures has provided the opportunity to image the same source with two different techniques. This allows for an evaluation of these different aperture designs and reconstruction algorithms.

  4. Homogeneous pinhole free 1 nm Al{sub 2}O{sub 3} tunnel barriers on graphene

    Energy Technology Data Exchange (ETDEWEB)

    Dlubak, B.; Martin, M.-B.; Deranlot, C.; Bouzehouane, K.; Fusil, S.; Mattana, R.; Petroff, F.; Anane, A.; Seneor, P.; Fert, A. [Unite Mixte de Physique CNRS/Thales, 91767 Palaiseau (France) and University of Paris-Sud, 91405 Orsay (France)

    2012-11-12

    We report on the topographical and electrical characterisations of 1 nm thick Al{sub 2}O{sub 3} dielectric films on graphene. The Al{sub 2}O{sub 3} is grown by sputtering a 0.6 nm Al layer on graphene and subsequentially oxidizing it in an O{sub 2} atmosphere. The Al{sub 2}O{sub 3} layer presents no pinholes and is homogeneous enough to act as a tunnel barrier. A resistance-area product in the mega-ohm micrometer-square range is found. Comparatively, the growth of Al{sub 2}O{sub 3} by evaporation does not lead to well-wetted films on graphene. Application of this high quality sputtered tunnel barrier to efficient spin injection in graphene is discussed.

  5. {sup 99m}Tc-MDP pinhole bone scintigraphic feature of fibrovascular zone: a new diagnostic sign of osteoid osteoma

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yong Whee [Sung Ae Hospital, Seoul (Korea, Republic of); Kim, Sung Hoon; Choi, Yeong Jin [Catholic University Medical School, Seoul (Korea, Republic of)

    2007-02-15

    Osteoid osteoma is a common benign tumor. Histologically, the tumor is characterized by the presence of the nidus, fibrovascular zone (FVZ) and reactive host bone scleroses of various intensities. A nidus consists of core meshwork of osteoid trabeculae, woven bone and osteoblastic rim and a FVZ, 1-2 mm rim, is composed of loose fibrovascular tissue and nerve fibers. The nidus and FVZ are readily identifiable on pathological specimen and CT when sclerosis is not too extensive. Recently on pinhole bone scan, we observed a peculiar rim sign that denoted FVZ in a patient with pathologically proven osteoid osteoma. Not previously described the sign appears to be pathognomonic of osteoid osteoma, uniquely providing metabolic information. The finding was correlated with that of radiography, CT and MRI and low power light microscopy.

  6. A new X-ray pinhole camera for energy dispersive X-ray fluorescence imaging with high-energy and high-spatial resolution

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Altana, C. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy); Cosentino, L.; Celona, L.; Gammino, S.; Mascali, D. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [INFN-LNS, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2013-08-01

    A new X-ray pinhole camera for the Energy Dispersive X-ray Fluorescence (ED-XRF) imaging of materials with high-energy and high-spatial resolution, was designed and developed. It consists of a back-illuminated and deep depleted CCD detector (composed of 1024 × 1024 pixels with a lateral size of 13 μm) coupled to a 70 μm laser-drilled pinhole-collimator, positioned between the sample under analysis and the CCD. The X-ray pinhole camera works in a coaxial geometry allowing a wide range of magnification values. The characteristic X-ray fluorescence is induced on the samples by irradiation with an external X-ray tube working at a maximum power of 100 W (50 kV and 2 mA operating conditions). The spectroscopic capabilities of the X-ray pinhole camera were accurately investigated. Energy response and energy calibration of the CCD detector were determined by irradiating pure target-materials emitting characteristic X-rays in the energy working-domain of the system (between 3 keV and 30 keV). Measurements were performed by using a multi-frame acquisition in single-photon counting. The characteristic X-ray spectra were obtained by an automated processing of the acquired images. The energy resolution measured at the Fe–Kα line is 157 eV. The use of the X-ray pinhole camera for the 2D resolved elemental analysis was investigated by using reference-patterns of different materials and geometries. The possibility of the elemental mapping of samples up to an area of 3 × 3 cm{sup 2} was demonstrated. Finally, the spatial resolution of the pinhole camera was measured by analyzing the profile function of a sharp-edge. The spatial resolution determined at the magnification values of 3.2 × and 0.8 × (used as testing values) is about 90 μm and 190 μm respectively. - Highlights: • We developed an X-ray pinhole camera for the 2D X-ray fluorescence imaging. • X-ray spectra are obtained by a multi-frame acquisition in single photon mode. • The energy resolution in the X

  7. Biodistribution on Tc-99m labeled somatostatin receptor-binding peptide (Depreotide, NeoTec) planar and SPECT studies

    Energy Technology Data Exchange (ETDEWEB)

    Shih, W; Hirschowitz, E.; Bensadoun, E.; Woodring, J.; Ryo, Y.U.; Kraman, S. [Kentucky Univ., Lexington, KY (United States). Medical Center

    2002-05-01

    The purpose of this study was to determine the biodistribution of Tc-99m labeled somatostatin receptor-binding peptide (Depreotide) on planar and SPECT studies of the thorax and upper abdomen in order to improve diagnostic accuracy. Retrospectively 29 planar and SPECT studies from 28 patients (all males, average age of 65.79) were reviewed. All the patients had been referred for evaluation of solitary pulmonary nodules. Two to four hours after IV injection of 555- to 740-MBq (15-20 mCi) Tc-99m Depreotide, anterior and posterior total body images, and anterior, posterior, right lateral and left lateral planar images were obtained, and thoracic SPECT was acquired with a three-head gamma camera. The degree of uptake in the lungs, thoracic cage, and organs of the upper abdomen was rated from ''0'' to ''++++''. The range of normal activity in the thorax includes cardiac, ''0''; pulmonary, +''; rib, ''+/++''; sternum, ''++''; vertebrae, ''++''. The degree of normal activity seen in the upper abdominal organs includes liver and spleen, +++'', and kidneys, '''+++/++++''. Eight patients with emphysema had diffuse pulmonary uptake graded as ''+/++''. One patient with left pneumonectomy and radiation therapy to the left hemithorax had photon-deficiency in the left hemithorax and decreased to absent uptake including the vertebrae and ribs. Although some cases had background pulmonary uptake of Tc-99m Depreotide, the bone/bone marrow activity of the thoracic cage including the ribs, sternum, and thoracic spine is sufficiently great enough to produce a clear distinction between bone and lung in the thoracic cavity that gives high-contrast resolution on SPECT. The intensity of radioactivity in the sub-diaphragmatic organs such as the liver, spleen, and kidneys provides useful guidance for the

  8. 3D SPECT/CT fusion using image data projection of bone SPECT onto 3D volume-rendered CT images: feasibility and clinical impact in the diagnosis of bone metastasis.

    Science.gov (United States)

    Ogata, Yuji; Nakahara, Tadaki; Ode, Kenichi; Matsusaka, Yohji; Katagiri, Mari; Iwabuchi, Yu; Itoh, Kazunari; Ichimura, Akira; Jinzaki, Masahiro

    2017-05-01

    We developed a method of image data projection of bone SPECT into 3D volume-rendered CT images for 3D SPECT/CT fusion. The aims of our study were to evaluate its feasibility and clinical usefulness. Whole-body bone scintigraphy (WB) and SPECT/CT scans were performed in 318 cancer patients using a dedicated SPECT/CT systems. Volume data of bone SPECT and CT were fused to obtain 2D SPECT/CT images. To generate our 3D SPECT/CT images, colored voxel data of bone SPECT were projected onto the corresponding location of the volume-rendered CT data after a semi-automatic bone extraction. Then, the resultant 3D images were blended with conventional volume-rendered CT images, allowing to grasp the three-dimensional relationship between bone metabolism and anatomy. WB and SPECT (WB + SPECT), 2D SPECT/CT fusion, and 3D SPECT/CT fusion were evaluated by two independent reviewers in the diagnosis of bone metastasis. The inter-observer variability and diagnostic accuracy in these three image sets were investigated using a four-point diagnostic scale. Increased bone metabolism was found in 744 metastatic sites and 1002 benign changes. On a per-lesion basis, inter-observer agreements in the diagnosis of bone metastasis were 0.72 for WB + SPECT, 0.90 for 2D SPECT/CT, and 0.89 for 3D SPECT/CT. Receiver operating characteristic analyses for the diagnostic accuracy of bone metastasis showed that WB + SPECT, 2D SPECT/CT, and 3D SPECT/CT had an area under the curve of 0.800, 0.983, and 0.983 for reader 1, 0.865, 0.992, and 0.993 for reader 2, respectively (WB + SPECT vs. 2D or 3D SPECT/CT, p images were 241 ± 75, 225 ± 73, and 182 ± 71 s for reader 1 and 207 ± 72, 190 ± 73, and 179 ± 73 s for reader 2, respectively. As a result, it took shorter time to read 3D SPECT/CT images than 2D SPECT/CT (p images (p reading time compared to 2D SPECT/CT fusion.

  9. Different SPECT findings before and after Capgras' syndrome in interictal psychosis.

    Science.gov (United States)

    Horikawa, Hideki; Monji, Akira; Sasaki, Masayuki; Maekawa, Toshihiko; Onitsuka, Toshiaki; Nitazaka, Yoko; Hirano, Yoji; Hirano, Shougo; Hashioka, Sadayuki; Kato, Takahiro; Yoshida, Ichiro; Kanba, Shigenobu

    2006-08-01

    We herein report a case of Capgras' syndrome observed in interictal psychosis in which the single-photon emission computed tomography (SPECT) findings before and after the appearance of the psychotic symptoms differed. SPECT with 99mTc-hexamethyl propyleneamine oxine (HMPAO) revealed worsening of hypoperfusion in the entire right hemisphere after onset of the psychotic symptoms. The enhanced hypoperfusion demonstrated by SPECT in the present case seems to indicate a right interhemispheric disconnection resulting in the occurrence of Capgras' syndrome.

  10. Epoxy catalyzed sol–gel method for pinhole-free pyrite FeS{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kment, S., E-mail: kment@fzu.cz [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 14800 Prague (Czech Republic); Department of Electrical Engineering, University of Nebraska-Lincoln, 209N Scott Engineering Center, Lincoln, NE 68588-0511 (United States); Kmentova, H. [Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 2/135, 165 02 Prague (Czech Republic); Department of Electrical Engineering, University of Nebraska-Lincoln, 209N Scott Engineering Center, Lincoln, NE 68588-0511 (United States); Sarkar, A.; Soukup, R.J.; Ianno, N.J.; Sekora, D. [Department of Electrical Engineering, University of Nebraska-Lincoln, 209N Scott Engineering Center, Lincoln, NE 68588-0511 (United States); Olejnicek, J.; Ksirova, P. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 14800 Prague (Czech Republic); Krysa, J. [Department of Inorganic Technology, Institute of Chemical Technology Prague, Technicka 5, 16628 Prague (Czech Republic); Remes, Z.; Hubicka, Z. [Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 14800 Prague (Czech Republic)

    2014-09-01

    Highlights: • Photoactive pyrite thin films can be fabricated by a novel sol–gel route. • The pyrite films are pinhole-free, phase-pure and without contaminants. • The pyrite film can photosensitize titanium dioxide in a photoelectrochemical cell. - Abstract: The uniform pinhole-free iron disulfide (FeS{sub 2}) pyrite thin films were fabricated. In the first step the FeO(OH){sub x} xerogel solution was synthetized by means of a novel epoxy catalyzed sol–gel method and next spin-coated onto various substrates to form the thin films. In the second step the xerogel coatings were annealed to yield hematite (α-Fe{sub 2}O{sub 3}) films, which were transformed into pyrite by chemical sulfurization. Among the main deposition parameters studied were the temperature of xerogel–hematite transformation and the optimal sufulrization temperature and duration. It has been observed that 15 min sulfurization at the temperature of 450 °C provided the pyrite films of sufficient quality. The estimated optical band gap of 0.98 eV is very close to the theoretical value of 0.95 eV. Auger electron spectroscopy showed almost ideal stoichiometry of FeS{sub 2}. However a trace amount of oxygen (approximately 0.5 at.%) present in the film was still detected. The photoinduced functionality of the films was assessed based on photoelectrochemical experiments. In order to demonstrate the ability of pyrite to photosensitize a large band gap semiconductor, a bilayer system of TiO{sub 2} anatase/FeS{sub 2} pyrite was prepared. The highest photocurrent reached was 45 μA cm{sup −2} at the light intensity of 10.5 mW cm{sup −2}.

  11. EANM procedural guidelines for radionuclide myocardial perfusion imaging with SPECT and SPECT/CT: 2015 revision

    Energy Technology Data Exchange (ETDEWEB)

    Verberne, Hein J.; Eck-Smit, Berthe L.F. van; Wit, Tim C. de [University of Amsterdam, Department of Nuclear Medicine, F2-238, Academic Medical Center, Amsterdam (Netherlands); Acampa, Wanda [National Council of Research, Institute of Biostructures and Bioimaging, Naples (Italy); Anagnostopoulos, Constantinos [Academy of Athens, Center for Experimental Surgery, Clinical and Translational Research, Biomedical Research Foundation, Athens (Greece); Ballinger, Jim [Guy' s Hospital - Guy' s and St Thomas' Trust Foundation, Department of Nuclear Medicine, London (United Kingdom); Bengel, Frank [Hannover Medical School, Department of Nuclear Medicine, Hannover (Germany); Bondt, Pieter De [OLV Hospital, Department of Nuclear Medicine, Aalst (Belgium); Buechel, Ronny R.; Kaufmann, Philip A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Cuocolo, Alberto [University Federico II, Department of Advanced Biomedical Sciences, Naples (Italy); Flotats, Albert [Universitat Autonoma de Barcelona, Nuclear Medicine Department, Hospital de la Santa Creu i Sant Pau, Barcelona (Spain); Hacker, Marcus [Medical University of Vienna, Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Vienna (Austria); Hindorf, Cecilia [Skaane University Hospital, Department of Radiation Physics, Lund (Sweden); Lindner, Oliver [University Hospital of the Ruhr-University Bochum, Heart and Diabetes Center North Rhine-Westphalia, Institute for Radiology, Nuclear Medicine and Molecular Imaging, Bad Oeynhausen (Germany); Ljungberg, Michael [Lund University, Department of Medical Radiation Physics, Lund (Sweden); Lonsdale, Markus [Bispebjerg Hospital, Department of Clinical Physiology and Nuclear Medicine, Copenhagen (Denmark); Manrique, Alain [Caen University Hospital, Department of Nuclear Medicine, Service Commun Investigations chez l' Homme, GIP Cyceron, Caen (France); Minarik, David [Skaane University Hospital, Radiation Physics, Malmoe (Sweden); Scholte, Arthur J.H.A. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Slart, Riemer H.J.A. [University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Traegaardh, Elin [Skaane University Hospital and Lund University, Clinical Physiology and Nuclear Medicine, Malmoe (Sweden); Hesse, Birger [University Hospital of Copenhagen, Department of Clinical Physiology and Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark)

    2015-11-15

    Since the publication of the European Association of Nuclear Medicine (EANM) procedural guidelines for radionuclide myocardial perfusion imaging (MPI) in 2005, many small and some larger steps of progress have been made, improving MPI procedures. In this paper, the major changes from the updated 2015 procedural guidelines are highlighted, focusing on the important changes related to new instrumentation with improved image information and the possibility to reduce radiation exposure, which is further discussed in relation to the recent developments of new International Commission on Radiological Protection (ICRP) models. Introduction of the selective coronary vasodilator regadenoson and the use of coronary CT-contrast agents for hybrid imaging with SPECT/CT angiography are other important areas for nuclear cardiology that were not included in the previous guidelines. A large number of minor changes have been described in more detail in the fully revised version available at the EANM home page: http://eanm.org/ publications/guidelines/2015{sub 0}7{sub E}ANM{sub F}INAL myocardial{sub p}erfusion{sub g}uideline.pdf. (orig.)

  12. High-order total variation minimization for interior SPECT

    Science.gov (United States)

    Yang, Jiansheng; Yu, Hengyong; Jiang, Ming; Wang, Ge

    2011-01-01

    Recently, we developed an approach for solving the computed tomography (CT) interior problem based on the high-order TV (HOT) minimization, assuming that a region-of-interest (ROI) is piecewise polynomial. In this paper, we generalize this finding from the CT field to the single-photon emission computed tomography (SPECT) field, and prove that if an ROI is piecewise polynomial, then the ROI can be uniquely reconstructed from the SPECT projection data associated with the ROI through the HOT minimization. Also, we propose a new formulation of HOT, which has an explicit formula for any n-order piecewise polynomial function, while the original formulation has no explicit formula for n ≥ 2. Finally, we verify our theoretical results in numerical simulation, and discuss relevant issues. PMID:22215932

  13. Molecular Imaging of Hydrolytic Enzymes Using PET and SPECT.

    Science.gov (United States)

    Rempel, Brian P; Price, Eric W; Phenix, Christopher P

    2017-01-01

    Hydrolytic enzymes are a large class of biological catalysts that play a vital role in a plethora of critical biochemical processes required to maintain human health. However, the expression and/or activity of these important enzymes can change in many different diseases and therefore represent exciting targets for the development of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) radiotracers. This review focuses on recently reported radiolabeled substrates, reversible inhibitors, and irreversible inhibitors investigated as PET and SPECT tracers for imaging hydrolytic enzymes. By learning from the most successful examples of tracer development for hydrolytic enzymes, it appears that an early focus on careful enzyme kinetics and cell-based studies are key factors for identifying potentially useful new molecular imaging agents.

  14. aSPECT - Measuring the proton spectrum in neutron decay

    Energy Technology Data Exchange (ETDEWEB)

    Simson, Martin; Soldner, Torsten; Zimmer, Oliver [Institut Laue-Langevin, Grenoble (France); Physik-Department E18, TU Muenchen (Germany); Ayala Guardia, Fidel; Borg, Michael; Heil, Werner; Konrad, Gertrud; Munoz Horta, Raquel; Ostrick, Beatrix [Institut fuer Physik, Universitaet Mainz (Germany); Baessler, Stefan [University of Virginia, Charlottesville, VA (United States); Glueck, Ferenc [IEKP, Universitaet Karlsruhe (Germany); Konorov, Igor [Physik-Department E18, TU Muenchen (Germany); Wirth, Hans-Friedrich [Fakultaet fuer Physik, LMU Muenchen (Germany)

    2010-07-01

    With the aSPECT spectrometer we measure the proton recoil spectrum in the decay of the free neutron. Its shape depends on the angular correlation between the momenta of the antineutrino and electron for kinematic reasons. A precision measurement of this correlation coefficient a allows to test the unitarity of the CKM matrix and provides limits on the existence of scalar and tensor currents. aSPECT is a retardation spectrometer, this means protons from neutron decay are guided by a strong magnetic field and the proton recoil spectrum is measured by counting all protons that overcome a electrostatic barrier. By varying the height of the barrier the shape of the proton spectrum can be reconstructed. After the barrier the protons are accelerated to {proportional_to}15 keV and detected by a silicon drift detector. This talk covers details of the spectrometer and detector, as well as techniques used in the data analysis.

  15. Utility of bone SPECT in temporomandibular joint pain

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dong Hunn; Sung, Mi Sook; Lee, Jung Whee; Chung, Soo Kyo; Shinn, Kyung Sub [College of Medicine, Catholic Univ., Pucheon (Korea, Republic of)

    1997-07-01

    Temporomandibular (TM) joint pain results from many etiologic factors. The aim of this study was to evaluate the utility of Bone SPECT in patients with TM joint pain. The subjects were 34 patients with TM joint pain. All patients underwent plain radiography, planar bone scan, and Bone SPECT. The intensity of radioisotope uptake at TM joint was graded into three; no increased uptake above the background activity as grade 0, uptake similar to occipital bone as grade I, and uptake similar to maxillary sinus as grade II. Clinical findings and therapeutic methods were reviewed. Twenty-seven patients (80%) out of 34 patients with TM joint pain had increased uptake in bone SPECT. Twenty-one (78%) out of 27 patients had increased uptake in the mandibular condyle and remaining six patients (22%) had uptake in the mandibular and maxillary arch, which proved to be dental problem. Seven patients (21%) out of 34 were grade as 0, four (12%) were grade I, 23 (68%) were grade. II. Four patients with grade I had clicking sound and symptoms which were subsided with medication in all cases. Among 23 patients with grade II, 7 patients had clicking sound and 14 patients underwent medication and decompression therapy. With Planar bone scan, 11 cases (32%) had increased uptake in TM joint area. Plain radiography revealed narrowing, distension, erosion and limitation of TM joint in 16 cases (47%). Bone SPECT can be valuable for screening and managing the patients with TM joint pain. Patients with grade II needed intensive treatment such as joint aspiration. However degree of the radioisotope uptake did not well correlated with clinical symptoms.

  16. SPECT brain imaging in epilepsy: a meta-analysis.

    Science.gov (United States)

    Devous, M D; Thisted, R A; Morgan, G F; Leroy, R F; Rowe, C C

    1998-02-01

    A meta-analysis of SPECT brain imaging in epilepsy was performed to derive the sensitivity and specificity of interictal, postictal or ictal rCBF patterns to identify a seizure focus in medically refractory patients. Papers were obtained by pooling all published articles identified by two independent literature searches: (a) Dialnet (EMBASE) or Radline by CD-ROM and (b) Current Contents searched manually. Literature inclusion criteria were: (a) patients had a localization-related epileptic syndrome; (b) more than six patients were reported; and (c) patients had at least an interictal EEG-documented epileptiform abnormality. Of 46 papers meeting these criteria, 30 contained extractable data. SPECT results were compared to localization by standard diagnostic evaluation and surgical outcome. Meta-analytic sensitivities for SPECT localization in patients with temporal lobe seizures relative to diagnostic evaluation were 0.44 (interictal), 0.75 (postictal) and 0.97 (ictal). Similar results were obtained relative to surgical outcome. False-positive rates were low relative to diagnostic evaluation (7.4% for interictal and 1.5% for postictal studies) and surgical outcome (4.4% for interictal and 0.0% for postictal studies). The results were not dependent on tracer used (or dose), the presence of CT-identified structural abnormalities, blinding of image interpretation or camera quality (although data were more variable with low-resolution cameras). There were insufficient data for conclusions regarding extratemporal-seizure or pediatric epilepsy populations. Insights gained from reviewing this literature yielded recommendations for minimal information that should be provided in future reports. Additional recommendations regarding the nature and focus of future studies also are provided. The most important of these is that institutions using SPECT imaging in epilepsy should perform ictal, preferably, or postictal scanning in combination with interictal scanning.

  17. In vivo SPECT reporter gene imaging of regulatory T cells.

    Directory of Open Access Journals (Sweden)

    Ehsan Sharif-Paghaleh

    Full Text Available Regulatory T cells (Tregs were identified several years ago and are key in controlling autoimmune diseases and limiting immune responses to foreign antigens, including alloantigens. In vivo imaging techniques including intravital microscopy as well as whole body imaging using bioluminescence probes have contributed to the understanding of in vivo Treg function, their mechanisms of action and target cells. Imaging of the human sodium/iodide symporter via Single Photon Emission Computed Tomography (SPECT has been used to image various cell types in vivo. It has several advantages over the aforementioned imaging techniques including high sensitivity, it allows non-invasive whole body studies of viable cell migration and localisation of cells over time and lastly it may offer the possibility to be translated to the clinic. This study addresses whether SPECT/CT imaging can be used to visualise the migratory pattern of Tregs in vivo. Treg lines derived from CD4(+CD25(+FoxP3(+ cells were retrovirally transduced with a construct encoding for the human Sodium Iodide Symporter (NIS and the fluorescent protein mCherry and stimulated with autologous DCs. NIS expressing self-specific Tregs were specifically radiolabelled in vitro with Technetium-99m pertechnetate ((99mTcO(4(- and exposure of these cells to radioactivity did not affect cell viability, phenotype or function. In addition adoptively transferred Treg-NIS cells were imaged in vivo in C57BL/6 (BL/6 mice by SPECT/CT using (99mTcO(4(-. After 24 hours NIS expressing Tregs were observed in the spleen and their localisation was further confirmed by organ biodistribution studies and flow cytometry analysis. The data presented here suggests that SPECT/CT imaging can be utilised in preclinical imaging studies of adoptively transferred Tregs without affecting Treg function and viability thereby allowing longitudinal studies within disease models.

  18. Bilateral anterior opercular syndrome: Localizing value of SPECT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Tohgi, H.; Sano, M.; Takahashi, S.; Chiba, K.; Matsuoka, S.

    1988-12-01

    Bilateral anterior opercular syndrome is clinically characterized by facio-pharyngo-glossomasticatory diplegia due to bilateral opercular lesions. Reported cases of the syndrome have been relatively rare probably because of difficulty in determining opercular damage on clinical symptoms alone. We report a case of this syndrome in whom bilateral opercular damage could be detected not by CT, but suspected by SPECT, and confirmed by MR imaging.

  19. Monte Carlo simulation in SPECT: a comparison of two approaches

    Science.gov (United States)

    Sled, John G.; Celler, Anna; Barney, J. Scott; Ivanovic, Marija

    1994-05-01

    Monte Carlo methods play an important role in medical imaging research. Direct analog Monte Carlo simulations can be very accurate but require considerable computational resources. Variance reduction techniques may offer a solution to this problem. In this paper we present a comparison of expected values of standard quantities of interest for SPECT using these two simulation methods. The effect of variance reduction on the statistical characteristics of the simulated data is also investigated.

  20. Evaluation of pelvic ring injuries using SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Scheyerer, Max J. [University Hospital Zurich, Division of Trauma Surgery, Department of Surgery, Zurich (Switzerland); University Medical Center, Centre for Orthopaedic and Trauma Surgery, Cologne (Germany); Huellner, Martin; Pietsch, Carsten [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Werner, Clement M.L. [University Hospital Zurich, Division of Trauma Surgery, Department of Surgery, Zurich (Switzerland); Veit-Haibach, Patrick [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); University Hospital Zurich, Diagnostic and Interventional Radiology, Department of Medical Radiology, Zurich (Switzerland)

    2014-08-12

    The incidence of pelvic fractures is relatively low compared with other fracture locations. The low incidence is in great contrast to the high morbidity and mortality. Particularly in the elderly, with apparently isolated fractures of the pubic rami, these observations are believed to be due to additional occult lesions of the posterior pelvic ring. In these cases diagnosis cannot be established by conventional imaging alone and SPECT/CT is considered as a diagnostic adjunct. The aim of this study was to assess concomitant bony or soft tissue lesions within the pelvic ring in a population of patients with fractures of the anterior elements. In all patients with no obvious lesions of the posterior pelvic ring on X-rays and CT or with suspicious but inconclusive findings on CT an additional SPECT/CT was carried out in a non-acute setting within 3 days of the trauma. In all cases additional lesions within the pelvic ring were found. Most lesions were vertical sacral fractures, followed by transverse fractures, one non-dislocated fracture of the acetabulum on the side of the pubic rami fracture, and one post-traumatic dilatation of the sacroiliac joint with increased tracer uptake. According to our results after SPECT/CT all patients with pubic rami fracture suffered additional lesions, none detectable previously by X-ray or CT, within the pelvic ring. In this context SPECT/CT has proved to be very helpful in the clinical routine to visualize occult fractures and instability within the sacroiliac joint. (orig.)

  1. Utility of subtraction ictal SPECT when video-EEG fails to distinguish atypical psychogenic and epileptic seizures.

    Science.gov (United States)

    Neiman, Eli S; Noe, Katherine H; Drazkowski, Joseph F; Sirven, Joseph I; Roarke, Michael C

    2009-06-01

    This study was designed to evaluate the utility of subtraction ictal SPECT coregistered to MRI (SISCOM) in atypical psychogenic nonepileptic seizures (PNES). Video-EEG monitoring (vEEG) is the gold standard for PNES diagnosis but, like any modality, has limitations. In difficult cases in which the diagnosis is suspected but remains in question after vEEG, a complementary study that could help differentiate epilepsy from PNES would be desirable. Thirteen SISCOM studies performed in patients with a final diagnosis of PNES were retrospectively reviewed. Common indications for SISCOM were semiology consistent with partial epilepsy (9/13), abnormal head MRI (5/13), and reported abnormal routine EEG (5/13). SISCOM was negative in 85% (11/13) of patients and was helpful in increasing the diagnostic certainty of PNES in these exceptional cases.

  2. Anatomy guided automated SPECT renal seed point estimation

    Science.gov (United States)

    Dwivedi, Shekhar; Kumar, Sailendra

    2010-04-01

    Quantification of SPECT(Single Photon Emission Computed Tomography) images can be more accurate if correct segmentation of region of interest (ROI) is achieved. Segmenting ROI from SPECT images is challenging due to poor image resolution. SPECT is utilized to study the kidney function, though the challenge involved is to accurately locate the kidneys and bladder for analysis. This paper presents an automated method for generating seed point location of both kidneys using anatomical location of kidneys and bladder. The motivation for this work is based on the premise that the anatomical location of the bladder relative to the kidneys will not differ much. A model is generated based on manual segmentation of the bladder and both the kidneys on 10 patient datasets (including sum and max images). Centroid is estimated for manually segmented bladder and kidneys. Relatively easier bladder segmentation is followed by feeding bladder centroid coordinates into the model to generate seed point for kidneys. Percentage error observed in centroid coordinates of organs from ground truth to estimated values from our approach are acceptable. Percentage error of approximately 1%, 6% and 2% is observed in X coordinates and approximately 2%, 5% and 8% is observed in Y coordinates of bladder, left kidney and right kidney respectively. Using a regression model and the location of the bladder, the ROI generation for kidneys is facilitated. The model based seed point estimation will enhance the robustness of kidney ROI estimation for noisy cases.

  3. Physiological imaging with PET and SPECT in Dementia

    Energy Technology Data Exchange (ETDEWEB)

    Jagust, W.J. (California Univ., San Francisco, CA (United States). Dept. of Neurology Lawrence Berkeley Lab., CA (United States))

    1989-10-01

    Dementia is a medical problem of increasingly obvious importance. The most common cause of dementia, Alzheimer's disease (AD) accounts for at least 50% of all cases of dementia, with multi-infarct dementia the next most common cause of the syndrome. While the accuracy of diagnosis of AD may range from 80 to 90%, there is currently no laboratory test to confirm the diagnosis. Functional imaging techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT) offer diagnostic advantages since brain function is unequivocally disturbed in all dementing illnesses. Both PET and SPECT have been utilized in the study of dementia. While both techniques rely on principles of emission tomography to produce three dimensional maps of injected radiotracers, the differences between positron and single photon emission have important consequences for the practical applications of the two procedures. This briefly reviews the technical differences between PET and SPECT, and discusses how both techniques have been used in our laboratory to elucidate the pathophysiology of dementia. 32 refs., 2 figs.

  4. Novel SPECT Technologies and Approaches in Cardiac Imaging

    Directory of Open Access Journals (Sweden)

    Piotr Slomka

    2016-12-01

    Full Text Available Recent novel approaches in myocardial perfusion single photon emission CT (SPECT have been facilitated by new dedicated high-efficiency hardware with solid-state detectors and optimized collimators. New protocols include very low-dose (1 mSv stress-only, two-position imaging to mitigate attenuation artifacts, and simultaneous dual-isotope imaging. Attenuation correction can be performed by specialized low-dose systems or by previously obtained CT coronary calcium scans. Hybrid protocols using CT angiography have been proposed. Image quality improvements have been demonstrated by novel reconstructions and motion correction. Fast SPECT acquisition facilitates dynamic flow and early function measurements. Image processing algorithms have become automated with virtually unsupervised extraction of quantitative imaging variables. This automation facilitates integration with clinical variables derived by machine learning to predict patient outcome or diagnosis. In this review, we describe new imaging protocols made possible by the new hardware developments. We also discuss several novel software approaches for the quantification and interpretation of myocardial perfusion SPECT scans.

  5. Evaluating low pass filters on SPECT reconstructed cardiac orientation estimation

    Science.gov (United States)

    Dwivedi, Shekhar

    2009-02-01

    Low pass filters can affect the quality of clinical SPECT images by smoothing. Appropriate filter and parameter selection leads to optimum smoothing that leads to a better quantification followed by correct diagnosis and accurate interpretation by the physician. This study aims at evaluating the low pass filters on SPECT reconstruction algorithms. Criteria for evaluating the filters are estimating the SPECT reconstructed cardiac azimuth and elevation angle. Low pass filters studied are butterworth, gaussian, hamming, hanning and parzen. Experiments are conducted using three reconstruction algorithms, FBP (filtered back projection), MLEM (maximum likelihood expectation maximization) and OSEM (ordered subsets expectation maximization), on four gated cardiac patient projections (two patients with stress and rest projections). Each filter is applied with varying cutoff and order for each reconstruction algorithm (only butterworth used for MLEM and OSEM). The azimuth and elevation angles are calculated from the reconstructed volume and the variation observed in the angles with varying filter parameters is reported. Our results demonstrate that behavior of hamming, hanning and parzen filter (used with FBP) with varying cutoff is similar for all the datasets. Butterworth filter (cutoff > 0.4) behaves in a similar fashion for all the datasets using all the algorithms whereas with OSEM for a cutoff < 0.4, it fails to generate cardiac orientation due to oversmoothing, and gives an unstable response with FBP and MLEM. This study on evaluating effect of low pass filter cutoff and order on cardiac orientation using three different reconstruction algorithms provides an interesting insight into optimal selection of filter parameters.

  6. Compact CT/SPECT Small-Animal Imaging System

    Science.gov (United States)

    Kastis, George A.; Furenlid, Lars R.; Wilson, Donald W.; Peterson, Todd E.; Barber, H. Bradford; Barrett, Harrison H.

    2015-01-01

    We have developed a dual-modality CT/SPECT imaging system for small-animal imaging applications. The X-ray system comprises a commercially available micro-focus X-ray tube and a CCD-based X-ray camera. X-ray transmission measurements are performed based on cone-beam geometry. Individual projections are acquired by rotating the animal about a vertical axis in front of the CCD detector. A high-resolution CT image is obtained after reconstruction using an ordered subsets-expectation maximization (OS-EM) reconstruction algorithm. The SPECT system utilizes a compact semiconductor camera module previously developed in our group. The module is mounted perpendicular to the X-ray tube/CCD combination. It consists of a 64×64 pixellated CdZnTe detector and a parallel-hole tungsten collimator. The field of view is 1 square inch. Planar projections for SPECT reconstruction are obtained by rotating the animal in front of the detector. Gamma-ray and X-ray images are presented of phantoms and mice. Procedures for merging the anatomical and functional images are discussed. PMID:26538684

  7. Clinical, MRI and perfusion SPECT findings in strategic infarct dementia

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Park, Kyung Won; Cha, Jae Kwan; Kim, Sang Ho; Kim, Jae Woo [Dong-A University College of Medicine, Busan (Korea, Republic of)

    2002-07-01

    Strategic infarct dementia (SID) is characterized by focal ischemic lesions involving specific sites that are critical for higher cortical functions. The mechanism of SID are not well understood. We evaluate lesion sites, neuropsychiatric symptoms, brain perfusion SPECT and neuropsychological findings in patients with SID. Eleven patients with SID according to NINDS-AIREN criteria for vascular dementia were included. All patients performed brain MR and MRA, Tc-99m HMPAO brain perfusion SPECT. Various sites were responsible for SID; thalamus(n=3), medial temporal lobe(n=3), medial frontal lobe(n=1), genu of internal capsule(n=1), caudate nucleus(n=1), angular gyrus(n=1) and temporooccipital lobe(n=1). The most common neuropsychiatric symptoms were apathy and indifference by K-NPI. Brain perfusion SPECT revealed ipsilateral cortical hypoperfusion, mainly in frontal and temporal lobe area, in patients with subcortical strategic infarct. On neuropsychological assessment, cognitive deficits on attention and frontal executive function were prominent. The thalamus and medial temporal lobe were the most common sites responsible for SID. It was suggested that strategic disruption of frontal-subcortical circuit be an important role to produce SID in patients with subcortical strategic lesions.

  8. SVD-Based Evaluation of Multiplexing in Multipinhole SPECT Systems

    Directory of Open Access Journals (Sweden)

    Aaron K. Jorgensen

    2008-01-01

    Full Text Available Multipinhole SPECT system design is largely a trial-and-error process. General principles can give system designers a general idea of how a system with certain characteristics will perform. However, the specific performance of any particular system is unknown before the system is tested. The development of an objective evaluation method that is not based on experimentation would facilitate the optimization of multipinhole systems. We derive a figure of merit for prediction of SPECT system performance based on the entire singular value spectrum of the system. This figure of merit contains significantly more information than the condition number of the system, and is therefore more revealing of system performance. This figure is then compared with simulated results of several SPECT systems and is shown to correlate well to the results of the simulations. The proposed figure of merit is useful for predicting system performance, but additional steps could be taken to improve its accuracy and applicability. The limits of the proposed method are discussed, and possible improvements to it are proposed.

  9. Brain SPECT imaging with blood flow markers in epilepsy and balloon occlusion; Hirn-SPECT mit Durchblutungsmarkern in der Epilepsiediagnostik und bei der Ballon-Okklusion

    Energy Technology Data Exchange (ETDEWEB)

    Gruenwald, F. [Bonn Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    1996-02-01

    Brain SPECT imaging is used as a routine technique in presurgical evaluation. In three fields (focus detection, prognosis, stimulation) the value of brain SPECT imaging in cost effective patient management is presented in this paper. Interictal and ictal brain SPECT imaging are used to detect the epileptic focus and are a powerful tool during implantation of subdural or depth electrodes, being able to replace an `invasive` evaluation in some cases. Brain SPECT can be used to estimate the patients` postoperative outcome (memory, seizure frequency). Using activation imaging, the functional activity of brain regions can be estimated prior to resection of larger areas. In balloon occlusion, the blood flow pattern during the occlusion and the risk of ischemia after resection or permanent occlusion of the careotid artery can be estimated by means of brain SPECT. (orig.) [Deutsch] Die Hirn-SPECT-Untersuchung hat inzwischen einen festen Platz in der praechirurgischen Epilepsiediagnostik. Anhand von drei Einsatzgebieten innerhalb dieser Thematik (Fokussuche, Prognose, Stimulationsuntersuchung) wird gezeigt, dass die Indikation zur Hirn-SPECT auch unter Kosten-Nutzen-Aspekten gestellt werden kann. Iktale und interiktale Untersuchungen werden im Rahmen der Fokussuche eingesetzt und koennen bei der Implantation von Subdural- oder Tiefen-Elektroden hilfreich sein und in einzelnen Faellen eine invasive Abklaerung ersetzen. Der Hirn-SPECT-Befund kann zur Abschaetzung des postoperativen `outcome` (Gedaechtnis, Anfallsfrequenz) beitragen. Mittels Aktivierungsuntersuchungen kann vor groesseren resektiven Eingriffen die funktionelle Aktivitaet von Hirnarealen beurteilt werden. Bei der Ballon-Okklusion ist es mit Hilfe der Hirn-SPECT-Untersuchung praeoperativ moeglich, die Durchblutungsverhaeltnisse waehrend der Okklusion und damit das Risiko einer Ischaemie nach Resektion oder permanenter Okklusion zu beurteilen. (orig.)

  10. FDG-SPECT and hibernation: an interim review; {sup 18}Fluor-FDG-SPECT zum Nachweis von hibernierendem Myokard: eine Zwischenbilanz

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, C. [Universitaetskliniken des Saarlandes, Homburg (Germany). Abt. fuer Nuklearmedizin; Schaefer, A. [Universitaetskliniken des Saarlandes, Homburg (Germany). Abt. fuer Nuklearmedizin; Trampert, L. [Universitaetskliniken des Saarlandes, Homburg (Germany). Abt. fuer Nuklearmedizin; Oberhausen, E. [Universitaetskliniken des Saarlandes, Homburg (Germany). Abt. fuer Nuklearmedizin; Kirsch, C.M. [Universitaetskliniken des Saarlandes, Homburg (Germany). Abt. fuer Nuklearmedizin; Berberich, R. [Universitaetskliniken des Saarlandes, Homburg (Germany). Abt. fuer Nuklearmedizin

    1997-06-01

    Aim: The present investigation demonstrates an intraindividual comparison of FDG-PET and FDG-SPECT. Material and Methods: Thirty patients with CHD and planed revascularisation underwent both modalities. Myocardial perfusion was evaluated by {sup 99m}Tc-MIBI SPECT. The myocardium was divided into 25 segments and the results were compared by two experienced observers. Results: Segmental concordance of FDG-PET and -SPECT was 94.1%. PET indicated a higher percentage of hibernating myocardium (8.9% vs. 5.7%) and a lower rate of matched defects (11.5% vs. 16.0%). In 22 cases the need for revascularisation was assessed identically. In the remaining 8 patients FDG-PET and FDG-SPECT required an intervention in 6 and 2 cases, respectively. Conclusion: The results of FDG-PET and FDG-SPECT showed a high segmental concordance, but the individual assessment of hibernation worthwhile for revascularisation demonstrated important differences in patient management. (orig.) [Deutsch] Ziel der vorliegenden Arbeit war ein intraindividueller Vergleich von FDG-PET und FDG-SPECT in der myokardialen Vitalitaetsdiagnostik. Material und Methodik: Bei 30 Patienten mit KHK wurden vor Revaskularisation beide Verfahren durchgefuehrt. Die Beurteilung der myokardialen Perfusion erfolgte mittels {sup 99m}Tc-MIBI SPECT. Die Resultate wurden von zwei erfahrenen Auswertern unter Verwendung einer 25-Segment-Einteilung des Myokards verglichen. Ergebnisse: Die segmentale Uebereinstimmung zwischen PET und SPECT betrug 94,1%. Die PET wies einen hoeheren Anteil hibernierendes Myokard aus (8,9% vs. 5,7%) und weniger Narbensegmente (11,5% bs. 16,0%). Die Indikation zur Revaskularisation wurde in 22 Faellen identisch beurteilt. Bei den uebrigen 8 Untersuchungen sprach sechsmal die PET und zweimal die SPECT fuer eine Intervention. Schlussfolgerung: Einer hohen segmentalen Uebereinstimmung stehen also erhebliche Unterschiede in der letztendlich entscheidenden klinischen Beurteilung der Untersuchungsergebnisse

  11. [Evaluation of regional cerebral blood flow using 99mTc-ECD SPECT in ethanol dependent patients: pilot study].

    Science.gov (United States)

    Pach, Dorota; Hubalewska-Dydejczyk, Alicja; Szurkowska, Magdalena; Kamenczak, Aleksandra; Targosz, Dorota; Gawlikowski, Tomasz; Huszno, Bohdan; Głowa, Bogusław

    2007-01-01

    The depressant actions of ethanol in the brain is known. SPECT is non invasive method to measure the regional cerebral blood flow (rCBF) and to evaluate indirectly the brain metabolism. The aim of the study is to evaluate morphologic and functional status of CNS using 99mTc-ECD SPECT in chronic alcoholics. Examined group consisted of 18 male alcoholic patients aged from 28 to 52 years (x = 42.1 +/- 5.4) treated at the Ward of Toxicology and Environmental Diseaes (Detoxification Unit). Only patients without prior head injury, CNS inflammatory changes, epilepsy, migraine, diabetes mellitus or other systemic injury were included. Alcohol dependence was diagnosed according to ICD-10 criteria. The intensity of withdrawal syndrome was measured using CIWA-A scale. The regional cerebral blood flow (rCBF) was measured using 99mTc-ECD SPECT with the double head E.CAM Siemens gamma camera. The reference group, necessary to obtain a normal values for the gamma camera applied, consisted of 31 healthy subjects (33.32 +/- 10.99 y). The mean values of rCBF in all examined region of frontal and temporal lobes, and in basal ganglia bothsided were significantly lower in the group of alcoholic patients than in the control group. No significant difference between rCBF in occipital lobes except the occipital inferior region, and in parietal lobes except the parietal superior region. Symetrical hypoperfusion (rCBF-2SD) in the frontal lobes was stated in 11 (61.1%), in temporal lobes in 4 (22.2%), in parietal and occipital lobes in 3 (16.7%) of the patients examined. In 7 the patients examined rCBF disturbances in basal ganglia were found (bothsided in 4, leftsided in 2, and rightsided in 2 the patients). Focal rCBF changes in the parietal, frontal and temporal lobes localised mostly on the left hemisphere were stated in 27.8% of the alcoholics examined. In concusion, the metabolic disturbances and the brain morphological changes mostly in frontal and temporal lobes due to chronic

  12. Clinical use of ictal SPECT in secondarily generalized tonic-clonic seizures.

    Science.gov (United States)

    Varghese, G I; Purcaro, M J; Motelow, J E; Enev, M; McNally, K A; Levin, A R; Hirsch, L J; Tikofsky, R; Paige, A L; Zubal, I G; Spencer, S S; Blumenfeld, H

    2009-08-01

    Partial seizures produce increased cerebral blood flow in the region of seizure onset. These regional cerebral blood flow increases can be detected by single photon emission computed tomography (ictal SPECT), providing a useful clinical tool for seizure localization. However, when partial seizures secondarily generalize, there are often questions of interpretation since propagation of seizures could produce ambiguous results. Ictal SPECT from secondarily generalized seizures has not been thoroughly investigated. We analysed ictal SPECT from 59 secondarily generalized tonic-clonic seizures obtained during epilepsy surgery evaluation in 53 patients. Ictal versus baseline interictal SPECT difference analysis was performed using ISAS (http://spect.yale.edu). SPECT injection times were classified based on video/EEG review as either pre-generalization, during generalization or in the immediate post-ictal period. We found that in the pre-generalization and generalization phases, ictal SPECT showed significantly more regions of cerebral blood flow increases than in partial seizures without secondary generalization. This made identification of a single unambiguous region of seizure onset impossible 50% of the time with ictal SPECT in secondarily generalized seizures. However, cerebral blood flow increases on ictal SPECT correctly identified the hemisphere (left versus right) of seizure onset in 84% of cases. In addition, when a single unambiguous region of cerebral blood flow increase was seen on ictal SPECT, this was the correct localization 80% of the time. In agreement with findings from partial seizures without secondary generalization, cerebral blood flow increases in the post-ictal period and cerebral blood flow decreases during or following seizures were not useful for localizing seizure onset. Interestingly, however, cerebral blood flow hypoperfusion during the generalization phase (but not pre-generalization) was greater on the side opposite to seizure onset in 90

  13. Real-time respiratory triggered SPECT myocardial perfusion imaging using CZT technology: impact of respiratory phase matching between SPECT and low-dose CT for attenuation correction.

    Science.gov (United States)

    Clerc, Olivier F; Fuchs, Tobias A; Possner, Mathias; Vontobel, Jan; Mikulicic, Fran; Stehli, Julia; Liga, Riccardo; Benz, Dominik C; Gräni, Christoph; Pazhenkottil, Aju P; Gaemperli, Oliver; Buechel, Ronny R; Kaufmann, Philipp A

    2017-01-01

    To assess the impact of respiratory phase matching between single-photon-emission computed tomography myocardial perfusion imaging (SPECT-MPI) and low-dose computed tomography (CT) for attenuation correction (AC). Forty patients underwent 1-day 99mTc-tetrofosmin pharmacological stress/rest SPECT-MPI using a cadmium-zinc-telluride gamma camera. Low-dose CT for AC was performed at deep-inspiration breath-hold. SPECT-MPI was acquired once with free-breathing (FB) and repeated at deep-inspiration breath-hold (BH) to match the respiratory phase of AC. From these acquisitions we reconstructed four data sets: free-breathing SPECT-MPI without AC (non-corrected; FB-NC), breath-hold SPECT-MPI without AC (non-corrected; BH-NC), free-breathing SPECT-MPI with AC (FB-AC), and breath-hold SPECT-MPI with AC (BH-AC), the latter representing respiratory-phase-matched AC SPECT-MPI. We compared semi-quantitative segmental tracer uptake, visual diagnosis, inter-observer agreement, and image quality. Compared with FB-NC, deep-inspiration BH-NC increases inferior and lateral uptake, but decreases septal uptake. Addition of AC to FB increases inferior and septal uptake, but decreases anterolateral uptake. Combining breath-hold MPI with breath-hold CT AC (BH-AC) increases inferior, inferolateral, and septal uptake, but reduces apical uptake, without affecting anterolateral uptake, with significant differences to all other protocols. Frequency of normal scans increases across protocols: 10% with FB-NC, 21% with BH-NC, 38% with FB-AC, and 51% with BH-AC. Image quality and inter-observer agreement were highest for BH-AC among all protocols. Compared with non-corrected breath-hold SPECT-MPI and with free-breathing AC SPECT-MPI, respiratory-phase-matched AC SPECT-MPI significantly affects segmental semi-quantitative uptake, increases the frequency of normal scans, yields the best inter-observer agreement, and significantly improves image quality. These findings suggest a potential role of

  14. Quantifying the Increase in Radiation Exposure Associated with SPECT/CT Compared to SPECT Alone for Routine Nuclear Medicine Examinations

    Directory of Open Access Journals (Sweden)

    Ann M. Larkin

    2011-01-01

    Full Text Available Purpose. We quantify the additional radiation exposure in terms of effective dose incurred by patients in the CT portion of SPECT/CT examinations. Methods. The effective dose from a variety of common nuclear medicine procedures is calculated and summarized. The extra exposure from the CT portion of the examination is summarized by examination and body part. Two hundred forty-eight scans from 221 patients are included in this study. The effective dose from the CT examination is also compared to average background radiation. Results. We found that the extra effective dose is not sufficient to cause deterministic effects. However, the stochastic effects may be significant, especially in patients undergoing numerous follow-up studies. The cumulative effect might increase the radiation exposure compared to patient management with SPECT alone. Conclusions. While the relative increase in radiation exposure associated with SPECT/CT is generally considered acceptable when compared with the benefits to the patient, physicians should make every effort to minimize this effect by using proper technical procedures and educating patients about the exposure they will receive.

  15. Count-based quantitation of functional renal volume by SPECT imaging

    Science.gov (United States)

    King, M. A.; Narayanan, M.; Bohyer, C.; Licho, R.; Fung, L. C. T.

    1998-08-01

    The quantitation of absolute renal functional volume is of interest because many pathological processes are known to affect the growth and parenchymal volume of kidneys. Unlike thresholding and edge-detection methods, the count-based method of volume quantitation is not highly sensitive to boundary definition. In this investigation, count-based kidney volume quantitation was compared to that of fixed threshold-based estimation with and without including attenuation and scatter compensation in the reconstruction. The Alderson Organ Scanning Phantom kidneys were filled with a Tc-99m solution and placed in the Organ scanning phantom. Inserts shaped like the pelvis region of the kidneys were used to vary kidney volume. Emission imaging of the Tc-99m, and transmission imaging of a Gd-153 line source were performed by a triple-headed SPECT system. Without compensating for attenuation and scatter, the count-based method significantly under-estimated kidney volume. When attenuation and scatter compensation were included, count-based volume quantitation was more accurate than volume estimation with a fixed threshold adapted to the image acquisition and reconstruction strategies employed.

  16. Progress In The Development Of A Tomographic SPECT System For Online Dosimetry In BNCT

    Science.gov (United States)

    Minsky, D. M.; Valda, A.; Kreiner, A. J.; Burlon, A. A.; Green, S.; Wojnecki, C.; Ghani, Z.

    2010-08-01

    In boron neutron capture therapy (BNCT) the delivered dose to the patient depends both on the neutron beam characteristics and on the 10B body distribution which, in turn, is governed by the tumor specificity of the 10B drug-carrier. BNCT dosimetry is a complex matter due to the several interactions that neutrons can undergo with the different nuclei present in tissue. However the boron capture reaction 10B(n,α)7Li accounts for about 80 % of the total dose in a tumor with 40 ppm in 10B concentration. Present dosimetric methods are indirect, based on drug biodistribution statistical data and subjected to inter and intra-patient variability. In order to overcome the consequences of the concomitant high dosimetric uncertainties, we propose a SPECT (Single Photon Emission Tomography) approach based on the detection of the prompt gamma-ray (478 keV) emitted in 94 % of the cases from 7Li. For this purpose we designed, built and tested a prototype based on LaBr3(Ce) scintillators. Measurements on a head and tumor phantom were performed in the accelerator-based BNCT facility of the University of Birmingham (UK). They result in the first tomographic image of the 10B capture distribution obtained in a BNCT facility.

  17. Using Rose’s metal alloy as a pinhole collimator material in preclinical small-animal imaging: A Monte Carlo evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Mikael, E-mail: Mikael.Peterson@med.lu.se; Strand, Sven-Erik; Ljungberg, Michael [Department of Medical Radiation Physics, Clinical Science, Lund University, Lund 221 85 (Sweden)

    2015-04-15

    Purpose: Pinhole collimation is the most common method of high-resolution preclinical single photon emission computed tomography imaging. The collimators are usually constructed from dense materials with high atomic numbers, such as gold and platinum, which are expensive and not always flexible in the fabrication step. In this work, the authors have investigated the properties of a fusible alloy called Rose’s metal and its potential in pinhole preclinical imaging. When compared to current standard pinhole materials such as gold and platinum, Rose’s metal has a lower density and a relatively low effective atomic number. However, it is inexpensive, has a low melting point, and does not contract when solidifying. Once cast, the piece can be machined with high precision. The aim of this study was to evaluate the imaging properties for Rose’s metal and compare them with those of standard materials. Methods: After validating their Monte Carlo code by comparing its results with published data and the results from analytical calculations, they investigated different pinhole geometries by varying the collimator material, acceptance angle, aperture diameter, and photon incident angle. The penetration-to-scatter and penetration-to-total component ratios, sensitivity, and the spatial resolution were determined for gold, tungsten, and Rose’s metal for two radionuclides, {sup 99}Tc{sup m} and {sup 125}I. Results: The Rose’s metal pinhole-imaging simulations show higher penetration/total and scatter/total ratios. For example, the penetration/total is 50% for gold and 75% for Rose’s metal when simulating {sup 99}Tc{sup m} with a 0.3 mm aperture diameter and a 60° acceptance angle. However, the degradation in spatial resolution remained below 10% relative to the spatial resolution for gold for acceptance angles below 40° and aperture diameters larger than 0.5 mm. Conclusions: Extra penetration and scatter associated with Rose’s metal contribute to degradation in the

  18. Complexity and accuracy of image registration methods in SPECT-guided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yin, L S; Duzenli, C; Moiseenko, V [Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1 (Canada); Tang, L; Hamarneh, G [Computing Science, Simon Fraser University, 9400 TASC1, Burnaby, BC, V5A 1S6 (Canada); Gill, B [Medical Physics, Vancouver Cancer Centre, BC Cancer Agency, 600 West 10th Ave, Vancouver, BC, V5Z 4E6 (Canada); Celler, A; Shcherbinin, S [Department of Radiology, University of British Columbia, 828 West 10th Ave, Vancouver, BC, V5Z 1L8 (Canada); Fua, T F; Thompson, A; Sheehan, F [Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, 600 West 10th Ave, Vancouver, BC, V5Z 4E6 (Canada); Liu, M [Radiation Oncology, Fraser Valley Cancer Centre, BC Cancer Agency, 13750 9th Ave, Surrey, BC, V3V 1Z2 (Canada)], E-mail: lyin@bccancer.bc.ca

    2010-01-07

    The use of functional imaging in radiotherapy treatment (RT) planning requires accurate co-registration of functional imaging scans to CT scans. We evaluated six methods of image registration for use in SPECT-guided radiotherapy treatment planning. Methods varied in complexity from 3D affine transform based on control points to diffeomorphic demons and level set non-rigid registration. Ten lung cancer patients underwent perfusion SPECT-scans prior to their radiotherapy. CT images from a hybrid SPECT/CT scanner were registered to a planning CT, and then the same transformation was applied to the SPECT images. According to registration evaluation measures computed based on the intensity difference between the registered CT images or based on target registration error, non-rigid registrations provided a higher degree of accuracy than rigid methods. However, due to the irregularities in some of the obtained deformation fields, warping the SPECT using these fields may result in unacceptable changes to the SPECT intensity distribution that would preclude use in RT planning. Moreover, the differences between intensity histograms in the original and registered SPECT image sets were the largest for diffeomorphic demons and level set methods. In conclusion, the use of intensity-based validation measures alone is not sufficient for SPECT/CT registration for RTTP. It was also found that the proper evaluation of image registration requires the use of several accuracy metrics.

  19. SPECT kombineret med CT-angiografi giver bedre diagnostik af lungeemboli--sekundaerpublikation

    DEFF Research Database (Denmark)

    Borgwardt, Henrik Gutte; Mortensen, Jann; Jensen, Claus Verner

    2010-01-01

    The aim of our study was to perform a prospective study that compared the diagnostic ability of V/Q single photon emission computer tomography (V/Q-SPECT), V/Q-SPECT combined with low-dose computed tomography (CT) and pulmonary multidetector computed tomography(MDCT)-angiography in patients suspe...

  20. A comparison of MR-based attenuation correction in PET versus SPECT

    Science.gov (United States)

    Marshall, H. R.; Stodilka, R. Z.; Theberge, J.; Sabondjian, E.; Legros, A.; Deans, L.; Sykes, J. M.; Thompson, R. T.; Prato, F. S.

    2011-07-01

    Attenuation correction (AC) is a critical step in the reconstruction of quantitatively accurate positron emission tomography (PET) and single photon emission computed tomography (SPECT) images. Several groups have proposed magnetic resonance (MR)-based AC algorithms for application in hybrid PET/MR systems. However, none of these approaches have been tested on SPECT data. Since SPECT/MR systems are under active development, it is important to ascertain whether MR-based AC algorithms validated for PET can be applied to SPECT. To investigate this issue, two imaging experiments were performed: one with an anthropomorphic chest phantom and one with two groups of canines. Both groups of canines were imaged from neck to abdomen, one with PET/CT and MR (n = 4) and the other with SPECT/CT and MR (n = 4), while the phantom was imaged with all modalities. The quality of the nuclear medicine reconstructions using MR-based attenuation maps was compared between PET and SPECT on global and local scales. In addition, the sensitivity of these reconstructions to variations in the attenuation map was ascertained. On both scales, it was found that the SPECT reconstructions were of higher fidelity than the PET reconstructions. Further, they were less sensitive to changes to the MR-based attenuation map. Thus, MR-based AC algorithms that have been designed for PET/MR can be expected to demonstrate improved performance when used for SPECT/MR.

  1. A comparison of MR-based attenuation correction in PET versus SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, H R; Stodilka, R Z; Theberge, J; Sabondjian, E; Legros, A; Deans, L; Sykes, J M; Thompson, R T; Prato, F S, E-mail: hmarshall@lawsonimaging.ca [The Lawson Health Research Institute, Imaging Program, 268 Grosvenor Street, London, Ontario N6A 4V2 (Canada)

    2011-07-21

    Attenuation correction (AC) is a critical step in the reconstruction of quantitatively accurate positron emission tomography (PET) and single photon emission computed tomography (SPECT) images. Several groups have proposed magnetic resonance (MR)-based AC algorithms for application in hybrid PET/MR systems. However, none of these approaches have been tested on SPECT data. Since SPECT/MR systems are under active development, it is important to ascertain whether MR-based AC algorithms validated for PET can be applied to SPECT. To investigate this issue, two imaging experiments were performed: one with an anthropomorphic chest phantom and one with two groups of canines. Both groups of canines were imaged from neck to abdomen, one with PET/CT and MR (n = 4) and the other with SPECT/CT and MR (n = 4), while the phantom was imaged with all modalities. The quality of the nuclear medicine reconstructions using MR-based attenuation maps was compared between PET and SPECT on global and local scales. In addition, the sensitivity of these reconstructions to variations in the attenuation map was ascertained. On both scales, it was found that the SPECT reconstructions were of higher fidelity than the PET reconstructions. Further, they were less sensitive to changes to the MR-based attenuation map. Thus, MR-based AC algorithms that have been designed for PET/MR can be expected to demonstrate improved performance when used for SPECT/MR.

  2. Distinction between hemangioma of the liver and hepatocellular carcinoma: value of labeled RBC-SPECT scanning

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, M.; Ikekubo, K.; Yamamoto, K.; Ibuki, Y.; Hino, M.; Tomita, S.; Komori, H.; Orino, A.; Todo, A.

    1989-05-01

    The role of adding single-photon emission CT (SPECT) to /sup 99m/Tc-labeled RBC imaging of the liver was evaluated by specifically focusing on the differentiation between hepatic hemangioma and hepatocellular carcinoma. Planar RBC imaging followed by blood-pool SPECT scanning was performed in 77 patients with a total of 108 hemangiomas and in 29 patients with a total of 46 hepatocellular carcinomas. All lesions were smaller than 5 cm in diameter. Thirty-six (33%) of 108 hemangiomas were detected by planar delayed RBC imaging, whereas 63 (58%) were detected by the delayed RBC-SPECT scan. The smallest hemangioma shown by delayed RBC-SPECT scanning was 1.4 cm in diameter, compared with 1.7 cm by planar RBC scanning. When confined to nodules larger than 1.4 cm in diameter, 42% of hemangiomas (36/85) were detected by planar delayed RBC imaging, whereas 74% (63/85) were detected by delayed RBC-SPECT. Increase in sensitivity was noted in nodules 2.1-4.0 cm in diameter. No hepatocellular carcinomas were shown by delayed RBC planar or SPECT scans. We concluded that with the addition of SPECT, the sensitivity of delayed RBC scans in the detection of small hemangiomas is considerably improved. Delayed RBC-SPECT scanning can be used to distinguish hemangioma from hepatocellular carcinoma.

  3. Evaluation of the Effect of Attenuation Correction by External CT in a Semiconductor SPECT.

    Science.gov (United States)

    Uchibe, Taku; Miyai, Masahiro; Yata, Nobuhiro; Haramoto, Masuo; Yamamoto, Yasushi; Nakamura, Megumi; Kitagaki, Hajime; Takahashi, Yasuyuki

    2016-07-01

    The discovery of NM530c with a cadmium-zinc-telluride detector (CdZnTe-SPECT) is superior to the conventional Anger-type SPECT with a sodium-iodide detector (NaI-SPECT) in terms of sensitivity and spatial resolution. However, in the clinical example, even in CdZnTe-SPECT, a count decrease in myocardium due to the attenuation of the gamma ray is an issue. This study was conducted to evaluate the effect of computed tomography attenuation correction (CTAC) in CdZnTe-SPECT with the help of external CT. We evaluated the revision effect of uniformity, influence by the difference in attenuation distance, contrast ratio, an uptake rate using the heart phantom. As a result of the phantom studies, a good revision effect was obtained. In the clinical study, there was a statistical significant difference between the contrast ratio before and after CTAC in the inferior wall. In addition, the contrast ratio before and after CTAC in CdZnTe-SPECT image was equal to those of NaI-SPECT image. It was suggested that CTAC using external CT in CdZnTe-SPECT was clinically useful for inferior wall.

  4. Lung volume calculations from 81Krm SPECT for the quantification of regional ventilation

    NARCIS (Netherlands)

    Zwijnenburg, A.; Klumper, A.; Roos, C. M.; Jansen, H. M.; van der Schoot, J. B.; van Zandwijk, N.; Marcuse, H. R.

    1988-01-01

    Lung volumes, calculated from 81Krm single-photon emission computed tomography (SPECT) of the lungs, were compared with functional residual capacity (FRC), measured with the helium dilution technique in controls and in patients with various pulmonary diseases. SPECT volume was greater than FRC,

  5. Case of constrictive pericarditis demonstrated specific change by /sup 99m/Tc cardiac SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Takeshi; Kawamura, Yasuaki; Okuzumi, Ichio; Okamoto, Kiyoshi; Wakakura, Manabu; Muto, Toshinori; Yamazaki, Junichi

    1987-11-01

    Pericardial diseases were mainly studied by ultrasound cardiography and CT. And there are few reports about the application of SPECT on pericardial diseases. Recently we experienced a case with pericardial diseases diagnosed clearly using SPECT method. This case was considered tuberculous constrictive pericarditis by the conventional methods. A specific cold area surrounding left ventricle was an important finding for the diagnosis of pericardial disease.

  6. Constrictive pericarditis causing a positive TI-201 SPECT stress test for myocardial ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, R.J.; Lightfoote, J.; Grusd, R.S. (Diagnostic Imaging of Southern California Medical Group, Sherman Oaks (USA))

    1990-08-01

    A case of constritive pericarditis was demonstrated by a positive thallium SPECT stress test for myocardial ischemia. After pericardiectomy, the repeat thallium stress test was normal. The disappearance of the criteria for a positive test suggests that constrictive pericarditis can cause myocardial ischemia, which can be demonstrated by thallium SPECT stress testing.

  7. Perfusion differences on SPECT and PWI in patients with acute ischemic stroke.

    Science.gov (United States)

    Nuutinen, Juho; Liu, Yawu; Laakso, Mikko P; Karonen, Jari O; Vanninen, Esko J; Kuikka, Jyrki T; Aronen, Hannu J; Vanninen, Ritva L

    2009-10-01

    The purposes of the present study were to compare the flow defect volumes on perfusion-weighted magnetic resonance imaging (PWI) and (99m)Tc-labeled ethylcysteinate dimer ((99m)Tc-ECD) single photon emission computed tomography (SPECT) at acute and subacute stages of ischemic stroke and to analyze the relationship between the detected flow defects on the two methods and neurological status and clinical outcomes. Perfusion defects on PWI and SPECT were measured within 48 h and on day 8 of the onset of stroke from 22 patients with their first-ever acute supratentorial ischemic stroke. The primary neurological status was evaluated prior to the imaging. Clinical outcome was assessed at 3 months after the onset of the stroke. The volumes of cerebral blood flow (CBF) defects did not differ between SPECT and PWI within the 48-h examinations. However, the volume of CBF defect was significantly larger on SPECT than on PWI on day 8 (p = 0.03). Within the 48-h examinations, the CBF defect volumes on SPECT and PWI were comparably related to the neurological status. On day 8, the CBF defect volume on SPECT showed higher correlation to the neurological status and more precisely predicted the clinical outcomes at 3 months than PWI. (99m)TC-ECD-SPECT and PWI both have ability to detect cerebral hypoperfusion in patients with ischemic stroke but with some differences. The value of SPECT is more accurate in terms of the delayed outcome, such as prognosis and rehabilitation planning.

  8. Single photon emission computed tomography (SPECT) and SPECT/low-dose computerized tomography did not increase sensitivity or specificity compared to planar bone scintigraphy for detection of bone metastases in advanced breast cancer.

    Science.gov (United States)

    Haraldsen, Ate; Bluhme, Henrik; Røhl, Lisbeth; Pedersen, Erik Morre; Jensen, Anders Bonde; Hansen, Eva Boysen; Nellemann, Hanne; Rasmussen, Finn; Morsing, Anni

    2016-01-01

    To evaluate and compare the diagnostic performance of whole-body planar bone scintigraphy (WBS), single photon emission computed tomography (SPECT), SPECT/low-dose computerized tomography (SPECT/ldCT) and SPECT/contrast enhanced diagnostic CT (SPECT/cdCT) in the staging of patients with advanced breast cancer. Seventy-eight patients with recurrence of biopsy-proven breast cancer and suspicion of disseminated disease were investigated with WBS, SPECT, SPECT/ldCT, SPECT/cdCT and MRI performed on the same day in this prospective study. Images were separately analysed in a blinded fashion by radiologists and nuclear medicine physicians regarding the presence of pathological findings. MRI served as reference standard. According to reference standard, 38 of 73 patients had bone metastases. The sensitivity was 87%, 87%, 79%, and 84% and specificity 63%, 71%, 63% and 83% for WBS, SPECT, SPECT/ldCT and SPECT/cdCT. A significantly increased specificity of SPECT/cdCT compared to WBS and SPECT/ldCT was found, and other parameters did not differ significantly between modalities. Additional two patients had bone metastases solely located outside the MRI scan field and seven patients had soft tissue metastases, but no skeletal changes on MRI. WBS, SPECT and SPECT/ldCT were less sensitive than MRI and equally specific for the detection of bone metastases in patients with advanced breast cancer. Based on our findings, we suggest that initial staging include WBS, MRI of the spine and CT for soft tissue evaluation. Further studies may clarify the potential benefits of whole-body MRI and 18F-NaF PET/CT or 18F-FDG PET/CT. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  9. PET and SPECT in medically non-refractory complex partial seizures. Temporal asymmetries of glucose consumption, Benzodiazepine receptor density

    Energy Technology Data Exchange (ETDEWEB)

    Matheja, P.; Kuwert, T.; Wolf, K.; Schober, O. [Muenster Univ. (Germany). Kliniken und Polikliniken fuer Nuklearmedizin; Stodieck, S.R.G.; Diehl, B.; Ringelstein, E.B. [Muenster Univ. (Germany). Klinik fuer Neurologie; Schuierer, G. [Muenster Univ. (Germany). Inst. fuer Klinische Radiologie

    1998-12-31

    Aim: In contrast to medically refractory complex partial seizures (CPS), only limited knowledge exists on cerebral perfusion and metabolism in medically non-refractory CPS. The aim of this study was to investigate the frequency of temporal asymmetries in regional cerebral glucose consumption (rCMRGlc), regional cerebral blood flow (rCBF), and regional cerebral benzodiazepine receptor density (BRD) in this group of patients. Methods: The study included 49 patients with medically non-refractory cryptogenic CPS (age: 36.0{+-}16.1 years). rCMRGlc was studied with F-18-FDG-PET (FDG), rCBF with Tc-99m-ECD-SPECT (ECD), and BRD with I-123-iomazenil-SPECT (IMZ). All studies were performed interictally and within four weeks in each patient. Duration of epilepsy ranged from 0.1 to 42 years (median 4.0 years). SPECT was performed with the triple-headed SPECT camera Multispect 3, PET with the PET camera ECAT EXACT 47. Using linear profiles, glucose consumption, as well as uptake of ECD and IMZ, were measured in four temporal regions of interest (ROIs), and asymmetry indices were calculated (ASY). The results were compared to 95% confidence intervals determined in control subjects. Results: Thirty-five of the 49 (71%) patients had at least one significantly elevated ASY; temporal rCMRGlc was asymmetrical in 41% of the patients, temporal BRD in 29%, and temporal rCBF in 24%. One patient had an asymmetry of all three variables, two of temporal rCMRGlc and BRD, three of temporal rCMRGlc and rCBF, and another four of rCBF and BRD. Fourteen patients had an isolated temporal asymmetry in rCMRGlc, seven in BRD, and four in rCBF. A discrepancy in lateralization between the three modalities was not observed. Conclusion: The majority of patients with medically non-refractory CPS have focal abnormalities of blood flow and metabolism in their temporal lobe. In this group of patients, FDG-PET demonstrates abnormalities with the highest frequency of the three modalities studied, followed by

  10. MRC-SPECT: A sub-500 μm resolution MR-compatible SPECT system for simultaneous dual-modality study of small animals.

    Science.gov (United States)

    Cai, Liang; Lai, Xiaochun; Shen, Zengming; Chen, Chin-Tu; Meng, Ling-Jian

    2014-01-11

    In this paper, we will report the development of an ultrahigh resolution MR-compatible SPECT system that can be operated inside a pre-existing clinical MR scanner for simultaneous dual-modality imaging of small animals. This system is constructed with 40 small-pixel CdTe detector modules assembled in a fully stationary ring SPECT geometry. We have experimentally demonstrated that this system is capable of providing an imaging resolution of operating inside MR scanners. We will report the design, construction of the MRI-compatible SPECT system, including the detector technology, collimator, system development and so on. The first imaging results obtained with this newly constructed SPECT system will also be reported.

  11. MRC-SPECT: A sub-500 μm resolution MR-compatible SPECT system for simultaneous dual-modality study of small animals

    Science.gov (United States)

    Cai, Liang; Lai, Xiaochun; Shen, Zengming; Chen, Chin-Tu; Meng, Ling-Jian

    2014-01-01

    In this paper, we will report the development of an ultrahigh resolution MR-compatible SPECT system that can be operated inside a pre-existing clinical MR scanner for simultaneous dual-modality imaging of small animals. This system is constructed with 40 small-pixel CdTe detector modules assembled in a fully stationary ring SPECT geometry. We have experimentally demonstrated that this system is capable of providing an imaging resolution of <500 μm when operating inside MR scanners. We will report the design, construction of the MRI-compatible SPECT system, including the detector technology, collimator, system development and so on. The first imaging results obtained with this newly constructed SPECT system will also be reported.

  12. Reduction in camera-specific variability in [{sup 123}I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings: impact on age-dependence of the specific binding ratio in the ENC-DAT database of healthy controls

    Energy Technology Data Exchange (ETDEWEB)

    Buchert, Ralph; Lange, Catharina [Charite - Universitaetsmedizin Berlin, Department of Nuclear Medicine, Berlin (Germany); Kluge, Andreas; Bronzel, Marcus [ABX-CRO advanced pharmaceutical services Forschungsgesellschaft m.b.H., Dresden (Germany); Tossici-Bolt, Livia [University Hospital Southampton NHS Foundation Trust, Department of Medical Physics, Southampton (United Kingdom); Dickson, John [University College London Hospital NHS Foundation Trust, Institute of Nuclear Medicine, London (United Kingdom); Asenbaum, Susanne [Medical University of Vienna, Department of Nuclear Medicine, Vienna (Austria); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Centre, Amsterdam (Netherlands); Kapucu, L. Oezlem Atay [Gazi University, Department of Nuclear Medicine, Faculty of Medicine, Ankara (Turkey); Svarer, Claus [Rigshospitalet and University of Copenhagen, Neurobiology Research Unit, Copenhagen (Denmark); Koulibaly, Pierre-Malick [University of Nice-Sophia Antipolis, Nuclear Medicine Department, Centre Antoine Lacassagne, Nice (France); Nobili, Flavio [University of Genoa, Department of Neuroscience (DINOGMI), Clinical Neurology Unit, Genoa (Italy); Pagani, Marco [CNR, Institute of Cognitive Sciences and Technologies, Rome (Italy); Karolinska Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Sabri, Osama [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Sera, Terez [University of Szeged, Department of Nuclear Medicine and Euromedic Szeged, Szeged (Hungary); Tatsch, Klaus [Municipal Hospital of Karlsruhe Inc, Department of Nuclear Medicine, Karlsruhe (Germany); Borght, Thierry vander [CHU Namur, IREC, Nuclear Medicine Division, Universite catholique de Louvain, Yvoir (Belgium); Laere, Koen van [University Hospital and K.U. Leuven, Nuclear Medicine, Leuven (Belgium); Varrone, Andrea [Karolinska University Hospital, Department of Clinical Neuroscience, Centre for Psychiatry Research, Karolinska Institutet, Stockholm (Sweden); Iida, Hidehiro [National Cerebral and Cardiovascular Center - Research Institute, Osaka (Japan)

    2016-07-15

    Quantitative estimates of dopamine transporter availability, determined with [{sup 123}I]FP-CIT SPECT, depend on the SPECT equipment, including both hardware and (reconstruction) software, which limits their use in multicentre research and clinical routine. This study tested a dedicated reconstruction algorithm for its ability to reduce camera-specific intersubject variability in [{sup 123}I]FP-CIT SPECT. The secondary aim was to evaluate binding in whole brain (excluding striatum) as a reference for quantitative analysis. Of 73 healthy subjects from the European Normal Control Database of [{sup 123}I]FP-CIT recruited at six centres, 70 aged between 20 and 82 years were included. SPECT images were reconstructed using the QSPECT software package which provides fully automated detection of the outer contour of the head, camera-specific correction for scatter and septal penetration by transmission-dependent convolution subtraction, iterative OSEM reconstruction including attenuation correction, and camera-specific ''to kBq/ml'' calibration. LINK and HERMES reconstruction were used for head-to-head comparison. The specific striatal [{sup 123}I]FP-CIT binding ratio (SBR) was computed using the Southampton method with binding in the whole brain, occipital cortex or cerebellum as the reference. The correlation between SBR and age was used as the primary quality measure. The fraction of SBR variability explained by age was highest (1) with QSPECT, independently of the reference region, and (2) with whole brain as the reference, independently of the reconstruction algorithm. QSPECT reconstruction appears to be useful for reduction of camera-specific intersubject variability of [{sup 123}I]FP-CIT SPECT in multisite and single-site multicamera settings. Whole brain excluding striatal binding as the reference provides more stable quantitative estimates than occipital or cerebellar binding. (orig.)

  13. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  14. Impact of image fusion and attenuation correction by SPECT-CT on the scintigraphic detection of parathyroid adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, J.; Denecke, T.; Stelter, L.; Felix, R.; Amthauer, H. [Campus Virchow-Klinikum, Charite-Universitaetsmedizin, Berlin (Germany). Klinik fuer Strahlenheilkunde; Seehofer, D.; Rayes, N. [Campus Virchow-Klinikum, Charite-Universitaetsmedizin, Berlin (Germany). Klinik fuer Allgemein-, Viszeral- und Transplantationschirurgie

    2007-07-01

    Aim: In addition to planar parathyroid scintigraphy, SPECT and image fusion with CT/MR improve adenoma detection in primary hyperparathyroidism (pHPT). This study evaluated the use of a hybrid SPECT-CT device concerning image fusion and attenuation correction (AC). Patients, methods: The data of 26 patients with pHPT, preoperatively examined by {sup 99m}Tc-sestamibi dual-phase scintigraphy plus SPECT-CT (low-dose CT), was retrospectively evaluated by two observers in a consensus reading. The images of planar scintigraphy, non-attenuation corrected SPECT (SPECT{sub NAC}), attenuation corrected SPECT (SPECT{sub AC}) and SPECT{sub AC}-CT were interpreted and compared to the results of surgery. The effect of AC on focus intensity was semiquantified by determination of the tumor-to-background (TB) ratio for SPECT{sub AC} and SPECT{sub NAC}. Finally, the TB{sub AC}/TB{sub NAC}-ratio was calculated for each focus and correlated to the distance of a focus from the body surface. Results: 20/26 (77%) patients were positive in planar scintigraphy. One focus was detected by SPECT only. AC of SPECT-data increased image contrast but had no impact on the detection rate. Additional SPECT{sub AC}-CT image fusion facilitated the localization of three mediastinal foci. In the semiquantitative analysis an increase in TB after AC was observed, although there was no strong correlation between depth of the focus (16-60 mm) and the TB{sub AC}/TB{sub NAC}-ratio (r = 0.213, p = 0.353). Conclusion: The detection rate of planar scintigraphy is only slightly improved by SPECT imaging. Due to the low spatial resolution of the CT component, the benefit of image fusion is limited to mediastinal foci. However, as TB and image contrast is measurably improved after AC there is a potential to improve the sensitivity of parathyroid SPECT. (orig.)

  15. Tumor dosimetry for I-131 trastuzumab therapy in a Her2+ NCI N87 xenograft mouse model using the Siemens SYMBIA E gamma camera with a pinhole collimator

    Science.gov (United States)

    Lee, Young Sub; Kim, Jin Su; Deuk Cho, Kyung; Kang, Joo Hyun; Moo Lim, Sang

    2015-07-01

    We performed imaging and therapy using I-131 trastuzumab and a pinhole collimator attached to a conventional gamma camera for human use in a mouse model. The conventional clinical gamma camera with a 2-mm radius-sized pinhole collimator was used for monitoring the animal model after administration of I-131 trastuzumab The highest and lowest radiation-received organs were osteogenic cells (0.349 mSv/MBq) and skin (0.137 mSv/MBq), respectively. The mean coefficients of variation (%CV) of the effective dose equivalent and effective dose were 0.091 and 0.093 mSv/MBq respectively. We showed the feasibility of the pinholeattached conventional gamma camera for human use for the assessment of dosimetry. Mouse dosimetry and prediction of human dosimetry could be used to provide data for the safety and efficacy of newly developed therapeutic schemes.

  16. Multicolor, time-gated, soft x-ray pinhole imaging of wire array and gas puff Z pinches on the Z and Saturn pulsed power generators.

    Science.gov (United States)

    Jones, B; Coverdale, C A; Nielsen, D S; Jones, M C; Deeney, C; Serrano, J D; Nielsen-Weber, L B; Meyer, C J; Apruzese, J P; Clark, R W; Coleman, P L

    2008-10-01

    A multicolor, time-gated, soft x-ray pinhole imaging instrument is fielded as part of the core diagnostic set on the 25 MA Z machine [M. E. Savage et al., in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, New York, 2007), p. 979] for studying intense wire array and gas puff Z-pinch soft x-ray sources. Pinhole images are reflected from a planar multilayer mirror, passing 277 eV photons with Saturn generator [R. B. Spielman et al., and A. I. P. Conf, Proc. 195, 3 (1989)] for imaging a bright Li-like Ar L-shell line. Ar gas puff Z pinches show an intense K-shell emission from a zippering stagnation front with L-shell emission dominating as the plasma cools.

  17. Interictal brain SPECT in patients with medically refractory temporal lobe epilepsy; SPECT cerebral interictal em pacientes com epilepsia do lobo temporal de dificil controle

    Energy Technology Data Exchange (ETDEWEB)

    Andraus, Maria Emilia Cosenza

    2000-06-01

    The brain single photon emission computed tomography (SPECT) is s functional neuroimaging method that can detect localized changes in cerebral blood flow. The temporal lobe epilepsy (TLE) is the most common epileptic syndrome in adults, and more than 50% are medically refractory. The SPECT can contribute to investigation of epileptogenic focus and is one of the methods of pre-surgical evaluation of these patients. (author)

  18. Detection of pars injury by SPECT in patients younger than age 10 with low back pain.

    Science.gov (United States)

    Spencer, Hillard T; Sokol, Levi O; Glotzbecker, Michael P; Grant, Frederick D; d'Hemecourt, Pierre A; Micheli, Lyle J; Treves, S Ted

    2013-06-01

    Evaluation of extension-based low back pain in young athletes with suspected pars injury may include a referral for skeletal single photon emission computed tomography (SPECT). However, the diagnostic yield of this technique in children with low back pain before the age of 10 years remains uncertain. We examined a series of consecutive SPECT scans to address this question. A retrospective review of department databases revealed 107 consecutive skeletal Tc-99m MDP SPECT scans performed between January 1, 2007 and December 31, 2009 in children less than 10 years of age. Of these, 72 studies were performed for a referral diagnosis of back pain. There were 43 girls (44 studies) and 28 boys (28 studies). The mean age was 7.2 years (range, 1.9 to 9.9 y). All SPECT scans were reviewed and positive findings documented. In addition, all available anatomic imaging, imaging reports (computed tomography, magnetic resonance, and x-ray) and clinical notes were reviewed, and results were compared with those of SPECT studies. Of the 72 SPECT studies, 35 (49%) identified a focal area in the spine of abnormal increased uptake, with 17 in the region of the pars interarticularis. With additional imaging, 1 case was demonstrated not to be a pars injury (computed tomography showed a transverse process fracture) and 2 patients with negative SPECT scans were shown to have pars injuries that SPECT scan had not detected, for a total of 18 pars injuries (25%) in this cohort. Reported participation in gymnastics or football was related to pars injury (odds ratio 4.3, P=0.04). Pars injury was found in 25% of children referred for SPECT scan with back pain below 10 years of age. SPECT scan was highly sensitive for this injury as well as in identifying other potential sites of pathology, and should be considered in the workup of persistent low back pain in young children. Level II, diagnostic study.

  19. Investigating the role of SPECT/CT in dynamic sentinel lymph node biopsy for penile cancers

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Ziauddin Zia; Bomanji, Jamshed [University College Hospitals London, Department of Nuclear Medicine, London (United Kingdom); UCLH NHS Foundation Trust, Institute of Nuclear Medicine, 5th Floor, London (United Kingdom); Omorphos, Savvas; Malone, Peter; Nigam, Raj; Muneer, Asif [University College Hospitals London, Department of Urology, London (United Kingdom); Michopoulou, Sofia; Gacinovic, Svetislav [University College Hospitals London, Department of Nuclear Medicine, London (United Kingdom)

    2017-07-15

    Currently, most centres use 2-D planar lymphoscintigraphy when performing dynamic sentinel lymph node biopsy in penile cancer patients with clinically impalpable inguinal nodes. This study aimed to investigate the role of SPECT/CT following 2-D planar lymphoscintigraphy (dynamic and static) in the detection and localization of sentinel lymph nodes in the groin. A qualitative (visual) review was performed on planar followed by SPECT/CT lymphoscintigraphy in 115 consecutive patients (age 28-86 years) who underwent injection of {sup 99m}Tc-nanocolloid followed by immediate acquisition of dynamic (20 min) and early static scans (5 min) initially and further delayed static (5 min) images at 120 min followed by SPECT/CT imaging. The lymph nodes detected in each groin on planar lymphoscintigraphy and SPECT/CT were compared. A total of 440 and 467 nodes were identified on planar scintigraphy and SPECT/CT, respectively. Overall, SPECT/CT confirmed the findings of planar imaging in 28/115 cases (24%). In the remaining 87 cases (76%), gross discrepancies were observed between planar and SPECT/CT images. SPECT/CT identified 17 instances of skin contamination (16 patients, 13%) and 36 instances of in-transit lymphatic tract activity (24 patients, 20%) that had been interpreted as tracer-avid lymph nodes on planar imaging. In addition, SPECT/CT identified 53 tracer-avid nodes in 48 patients (42%) that were not visualized on planar imaging and led to reclassification of the drainage basins (pelvic/inguinal) of 27 tracer-avid nodes. The addition of SPECT/CT improved the rate of detection of true tracer-avid lymph nodes and delineated their precise (3-D) anatomic localization in drainage basins. (orig.)

  20. The yield of SPECT/CT for anatomical lymphatic mapping in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ploeg, Iris M.C. van der; Nieweg, Omgo E.; Kroon, Bin B.R.; Rutgers, Emiel J.T.; Baas-Vrancken Peeters, Marie-Jeanne T.F.D. [The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Department of Surgery, Amsterdam (Netherlands); Vogel, Wouter V.; Hoefnagel, Cornelis A.; Valdes Olmos, Renato A. [The Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands)

    2009-06-15

    The recently introduced hybrid single-photon emission computed tomography camera with integrated CT (SPECT/CT) fuses tomographic lymphoscintigrams with anatomical data from CT. The purpose of this study was to explore this sophisticated technique in lymphatic mapping in breast cancer patients. We studied 134 patients who underwent SPECT/CT immediately after late planar imaging when these images showed an unusual drainage pattern (85 patients), a pattern that was difficult to interpret (27 patients), or nonvisualization (22 patients). Planar imaging suggested 271 sentinel nodes in 112 of the 134 patients (84%). SPECT/CT showed 269 of these same nodes and indicated that two sites of radioactivity were caused by skin contamination. SPECT/CT visualized 19 additional sentinel nodes in 15 patients, of whom 11 had non-visualization on planar images. One or more tumour-positive sentinel nodes were seen in 27 patients, and in 4 of these patients (15%), these were visualized only by SPECT/CT. SPECT/CT had no additional value for the surgical approach in 11 patients with persisting nonvisualization (8%), and was of questionable value in 67 other patients (50%). Based on the SPECT/CT images, a more precise incision was made in 48 patients (36%), an extra incision was made in 6 (4%), and an incision was omitted in 2 (1.5%). SPECT/CT detected additional sentinel nodes and showed the exact anatomical location of sentinel nodes in breast cancer patients with inconclusive planar images. SPECT/CT was able to visualize drainage in patients whose planar images did not reveal a sentinel node. Therefore, SPECT/CT facilitates surgical exploration in difficult cases and may improve staging. (orig.)

  1. Serotonin transporters in Parkinson's disease studied with [I-123]{beta}-CIT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Eun; Choi, Joon Young; Choe, Yearn Seong; Lee, Won Yong; Choi, Yong; Lee, Kyung Han; Kim, Byung Tae [Samsung Medical Center, Seoul (Korea, Republic of)

    1997-07-01

    In Parkinson's disease (PD), both neuropathological and biochemical studies suggest that serotonin (5-HT) neurons are affected by the disease process. The purpose of this study was to assess the integrity of 5-HT transporters in PD using [I-123]{beta}-CIT (2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane], which binds to both 5-HT and dopamine transporters, and SPECT. Forty-five patients with PD at relatively early stages (Hoehn-Yahr stages I-3) and seven agematched healthy controls were injected with 185-370 MBq(I-123]{beta}-CIT. A total of 15 SPECT scans were acquired over a 24 hr period in each subject using a three-headed system. Time activity curves were obtained in the hypothalamic/midbrain region, where the binding of [I-123] {beta}-CIT is associated primarily with 5-HT transporters, and cerebellum, which was assumed to include only nondisplaceable activity. The parameter k3/k4 (forward/dissociation rate), which is a measure of 5-HT transporter density, was estimated by four noninvasive methods: peak equilibrium ratio (PER) [the ratio of specific binding (hypothalamic/midbrain region-cerebellar activity) to nondisplaceable (cerebella) activity when specific binding reaches a peak], area ratio (the ratio of the areas under the specific binding and nondisplaceable activity curves), k3/k4 obtained using a kinetic two-compartment model [R(2C)], and k3/k4 from a modified graphic method [R(DV)] (Ichise et al., 1996). In the healthy controls, the activity in the hypothalamic/midbrain area generally peaked by 3 hr after tracer injection, then decreased slowly; similar patterns were observed in the PD patients. The k3/k4 values estimated by four different methods in the PD patients did not differ significanlty from those in the healthy controls. In the PD patients, the k3/k4 estimates were not significantly correlated with either Hoehn-Yahr scale or UPDRS (Unified Parkinson's Disease Rating Scale) scores, including total, motor, activities of daily living

  2. Diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT: A clinical follow up study

    OpenAIRE

    Manuel eMenéndez-González; Manuel eMenéndez-González; Manuel eMenéndez-González; Francisco eTavares; Nahla eZeidan; José M Salas-Pacheco; Oscar eArias-Carrión

    2014-01-01

    The [123I]ioflupane - a dopamine transporter radioligand - SPECT (DaT-SPECT) has proven to be useful in the differential diagnosis of tremor. Here, we investigate the diagnoses behind patients with hard-to-classify tremor and normal DaT-SPECT. Therefore, 30 patients with tremor and normal DaT-SPECT were followed up for 2 years. In 18 cases we were able to make a diagnosis. The residual 12 patients underwent a second DaT-SPECT, were then followed for additional 12 months and thereafter the dia...

  3. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  4. Multipinhole collimator with 20 apertures for a brain SPECT application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tzu-Cheng; Ellin, Justin R.; Shrestha, Uttam; Seo, Youngho, E-mail: youngho.seo@ucsf.edu [Physics Research Laboratory, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California 94107 (United States); Huang, Qiu [School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China); Gullberg, Grant T. [Department of Radiotracer Development and Imaging Technology, Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94702 (United States)

    2014-11-01

    Purpose: Several new technologies for single photon emission computed tomography (SPECT) instrumentation with parallel-hole collimation have been proposed to improve detector sensitivity and signal collection efficiency. Benefits from improved signal efficiency include shorter acquisition times and lower dose requirements. In this paper, the authors show a possibility of over an order of magnitude enhancement in photon detection efficiency (from 7.6 × 10{sup −5} to 1.6 × 10{sup −3}) for dopamine transporter (DaT) imaging of the striatum over the conventional SPECT parallel-hole collimators by use of custom-designed 20 multipinhole (20-MPH) collimators with apertures of 0.75 cm diameter. Methods: Quantifying specific binding ratio (SBR) of {sup 123}I-ioflupane or {sup 123}I-iometopane’s signal at the striatal region is a common brain imaging method to confirm the diagnosis of the Parkinson’s disease. The authors performed imaging of a striatal phantom filled with aqueous solution of I-123 and compared camera recovery ratios of SBR acquired between low-energy high-resolution (LEHR) parallel-hole collimators and 20-MPH collimators. Results: With only two-thirds of total acquisition time (20 min against 30 min), a comparable camera recovery ratio of SBR was achieved using 20-MPH collimators in comparison to that from the LEHR collimator study. Conclusions: Their systematic analyses showed that the 20-MPH collimator could be a promising alternative for the DaT SPECT imaging for brain over the traditional LEHR collimator, which could give both shorter scan time and improved diagnostic accuracy.

  5. Longitudinal evaluation of early Alzheimer's disease using brain perfusion SPECT.

    Science.gov (United States)

    Kogure, D; Matsuda, H; Ohnishi, T; Asada, T; Uno, M; Kunihiro, T; Nakano, S; Takasaki, M

    2000-07-01

    The aim of this SPECT study was to determine the initial abnormality and longitudinal changes in regional cerebral blood flow (rCBF) in early Alzheimer's disease (AD) using statistical parametric mapping (SPM). rCBF was noninvasively measured using (99m)Tc-ethyl cysteinate dimer SPECT in 32 patients complaining of mild cognitive impairment, with a Mini-Mental State Examination score more than 24 at the initial study, and 45 age-matched healthy volunteers. All patients satisfied the diagnostic criteria of AD during the follow-up period of at least 2 y. Follow-up SPECT studies were performed on the patients at a mean interval of 15 mo. We used the raw data (absolute rCBF parametric maps) and the adjusted rCBF images of relative flow distribution (normalization of global cerebral blood flow [CBF] for each subject to 50 mL/100 g/min with proportional scaling) to compare these groups with SPM. In the baseline study, the adjusted rCBF was significantly and bilaterally decreased in the posterior cingulate gyri and precunei of patients compared with healthy volunteers. In the follow-up study, selected reduction of the adjusted rCBF was observed in the left hippocampus and parahippocampal gyrus. These areas showed the most prominent reduction in absolute rCBF on each occasion. Moreover, further decline of the absolute rCBF was longitudinally observed in extensive areas of the cerebral association cortex. SPM analysis showed the characteristic early-AD rCBF pattern of selective decrease and longitudinal decline, which may be overlooked by a conventional region-of-interest technique with observer a priori choice and hypothesis. This alteration in rCBF may closely relate to the pathophysiologic process of this disease.

  6. Reduced contralateral hemispheric flow measured by SPECT in cerebellar lesions

    DEFF Research Database (Denmark)

    Sönmezoğlu, K; Sperling, B; Henriksen, T

    1993-01-01

    Four patients with clinical signs of cerebellar stroke were studied twice by SPECT using 99mTc-HMPAO as a tracer for cerebral blood flow (CBF). When first scanned 6 to 22 days after onset, all had a region of very low CBF in the symptomatic cerebellar hemisphere, and a mild to moderate CBF...... reduction (average 10%) in contralateral hemispheric cortex. In all four cases clinical signs of unilateral cerebellar dysfunction were still present when rescanned 1 to 4 months later and the relative CBF decrease in the contralateral cortex of the forebrain also remained. The basal ganglia contralateral...

  7. Molecular imaging of cancer using PET and SPECT

    DEFF Research Database (Denmark)

    Kjaer, Andreas

    2006-01-01

    Molecular imaging allows for the study of molecular and cellular events in the living intact organism. The nuclear medicine methodologies of positron emission tomography (PET) and single photon emission computer tomography (SPECT) posses several advantages, which make them particularly suited...... for molecular imaging of cancer. Especially the possibility of a quick transfer of methods developed in animals to patients (translational research) is an important strength. This article will briefly discuss the newest applications and their importance and perspective in relation to the shift in paradigm...

  8. The neutron decay spectrometer aSPECT: Latest results

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, Hans-Friedrich; Angerer, Heinz; Konorov, Igor; Petzoldt, Gerd; Simson, Martin; Zimmer, Oliver [Physik-Department, Technische Universtitaet Muenchen (Germany); Ayala Guardia, Fidel; Borg, Michael; Glueck, Ferenc; Heil, Werner; Konrad, Gertrud; Munoz Horta, Raquel; Sobolev, Yury [Institut fuer Physik, Universitaet Mainz (Germany); Baessler, Stefan [Department of Physics, University of Virginia, Charlottesville (United States); Eberhardt, Klaus [Institut fuer Kernchemie, Universitaet Mainz (Germany)

    2008-07-01

    The neutron decay spectrometer aSPECT was designed to measure accurately the proton spectrum of the free neutron decay. The knowledge of the proton spectrum allows to extract the neutrino electron angular correlation coefficient a, from which we will determine with highest accuracy the ratio {lambda}= g{sub A}/g{sub V} of the weak coupling constants of the nucleon. After successful beamtimes in 2005/06 at the FRM-II near Munich we continue the measurements at the ILL in Grenoble. Latest results and experiences with a new proton detector, which is a silicon drift detector, are presented.

  9. Myocardial Perfusion Spect Imaging in Dextrocardia: A Case Report

    Directory of Open Access Journals (Sweden)

    Semra Özdemir

    2013-08-01

    Full Text Available The myocardial perfusion scintigraphy acquisition and analysis present some technical differences in the rare dextrocardia cases. Here we report a case of a 38 year-old woman with dextrocardia who had been applied myocardial perfusion scintigraphy. Presented case showed that the thoracic and abdominal organs had a mirror image with situs inversus totalis type dextrocardia. The incidence of coronary heart disease and life span of people with situs inversus totalis are the same as the normal population. So we may apply myocardial perfusion scintigraphy to this patient group. The current case is presented in order to remind the special applications of myocardial perfusion SPECT imaging in patients with dextrocardia.

  10. Bone scintigraphy in breast cancer: added value of hybrid SPECT-CT and its impact on patient management.

    Science.gov (United States)

    Sharma, Punit; Singh, Harmandeep; Kumar, Rakesh; Bal, Chandrasekhar; Thulkar, Sanjay; Seenu, Vulatheru; Malhotra, Arun

    2012-02-01

    To evaluate the incremental value of single-photon emission computed tomography-computed tomography (SPECT-CT) over planar scintigraphy and SPECT alone for equivocal bone scintigraphy lesions in patients with breast cancer and to assess its impact on patient management. A total of 102 patients with 115 equivocal lesions on planar scintigraphy underwent SPECT and SPECT-CT of selected volume. Images were evaluated in separate sessions to minimize recall bias. A scoring scale of 1-5 was used, where 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign, and 5 is definitely benign. With receiver operating characteristic analysis, area under the curves was constructed for each modality. Clinical/imaging follow-up and/or histopathology were taken as the reference standard. There were 52 indeterminate lesions on planar scintigraphy, 15 on SPECT, and three on SPECT-CT. Area under the curve for SPECT-CT was significantly larger compared with planar scintigraphy (Pimprovement was mostly for lytic lesions (P<0.0001). In patients (n=67) in whom the lesions under evaluation were the only lesions and hence whose management was decided, SPECT-CT was superior to SPECT (P=0.045) and planar scintigraphy (P <0.001). SPECT-CT is better than planar scintigraphy and SPECT alone for characterizing equivocal bone scintigraphy lesions in patients with breast cancer and can have a significant impact on patient management.

  11. Monte Carlo simulation of PET and SPECT imaging of {sup 90}Y

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Akihiko, E-mail: takahsr@hs.med.kyushu-u.ac.jp; Sasaki, Masayuki [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Himuro, Kazuhiko; Yamashita, Yasuo; Komiya, Isao [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Baba, Shingo [Department of Clinical Radiology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2015-04-15

    Purpose: Yittrium-90 ({sup 90}Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because {sup 90}Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of {sup 90}Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation–reconstruction framework for {sup 90}Y to comprehensively analyze the PET and SPECT imaging techniques and to quantitatively consider the disadvantages associated with them. Methods: Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of {sup 18}F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded {sup 90}Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of {sup 90}Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. Results: The simulated {sup 90}Y-PET image accurately simulated the experimental results. PET image is visually

  12. THE DIAGNOSTIC EFFICACY OF SPECT/CT IN DETECTION OF BONE METASTASES IN PATIENTS WITH BREAST AND PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    Е. А. Glushkov

    2015-01-01

    Full Text Available The present study was undertaken to evaluate the benefit of single photon emission computed tomography/ computed tomography (SPECT/CT over SPECT alone, osteoscintigraphy (OSG, CT and conventional X-ray for the detection of bone metastasis in patients with breast cancer (BC and prostate cancer (PC. 72 BC patients and 17 PC patients at high risk of developing bone metastasis were examined by (SPECT/ CT, SPECT,OSG,CTand conventional X-ray. Bone metastases were detected in 33 (37.1 % patients. It was found that the diagnostic efficacy (sensitivity, specificity and accuracy of SPECT/CT was significantly superior to that of the other types of imaging modalities in detection of bone metastases from BC. In addition, the combination of SPECT with CT resulted in a change in SPECT and CT findings on skeletal metastasis in 5 (6 % and 11 (12 % cases, respectively.

  13. Impact of SPECT/CT in imaging inflammation and infection; Wertigkeit der SPECT/CT fuer die nuklearmedizinische Entzuendungsdiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Linke, R. [Klinikum Bremen-Mitte, Bremen (Germany). Klinik fuer Nuklearmedizin; Kuwert, T. [Erlangen-Nuernberg Univ., Erlangen (Germany). Nuklearmedizinische Klinik mit Poliklinik

    2011-03-15

    Even today infection remains a significant concern, and the diagnosis and localization of infectious foci is an important health issue. As an established infection-imaging modality, nuclear medicine plays a vital health-care role in the diagnosis and subsequent effective treatment of this condition. Several techniques in nuclear medicine significantly aid infection diagnosis, including triple-phase bone scanning, {sup 18}F-FDG-PET and imaging with {sup 111}In-oxine-, {sup 99m}Tc-HMPAO-labeled leukocytes. Each radiopharmaceutical has specific advantages and disadvantages that makes it suitable to diagnose different infectious processes (e.g., soft-tissue sepsis, inflammatory bowel disease, osteomyelitis, occult fever, fever of unknown origin, and infections commonly found in immuno-compromised patients). However, their clinical applications may be limited by the relatively low spatial resolution and the lack of anatomic landmarks of a highly specific tracer with only scarce background uptake to use as a framework for orientation. Anatomic imaging modalities such as CT provide a high-quality assessment of structural abnormalities related to infection, but these structural abnormalities may be unspecific. Furthermore, to detect infection before anatomical changes are present, functional imaging could have some advantages over anatomical imaging. Scintigraphic studies have demonstrated high sensitivity and specificity to an infectious process. Diagnosis and precise delineation of infection may be challenging in certain clinical scenarios, rendering decisions concerning further patient management difficult. The SPECT/CT-technology combines the acquisition of SPECT and CT data with the same imaging device enabling perfect overlay of anatomical and functional images. SPECT/CT imaging data has been shown to be beneficial for many clinical settings such as indeterminate findings in bone scintigraphy, orthopaedic disorders, endocrine, and neuroendocrine tumors. Therefore

  14. MRI and brain spect findings in patients with unilateral temporal lobe epilepsy and normal CT scan

    Directory of Open Access Journals (Sweden)

    P.G. Carrilho

    1994-06-01

    Full Text Available 26 patients with temporal lobe epilepsy clinically documented by several abnormal interictal surface EEGs with typical unitemporal epileptiform activity and a normal CT scan were studied. Interictal99mTC HMPAO brain SPECT and MRI were performed in all subjects. Abnormalities were shown in 61.5% of MRI (n=16 and 65.4% of SPECT (n=17. Hippocampal atrophy associated to a high signal on T2-weighted MRI slices suggesting mesial temporal sclerosis was the main finding (n=12; 75% of abnormal MRI. MRI correlated well to surface EEG in 50% (n=13. There was also a good correlation between MRI and SPECT in 30.7% (n=8. SPECT and EEG were in agreement in 57.7% (n=l5. MRI, SPECT and EEG were congruent in 26.9% (n=7. These results support the usefulness of interictal brain SPECT and MRI in detecting lateralized abnormalities in temporal lobe epilepsy. On the other hand, in two cases, interictal SPECT correlated poorly with surface EEG. This functional method should not be used isolately in the detection of temporal lobe foci. MRI is more useful than CT as a neuroimaging technique in temporal lobe epilepsy. It may detect small structural lesions and mesial temporal lobe sclerosis which are not easily seen with traditional CT scanning.

  15. [sup 99m]Tc-ECD SPECT study in dementia and aphasia

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, Yasuo; Ichiya, Yuichi; Otsuka, Makoto; Sasaki, Masayuki; Akashi, Yuko; Fukumura, Toshimitsu; Yoshida, Tsuyoshi; Masuda, Kouji; Ichimiya, Atsushi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1993-09-01

    We studied clinical significance of [sup 99m]Tc-L,L,-ethyl cysteine dimer ([sup 99m]Tc-ECD) SPECT study in dementia and aphasia, and compared it with [sup 99m]Tc-HMPAO SPECT study. The subjects consisted of 13 patients, including 10 patients with dementia and 3 patients with aphasia. Hypoperfusion areas were detected in 5 out of 10 patients with dementia and 2 out of 3 patients with aphasia in [sup 99m]Tc-ECD SPECT, and in 4 out of 10 patients with dementia and all of 3 patients with aphasia in [sup 99m]Tc-HMPAO SPECT. The count rate ratios in [sup 99m]Tc-ECD and [sup 99m]Tc-HMPAO SPECT were correlated well with each other, and the contrast of the [sup 99m]Tc-ECD SPECT image was equivalent or slightly higher as compared with [sup 99m]Tc-HMPAO. Therefore, [sup 99m]Tc-ECD SPECT study was considered to be useful for the evaluation of cerebral perfusion in dementia and aphasia. (author).

  16. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray ... Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT or CAT ...

  17. Sequential MRI, SPECT and PET in respiratory syncytial virus encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, K.; Sakazaki, Hiromi; Murakami, Seiko; Yonezawa, Sumiko [Department of Paediatrics, Izumi Municipal Hospital, Osaka (Japan); Fujimoto, Keiji [Dept. of Radiology, Izumi Municipal Hospital, Osaka (Japan); Seto, Toshiyuki; Tanaka, Katsuji; Hattori, Hideji; Matsuoka, Osamu [Dept. of Paediatrics, Osaka City University Medical School, Osaka (Japan); Murata, Ryosuke [Children`s Medical Centre, Osaka City General Hospital, Osaka (Japan)

    1999-04-01

    We report on a 3-year-old girl with respiratory syncytial virus (RSV) encephalitis manifested by disturbance of consciousness, conjugate eye deviation, anuria, truncal ataxia and intention tremor. T2-weighted magnetic resonance imaging (MRI) showed hyperintense areas in the cerebellar cortex. No lesion was detected in the cerebral cortex, pons or spinal cord. The hyperintense areas in the cerebellar cortex diminished with recovery from the clinical manifestations and had resolved 2 months after onset. The MRI lesions in the cerebellum were considered to be due to oedema. SPECT and positron emission tomography (PET), performed 3 months after onset, disclosed areas of hypoperfusion and hypometabolism at the same sites. One year after onset, MRI showed mild atrophy of the cerebellum. Hypoperfusion on SPECT and hypometabolism on PET remained. Neuroimaging showed that ataxia and tremor in this case were the result of cerebellitis. The patient has no neurological deficit except for mild truncal ataxia. This patient is a rare example of RSV encephalitis. (orig.) With 4 figs., 16 refs.

  18. Quantitative SPECT reconstruction using CT-derived corrections

    Science.gov (United States)

    Willowson, Kathy; Bailey, Dale L.; Baldock, Clive

    2008-06-01

    A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume effects in small volumes of interest. The accuracy of the quantitative technique has been evaluated with phantom experiments and clinical lung ventilation/perfusion SPECT/CT studies. A comparison of calculated values with the known total activities and concentrations in a mixed-material cylindrical phantom, and in liver and cardiac inserts within an anthropomorphic torso phantom, produced accurate results. The total activity in corrected ventilation-subtracted perfusion images was compared to the calibrated injected dose of [99mTc]-MAA (macro-aggregated albumin). The average difference over 12 studies between the known and calculated activities was found to be -1%, with a range of ±7%.

  19. Applications of SPECT imaging of dopaminergic neurotransmission in neuropsychiatric disorders

    Energy Technology Data Exchange (ETDEWEB)

    Kugaya, Akira; Fujita, Masahiro; Innis, R.B. [Yale Univ., New Haven, CT (United States). School of Medicine

    2000-02-01

    Single photon emission computed tomography (SPECT) tracers selective for pre- and post-synaptic targets have allowed measurements of several aspects of dopaminergic (DA) neurotransmission. In this article, we will first review our DA transporter imaging in Parkinson's disease. We have developed the in vivo dopamine transporter (DAT) imaging with [{sup 123}I]{beta}-CIT ((1R)-2{beta}-Carbomethoxy-3{beta}-(4-iodophenyl)tropane). This method showed that patients with Parkinson's disease have markedly reduced DAT levels in striatum, which correlated with disease severity and disease progression. Second, we applied DA imaging techniques in patients with schizophrenia. Using amphetamine as a releaser of DA, we observed the enhanced DA release, which was measured by imaging D2 receptors with [{sup 123}I]IBZM (iodobenzamide), in schizophrenics. Further we developed the measurement of basal synaptic DA levels by AMPT (alpha-methyl-paratyrosine)-induced unmasking of D2 receptors. Finally, we expanded our techniques to the measurement of extrastriatal DA receptors using [{sup 123}I]epidepride. The findings suggest that SPECT is a useful technique to measure DA transmission in human brain and may further our understanding of the pathophysiology of neuropsychiatric disorders. (author)

  20. aSPECT - Measuring the proton spectrum in neutron decay

    Energy Technology Data Exchange (ETDEWEB)

    Simson, Martin; Leung, Kent; Zimmer, Oliver [Institut Laue-Langevin, Grenoble (France); Physik-Department E18, TU, Muenchen (Germany); Ayala Guardia, Fidel; Borg, Michael; Heil, Werner; Konrad, Gertrud; Munoz Horta, Raquel; Sobolev, Yury [Institut fuer Physik, Universitaet Mainz (Germany); Baessler, Stefan [University of Virginia, Charlottesville, VA (United States); Glueck, Ferenc [IEKP, Universitaet Karlsruhe (Germany); Konorov, Igor [Physik-Department E18, TU, Muenchen (Germany); Soldner, Torsten [Institut Laue-Langevin, Grenoble (France); Wirth, Hans-Friedrich [Fakultaet fuer Physik, LMU, Muenchen (Germany)

    2009-07-01

    With the aSPECT spectrometer we measure the proton recoil spectrum in the decay of the free neutron. Its shape depends on the angular correlation between the momenta of the antineutrino and electron for kinematic reasons. A precision measurement of this correlation coefficient a allows to test the unitarity of the CKM matrix and provides limits on the existence of scalar and tensor currents. aSPECT is a retardation spectrometer, i.e. the proton recoil spectrum is measured by counting all decay protons that overcome a potential barrier. By varying the height of the barrier the shape of the proton spectrum can be reconstructed. After the barrier the protons are accelerated to {proportional_to}15 keV and detected by a silicon drift detector. Unpolarized cold neutrons are guided through the decay volume of the spectrometer where a fraction of them decays. The recoil protons produced in these decays are guided to the detector by magnetic field lines. In the last beam time a statistical accuracy of about 2 % per 24 hours measurement time was reached, the total error is expected to be well below 5 %. Details of the spectrometer setup as well as the status of the ongoing data analysis are presented in the talk.

  1. Detection of Sentinel Lymph Nodes in Gynecologic Tumours by Planar Scintigraphy and SPECT/CT

    Directory of Open Access Journals (Sweden)

    Otakar Kraft

    2012-08-01

    Full Text Available Objective: Assess the role of planar lymphoscintigraphy and fusion imaging of SPECT/CT in sentinel lymph node (SLN detection in patients with gynecologic tumours. Material and Methods: Planar scintigraphy and hybrid modality SPECT/CT were performed in 64 consecutive women with gynecologic tumours (mean age 53.6 with range 30-77 years: 36 pts with cervical cancer (Group A, 21 pts with endometrial cancer (Group B, 7 pts with vulvar carcinoma (Group C. Planar and SPECT/CT images were interpreted separately by two nuclear medicine physicians. Efficacy of these two techniques to image SLN were compared. Results: Planar scintigraphy did not image SLN in 7 patients (10.9%, SPECT/CT was negative in 4 patients (6.3%. In 35 (54.7% patients the number of SLNs captured on SPECT/CT was higher than on planar imaging. Differences in detection of SLN between planar and SPECT/CT imaging in the group of all 64 patients are statistically significant (p<0.05. Three foci of uptake (1.7% from totally visible 177 foci on planar images in 2 patients interpreted on planar images as hot LNs were found to be false positive non-nodal sites of uptake when further assessed on SPECT/CT. SPECT/CT showed the exact anatomical location of all visualised sentinel nodes. Conclusion: In some patients with gynecologic cancers SPECT/CT improves detection of sentinel lymph nodes. It can image nodes not visible on planar scintigrams, exclude false positive uptake and exactly localise pelvic and paraaortal SLNs. It improves anatomic localization of SLNs. (MIRT 2012;21:47-55

  2. Evaluation of usefulness of radio-iodine SPECT/CT in differentiated thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Won; Lee, Ho Young; Oh, So Won; Kim, Seok Ki; Jeong, Ki Wook; Kim, Seon Wook; Kang, Keon Wook [National Cancer Center, Goyang (Korea, Republic of)

    2007-10-15

    Localizing and differentiating a metastatic lesion of differentiated thyroid cancer (DTC) by using radio iodine whole body scan could be difficult because a whole body scan (WBS) lacks anatomic information. This study was performed to evaluate the usefulness of radio-iodine SPECT/CT for differentiating equivocal lesions. Among 253 patients with DTC who had undergone radio-iodine scan between February and July 2006, 26 patients were enrolled (M:F = 8:18, Age 50.7 {+-} 12.5 years) in the study. The patients had abnormal uptakes in the WBSs that necessitated precise anatomical localization of differentiating between a metastatic lesion and a false-positive lesion. SPECT/CT was performed for the region with abnormal uptake in the WBS. WBS and SPECT/CT were evaluated visually. Metastases were diagnosed based on the results of the radio-iodine scan along with the results of other radiological examinations and serological tests. Based on the WBS images, 13 were suspected with cervical lymph mode (LN) metastases in 16 patients with abnormal neck uptake, and in the 11 patients with abnormal extra-cervical uptakes, extra-cervical metastases were doubtful in all. After SPECT/CT was performed, the diagnostic results were altered for 16 patients (62%). SPECT/CT revealed that only 5 patients had cervical LN metastases, while 3 patients had extra-cervical (mediastinal) LN metastases. Overall there was a 58% (15/26) change in diagnoses and plans for treatment due to SPECT/CT. Among 8 patients suspected with metastases on SPECT/CT, 6 patients underwent another radio-iodine therapy. In 96% (24/25) of the patients, the results of SPECT/CT corresponded with those of further radiological examinations and with other clinical information. Radio-iodine SPECT/CT images permitted the differentiation of abnormal radio-iodine uptake and improved anatomical interpretation in DTC.

  3. Lymphoscintigraphic sentinel node identification in patients with breast cancer: the role of SPECT-CT

    Energy Technology Data Exchange (ETDEWEB)

    Lerman, H.; Metser, U.; Lievshitz, G. [Tel-Aviv Sourasky Medical Center, Department of Nuclear Medicine, Tel-Aviv (Israel); Sperber, F. [Tel-Aviv Sourasky Medical Center, Department of Mammography Unit of Radiology, Tel-Aviv (Israel); Shneebaum, S. [Tel-Aviv Sourasky Medical Center, Department of RIGS Unit of Surgery A, Tel-Aviv (Israel); Tel-Aviv University, Sackler Faculty of Medicine, Tel-Aviv (Israel); Even-Sapir, E. [Tel-Aviv Sourasky Medical Center, Department of Nuclear Medicine, Tel-Aviv (Israel); Tel-Aviv University, Sackler Faculty of Medicine, Tel-Aviv (Israel)

    2006-03-15

    Lymph node status is a major factor in determining the stage, appropriate therapy and outcome in patients with breast cancer. It is therefore of clinical importance to accurately identify all sentinel nodes (SNs) for each individual tumour before surgery. The purpose of this study was to assess the role of SPECT-CT lymphoscintigraphy in SN identification in patients with breast cancer. Lymphoscintigraphy comprising planar and SPECT-CT acquisition was performed in 157 consecutive patients with breast cancer (mean age 54.7{+-}10.6, range 27-81 years) with a palpable mass (n=100), with a non-palpable mass (n=52) or post lumpectomy (n=5). Planar and SPECT-CT images were interpreted separately and the two imaging techniques were compared with respect to their ability to identify hot nodes. Planar imaging alone was negative for identification of hot nodes in 15% of the patients. SPECT-CT alone was negative in 10% and both techniques were negative in 9% of the patients. Forty-six of the total of 361 (13%) hot nodes identified by lymphoscintigraphy were detected only on SPECT-CT, including 21 nodes obscured by the scattered radiation from the injection site, nine adjacent nodes misinterpreted on planar images as a single node and 16 nodes which were missed on planar images and detected on SPECT data. SPECT-CT detected additional sites of drainage unexpected on planar images, including axillary (n=23 patients), internal mammary (n=5 patients), interpectoral (n=3 patients) and intramammary (n=2 patients) lymph node sites. Fourteen of the 329 (4%) hot lesions seen on planar images were false positive non-nodal sites of uptake that were accurately assessed by SPECT-CT and further validated by surgery. In a single patient, SPECT-CT was negative while planar images identified the SN. (orig.)

  4. V/P SPECT as a diagnostic tool for pregnant women with suspected pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Bajc, Marika; Olsson, Berit; Joegi, Jonas [Skaane University Hospital and Lund University, Clinical Physiology and Nuclear Medicine, Lund (Sweden); Gottsaeter, Anders [Skaane University Hospital, Vascular Diseases, Malmoe (Sweden); Hindorf, Cecilia [Skaane University Hospital, Radiation Physics, Lund (Sweden)

    2015-07-15

    The purpose of the study was to assess the prevalence of pulmonary embolism (PE) and other lung diseases among pregnant women with suspected PE and to calculate the radiation exposure to patient and fetus in this population. As a secondary aim, we evaluated the negative predictive value of a normal ventilation/perfusion single photon emission computed tomography (V/P SPECT) examination in pregnancy. We studied all 127 pregnant women who had suspected PE and had undergone V/P SPECT at our institution in the course of a 5-year period. Radiation exposure to patient and fetus and the negative predictive value of a normal V/P SPECT examination were also measured. V/P SPECT identified PE in 11 women (9 %). Moreover, in 15 women (12 %) the examination revealed pneumonia (in 2 cases in addition to PE) and in 1 woman signs of airway obstruction were revealed. Among the 116/127 women (91 %) where PE was ruled out by V/P SPECT, none was diagnosed subsequently with PE or deep venous thrombosis (DVT) during the same pregnancy or puerperal period. For P SPECT, the calculated fetal absorbed dose was < 0.6 mGy,and the calculated breast absorbed dose 0.6 mGy. For V SPECT, the calculated fetal absorbed dose was < 0.014 mGy and the breast absorbed dose 0.25 mGy. The prevalence of PE was low (9 %) among pregnant women with suspected disease. Pneumonia was diagnosed in 12 % of patients. The negative predictive value of V/P SPECT was high, and the radiation exposure from V/P SPECT was low both for fetus and patient. (orig.)

  5. Tc-99m-bicisate (ECD)-brain-SPECT in rapidly progressive dementia; Hirn-SPECT mit Tc-99m-Bicisat (ECD) bei rasch progredientem dementiellen Syndrom

    Energy Technology Data Exchange (ETDEWEB)

    Marienhagen, J.; Eilles, C. [Regensburg Univ. (Germany). Abt. fuer Nuklearmedizin; Weingaertner, U.; Blaha, L. [Bezirkskrankenhaus Mainkofen (Germany). Psychiatrische Klinik; Zerr, I.; Poser, S. [Goettingen Univ. (Germany). Klinik und Poliklinik fuer Neurologie

    1999-07-01

    We present a 61-year-old male patient with progressive dementia. A brain SPECT with Tc-99m-bicisate was performed for confirmation of clinically suspected Alzheimer-dementia. At the time of the SPECT-investigation marked apraxia and aphasia besides severe dementia were present. Electrophysiological as well as anatomical neuroimaging findings showed non-diagnostic alterations. SPECT revealed distinct perfusion defects, which made Alzheimer Dementia unlikely. The further course of the patient was determined by rapidly progressive deterioration with development of akinetic mutism. Thereafter, increased levels of neuron-specific enolase as well as 14-3-3 proteins were found in the cerebro-spinal fluid (CSF). The patient finally died with signs of cerebral decortication. Due to the clinical course and the CSF-findings the patient's final diagnosis was Creutzfeld-Jakob-disease, nevertheless no autopsy was performed. The presented case report underscores the clinical utility of perfusion brain SPECT in the differential diagnosis of dementias. (orig.) [German] Wir berichten ueber einen 61jaehrigen Patienten mit progredientem dementiellen Syndrom, der unter der Verdachtsdiagnose einer Demenz vom Alzheimer-Typ (DAT) zur Hirn-SPECT-Untersuchung mit TC-99m-Bicisat (ECD) vorgestellt wurde. Zum Untersuchungszeitpunkt bestanden neben dem Vollbild einer Demenz eine ausgepraegte Apraxie und Aphasie bei unspezifischen Veraenderungen im EEG sowie der neuroradiologischen Bildgebung. In der Hirn-SPECT-Untersuchung fanden sich fuer eine DAT untypische ausgedehnte, vorwiegend rechtshemisphaerische Perfusionsstoerungen. Im weiteren Verlauf rasche Progredienz des Krankheitsbildes mit Entwicklung eines akinetischen Mutismus sowie Nachweis erhoehter Werte der neuronspezifischen Enolase und des 14-3-3-Proteins im Liquor. Der Patient verstarb schliesslich unter dem Bild einer Decortication. Aufgrund des klinischen Verlaufs sowie der Liquorbefunde wurde, da eine autoptische Befundsicherung

  6. Sequential sup 123 I-IMP-SPECT in acute infantile hemiplegia

    Energy Technology Data Exchange (ETDEWEB)

    Shirasaka, Y.; Ito, M.; Okuno, T.; Fujii, T.; Mikawa, H. (Kyoto Univ. (Japan))

    1989-09-01

    Sequential {sup 123}I-N-isopropyl-p-iodoamphetamine (IMP) single-photon emission computed tomography (SPECT) was performed in 2 patients with acute infantile hemiplegia. In both patients, low uptake of IMP was detected in the targeted abnormal hemisphere. The {sup 123}I-IMP-SPECT findings indicative of a pathologic condition persisted even when the clinical findings and electroencephalographic abnormalities improved. Because of its sensitivity, noninvasiveness, and accurate reflection of the cerebral blood flow distribution, {sup 123}I-IMP-SPECT is useful in the examination of acute infantile hemiplegia and in the evaluation of prognosis.

  7. Development of a high-resolution detection module for the INSERT SPECT/MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Busca, Paolo; Fiorini, Carlo; Butt, Arslan D; Occhipinti, Michele; Quaglia, Riccardo; Trigilio, Paolo [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Via Golgi 40, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, 20133 Milano (Italy); Nemeth, Gabor; Major, Peter; Bukki, Tamas; Nagy, Kalman [Mediso Medical Imaging Systems, Alsotorokvesz 14, H-1022 Budapest (Hungary); Piemonte, Claudio; Ferri, Alessandro; Gola, Alberto [Fondazione Bruno Kessler (FBK), Via Sommarive, 18, 38123 Trento (Italy); Rieger, Jan [MRI.TOOLS GmbH, Robert-Roessle-Str. 10, 13125 Berlin (Germany); Niendorf, Thoralf [MRI.TOOLS GmbH, Robert-Roessle-Str. 10, 13125 Berlin (Germany); Berlin Ultrahigh Field Facility (B.UniversityF.F.), Max-Delbrueck-Center for Molecular Medicine, Berlin (Germany)

    2014-07-29

    A new multi-modality imaging tool is under development in the framework of the INSERT (Integrated SPECT/MRI for Enhanced Stratification in Radio-chemo Therapy) project, supported by the European Community. The final goal is to develop a custom SPECT apparatus that can be used as an insert for commercially available MRI systems. INSERT is expected to offer more effective and earlier diagnosis with potentially better outcome in survival for the treatment of brain tumors, primarily glioma. Two SPECT prototypes are being developed, one dedicated to preclinical imaging (7 and 9.4 T), the second one dedicated to clinical imaging (3 T).

  8. Contribution of V/Q SPECT to planar scintigraphy in the diagnosis of pulmonary embolism.

    Science.gov (United States)

    Quirce, R; Ibáñez-Bravo, S; Jiménez-Bonilla, J; Martínez-Rodríguez, I; Martínez-Amador, N; Ortega-Nava, F; Lavado-Pérez, C; Bravo-Ferrer, Z; Carril, J M

    2014-01-01

    To evaluate the feasibility of V/Q SPECT and analyze its contribution to planar V/Q lung scintigraphy in the diagnosis of pulmonary embolism (PE). A total of 109 patients with suspected PE showing Wells score>2 and elevated D-dimer were studied. The V/Q could not be completed in 7 patients, so they were excluded. Ventilation and perfusion scans were done using Technegas and (99m)Tc-MAA. Planar study included 8 projections on a 256×256 matrix and 128 projections on a 128×128 matrix were acquired for the SPECT study, applying an iterative method. Planar images were interpreted according to modified PIOPED criteria, and SPECT by the guidelines of the EANMMI. The results with both techniques were compared. V/Q planar scintigraphy and SPECT could be performed in 102 patients. V/Q planar scintigraphy was considered "diagnostic" in 39 of the 102 patients, and "non-diagnostic" in 63. Of the 39 "diagnostic" studies, 31 were reported as high probability of PE and 8 as normal. Of the 63 "non-diagnostic", 26 corresponded to intermediate, 29 to low, and 8 to very low probability. The SPECT study was "diagnostic" in 97 and indeterminate in only 5. All patients with a high probability planar scintigraphy had a positive SPECT. In the 8 patients with a normal planar scintigraphy SPECT was negative in 5 and positive in 3. In the 63 patients with a "non-diagnostic" planar scintigraphy SPECT was "diagnostic" in 58 of them, positive in 17 and negative in 41. V/Q SPECT is a feasible technique as it was performed in 102 of the 109 patients who were enrolled in the study (94%). The addition of V/Q SPECT to planar V/Q decreases the number of "non-diagnostic" reports from 62% in planar scintigraphy to 4.9% in SPECT. Therefore, V/Q SPECT should be included in the diagnosis approach of PE due to its high diagnostic yield. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  9. Brain PET and technetium-99m-ECD SPECT imaging in Lhermitte-Duclos disease

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, K.; Yasuda, S.; Beppu, T.; Kobayashi, M.; Doi, M.; Kuroda, K.; Ogawa, A. [Dept. of Neurosurgery, Iwate Medical Univ., Morioka (Japan)

    2001-11-01

    Two patients with Lhermitte-Duclos disease were evaluated by brain positron emission tomography (PET) and technetium-99m-ethyl cysteinate dimer ({sup 99m}Tc-ECD) single-photon emission computed tomography (SPECT). In the lesions in both patients, hyperperfusion was detected on cerebral blood flow images obtained by PET, and hyperactivity by standard {sup 99m}Tc-ECD SPECT. Dynamic {sup 99m}Tc-ECD SPECT images demonstrated a plateau of activity in each lesion. These findings suggest that lesions in Lhermitte-Duclos disease have a retention mechanism for {sup 99m}Tc-ECD equivalent to that of normal neural tissue. (orig.)

  10. Measurment of radon, thoron and their progeny in indoor environment of Mohali, Punjab, Northern India, using pinhole dosimeters

    Directory of Open Access Journals (Sweden)

    Mehta Vimal

    2016-01-01

    Full Text Available The health hazards of radon and its decay products above certain levels are well known. However, for any preventive measures to be taken, we have to be aware of radon levels of that particular area. Measurement of radon and its decay products in indoor environments is an important aspect of assessing indoor air quality and health conditions associated with it. Keeping this in mind, measurements of radon, thoron and their progeny concentrations were carried out in Mohali, Northern India, using pinhole-based twin cup dosimeters. Radon exhalation rates of soil samples in the dwellings/areas were measured via an active technique of a continuous radon monitor. The indoor radon concentration in Mohali varied from 15.03 ± 0.61 Bq/m3 to 39.21 ± 1.46 Bq/m3 with an average of 26.95 Bq/m3 ,while thoron concentration in the same dwellings varied from 9.62 ± 0.54 Bq/m3 to 52.84 ± 2.77 Bq/m3 with an average of 31.09 Bq/m3. Radon progeny levels in dwellings under study varied from 1.63 to 4.24 mWL, with an average of 2.94 mWL, while thoron progeny levels varied from 0.26 to 1.43 mWL , with an average of 0.84 mWL. The annual dose received by the inhabitants of dwellings under study varied from 0.78 to 2.36 mSv, with an average of 1.61 mSv. The in situ gamma dose rate varied from 0.12 to 0.32 mSv/h.

  11. Determinação dos fatores de recuperação do 111In e do 99mTc na quantificação de atividade com imagens SPECT Determination of 111In and 99mTc recovery in the quantification of activity with SPECT imaging

    Directory of Open Access Journals (Sweden)

    Jucilene Maria Pereira

    2010-02-01

    Full Text Available OBJETIVO: Determinar, experimentalmente, os coeficientes de recuperação do 111In e do 99mTc usando imagens SPECT. MATERIAIS E MÉTODOS: Quatro diferentes concentrações de 111In e de 99mTc foram usadas para quantificar a atividade em esferas de diferentes tamanhos. As imagens foram obtidas com um equipamento híbrido SPECT/CT, com dois detectores. A reconstrução das imagens foi realizada usando o método iterativo ordered subset expectation maximization (OSEM. A correção de atenuação foi realizada com o uso de um mapa de atenuação e a correção de espalhamento foi realizada usando a técnica das janelas de energia. RESULTADOS: Os resultados mostraram que o efeito do volume parcial foi observado de forma mais significativa para as esferas com volume OBJECTIVE: To experimentally determine the 99mTc and 111In activity recovery coefficients in SPECT imaging. MATERIALS AND METHODS: Four different 99mTc and 111In concentrations were utilized for quantifying activity in spheres of four different sizes. Images were obtained with a hybrid dual-head SPECT-CT imaging system. The ordered subset expectation maximization (OSEM iterative method was utilized for images reconstruction. An attenuation map was utilized for attenuation correction, and the multiple energy window technique for scattering correction. RESULTS: Results for spheres < 6 ml in volume were significantly affected by the partial volume effect. For 111In quantification, results show a dependence on sphere concentrations and background levels. For 99mTc quantification, there was a tendency towards values underestimation with higher background levels. CONCLUSION: Correction factors must be utilized for compensating the partial volume effect on objects with < 6 ml in volume for both radionuclides. Background subtraction to compensate spurious count present on SPECT images has a significant influence on the quantification of activity, especially for the smaller objects.

  12. Validation of a method for radionuclide activity optimize in SPECT; Validacion de un Metodo para optimizar actividad radionuclidica en SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Perez Diaz, M.; Diaz Rizo, O.; Lopez Diaz, A.; Estevez Aparicio, E.; Roque Diaz, R.

    2007-07-01

    A discriminant method for optimizing the activity administered in NM studies is validated by comparison with ROC curves. the method is tested in 21 SPECT, performed with a Cardiac phantom. Three different cold lesions (L1, L2 and L3) were placed in the myocardium-wall for each SPECT. Three activities (84 MBq, 37 MBq or 18.5 MBq) of Tc-99m diluted in water were used as background. The linear discriminant analysis was used to select the parameters that characterize image quality (Background-to-Lesion (B/L) and Signal-to-Noise (S/N) ratios). Two clusters with different image quality (p=0.021) were obtained following the selected variables. the first one involved the studies performed with 37 MBq and 84 MBq, and the second one included the studies with 18.5 MBq. the ratios B/L, B/L2 and B/L3 are the parameters capable to construct the function, with 100% of cases correctly classified into the clusters. The value of 37 MBq is the lowest tested activity for which good results for the B/Li variables were obtained,without significant differences from the results with 84 MBq (p>0.05). The result is coincident with the applied ROC-analysis. A correlation between both method of r=890 was obtained. (Author) 26 refs.

  13. The role of preclinical SPECT in oncological and neurological research in combination with either CT or MRI

    Energy Technology Data Exchange (ETDEWEB)

    Bernsen, Monique R.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Erasmus MC, Department of Radiology, Rotterdam (Netherlands); Vaissier, Pieter E.B. [Delft University of Technology, Section Radiation Detection and Medical Imaging, Delft (Netherlands); Holen, Roel van [Ghent University, iMinds, ELIS Department, MEDISIP, Ghent (Belgium); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands); Beekman, Freek J. [Delft University of Technology, Section Radiation Detection and Medical Imaging, Delft (Netherlands); MILabs B.V., Utrecht (Netherlands)

    2014-05-15

    Preclinical imaging with SPECT combined with CT or MRI is used more and more frequently and has proven to be very useful in translational research. In this article, an overview of current preclinical research applications and trends of SPECT combined with CT or MRI, mainly in tumour imaging and neuroscience imaging, is given and the advantages and disadvantages of the different approaches are described. Today SPECT and CT systems are often integrated into a single device (commonly called a SPECT/CT system), whereas at present combined SPECT and MRI is almost always carried out with separate systems and fiducial markers to combine the separately acquired images. While preclinical SPECT/CT is most widely applied in oncology research, SPECT combined with MRI (SPECT/MRI when integrated in one system) offers the potential for both neuroscience applications and oncological applications. Today CT and MRI are still mainly used to localize radiotracer binding and to improve SPECT quantification, although both CT and MRI have additional potential. Future technology developments may include fast sequential or simultaneous acquisition of (dynamic) multimodality data, spectroscopy, fMRI along with high-resolution anatomic MRI, advanced CT procedures, and combinations of more than two modalities such as combinations of SPECT, PET, MRI and CT all together. This will all strongly depend on new technologies. With further advances in biology and chemistry for imaging molecular targets and (patho)physiological processes in vivo, the introduction of new imaging procedures and promising new radiopharmaceuticals in clinical practice may be accelerated. (orig.)

  14. Comparison between stress myocardial perfusion SPECT recorded with cadmium-zinc-telluride and Anger cameras in various study protocols

    Energy Technology Data Exchange (ETDEWEB)

    Verger, Antoine; Karcher, Gilles [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Djaballah, Wassila [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947, Nancy (France); Fourquet, Nicolas [Clinique Pasteur, Toulouse (France); Rouzet, Francois; Le Guludec, Dominique [AP-HP, Hopital Bichat, Department of Nuclear Medicine, Paris (France); INSERM U 773 Inserm and Denis Diderot University, Paris (France); Koehl, Gregoire; Roch, Veronique [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Imbert, Laetitia [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Centre Alexis Vautrin, Department of Radiotherapy, Vandoeuvre (France); Poussier, Sylvain [INSERM U947, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); Fay, Renaud [INSERM, Centre d' Investigation Clinique CIC-P 9501, Nancy (France); Marie, Pierre-Yves [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep Experimental Imaging Platform, Nancy (France); INSERM U961, Nancy (France); Hopital de Brabois, CHU-Nancy, Medecine Nucleaire, Vandoeuvre-les-Nancy (France)

    2013-03-15

    The results of stress myocardial perfusion SPECT could be enhanced by new cadmium-zinc-telluride (CZT) cameras, although differences compared to the results with conventional Anger cameras remain poorly known for most study protocols. This study was aimed at comparing the results of CZT and Anger SPECT according to various study protocols while taking into account the influence of obesity. The study population, which was from three different institutions equipped with identical CZT cameras, comprised 276 patients referred for study using protocols involving {sup 201}Tl (n = 120) or {sup 99m}Tc-sestamibi injected at low dose at stress ({sup 99m}Tc-Low; stress/rest 1-day protocol; n = 110) or at high dose at stress ({sup 99m}Tc-High; rest/stress 1-day or 2-day protocol; n = 46). Each Anger SPECT scan was followed by a high-speed CZT SPECT scan (2 to 4 min). Agreement rates between CZT and Anger SPECT were good irrespective of the study protocol (for abnormal SPECT, {sup 201}Tl 92 %, {sup 99m}Tc-Low 86 %, {sup 99m}Tc-High 98 %), although quality scores were much higher for CZT SPECT with all study protocols. Overall correlations were high for the extent of myocardial infarction (r = 0.80) and a little lower for ischaemic areas (r = 0.72), the latter being larger on Anger SPECT (p < 0.001). This larger extent was mainly observed in 50 obese patients who were in the {sup 201}Tl or {sup 99m}Tc-Low group and in whom stress myocardial counts were particularly low with Anger SPECT (228 {+-} 101 kcounts) and dramatically enhanced with CZT SPECT (+279 {+-} 251 %). Concordance between the results of CZT and Anger SPECT is good regardless of study protocol and especially when excluding obese patients who have low-count Anger SPECT and for whom myocardial counts are dramatically enhanced on CZT SPECT. (orig.)

  15. Brain SPECT in dementia a clinical-scintigraphic correlation SPECT cerebral na demência: uma correlação clínico-cintilográfica

    Directory of Open Access Journals (Sweden)

    Carlos A. Buchpiguel

    1996-09-01

    Full Text Available The aim of this study was to compare the accuracy of computed tomography (CT and single photon emission computerized tomography (SPECT in the diagnosis of dementia. Fifty-two patients with clinical diagnosis of dementia and 11 controls were studied. The scans were interpreted by one experienced neuroradiologist and one nuclear radiologist, both blinded to the clinical data. In the diagnosis of dementia, CT and SPECT showed equal sensitivity (82.7% and statistically similar specificity (63.8 and 81.8%, respectively. The specificity of SPECT in diagnosing Alzheimer's disease (100% was statistically superior to CT (69%. However, both methods showed similar sensitivity in detecting Alzheimer's disease. In conclusion, SPECT and CT showed similar accuracy in the diagnosis of dementia. The quite high specificity of SPECT in Alzheimer's disease may be useful for confirming that diagnosis, particularly for patients with presenile onset of the disease.O objetivo deste estudo foi comparar a acurácia da tomografia computadorizada (TC e da tomografia computadorizada por emissão de fóton único (SPECT no diagnóstico de demência. Cinquenta e dois pacientes com diagnóstico clínico de demência e 11 controles foram estudados. Os exames foram interpretados por um neuroradiologista e um radiologista nuclear, ambos cegos quanto aos dados clínicos. No diagnóstico de demência, a TC e a SPECT mostraram sensibilidades iguais (82,7% e estatisticamente especificidades semelhantes (63,8 e 81,8%, respectivamente. A especificidade da SPECT no diagnóstico da doença de Alzheimer (100% foi significativamente superior à da TC (69%. Contudo, ambos os métodos mostraram sensibilidades semelhantes na detecção de doença de Alzheimer. Em conclusão, TC e SPECT mostraram acurácia similar no diagnóstico de demência. A alta especificidade observada no diagnóstico de doença de Alzheimer pode ser útil na confirmação do diagnóstico clínico, especialmente na forma

  16. Navigation of a robot-integrated fluorescence laparoscope in preoperative SPECT/CT and intraoperative freehand SPECT imaging data: a phantom study

    Science.gov (United States)

    van Oosterom, Matthias Nathanaël; Engelen, Myrthe Adriana; van den Berg, Nynke Sjoerdtje; KleinJan, Gijs Hendrik; van der Poel, Henk Gerrit; Wendler, Thomas; van de Velde, Cornelis Jan Hadde; Navab, Nassir; van Leeuwen, Fijs Willem Bernhard

    2016-08-01

    Robot-assisted laparoscopic surgery is becoming an established technique for prostatectomy and is increasingly being explored for other types of cancer. Linking intraoperative imaging techniques, such as fluorescence guidance, with the three-dimensional insights provided by preoperative imaging remains a challenge. Navigation technologies may provide a solution, especially when directly linked to both the robotic setup and the fluorescence laparoscope. We evaluated the feasibility of such a setup. Preoperative single-photon emission computed tomography/X-ray computed tomography (SPECT/CT) or intraoperative freehand SPECT (fhSPECT) scans were used to navigate an optically tracked robot-integrated fluorescence laparoscope via an augmented reality overlay in the laparoscopic video feed. The navigation accuracy was evaluated in soft tissue phantoms, followed by studies in a human-like torso phantom. Navigation accuracies found for SPECT/CT-based navigation were 2.25 mm (coronal) and 2.08 mm (sagittal). For fhSPECT-based navigation, these were 1.92 mm (coronal) and 2.83 mm (sagittal). All errors remained below the surgery procedures.

  17. Dopamine-transporter SPECT and Dopamine-D{sub 2}-receptor SPECT in basal ganglia diseases; Dopamin-Transporter- und Dopamin-D{sub 2}-Rezeptor-SPECT bei Erkrankungen der Basalganglien

    Energy Technology Data Exchange (ETDEWEB)

    Hesse, S.; Barthel, H.; Seese, A.; Sabri, O. [Universitaetsklinikum Leipzig A.oe.R. (Germany). Klinik und Poliklinik fuer Nuklearmedizin

    2007-09-15

    The basal ganglia comprise a group of subcortical nuclei, which are essential for motor control. Dysfunction of these areas, especially in dopaminergic transmission, results in disordered movement and neurological diseases such as Parkinson's disease, Wilson's disease, or Huntington disease. Positron emission tomography and single photon emission computed tomography (SPECT) have enhanced the understanding of the underlying pathophysiology, but they much more contribute to the early differential diagnosis of patients suffering from Parkinsonian syndrome in routine care. The present article provides dopamine transporter and D{sub 2} receptor SPECT findings in selected movement disorders. (orig.)

  18. Improved scatter correction with factor analysis for planar and SPECT imaging

    Science.gov (United States)

    Knoll, Peter; Rahmim, Arman; Gültekin, Selma; Šámal, Martin; Ljungberg, Michael; Mirzaei, Siroos; Segars, Paul; Szczupak, Boguslaw

    2017-09-01

    Quantitative nuclear medicine imaging is an increasingly important frontier. In order to achieve quantitative imaging, various interactions of photons with matter have to be modeled and compensated. Although correction for photon attenuation has been addressed by including x-ray CT scans (accurate), correction for Compton scatter remains an open issue. The inclusion of scattered photons within the energy window used for planar or SPECT data acquisition decreases the contrast of the image. While a number of methods for scatter correction have been proposed in the past, in this work, we propose and assess a novel, user-independent framework applying factor analysis (FA). Extensive Monte Carlo simulations for planar and tomographic imaging were performed using the SIMIND software. Furthermore, planar acquisition of two Petri dishes filled with 99mTc solutions and a Jaszczak phantom study (Data Spectrum Corporation, Durham, NC, USA) using a dual head gamma camera were performed. In order to use FA for scatter correction, we subdivided the applied energy window into a number of sub-windows, serving as input data. FA results in two factor images (photo-peak, scatter) and two corresponding factor curves (energy spectra). Planar and tomographic Jaszczak phantom gamma camera measurements were recorded. The tomographic data (simulations and measurements) were processed for each angular position resulting in a photo-peak and a scatter data set. The reconstructed transaxial slices of the Jaszczak phantom were quantified using an ImageJ plugin. The data obtained by FA showed good agreement with the energy spectra, photo-peak, and scatter images obtained in all Monte Carlo simulated data sets. For comparison, the standard dual-energy window (DEW) approach was additionally applied for scatter correction. FA in comparison with the DEW method results in significant improvements in image accuracy for both planar and tomographic data sets. FA can be used as a user

  19. Development of new peripheral benzodiazepine receptor ligands for SPECT and PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, A.; Fookes, C.; Pham, T.; Holmes, T.; Mattner, F.; Berghoffer, P.; Gregoire, M.C.; Loc' h, C.; Greguric, I. [Radiopharmaceuticas Research Institute, ANSTO, Menai, N.S.W. Sydney (Australia); Thominiaux, C.; Boutin, H.; Chauveau, F.; Gregoire, M.C.; Hantraye, Ph.; Tavitain, B.; Dolle, F. [Service Hospitalier Frederic Joliot, CEA/DSV, 91 - Orsay (France); Arlicot, N.; Chalon, S.; Guilloteau, D. [Universite Francois Rabelais, Inserm U619, 37 - Tours (France)

    2008-02-15

    This study aims to demonstrate that a number of radiolabelled ({sup 123}I,{sup 11}C, {sup 18}F) imidazo pyridines, imidazo pyridazines and indolglyoxylamides can be developed as potential tracers for SPECT and PET imaging. (N.C.)

  20. Correlation between high-sensitive collimator and quantitative analysis in lung ventilation SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Soo [Dept. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Kim, Sang Hyun [Dept. of Diagnostic Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2015-06-15

    This study investigated the correlation between the characteristics of collimator in accordance with the efficiency of detecting photon signals and the quantitative analysis of the lung function, thereby assessing the possibility of clinically applying high sensitivity lung ventilation SPECT. From March to May, 2014, 10 subjects in normal volunteers underwent an ultra high resolution, high resolution a nd high sensitivity collimator planar scan and SPECT. The experiment showed t hat compared with the collimator scan, the quantitative analysis results were significant (p=0.89), and compared to the high resolution collimator SPECT, the time was reduced by 4.9 fold. Therefore, the lung ventilation SPECT that had not been used due to an undermined effectiveness can offer usefulness when clinically applied if a high sensitivity collimator is used since the quality and quantity of information and the duration of scan time all offer an improvement.

  1. A New Approach for Scatter Removal and Attenuation Compensation from SPECT/CT Images

    Directory of Open Access Journals (Sweden)

    Shabnam Oloomi

    2013-11-01

    In conclusion, by applying the proposed formula we were able to correct attenuation and scatter via MLEM and improve the image quality, which is a necessary step for both qualitative and quantitative SPECT images.

  2. Combined SPECT/CT and PET/CT for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Paolo [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Larobina, Michele [Istituto di Biostrutture e Bioimmagini, Consiglio Nazionale delle Ricerche, Via Tommaso De Amicis, 95, Naples I-80145 (Italy); Di Lillo, Francesca [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy); Del Vecchio, Silvana [Università di Napoli Federico II, Dipartimento di Scienze Biomediche Avanzate, Via Pansini, 5, Naples I-80131 (Italy); Mettivier, Giovanni, E-mail: mettivier@na.infn.it [Università di Napoli Federico II, Dipartimento di Fisica, Via Cintia, Naples I-80126 (Italy); INFN Sezione di Napoli, Via Cintia, Naples I-80126 (Italy)

    2016-02-11

    In the field of nuclear medicine imaging, breast imaging for cancer diagnosis is still mainly based on 2D imaging techniques. Three-dimensional tomographic imaging with whole-body PET or SPECT scanners, when used for imaging the breast, has performance limits in terms of spatial resolution and sensitivity, which can be overcome only with a dedicated instrumentation. However, only few hybrid imaging systems for PET/CT or SPECT/CT dedicated to the breast have been developed in the last decade, providing complementary functional and anatomical information on normal breast tissue and lesions. These systems are still under development and clinical trials on just few patients have been reported; no commercial dedicated breast PET/CT or SPECT/CT is available. This paper reviews combined dedicated breast PET/CT and SPECT/CT scanners described in the recent literature, with focus on their technological aspects.

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  4. SPECT assay of radiolabeled monoclonal antibodies. Comprehensive progress report, September 1989--February 1992

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1992-02-01

    The long-term goal of this research project is to develop methods to improve the utility of single photon emission computed tomography (SPECI) to quantify the biodistribution of monoclonal antibodies (MoAbs) labeled with clinically relevant radionuclides ({sup 123}I, {sup 131}I, and {sup 111}In) and with another radionuclide,{sup 211}At, recently used in therapy. We describe here our progress in developing quantitative SPECT methodology for {sup 111}In and {sup 123}I. We have focused our recent research thrusts on the following aspects of SPECT: (1) The development of improved SPECT hardware, such as improved acquisition geometries. (2) The development of better reconstruction methods that provide accurate compensation for the physical factors that affect SPECT quantification. (3) The application of carefully designed simulations and experiments to validate our hardware and software approaches.

  5. Discriminating among degenerative parkinsonisms using advanced 123I-ioflupane SPECT analyses

    Directory of Open Access Journals (Sweden)

    Simon Badoud

    2016-01-01

    PD, MSA, PSP and CBD have distinct patterns of dopaminergic depletion on 123I-ioflupane SPECT. The high specificity of 84–90% for PD versus APS indicates that the classifier is particularly useful for confirming APS cases.

  6. Hyperpolarized 3He MRI and 81mKr SPECT in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Stavngaard, Trine; Søgaard, Lise; Mortensen, J

    2005-01-01

    was to compare ventilation imaging methods in 26 patients with chronic obstructive pulmonary disease (COPD) and nine lung healthy volunteers. METHODS: HP 3He MRI, 81mKr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed....... The three scans were scored visually as percentage of non-ventilated/diseased lung, and a computer-based objective measure of the ventilated volume in HP 3He MRI and 81mKr SPECT and an emphysema index in HRCT were calculated. RESULTS: We found a good correlation between HP 3He MRI and 81mKr SPECT for both...... visual defect score (r=0.80, pemphysema (pulmonary function test and HRCT). The defect scores were largest on 81mKr SPECT (the score on HP 3He MRI...

  7. Role of perfusion SPECT in prediction and measurement of pulmonary complications after radiotherapy for lung cancer

    DEFF Research Database (Denmark)

    Farr, Katherina P; Kramer, Stine; Khalil, Azza A

    2015-01-01

    . Baseline DS was associated with chronic obstructive pulmonary disease. A significant inverse correlation was found between baseline DS and forced expiratory volume in 1 s and diffusing capacity of the lung for carbon monoxide. Patients with severe RP had significantly higher baseline total lung DS (mean 5......PURPOSE: The purpose of the study was to evaluate the ability of baseline perfusion defect score (DS) on SPECT to predict the development of severe symptomatic radiation pneumonitis (RP) and to evaluate changes in perfusion on SPECT as a method of lung perfusion function assessment after curative...... radiotherapy (RT) for non-small-cell lung cancer (NSCLC). METHODS: Patients with NSCLC undergoing curative RT were included prospectively. Perfusion SPECT/CT and global pulmonary function tests (PFT) were performed before RT and four times during follow-up. Functional activity on SPECT was measured using...

  8. Brain SPECT in subtypes of mild cognitive impairment Findings from the DESCRIPA multicenter study

    NARCIS (Netherlands)

    Nobili, F.; Frisoni, G. B.; Portet, F.; Verhey, F.; Rodriguez, G.; Caroli, A.; Touchon, J.; Calvini, P.; Morbelli, S.; De Carli, F.; Guerra, U.P.; van de Pol, L.A.; Visser, P.J.

    2008-01-01

    The Development of Screening Guidelines and Clinical Criteria of Predementia Alzheimer's Disease (DESCRIPA) multicenter study enrolled patients with MCI or subjective cognitive complaints (SUBJ), a part of whom underwent optional brain perfusion SPECT. These patients were classified as SUBJ (n =

  9. Clinical application of quantitative spect in patient specific dosimetry and beta cell quantification

    NARCIS (Netherlands)

    Woliner-van der Weg, Wietske

    2015-01-01

    This thesis demonstrates how, despite different challenges, quantitative analysis of single photon emission computed tomography (SPECT) images, facilitates in answering specific clinical questions that cannot (yet) be answered with another method. First, different technical and practical challenges

  10. Direct comparison of spatially normalized PET and SPECT scans in Alzheimer's disease.

    Science.gov (United States)

    Herholz, Karl; Schopphoff, Helge; Schmidt, Mathias; Mielke, Rüdiger; Eschner, Wolfgang; Scheidhauer, Klemens; Schicha, Harald; Heiss, Wolf-Dieter; Ebmeier, Klaus

    2002-01-01

    Hexamethylpropyleneamine oxime (HMPAO) SPECT and 18F-FDG PET depict similar aspects of perfusion and metabolic abnormalities in Alzheimer's disease (AD), but the correspondence between them is not known in detail. We therefore used statistical parametric mapping to detect and compare abnormal brain areas objectively and quantitatively. Twenty-six patients with probable AD (mean age +/- SD, 66 +/- 9 y; mean Mini-Mental State Examination score, 22.5 +/- 4.2) and 6 nondemented healthy volunteers (mean age, 63 +/- 11 y) were studied with HMPAO SPECT and 18F-FDG PET. All images underwent the same processing steps, including 12-mm gaussian smoothing, spatial normalization, and z transformation with respect to normal average and SD. Thresholding of z maps was used to detect abnormal voxels. The overall correlation between PET and SPECT across the entire brain was significant but not close (average r = 0.43). The best correspondence was found in the temporoparietal and posterior cingulate association cortices. There, the number of abnormal voxels for PET correlated strongly with the number for SPECT (r = 0.90 at a z threshold of -2.25), but tracer uptake reductions were significantly more pronounced for PET than for SPECT. Discordant findings were most frequently seen in the temporobasal and orbitofrontal areas (PET low, SPECT high) and in the cerebellum, parahippocampal cortex, and midcingulate cortex (PET high, SPECT low). The correlation between dementia severity and the number of abnormal voxels was closer for PET than for SPECT. Separation of patients from healthy volunteers by counting the number of abnormal voxels was possible over a much wider range of z thresholds with PET than with SPECT. Correspondence between 18F-FDG PET and HMPAO SPECT is limited to the main finding of temporoparietal and posterior cingulate functional impairment in mild to moderate AD. The distinction between healthy volunteers and patients is less sensitive to threshold selection with PET

  11. Perfusion differences on SPECT and PWI in patients with acute ischemic stroke

    Energy Technology Data Exchange (ETDEWEB)

    Nuutinen, Juho [Kuopio University Hospital, University of Kuopio, Department of Neurology, Kuopio (Finland); Liu, Yawu; Laakso, Mikko P. [Kuopio University Hospital, University of Kuopio, Department of Neurology, Kuopio (Finland); Kuopio University Hospital, University of Kuopio, Department of Clinical Radiology, P. O. Box 1777, Kuopio (Finland); Karonen, Jari O. [Mikkeli Central Hospital, Department of Radiology, Mikkeli (Finland); Vanninen, Esko J. [Kuopio University Hospital, University of Kuopio, Department of Clinical Physiology and Nuclear Medicine, Kuopio (Finland); Kuikka, Jyrki T. [Kuopio University Hospital, University of Kuopio, Department of Clinical Physiology and Nuclear Medicine, Kuopio (Finland); Niuvanniemi Hospital, Kuopio (Finland); Aronen, Hannu J. [University of Turku, Department of Radiology, Turku (Finland); Vanninen, Ritva L. [Kuopio University Hospital, University of Kuopio, Department of Clinical Radiology, P. O. Box 1777, Kuopio (Finland)

    2009-10-15

    The purposes of the present study were to compare the flow defect volumes on perfusion-weighted magnetic resonance imaging (PWI) and {sup 99m}Tc-labeled ethylcysteinate dimer ({sup 99m}Tc-ECD) single photon emission computed tomography (SPECT) at acute and subacute stages of ischemic stroke and to analyze the relationship between the detected flow defects on the two methods and neurological status and clinical outcomes. Perfusion defects on PWI and SPECT were measured within 48 h and on day 8 of the onset of stroke from 22 patients with their first-ever acute supratentorial ischemic stroke. The primary neurological status was evaluated prior to the imaging. Clinical outcome was assessed at 3 months after the onset of the stroke. The volumes of cerebral blood flow (CBF) defects did not differ between SPECT and PWI within the 48-h examinations. However, the volume of CBF defect was significantly larger on SPECT than on PWI on day 8 (p = 0.03). Within the 48-h examinations, the CBF defect volumes on SPECT and PWI were comparably related to the neurological status. On day 8, the CBF defect volume on SPECT showed higher correlation to the neurological status and more precisely predicted the clinical outcomes at 3 months than PWI. {sup 99m}TC-ECD-SPECT and PWI both have ability to detect cerebral hypoperfusion in patients with ischemic stroke but with some differences. The value of SPECT is more accurate in terms of the delayed outcome, such as prognosis and rehabilitation planning. (orig.)

  12. Comparison of knee SPECT and MRI in evaluating meniscus injuries in soldiers.

    Science.gov (United States)

    Wertman, Maya; Milgrom, Charles; Agar, Gabriel; Milgrom, Yael; Yalom, Newton; Finestone, Aharon S

    2014-11-01

    Medical evaluation of a suspected meniscus injury begins with a history-taking and physical examination. Suspected meniscus injuries not responding to treatment are usually sent for imaging to confirm the diagnosis before arthroscopy. Tc-MDP bone single photon emission computed tomography (SPECT) scan has been suggested as an alternative to magnetic resonance imaging (MRI) in evaluating suspected knee meniscus tears. To examine the accuracy of knee SPECT as a tool to identify meniscus tears versus that of MRI as compared to the gold standard of arthroscopy. The Israel Defense Forces database for 2005 through 2009 was searched using the key words: knee MRI, knee SPECT and knee arthroscopy. We identified 330 subjects who had undergone both a single knee SPECT and a single knee MRI prior to knee surgery. The medical files of 193 of the 330 subjects were randomly selected for review. A comparison was made between the preoperative SPECT and MRI studies and the arthroscopic finding. The sensitivity, specificity and accuracy were calculated. The subjects' age was 21.3 ± 3.9. The agreement between SPECT and arthroscopy was 0.14 forthe medial meniscus and 0.29 for the lateral meniscus. The agreement between MRI and arthroscopy was 0.59 for the medial meniscus and 0.69 for the lateral meniscus. SPECT scan was found to be 61% sensitive, 54% specific and 58% accurate in detecting common knee pathology, whereas MRI was found to be 95% sensitive, 67% specific and 85% accurate. Knee SPECT has a lower sensitivity, specificity and accuracy than MRI in evaluating meniscal injuries and its use can result in increased unnecessary surgery.

  13. Combining SPECT and Quantitative EEG Analysis for the Automated Differential Diagnosis of Disorders with Amnestic Symptoms

    Directory of Open Access Journals (Sweden)

    Yvonne Höller

    2017-09-01

    Full Text Available Single photon emission computed tomography (SPECT and Electroencephalography (EEG have become established tools in routine diagnostics of dementia. We aimed to increase the diagnostic power by combining quantitative markers from SPECT and EEG for differential diagnosis of disorders with amnestic symptoms. We hypothesize that the combination of SPECT with measures of interaction (connectivity in the EEG yields higher diagnostic accuracy than the single modalities. We examined 39 patients with Alzheimer's dementia (AD, 69 patients with depressive cognitive impairment (DCI, 71 patients with amnestic mild cognitive impairment (aMCI, and 41 patients with amnestic subjective cognitive complaints (aSCC. We calculated 14 measures of interaction from a standard clinical EEG-recording and derived graph-theoretic network measures. From regional brain perfusion measured by 99mTc-hexamethyl-propylene-aminoxime (HMPAO-SPECT in 46 regions, we calculated relative cerebral perfusion in these patients. Patient groups were classified pairwise with a linear support vector machine. Classification was conducted separately for each biomarker, and then again for each EEG- biomarker combined with SPECT. Combination of SPECT with EEG-biomarkers outperformed single use of SPECT or EEG when classifying aSCC vs. AD (90%, aMCI vs. AD (70%, and AD vs. DCI (100%, while a selection of EEG measures performed best when classifying aSCC vs. aMCI (82% and aMCI vs. DCI (90%. Only the contrast between aSCC and DCI did not result in above-chance classification accuracy (60%. In general, accuracies were higher when measures of interaction (i.e., connectivity measures were applied directly than when graph-theoretical measures were derived. We suggest that quantitative analysis of EEG and machine-learning techniques can support differentiating AD, aMCI, aSCC, and DCC, especially when being combined with imaging methods such as SPECT. Quantitative analysis of EEG connectivity could become

  14. Crossed cerebellar diaschisis demonstrated by SPECT in hemiplegic children

    Energy Technology Data Exchange (ETDEWEB)

    Hamano, Shin-ichiro; Nara, Takahiro; Nozaki, Hidetsugu; Fukushima, Kiyomi (Saitama Children' s Medical Center, Iwatsuki (Japan)); Imai, Masayuki; Kumagai, Koumei; Maekawa, Kihei

    1991-01-01

    Crossed cerebellar diaschisis (CCD) in twenty five children with hemiplegia were studied using single photon emission computed tomography (SPECT) with N-isopropyl-p-I-123-iodoamphetamine. Seven of twenty-five patients had cerebral palsy, and the others were impaired by acquired brain injury between ten months and fourteen years of age. CCD was demonstrated in five patients (20%), who were impaired by acquired brain injury after seven years of age. CCD could never be detected in patients with cerebral palsy. Ipsilateral cerebellar diaschisis was also demonstrated in two patients with cerebral palsy and three with early acquired brain injury before three years of age. It is suggested that diaschisis presents itself as a different form in a contralateral and ipsilateral cerebellum before three years of age from a form which presents after seven years of age. (author).

  15. Brain abscess uptake at TI-201 brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Hyoung; Han, Eun Ji; Yoo, Ie Ryung; Chung, Yong An; Sohn, Hyung Sun; Kim, Sung Hoon; Chung, Soo Kyo; Choi, Yeong Jin [The Catholic University of Korea, Seoul (Korea, Republic of)

    2007-08-15

    A 22-year-old woman with a history of acute lymphoblastic leukemia was hospitalized for headache and vomiting CT scan showed a well-defined, ring like enhancing mass in the left frontal lobe with surrounding edema and midline shift. Magnetic resonance imaging demonstrated a round homogeneous mass with a ring of enhancement in the left frontal lobe. TI-201 brain SPECT showed increased focal uptake coinciding with the CT and MRI abnormality. Aspiration of the lesion performed through a burr hole yielded many neutrophils, a few lymphocytes and histiocytes with some strands of filamentous microorganism-like material. Modified AFB stained negative for norcardia. Gram stain showed a few white blood cells and no microorganism. Antibiotics were started and produced a good clinical response. After one month, CT scan showed markedly reduction in size and extent was observed.

  16. [Verbal auditory agnosia: SPECT study of the brain].

    Science.gov (United States)

    Carmona, C; Casado, I; Fernández-Rojas, J; Garín, J; Rayo, J I

    1995-01-01

    Verbal auditory agnosia are rare in clinical practice. Clinically, it characterized by impairment of comprehension and repetition of speech but reading, writing, and spontaneous speech are preserved. So it is distinguished from generalized auditory agnosia by the preserved ability to recognize non verbal sounds. We present the clinical picture of a forty-years-old, right handed woman who developed verbal auditory agnosic after an bilateral temporal ischemic infarcts due to atrial fibrillation by dilated cardiomyopathie. Neurophysiological studies by pure tone threshold audiometry: brainstem auditory evoked potentials and cortical auditory evoked potentials showed sparing of peripheral hearing and intact auditory pathway in brainstem but impaired cortical responses. Cranial CT-SCAN revealed two large hypodenses area involving both cortico-subcortical temporal lobes. Cerebral SPECT using 99mTc-HMPAO as radiotracer showed hypoperfusion just posterior in both frontal lobes nect to Roland's fissure and at level of bitemporal lobes just anterior to Sylvian's fissure.

  17. Radiolabeled Sugars Used for PET and SPECT Imaging.

    Science.gov (United States)

    Barrios-Lopez, Brianda; Bergstrom, Kim

    2016-01-01

    There are new efforts to develop "sugar" probes for molecular imaging focusing on human clinical studies. Radiolabeled carbohydrates are used as substrate probes for studying specific processes in tissues and organisms. The best application case is 2-Deoxy-2-[18F]fluoro-D-glucose (18F-FDG), which is incorporated by cancer cells. The introduction of ltF-FDG has advanced enormously human Positron Emission Tomography (PET). This review focuses on the importance of 18FFDG and other sugars as imaging probes in PET and Single Photon Emission Computed Tomography (SPECT) imaging. In conclusion, new radiolabeled molecules that can be used as radiopharmaceuticals also would possibly help in the treatment of cancer cells in human patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. SPECT Imaging Agents for Detecting Cerebral β-Amyloid Plaques

    Directory of Open Access Journals (Sweden)

    Masahiro Ono

    2011-01-01

    Full Text Available The development of radiotracers for use in vivo to image β-amyloid (Aβ plaques in cases of Alzheimer's disease (AD is an important, active area of research. The presence of Aβ aggregates in the brain is generally accepted as a hallmark of AD. Since the only definitive diagnosis of AD is by postmortem staining of affected brain tissue, the development of techniques which enable one to image Aβ plaques in vivo has been strongly desired. Furthermore, the quantitative evaluation of Aβ plaques in the brain could facilitate evaluation of the efficacy of antiamyloid therapies currently under development. This paper reviews the current situation in the development of agents for SPECT-based imaging of Aβ plaques in Alzheimer's brains.

  19. Fixed forced detection for fast SPECT Monte-Carlo simulation.

    Science.gov (United States)

    Cajgfinger, Thomas; Rit, Simon; Letang, Jean Michel; Halty, Adrien; Sarrut, David

    2017-11-29

    Monte-Carlo simulations of SPECT images are notoriously slow to converge due to the large ratio between the number of photons emitted and detected in the collimator. This work proposes a method to accelerate the simulations based on Fixed Forced Detection (FFD) combined with an analytical response of the detector. FFD is based on a Monte-Carlo simulation but forces the detection of a photon in each detector pixel weighted by the probability of emission (or scattering) and transmission to this pixel. The method was evaluated with numerical phantoms and on patient images. We obtained differences with analog Monte-Carlo lower than the statistical uncertainty. The overall computing time gain can reach up to 5 orders of magnitude. Source code and examples are available in the Gate V8.0 release. . © 2017 Institute of Physics and Engineering in Medicine.

  20. Diamox-enhanced brain SPECT in cerebrovascular diseases

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Young [College of Medicine, Hanyang University, Seoul (Korea, Republic of)

    2007-04-15

    Acute event in cerebrovascular disease is the second most common cause of death in Korea following cancer, and it can also cause serious neurologic deficits. Understanding of perfusion status is important for clinical applications in management of patients with cerebrovascular diseases, and then the attacks of ischemic neurologic symptoms and the risk of acute events can be reduced. Therefore, the normal vascular anatomy of brain, various clinical applications of acetazolamide-enhanced brain perfusion SPECT, including meaning and role of assessment of vascular reserve in carotid stenosis before procedure, in pediatric Moyamoya disease before and after operation, in prediction of development of hyperperfusion syndrome before procedure, and in prediction of vasospasm and of prognosis in subarachnoid hemorrhage were reviewed in this paper.

  1. Brain perfusion SPECT and EEG findings in Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lappalainen, R. [Children`s Castle Hospital, Dept. of Child Neurology, Helsinki (Finland); Liewendahl, K.; Nikkinen, P. [Univ. Central Hospital, Division of Nuclear Medicine, Laboratory Dept., Helsinki (Finland); Sainio, K.; Riikonen, R.S. [Univ. Central Hospital, Child Neurology, Helsinki (Finland)

    1997-01-01

    Thirteen patients (mean age 8.4 + 5.3 years) with Rett syndrome (RS) were studied with EEG and {sup 99m}Tc-HMPAO SPECT. Eleven patients had background abnormalities and 10 patients paroxysmal activity in EEG. Hypoperfusion of varying severity was detected in 11 patients, 7 patients having multiple lesions. Bifrontal hypoperfusion, observed in 6 patients, was the most distinctive finding. Hypoperfusion was observed also in other cortical regions, except for the occipital lobes. There was no correlation between severity of the background abnormality or presence of paroxysmal activity in EEG and grade of hypoperfusion. There was, however, an association between the severity of hypoperfusion and early manifestation of symptoms in patients with RS. Whether this early-onset group of patients represents a different disease entity or only reflects disease variability the basic pathology being the same, is a possibility that deserves further clarification. (au) 37 refs.

  2. Latest results with the neutron decay spectrometer a SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Gertrud; Ayala Guardia, Fidel; Borg, Michael; Heil, Werner; Munoz Horta, Raquel; Sobolev, Yury [Institut fuer Physik, Universitaet Mainz (Germany); Baessler, Stefan [University of Virginia, Charlottesville, VA (United States); Glueck, Ferenc [IEKP, Universitaet Karlsruhe (Germany); Konorov, Igor [Physik-Department E18, TU Muenchen (Germany); Leung, Kent; Soldner, Torsten [Institut Laue-Langevin, Grenoble (France); Simson, Martin; Zimmer, Oliver [Physik-Department E18, TU Muenchen (Germany); Institut Laue-Langevin, Grenoble (France); Wirth, Hans-Friedrich [Fakultaet fuer Physik, LMU Muenchen (Germany)

    2009-07-01

    The purpose of the retardation spectrometer a SPECT is to determine the antineutrino electron angular correlation coefficient a with high precision, by measuring the integral proton spectrum in free neutron decay. With a precise measurement of the correlation coefficient a tests of the validity of the Standard Model become possible. Of great interest are here the search for scalar and tensor interactions, and to test the unitarity of the CKM matrix. In a beam time performed during April/May 2008 at the neutron research reactor ILL in Grenoble/ France we reached a statistical accuracy of about 2 % per 24 hours measurement time. From the investigated systematic effects and the collected statistics, we expect a total relative error well below the present literature value of 5 %. The physical motivation and the design and optimization of the spectrometer as well as the status and first results of the data analysis are presented in this talk.

  3. Myocardial Perfusion Spect Imaging in Dextrocardia: A Case Report

    Science.gov (United States)

    Özdemir, Semra; Gazi, Emine

    2013-01-01

    The myocardial perfusion scintigraphy acquisition and analysis present some technical differences in the rare dextrocardia cases. Here we report a case of a 38 year-old woman with dextrocardia who had been applied myocardial perfusion scintigraphy. Presented case showed that the thoracic and abdominal organs had a mirror image with situs inversus totalis type dextrocardia. The incidence of coronary heart disease and life span of people with situs inversus totalis are the same as the normal population. So we may apply myocardial perfusion scintigraphy to this patient group. The current case is presented in order to remind the special applications of myocardial perfusion SPECT imaging in patients with dextrocardia. Conflict of interest:None declared. PMID:24003402

  4. D-SPECT, a semiconductor camera: Technical aspects and clinical applications;La camera a semi-conducteur D-Spect: aspects techniques et applications cliniques

    Energy Technology Data Exchange (ETDEWEB)

    Merlin, C.; Bertrand, S.; Kelly, A.; Veyre, A.; Mestas, D.; Cachin, F. [CLCC Jean-Perrin, Service de medecine nucleaire, 63 - Clermont-Ferrand (France); Motreff, P.; Levesque, S. [CHU Gabriel-Montpied, Service de cardiologie, 63 - Clermont-Ferrand (France); Cachin, F. [Universite d' Auvergne, UMR 990 Inserm, 63 - Clermont-Ferrand (France); Askienazy, S. [Cyclopharma, biopole Clermont-Limagne, 63 -Saint-Beauzire (France)

    2010-03-15

    Clinical practice in nuclear medicine has largely changed in the last decade, particularly with the arrival of PET/CT and SPECT/CT. New semiconductor cameras could represent the next evolution in our nuclear medicine practice. Due to the resolution and sensitivity improvement, this technology authorizes fast speed acquisitions, high contrast and resolution images performed with low activity injection. The dedicated cardiology D-SPECT camera (Spectrum Dynamics, Israel) is based on semiconductor technology and provides an original system for collimation and images reconstruction. We describe here our clinical experience in using the D-SPECT with a preliminary study comparing D-D.P.E.C.T. and conventional gamma camera. (authors)

  5. Comparison of HR-SPECT and MR-imaging in the diagnosis of Perthes disease; Vergleich von HR-SPECT und MRT bei der Diagnostik des Morbus Perthes

    Energy Technology Data Exchange (ETDEWEB)

    Mellerowicz, H. [Orthopaedische Klinik und Poliklinik, Oskar-Helene-Heim, Freie Univ. Berlin (Germany); Schulze, C. [Orthopaedische Klinik und Poliklinik, Oskar-Helene-Heim, Freie Univ. Berlin (Germany); Stelling, E. [Orthopaedische Klinik und Poliklinik, Oskar-Helene-Heim, Freie Univ. Berlin (Germany); Stabell, U. [Praxis fuer Nuklearmedizin, Berlin (Germany); Schedel, H. [Strahlenklinik und Poliklinik, Klinikum Rudolf Virchow, Freie Univ. Berlin (Germany)

    1993-12-31

    Children, who are supposed to suffer from M. Legg-Perthes, are diagnosed by clinical-, X-ray examination and today mostly by MRT. MRT gives the most reliable information but high cost, small availability and the demand for resting motionless during the examination is regarded as a problem, especially concerning children. The aim of our study was to evaluate 3D-HR-SPECT as an alternative diagnostic procedure to MRT. 28 children (2-12 years, mean 6,2 years) suspected of suffering from M. Legg-Perthes underwent 3D-HR-SPECT and 16 of them MRT examination. In all 28 children diagnostic assessment of M. Legg-Perthes could be achieved by HR-SPECT (incl. 4 negative cases of transient synovialitis). In 10 cases findings corresponded to MRT evaluation. The statement upon the area of necrosis was similar in both methods, but the reaction of bone to necrosis could be judged in a more differentiated way in HR-SPECT. Besides lower costs further advantages of HR-SPECT were found due to the deficit of movement artifacts (no sedation was required). A disadvantage of this method is X-ray contamination at a low level of 250-400 MBrg. To our experience HR-SPECT is an alternative to MRT for early diagnosis of M. Calve-Legg-Perthes. (orig.) [Deutsch] Bei Kindern mit klinischem Verdacht auf einen M. Perthes ist neben der Anamnese, der klinischen Untersuchung und dem konventionellen Roentgenbild heute haeufig die Durchfuehrung einer kernspintomographischen Untersuchung der naechste Schritt. Der hohen Treffsicherheit dieses Verfahrens stehen jedoch die vergleichsweise geringe Verfuegbarkeit, die hohen Kosten und die Notwendigkeit, waehrend der Untersuchung ruhig zu liegen, was vor allem juengeren Kindern nicht immer gelingt, gegenueber. Ziel unserer Studie war es, die diagnostische Wertigkeit der 3D-HR-SPECT (High Resolution - Single Photonen Emission Computed Tomography) als alternatives Verfahren zur MRT zu ueberpruefen. Hierzu wurden 28 Kinder im Alter von 2-12 Jahren mit klinischem

  6. Gated SPECT offers improved interobserver agreement compared with echocardiography.

    Science.gov (United States)

    Hovland, Anders; Staub, Uwe H; Bjørnstad, Hanne; Prytz, Jan; Sexton, Joe; Støylen, Asbjørn; Vik-Mo, Harald

    2010-12-01

    Left ventricular ejection fraction (EF) is a powerful predictor of prognosis in coronary artery disease. The purpose of the present study was to measure interobserver differences for gated SPECT (GSPECT) software and echocardiography, and to compare these modalities regarding left ventricular volumes and EF. Eighty-four patients scheduled for nuclear imaging underwent a 1-day GSPECT with Tc-99m-tetrofosmin. Images were processed by 2 raters who calculated volumes and EF using Cedar-Sinai quantitative gated-SPECT (QGS), Emory Cardiac Toolbox (ECT), and 4D-MSPECT of the University of Michigan. Echocardiographic volumes were measured by 2 raters. Interobserver reliability was assessed by intraclass correlation coefficient (ICC). Differences in volumes and EF between echocardiography and GSPECT were compared with t-tests. ICC was 0.61 for echocardiography, 0.94 for QGS, 0.88 for ECT, and 0.91 for 4D-MSPECT (P < 0.0001 compared with echocardiography). For small ventricles (ESV ≤30 mL), ICC was 0.58 for echocardiography and 0.90 for QGS (P = 0.008 compared with echocardiography); 0.77 and 0.73 for ECT and 4D-MSPECT, respectively (P = ns). End-diastolic and end-systolic volumes were significantly larger with GSPECT than with echocardiography, also echocardiographic ejection fraction was significantly different from GSPECT. There is better interobserver reliability in GSPECT as compared with echocardiography, and QGS seems more robust in this study especially when it comes to small ventricles.

  7. The clinical utility acetazolamide enhanced cerebral SPECT in dementia

    Energy Technology Data Exchange (ETDEWEB)

    Gearing, G.; Borham, P.; Southee, A. [North Coast Nuclear Medicine, Buderim, QLD, (Australia)

    1997-09-01

    Full text: This case report examines a combined stress-rest cerebral perfusion scan to differentiate vascular from other non-vascular dementias. Cerebrovascular reserve can be assessed following the vasodilatory response to CO{sub 2}, or acetazolamide (Diamox) when conventional resting tests fail to identify perfusion abnormalities. The patient was a 70-year-women with a 10-year history of dementing disease. A recent MRI examination raised the possibility of Binswanger`s Disease (DBT). Previously normal pressure hydrocephalus has been diagnosed but the patient did not respond to a subsequent ventricular shunting procedure. A resting HMPAO Ceretec SPECT scan was performed on a Siemens Diacam after injection of 1 GBq of HMPAO. For the stress scan (separate day study), Diamox (1g) was injected, 20 minutes prior to tracer injection. Resting HMPAO images were abnormal with a severe reduction in perfusion to the temporo-parietal lobes bilaterally. The `stress` Diamox SPECT images showed no significant change from the baseline study. The severe reduction in perfusion to both temporoparietal regions remained constant. DBT is a rare variant of multi-infarct dementia with a gradual progression of ischemic injury to the deep white matter of the cerebral cortex than either Alzheimer`s of multi-infarct dementia, and this can be assessed indirectly utilising rCBF with Diamox which test cerebrovascular haemodynamic reserve. Ischaemic areas have already vasodilated in response to Ischemia, they have decreased perfusion reserve and therefore can not respond to pharmacologic stress. In this care the unaltered rCBF before and after the administration of Diamox made a neurometabolic dysfunction the likely cause for the patient`s symptoms and Alzheimer`s Disease was diagnosed due to the constant decreased rCBF to the temporo-parietal regions. This case demonstrates the utility of Diamox rCBF in the differentiation between vascular and non-vascular dementia, as an adjunct to the

  8. Usefulness of {sup 99m}Tc-HMPAO SPECT in Patients with Subarachnoid Hemorrhage due to Ruptured Intracranial Aneurysm

    Energy Technology Data Exchange (ETDEWEB)

    Choi, C. W.; Lee, K. H.; Kim, J. H.; Kwark, C. E.; Lee, D. S.; Chung, J. K.; Lee, M. C.; Han, D. H.; Koh, C. S. [Seoul National University Hospital, Seoul (Korea, Republic of)

    1993-07-15

    We evaluated the usefulness of {sup 99m}Tc-HMPAO SPECT in 21 Patients with subarachnoid hemorrhage due to ruptured intracranial aneurysm and in 3 patients with unruptured intracranial aneurysm. SPECT study could detect the bilaterally hypoperfused cases in 10 patients(48%), but CT/MRI showed the bilateral abnormalities in only 3 patients(14%). The number of abnormal lesions were 56 in SPECT and 25 in CT/MRI. The lesions found in SPECT were well correlated with the neurological signs of the patients such as aphasia or hemiplegia. SPECT study during Matas test was helpful in evaluating the risk for carotid artery occlusion therapy. We thought that {sup 99m}Tc-HMPAO brain SPECT is helpful in evaluating the functional changes in patients with subarachnoid hemorrhage.

  9. The Performance of Ictal Brain SPECT Localizing for Epileptogenic Zone in Neocortical Epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Sik; Lee, Dong Soo; Hyun, In Young; Chung, June Key; Lee, Myung Chul; Koh, Chang Soon; Lee, Sang Kun; Chang, Kee Hyun [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1995-09-15

    The epileptogenic zones should be localized precisely before surgical resection of these zones in intractable epilepsy. The localization is more difficult in patients with neocortical epilepsy than in patients with temporal lobe epilepsy. This study aimed at evaluation of the usefulness of ictal brain perfusion SPECT for the localization of epileptogenic zones in neocortical epilepsy. We compared the performance of ictal SPECT with MRI referring to ictal scalp electroencephalography (sEEG). Ictal {sup 99m}Tc-HMPAO SPECT were done in twenty-one patients. Ictal EEG were also obtained during video monitoring. MRI were reviewed. According to the ictal sEEG and semiology, 8 patients were frontal lobe epilepsy, 7 patients were lateral temporal lobe epilepsy, 2 patients were parietal lobe epilepsy, and 4 patients were occipital lobe epilepsy. Ictal SPECT showed hyperperfusion in 14 patients(67%) in the zones which were suspected to be epileptogenic according to ictal EEG and semiology. MRI found morphologic abnormalities in 9 patients(43%). Among the 12 patients, in whom no epileptogenic zones were revealed by MR1, ictal SPECT found zones of hyperperfusion concordant with ictal sEEG in 9 patients(75%). However, no zones of hyperperfusion were found in 4 among 9 patients who were found to have cerebromalacia, abnormal calcification and migration anomaly in MRI. We thought that ictal SPECT was useful for localization of epileptogenic zones in neocortical epilepsy and especially in patients with negative findings in MRI.

  10. SPECT assay of radiolabeled monoclonal antibodies. Third yearly progress report, September 1991--February 1992

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1992-02-01

    The accurate determination of the biodistribution of radiolabeled monoclonal antibodies (MoAbs) is important for calculation of dosimetry and evaluation of pharmacokinetic variables such as antibody dose and route of administration. The hypothesis of this application is that the biodistribution of radiolabeled monoclonal antibodies (MoAbs) can be quantitatively determined using single photon emission computed tomography (SPECT). The major thrusts during the third year include the continued development and evaluation of improved 3D SPECT acquisition and reconstruction approaches to improve quantitative imaging of radiolabeled monoclonal antibodies (MoAbs), and the implementation and evaluation of algorithms to register serial SPECT image data sets, or to register 3D SPECT images with 3D image data sets acquired from positron emission tomography (PEI) and magnetic resonance images (MRI). The research has involved the investigation of statistical models and iterative reconstruction algorithms that accurately account for the physical characteristics of the SPECT acquisition system. It is our belief that SPECT quantification can be improved by accurately modeling the physical processes such as attenuation, scatter, geometric collimator response, and other factors that affect the measured projection data.

  11. The Role of CT-Based Attenuation Correction and Collimator Blurring Correction in Striatal Spect Quantification

    Directory of Open Access Journals (Sweden)

    J. M. Warwick

    2011-01-01

    Full Text Available Purpose. Striatal single photon emission computed tomography (SPECT imaging of the dopaminergic system is becoming increasingly used for clinical and research studies. The question about the value of nonuniform attenuation correction has become more relevant with the increasing availability of hybrid SPECT-CT scanners. In this study, the value of nonuniform attenuation correction and correction for collimator blurring were determined using both phantom data and patient data. Methods. SPECT imaging was performed using 7 anthropomorphic phantom measurements, and 14 patient studies using [I-123]-FP-CIT (DATSCAN. SPECT reconstruction was performed using uniform and nonuniform attenuation correction and collimator blurring corrections. Recovery values (phantom data or average-specific uptake ratios (patient data for the different reconstructions were compared at similar noise levels. Results. For the phantom data, improved recovery was found with nonuniform attenuation correction and collimator blurring corrections, with further improvement when performed together. However, for patient data the highest average specific uptake ratio was obtained using collimator blurring correction without nonuniform attenuation correction, probably due to subtle SPECT-CT misregistration. Conclusions. This study suggests that an optimal brain SPECT reconstruction (in terms of the lowest bias in patients would include a correction for collimator blurring and uniform attenuation correction.

  12. Filters in 2D and 3D Cardiac SPECT Image Processing

    Directory of Open Access Journals (Sweden)

    Maria Lyra

    2014-01-01

    Full Text Available Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast.

  13. Assessment of hibernating myocardium following coronary artery bypass grafting using resting {sup 201}Tl myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Oshima, Motoo; Higashi, Shizuka; Yasukochi, Hiroshi [Teikyo Univ., Tokyo (Japan). Faculty of Medicine; Hayase, Shuhei

    1995-03-01

    In this study, the effect of coronary artery bypass grafting (CABG) in 35 patients (pts) (male 29, female 6) with fixed defects were evaluated before and one month after surgery using resting {sup 201}Tl SPECT. Nine pts (7 old myocardial infarction; OMI) had 2 vessel disease (VD) and 26 pts (19 OMI) had 3 VD. Pts ages ranged from 41 to 75 (mean 61.4{+-}8.4) years. All 35 pts were divided into 4 groups according to the results of {sup 201}Tl SPECT and left ventriculogram pre- and post-CABG. Thirteen pts who improved of both {sup 201}Tl SPECT and wall motion scores post-CABG were considered as hibernating myocardium (group I). Nine patients who improved of {sup 201}Tl SPECT score but no change of wall motion were group II. Seven pts who improved of wall motion but no change of {sup 201}Tl SPECT score were group III. Six pts who had no improvement of both {sup 201}Tl SPECT and wall motion scores were group IV and considered as myocardial infarction. (author).

  14. Head injury - first aid

    Science.gov (United States)

    ... medlineplus.gov/ency/article/000028.htm Head injury - first aid To use the sharing features on this page, ... a concussion can range from mild to severe. First Aid Learning to recognize a serious head injury and ...

  15. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the head is typically used to detect: bleeding, brain injury and skull fractures in patients with head injuries. ... hard time staying still, are claustrophobic or have chronic pain, you may find a CT exam to ...

  16. Head and face reconstruction

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002980.htm Head and face reconstruction To use the sharing features on this page, please enable JavaScript. Head and face reconstruction is surgery to repair or reshape deformities ...

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... the limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, ... than regular radiographs (x-rays). top of page What are some common uses of the procedure? CT ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others American Stroke Association National Stroke Association ... Computer Tomography (CT) Safety During Pregnancy Head and Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine ...

  19. Newborn head molding

    Science.gov (United States)

    Newborn cranial deformation; Molding of the newborn's head; Neonatal care - head molding ... The bones of a newborn baby's skull are soft and flexible, with gaps between the plates of bone. The spaces between the bony plates of ...

  20. Diagnosis of SDAT by HMPAO SPECT and vitamin B{sub 12} serum concentration; Diagnostik der SDAT mittels HMPAO-SPECT und Serumvitamin-B{sub 12}-Spiegel

    Energy Technology Data Exchange (ETDEWEB)

    Mikosch, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Gallowitsch, H.J. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Gomez, I. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Kresnik, E. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Ploeb, H. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin; Lind, P. [Landeskrankenhaus Klagenfurt (Austria). Abt. fuer Nuklearmedizin

    1995-06-01

    It is quite difficult to confirm the diagnosis of demential disorders, including senile dementia of the Alzheimer type (SDAT) by clinical means only. Through the combination of {sup 99m}Tc-HMPAO brain SPECT and serum vitamin B{sub 12} determination it was hoped to speed up and improve the diagnosis of SDAT. 116 patients who had been divided into four groups according to their defect pattern in the {sup 99m}Tc-HMPAO brain SPECT 17 very probably had SDAT; of these 15 showed a defect pattern with brain SPECT which could be associated to SDAT. The majority of SDAT patients had serum vitamin B{sub 12} levels in the lower normal range or pathologically below that range. Both investigations contributed to establishing the SDAT diagnosis without replacing other investigations. The determination of serum vitamin B{sub 12} does not require any major additional effort. (orig.) [Deutsch] Die alleinige klinische Abklaerung dementieller Zustandsbilder, so auch der senilen Demenz vom Alzheimertyp (SDAT), ist schwierig. Durch die Kombination von {sup 99m}Tc-HMPAO-Gehirn-SPECT und Serumvitamin-B{sub 12}-Bestimmung erwarteten wir eine Beschleunigung und Verbesserung der Diagnostik der SDAT. Von 116 Patienten, die in 4 Gruppen, entsprechend ihrem {sup 99m}Tc-HMPAO-Verteilungsmuster eingeteilt worden waren, konnten bei 17 klinisch sehr wahrscheinlichen SDAT-Patienten bei 15 Auffaelligkeiten mit Hinweis auf SDAT im Gehirn SPECT gefunden werden. Ein Teil der Patienten wies einen niedrig-normalen bzw. pathologisch niedrigen Vitamin-B{sub 12}-Spiegel auf. Andere Untersuchungen wuerden durch die Kombination von Gehirn-SPECT und Serumvitamin-B{sub 12}-Bestimmung nicht ueberfluessig werden, obwohl beide Untersuchungen Informationen lieferten, die die Zuordnung zur Diagnose SDAT erleichterten. Die zusaetzliche Serumvitamin-B{sub 12}-Bestimmung stellt keinen wesentlichen Mehraufwand dar. (orig.)

  1. Performance of a high-sensitivity dedicated cardiac SPECT scanner for striatal uptake quantification in the brain based on analysis of projection data

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mi-Ae; Moore, Stephen C.; McQuaid, Sarah J.; Kijewski, Marie Foley [Department of Radiology, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts 02115 (United States); Mueller, Stefan P. [Abteilung Nuklearmedizin, Universitaetsklinikum Essen, 45147 Essen (Germany)

    2013-04-15

    Purpose: The authors have previously reported the advantages of high-sensitivity single-photon emission computed tomography (SPECT) systems for imaging structures located deep inside the brain. DaTscan (Isoflupane I-123) is a dopamine transporter (DaT) imaging agent that has shown potential for early detection of Parkinson disease (PD), as well as for monitoring progression of the disease. Realizing the full potential of DaTscan requires efficient estimation of striatal uptake from SPECT images. They have evaluated two SPECT systems, a conventional dual-head gamma camera with low-energy high-resolution collimators (conventional) and a dedicated high-sensitivity multidetector cardiac imaging system (dedicated) for imaging tasks related to PD. Methods: Cramer-Rao bounds (CRB) on precision of estimates of striatal and background activity concentrations were calculated from high-count, separate acquisitions of the compartments (right striata, left striata, background) of a striatal phantom. CRB on striatal and background activity concentration were calculated from essentially noise-free projection datasets, synthesized by scaling and summing the compartment projection datasets, for a range of total detected counts. They also calculated variances of estimates of specific-to-nonspecific binding ratios (BR) and asymmetry indices from these values using propagation of error analysis, as well as the precision of measuring changes in BR on the order of the average annual decline in early PD. Results: Under typical clinical conditions, the conventional camera detected 2 M counts while the dedicated camera detected 12 M counts. Assuming a normal BR of 5, the standard deviation of BR estimates was 0.042 and 0.021 for the conventional and dedicated system, respectively. For an 8% decrease to BR = 4.6, the signal-to-noise ratio were 6.8 (conventional) and 13.3 (dedicated); for a 5% decrease, they were 4.2 (conventional) and 8.3 (dedicated). Conclusions: This implies that PD can

  2. SU-E-I-80: Quantification of Respiratory and Cardiac Motion Effect in SPECT Acquisitions Using Anthropomorphic Models: A Monte Carlo Simulation Study

    Energy Technology Data Exchange (ETDEWEB)

    Papadimitroulas, P; Kostou, T; Kagadis, G [University of Patras, Rion, Ahaia (Greece); Loudos, G [Technological Educational Institute of Athens, Egaleo, Attika (Greece)

    2015-06-15

    Purpose: The purpose of the present study was to quantify, evaluate the impact of cardiac and respiratory motion on clinical nuclear imaging protocols. Common SPECT and scintigraphic scans are studied using Monte Carlo (MC) simulations, comparing the resulted images with and without motion. Methods: Realistic simulations were executed using the GATE toolkit and the XCAT anthropomorphic phantom as a reference model for human anatomy. Three different radiopharmaceuticals based on 99mTc were studied, namely 99mTc-MDP, 99mTc—N—DBODC and 99mTc—DTPA-aerosol for bone, myocardium and lung scanning respectively. The resolution of the phantom was set to 3.5 mm{sup 3}. The impact of the motion on spatial resolution was quantified using a sphere with 3.5 mm diameter and 10 separate time frames, in the ECAM modeled SPECT scanner. Finally, respiratory motion impact on resolution and imaging of lung lesions was investigated. The MLEM algorithm was used for data reconstruction, while the literature derived biodistributions of the pharmaceuticals were used as activity maps in the simulations. Results: FWHM was extracted for a static and a moving sphere which was ∼23 cm away from the entrance of the SPECT head. The difference in the FWHM was 20% between the two simulations. Profiles in thorax were compared in the case of bone scintigraphy, showing displacement and blurring of the bones when respiratory motion was inserted in the simulation. Large discrepancies were noticed in the case of myocardium imaging when cardiac motion was incorporated during the SPECT acquisition. Finally the borders of the lungs are blurred when respiratory motion is included resulting to a dislocation of ∼2.5 cm. Conclusion: As we move to individualized imaging and therapy procedures, quantitative and qualitative imaging is of high importance in nuclear diagnosis. MC simulations combined with anthropomorphic digital phantoms can provide an accurate tool for applications like motion correction

  3. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    OpenAIRE

    Winant, Celeste D.; Aparici, Carina Mari; Zelnik, Yuval R.; Reutter, Bryan W.; Sitek, Arkadiusz; Bacharach, Stephen L.; Gullberg, Grant T

    2011-01-01

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomograp...

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... top of page What are some common uses of the procedure? CT scanning of the head is ...

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the head uses special x-ray equipment to help assess head injuries, severe headaches, dizziness, and other symptoms of ... content. Related Articles and Media Radiation Dose in X-Ray and CT ... Perfusion of the Head CT Angiography (CTA) Stroke Brain Tumors Computer Tomography ( ...

  6. CT ventilation functional image-based IMRT treatment plans are comparable to SPECT ventilation functional image-based plans.

    Science.gov (United States)

    Kida, Satoshi; Bal, Matthieu; Kabus, Sven; Negahdar, Mohammadreza; Shan, Xin; Loo, Billy W; Keall, Paul J; Yamamoto, Tokihiro

    2016-03-01

    To investigate the hypothesis that CT ventilation functional image-based IMRT plans designed to avoid irradiating highly-functional lung regions are comparable to single-photon emission CT (SPECT) ventilation functional image-based plans. Three IMRT plans were created for eight thoracic cancer patients using: (1) CT ventilation functional images, (2) SPECT ventilation functional images, and (3) anatomic images (no functional images). CT ventilation images were created by deformable image registration of 4D-CT image data sets and quantitative analysis. The resulting plans were analyzed for the relationship between the deviations of CT-functional plan metrics from anatomic plan metrics (ΔCT-anatomic) and those of SPECT-functional plans (ΔSPECT-anatomic), and moreover for agreements of various metrics between the CT-functional and SPECT-functional plans. The relationship between ΔCT-anatomic and ΔSPECT-anatomic was strong (e.g., R=0.94; linear regression slope 0.71). The average differences and 95% limits of agreement between the CT-functional and SPECT-functional plan metrics (except for monitor units) for various structures were mostly less than 1% and 2%, respectively. This study demonstrated a reasonable agreement between the CT ventilation functional image-based IMRT plans and SPECT-functional plans, suggesting the potential for CT ventilation imaging to serve as a surrogate for SPECT ventilation in functional image-guided radiotherapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Ventilation/Perfusion SPECT lung scintigraphy and computed tomography pulmonary angiography in patients with clinical suspicion of pulmonary embolism.

    Science.gov (United States)

    Ibáñez-Bravo, S; Banzo, I; Quirce, R; Martínez-Rodríguez, I; Jiménez-Bonilla, J; Martínez-Amador, N; Parra, J A; González-Macías, J; Carril, J M

    2016-01-01

    The aim was to compare ventilation/perfusion SPECT lung scintigraphy (V/Q-SPECT) and computed tomography pulmonary angiography (CTPA) in patients with suspicion of pulmonary embolism (PE). This prospectively designed study included 53 patients with intermediate or high clinical probability of PE. A V/Q-SPECT and CTPA was performed on all patients. The V/Q-SPECT was interpreted according to the European Association of Nuclear Medicine and Molecular Imaging (EANMMI) guidelines. CTPA was reported as positive, negative, or indeterminate. CTPA was positive in 22 cases, negative in 28, and indeterminate in 3. V/Q-SPECT was positive in 27 cases, negative in 24, and non-diagnostic in 2. In the 22 with positive CTPA, V/Q-SPECT was positive in 18, negative in 3, and non-diagnostic in 1. In the 28 with negative CTPA, V/Q-SPECT was positive in 8, negative in 19, and non-diagnostic in 1. In the 3 with indeterminate CTPA, V/Q-SPECT was positive in 1 and negative in 2. In the 2 non-diagnostic cases V/Q-SPECT, CTPA was positive in 1 and negative in one. In the 10 high clinical probabilities, CTPA and V/Q-SPECT were positive in 7, negative in 2, and in 1, CTPA was positive and V/Q-SPECT negative. In the 38 intermediate probability group, CTPA and V/Q-SPECT were positive in 11, negative in 17, with CTPA negative and V/Q-SPECT positive in 8, and in 2 CTPA was positive and V/Q-SPECT negative. The results show that V/Q-SPECT detected PE in 5 patients more than CTPA. Our results show a 77% concordance of both techniques. Overall V/Q-SPECT detected PE in 18% more patients than CTPA in the intermediate group. Both techniques have a complementary role when a diagnosis cannot be made with one of them. Copyright © 2016 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

  8. Automatic semi-quantification of [(123)I]FP-CIT SPECT scans in healthy volunteers using BasGan version 2

    DEFF Research Database (Denmark)

    Nobili, Flavio; Naseri, Mehrdad; De Carli, Fabrizio

    2013-01-01

    Medicine). Brain single photon emission computed tomography (SPECT) was acquired by means of dual-head cameras 3 h after [(123)I]FP-CIT administration. Specific to nondisplaceable binding ratios (SBRs) in the basal ganglia were computed using the 'BasGan' software, allowing automatic value extraction...... with partial volume effect correction. Multicentre camera inhomogeneity was taken into account by calibrating values on basal ganglia phantom data. SBR in each caudate nucleus (C) and putamen (P) were the dependent variables in a repeated measures general linear model analysis; age, gender, handedness and body...... mass index (BMI) were the independent variables. RESULTS: SBR values in C and P were significantly associated with age (mean rate decrease with age: 0.0306 per year, or 0.57 % of the general mean; p ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  10. An isopropanol-assisted fabrication strategy of pinhole-free perovskite films in air for efficient and stable planar perovskite solar cells

    Science.gov (United States)

    Ren, Ziqiu; Zhu, Menghua; Li, Xin; Dong, Cunku

    2017-09-01

    As a promising photovoltaic device, perovskite solar cells have attracted numerous attention in recent years, where forming a compact and pinhole-free perovskite film in air is of great importance. Herein, we evaluate highly efficient and air stable planar perovskite solar cells in air (relative humidity over 50%) with the modified two-step sequential deposition method by adjusting the CH3NH3I (MAI) concentrations and regulating the crystallization process of the perovskite film. The optimum MAI concentration is 60 mg mL-1 in isopropanol. With a planar structure of FTO/TiO2/MAPbI3/spiro-OMeTAD/Au, the efficient devices composed of compact and pinhole-free perovskite films are constructed in air, achieving a high efficiency of up to 15.10% and maintaining over 80% after 20 days storing without any encapsulation in air. With a facile fabrication process and high photovoltaic performance, this work represents a promising method for fabricating low-cost, highly efficient and stable photovoltaic device.

  11. Ictal SPECT in neocortical epilepsies: clinical usefulness and factors affecting the pattern of hyperperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kun [Seoul National University Hospital, Department of Neurology, Seoul (Korea); Lee, Seo-Young [Kangwon National University Hospital, Department of Neurology, Chuncheon (Korea); Yun, Chang-Ho [Inha University Hospital, Department of Neurology, Incheon (Korea); Lee, Ho-Young; Lee, Jae-Sung; Lee, Dong-Soo [Seoul National University Hospital, Department of Nuclear Medicine, Seoul (Korea)

    2006-09-15

    The aims of this analysis were to: (1) determine the value of ictal SPECT in the localization of neocortical epileptogenic foci, (2) evaluate the relationships between the results of ictal SPECT and other potential affecting factors, and (3) compare traditional visual analysis and the subtraction method. We retrospectively analyzed 81 consecutive patients with neocortical epilepsy who underwent epilepsy surgery and achieved a favourable surgical outcome, including 36 patients with normal MRI. Side-by-side visual analysis and subtraction images were classified as correctly localizing,correctly lateralizing, or non-localizing/non-lateralizing images according to the resected lobe. Side-by-side visual analysis and subtraction SPECT correctly localized the epileptogenic lobe in 58.9% and 63.0% of patients, respectively. The two methods were complementary and the diagnostic sensitivity of ictal SPECT using the two methods was 79.0%. Ictal SPECT using the visual method correctly localized the epileptogenic lobe more frequently in patients with a localizing pattern of ictal scalp EEG at the time of radioligand injection. When using subtraction images, an injection delay of less than 20 s after seizure onset was significantly correlated with correct localization. The subtraction method was superior to the visual method for localizing frontal lobe epilepsy (FLE) and parietal lobe epilepsy (PLE), and in patients with non-localizing/non-lateralizing EEG at onset. Ictal SPECT analyses using visual and subtraction methods are useful and complementary for the localization of the epileptogenic foci of neocortical epilepsy. Early radioligand injection and ictal EEG patterns are related to ictal SPECT localization. The subtraction method may be more useful in some epileptic syndromes. (orig.)

  12. Brain spect in the pre-surgical evaluation of epileptic patients preliminary results

    Directory of Open Access Journals (Sweden)

    Carlos A. Buchpiguel

    1992-03-01

    Full Text Available Pre-surgical evaluation of epileptic patients consists of neurological examination, intensive electroencephalographic (EEG monitoring and anatomical studies (CT and MRI. Functional methods such as PET and SPECT imaging are now used more frequently. We have studied pre-operatively 15 adult epileptic patients (8 female, 7 male using a rotational scintillation camera interfaced to a dedicated computer. The tomographic images were obtained 15 minutes after intravenous injection of 99mTc_HMPAO. All had MRI scanning and intensive EEG monitoring which generally included seizure recording. Five patients had progressive lesions (3 meningiomas, 2 astrocytomas. In 10 patients, neuroradiological studies did not show the presence of progressive lesions (2 normal scans and 8 cases with inactive lesions. Two patients with meningioma showed hypoperfusion at the lesion site while the third patient had a marked hyperperfusion which might correlate with the clinical diagnosis of epilepsia partialis continua. In the astrocytoma patients SPECT scans showed hypoperfusion at the lesion site. Data obtained from the 10 patients without progressive CNS lesions showed: (a in 4, SPECT findings correlated well with the anatomical findings; (b in 5 instances, SPECT was able to disclose additional functional deficits; (c in one case, there was no SPECT correlate of a discrete anatomical lesion. In 5 of these cases with no progressive lesions (n=10 SPECT findings were useful as a complementary tool in determining the clinical or surgical management of these patients. Despite the small number and hete-rogenicity of the present sample, SPECT seems to be an useful tool as part of the clinical workup of epileptic patients who are candidates for epilepsy surgery.

  13. Comparative study of interictal PET and ictal SPECT in complex partial seizures

    Energy Technology Data Exchange (ETDEWEB)

    Markand, O.N.; Salanova, V. [Indiana Univ. School of Medicine, Dept. of Neurology, Indianapolis, Indiana (United States); Worth, R. [Indiana Univ. School of Medicine, Div. of Neurosurgery, Indianapolis, Indiana (United States); Park, H.M.; Wellman, H.N. [Indiana Univ. School of Medicine, Dept. of Nuclear Medicine, Indianapolis, Indiana (United States)

    1997-03-01

    Objective - To compare the sensitivity of ictal {sup 99m}Tc-HMPAO single photon emission computed tomography (SPECT) with interictal {sup 18}F-Fluoro-deoxyglucose positron emission tomography (PET) in localization of the epileptogenic focus in patients with medically intractable complex partial seizures (MI-CPS). Material and methods -Retrospective analysis was performed on patients with MI-CPS who underwent anterior temporal lobectomy from January 1993 onwards when PET became available to us. There were 38 female and 29 male patients (total=67) with MI-CPS, 10 to 55.5 years of age (mean 31) and duration of their epilepsy from 1-46 years (mean 21). Interictal PET was evaluated for evidence of focal hypometabolism and ictal SPECT for focal perfusion abnormality (hyperperfusion or hypoperfusion) by visual analysis. Results - Both ictal SPECT and interictal FDG-PET studies were obtained in 36 patients with MI-CPS. PET showed definite hypometabolism in 30 and questionable hypometabolism in an additional two patients. Ictal SPECT correctly localized the seizure focus in 27 patients by demonstrating ictal hyperperfusion whereas in one the hyperperfusion was falsely localized. In an additional seven patients the ictal SPECT provided probable localization by demonstrating ictal hypoperfusion in the appropriate temporal lobe. The sensitivity of ictal SPECT and interictal PET was 34/36 and 32/36, respectively, the difference was not statistically significant ({chi}{sup 2}{sub y}=0.18, DF=1, P=0.67). In six of the 36 patients the two test were complementary to each other in providing localizing information. Conclusion - Ictal SPECT and interictal PET are equally sensitive and reliable techniques in localizing the epileptogenic focus in patients with MI-CPS. They play a critical role in providing localization in MRI negative patients allowing surgical resection to be undertaken in many without additional invasive electrographic monitoring. 37 refs.

  14. Semiquantitative slab view display for visual evaluation of 123I-FP-CIT SPECT.

    Science.gov (United States)

    Buchert, Ralph; Hutton, Chloe; Lange, Catharina; Hoppe, Peter; Makowski, Marcus; Bamousa, Thamer; Platsch, Günther; Brenner, Winfried; Declerck, Jerome

    2016-05-01

    Dopamine transporter single-photon emission computed tomography (SPECT) with I-FP-CIT is used widely in the diagnosis of clinically uncertain parkinsonian syndromes. In terms of the evaluation of FP-CIT SPECT, some practice guidelines state that visual interpretation alone is generally sufficient in clinical patient care, whereas other guidelines consider semiquantitative analysis of striatal dopamine transporter availability mandatory. This discrepancy might be because of a relative lack of widely available display tools for FP-CIT SPECT. In this study, we evaluate a semiquantitative slab view display optimized for visual evaluation of FP-CIT SPECT that might resolve the discrepancy. The reconstructed FP-CIT SPECT image was stereotactically normalized and scaled voxel by voxel to the mean uptake in the entire brain without striata. From the resulting distribution volume ratio image, a 12-mm-thick transversal slice (slab) through the striata was displayed with a standard colour table with predefined fixed thresholds on the distribution volume ratio. Visual scoring of the semiquantitative slab view was performed twice by four independent readers in 235 unselected patients. The specific binding ratio in the caudate and putamen was computed by fully automated semiquantitative analysis with predefined standard regions of interest in template space. Intrarater and inter-rater agreement of binary visual categorization as 'normal' or 'reduced' was excellent (mean Cohen's κ=0.88 and 0.83, respectively). The area under the receiver-operator characteristic curve of the specific putamen-binding ratio for differentiation between visually normal and visually reduced (majority read) was 0.96. Visual interpretation of FP-CIT SPECT on the basis of the semiquantitative slab view display provides excellent stability within and between readers as well as very high agreement with semiquantitative analysis. This suggests that the slab view display enables reliable visual

  15. The hidden sentinel node and SPECT/CT in breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Ploeg, Iris M.C. van der; Kroon, Bin B.R.; Rutgers, Emiel J.T.; Nieweg, Omgo E. [The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Surgery, Amsterdam (Netherlands); Valdes Olmos, Renato A. [The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands)

    2009-01-15

    In a minority of breast cancer patients, lymphoscintigraphy shows no lymphatic drainage and 'hidden' sentinel nodes may remain undiscovered. The purpose of this study was to explore the additional value of the recently introduced hybrid SPECT/CT in breast cancer patients with axillary non-visualisation on planar images. The role of blue dye and careful palpation of the axilla was evaluated in patients in whom axillary sentinel nodes remained hidden after SPECT/CT. Fifteen breast cancer patients with non-visualisation on planar lymphoscintigraphy and 13 women with only extra-axillary sentinel nodes underwent SPECT/CT following late planar imaging without re-injection of the radiopharmaceutical. SPECT/CT visualised lymphatic drainage in eight of the 15 patients (53%) with non-visualisation on planar imaging, depicted nine of the 14 harvested sentinel nodes (64%) and three of five tumour-positive sentinel nodes. In two of the 13 patients (15%) with only extra-axillary sentinel nodes on their planar lymphoscintigram, SPECT/CT showed an axillary sentinel node that appeared to be uninvolved. Careful exploration of the axilla with the combined use of blue dye, a gamma probe and intra-operative palpation revealed an axillary sentinel node in the remaining 18 patients. SPECT/CT showed the exact anatomical location of all visualised sentinel nodes. SPECT/CT discovered 'hidden' sentinel nodes in the majority of patients with non-visualisation, but was less valuable in patients with only extra-axillary lymphatic drainage on the planar images. Exploration of the axilla in patients with persistent non-visualisation improved the identification of axillary (involved) sentinel nodes. (orig.)

  16. SPECT imaging evaluation in movement disorders: far beyond visual assessment

    Energy Technology Data Exchange (ETDEWEB)

    Badiavas, Kosmas [General Hospital, Medical Physics Department, Thessaloniki (Greece); Molyvda, Elisavet; Psarrakos, Kyriakos [Medical Physics Dept., General Hospital, Thessaloniki (Greece); Iakovou, Ioannis; Karatzas, Nikolaos [Medical Physical Dept., Aristotle Univ., Thessaloniki (Greece); Tsolaki, Magdalini [3. Neurology Clinic, Aristotle Univ., Thessaloniki (Greece)

    2011-04-15

    Single photon emission computed tomography (SPECT) imaging with {sup 123}I-FP-CIT is of great value in differentiating patients suffering from Parkinson's disease (PD) from those suffering from essential tremor (ET). Moreover, SPECT with {sup 123}I-IBZM can differentiate PD from Parkinson's ''plus'' syndromes. Diagnosis is still mainly based on experienced observers' visual assessment of the resulting images while many quantitative methods have been developed in order to assist diagnosis since the early days of neuroimaging. The aim of this work is to attempt to categorize, briefly present and comment on a number of semi-quantification methods used in nuclear medicine neuroimaging. Various arithmetic indices have been introduced with region of interest (ROI) manual drawing methods giving their place to automated procedures, while advancing computer technology has allowed automated image registration, fusion and segmentation to bring quantification closer to the final diagnosis based on the whole of the patient's examinations results, clinical condition and response to therapy. The search for absolute quantification has passed through neuroreceptor quantification models, which are invasive methods that involve tracer kinetic modelling and arterial blood sampling, a practice that is not commonly used in a clinical environment. On the other hand, semi-quantification methods relying on computers and dedicated software try to elicit numerical information out of SPECT images. The application of semi-quantification methods aims at separating the different patient categories solving the main problem of finding the uptake in the structures of interest. The semi-quantification methods which were studied fall roughly into three categories, which are described as classic methods, advanced automated methods and pixel-based statistical analysis methods. All these methods can be further divided into various subcategories. The plethora of

  17. The significance of Bremsstrahlung SPECT/CT after yttrium-90 radioembolization treatment in the prediction of extrahepatic side effects

    Energy Technology Data Exchange (ETDEWEB)

    Ahmadzadehfar, Hojjat; Muckle, Marianne; Sabet, Amir; Biermann, Kim; Haslerud, Torjan; Biersack, Hans-Juergen; Ezziddin, Samer [University Hospital Bonn, Department of Nuclear Medicine, Bonn (Germany); Wilhelm, Kai [University Hospital Bonn, Department of Radiology, Bonn (Germany); Kuhl, Christiane [University Hospital Aachen, Department of Radiology, Aachen (Germany)

    2012-02-15

    Unwanted deposition of {sup 90}Y microspheres in organs other than the liver during radioembolization of liver tumours may cause severe side effects such as duodenal ulcer. The aim of this study was to evaluate the significance of posttherapy bremsstrahlung (BS) SPECT/CT images of the liver in comparison to planar and SPECT images in the prediction of radioembolization-induced extrahepatic side effects. A total of 188 radioembolization procedures were performed in 123 patients (50 women, 73 men) over a 2-year period. Planar, whole-body and BS SPECT/CT imaging were performed 24 h after treatment as a part of therapy work-up. Any focally increased extrahepatic accumulation was evaluated as suspicious. Clinical follow-up and gastroduodenoscopy served as reference standards. The studies were reviewed to evaluate whether BS SPECT/CT imaging was of benefit. In the light of anatomic data obtained from SPECT/CT, apparent extrahepatic BS in 43% of planar and in 52% of SPECT images proved to be in the liver and hence false-positive. The results of planar scintigraphy could not be analysed further since 12 images were not assessable due to high scatter artefacts. On the basis of the gastrointestinal (GI) complications and the results of gastroduodenoscopy, true-positive, true-negative, false-positive and false-negative results of BS SPECT and SPECT/CT imaging in the prediction of GI ulcers were determined. The sensitivity, specificity, positive and negative predictive values and the accuracy of SPECT and SPECT/