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Sample records for cardiac spect systems

  1. End-expiration Respiratory Gating for a High Resolution Stationary Cardiac SPECT system

    Science.gov (United States)

    Chan, Chung; Harris, Mark; Le, Max; Biondi, James; Grobshtein, Yariv; Liu, Yi-Hwa; Sinusas, Albert J.; Liu, Chi

    2014-01-01

    Respiratory and cardiac motions can degrade myocardial perfusion SPECT (MPS) image quality and reduce defect detection and quantitative accuracy. In this study, we developed a dual-respiratory and cardiac gating system for a high resolution fully stationary cardiac SPECT scanner in order to improve the image quality and defect detection. Respiratory motion was monitored using a compressive sensor pillow connected to a dual respiratory-cardiac gating box, which sends cardiac triggers only during end-expiration phases to the single cardiac trigger input on the SPECT scanners. The listmode data were rebinned retrospectively into end-expiration frames for respiratory motion reduction or 8 cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (pdefect, EXG-SPECT improved the defect contrast and definition. The dual respiratory-cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (pdefect characteristics and visualization of fine structures at the expense of increased noise on the patient with defect. The results showed that the proposed methods can effectively reduce motion blur in the images caused by both respiratory and cardiac motions, which may lead to more accurate defect detection and

  2. End-expiration respiratory gating for a high-resolution stationary cardiac SPECT system

    Science.gov (United States)

    Chan, Chung; Harris, Mark; Le, Max; Biondi, James; Grobshtein, Yariv; Liu, Yi-Hwa; Sinusas, Albert J.; Liu, Chi

    2014-10-01

    Respiratory and cardiac motions can degrade myocardial perfusion SPECT (MPS) image quality and reduce defect detection and quantitative accuracy. In this study, we developed a dual respiratory and cardiac gating system for a high-resolution fully stationary cardiac SPECT scanner in order to improve the image quality and defect detection. Respiratory motion was monitored using a compressive sensor pillow connected to a dual respiratory-cardiac gating box, which sends cardiac triggers only during end-expiration phases to the single cardiac trigger input on the SPECT scanners. The listmode data were rebinned retrospectively into end-expiration frames for respiratory motion reduction or eight cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (p defect, EXG-SPECT improved the defect contrast and definition. The dual respiratory-cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (p defect characteristics and visualization of fine structures at the expense of increased noise on the patient with defect. The results showed that the proposed methods can effectively reduce motion blur in the images caused by both respiratory and cardiac motions, which may lead to more accurate defect detection and

  3. Dynamic molecular imaging of cardiac innervation using a dual headpinhole SPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jicun; Boutchko, Rostyslav; Sitek, Arkadiusz; Reutter, BryanW.; Huesman, Ronald H.; Gullberg, Grant T.

    2008-03-29

    Typically 123I-MIBG is used for the study of innervation andfunction of the sympathetic nervous system in heart failure. The protocolinvolves two studies: first a planar or SPECT scan is performed tomeasure initial uptake of the tracer, followed some 3-4 hours later byanother study measuring the wash-out of the tracer from the heart. A fastwash-out is indicative of a compromised heart. In this work, a dual headpinhole SPECT system was used for imaging the distribution and kineticsof 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) andnormotensive Wistar Kyoto (WKY) rats. The system geometry was calibratedbased on a nonlinear point projection fitting method using a three-pointsource phantom. The angle variation effect of the parameters was modeledwith a sinusoidal function. A dynamic acquisition was performed byinjecting 123I-MIBG into rats immediately after starting the dataacquisition. The detectors rotated continuously performing a 360o dataacquisition every 90 seconds. We applied the factor analysis (FA)methodand region of interest (ROI) sampling method to obtain time activitycurves (TACs)in the blood pool and myocardium and then appliedtwo-compartment modeling to estimate the kinetic parameters. Since theinitial injection bolus is too fast for obtaining a consistenttomographic data set in the first few minutes of the study, we appliedthe FA method directly to projections during the first rotation. Then thetime active curves for blood and myocardial tissue were obtained from ROIsampling. The method was applied to determine if there were differencesin the kinetics between SHR and WKY rats and requires less time byreplacing the delayed scan at 3-4 hours after injection with a dynamicacquisition over 90 to 120 minutes. The results of a faster washout and asmaller distribution volume of 123IMIBG near the end of life in the SHRmodel of hypertrophic cardiomyopthy may be indicative of a failing heartin late stages of heart failure.

  4. SPECT imaging of cardiac reporter gene expression in living rabbits

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; LAN Xiaoli; ZHANG Liang; WU Tao; JIANG Rifeng; ZHANG Yongxue

    2009-01-01

    This work is to demonstrate feasibility of imaging the expression of herpes simplex virus 1-thymidine ki-nase (HSV1-tk) reporter gene in rabbits myocardium by using the reporter probe 131I-2'-fluoro-2'-deoxy-1-β-D- arabi-nofuranosyl-5-iodouracil (131I-FIAU) and SPECT. Rabbits of the study group received intramyocardial injection of Ad5-tk and control group received aseptic saline injection. Two sets of experiments were performed on the study group. Rabbits of the 1st set were injected with 131I-FIAU 600 μCi at Day 2 after intramyocardial transfection of Ad5-tk in 1×109, 5×108, 1×108, 5×107 and 1×107 pfu, and heart SPECT imaging was done at different hours. Rabbits of the 2nd were transferred various titers of Ad5-tk (1×109, 5×108, 1×108, 5×107, 1×107 pfu) to determine the threshold and optimal viral titer needed for detection of gene expression. Two days later, 131I-FIAU was injected and heart SPECT imaging was performed at 6, 24 and 48 h, before killing them for gamma counting of the hearts. Reverse tran-scription-polymerase chain reaction (RT-PCR) was used to verify the transferred HSV1-tk gene expression. Semi-quantitative analysis derived of region of interest (ROI) of SPECT images and RT-PCR images was performed and the relationship of SPECT images with ex vivo gamma counting and mRNA level were evaluated. SPECT images conformed 131I-FIAU accumulation in rabbits injected with Ad5-tk in the anterolateral wall. The optimal images qual-ity was obtained at 24~48 h for different viral titers. The highest radioactivity in the focal myocardium was seen at 6 h, and then declined with time. The threshold was 5×107 pfu of virus titer. The result could be set better in 1~5×108 pfu by SPECT analysis and gamma counting. ROI-derived semi-quantitative study on SPECT images correlated well with ex vivo gamma counting and mRNA levels from RT-PCR analysis. The HSV1-tk/131I-FIAU reporter gene/reporter probe system is feasible for cardiac SPECT reporter gene imaging

  5. A multiresolution restoration method for cardiac SPECT

    Science.gov (United States)

    Franquiz, Juan Manuel

    Single-photon emission computed tomography (SPECT) is affected by photon attenuation and image blurring due to Compton scatter and geometric detector response. Attenuation correction is important to increase diagnostic accuracy of cardiac SPECT. However, in attenuation-corrected scans, scattered photons from radioactivity in the liver could produce a spillover of counts into the inferior myocardial wall. In the clinical setting, blurring effects could be compensated by restoration with Wiener and Metz filters. Inconveniences of these procedures are that the Wiener filter depends upon the power spectra of the object image and noise, which are unknown, while Metz parameters have to be optimized by trial and error. This research develops an alternative restoration procedure based on a multiresolution denoising and regularization algorithm. It was hypothesized that this representation leads to a more straightforward and automatic restoration than conventional filters. The main objective of the research was the development and assessment of the multiresolution algorithm for compensating the liver spillover artifact. The multiresolution algorithm decomposes original SPECT projections into a set of sub-band frequency images. This allows a simple denoising and regularization procedure by discarding high frequency channels and performing inversion only in low and intermediate frequencies. The method was assessed in bull's eye polar maps and short- axis attenuation-corrected reconstructions of a realistic cardiac-chest phantom with a custom-made liver insert and different 99mTc liver-to-heart activity ratios. Inferior myocardial defects were simulated in some experiments. The cardiac phantom in free air was considered as the gold standard reference. Quantitative analysis was performed by calculating contrast of short- axis slices and the normalized chi-square measure, defect size and mean and standard deviation of polar map counts. The performance of the multiresolution

  6. Bayesian learning for cardiac SPECT image interpretation.

    Science.gov (United States)

    Sacha, Jarosław P; Goodenday, Lucy S; Cios, Krzysztof J

    2002-01-01

    In this paper, we describe a system for automating the diagnosis of myocardial perfusion from single-photon emission computerized tomography (SPECT) images of male and female hearts. Initially we had several thousand of SPECT images, other clinical data and physician-interpreter's descriptions of the images. The images were divided into segments based on the Yale system. Each segment was described by the physician as showing one of the following conditions: normal perfusion, reversible perfusion defect, partially reversible perfusion defect, fixed perfusion defect, defect showing reverse redistribution, equivocal defect or artifact. The physician's diagnosis of overall left ventricular (LV) perfusion, based on the above descriptions, categorizes a study as showing one or more of eight possible conditions: normal, ischemia, infarct and ischemia, infarct, reverse redistribution, equivocal, artifact or LV dysfunction. Because of the complexity of the task, we decided to use the knowledge discovery approach, consisting of these steps: problem understanding, data understanding, data preparation, data mining, evaluating the discovered knowledge and its implementation. After going through the data preparation step, in which we constructed normal gender-specific models of the LV and image registration, we ended up with 728 patients for whom we had both SPECT images and corresponding diagnoses. Another major contribution of the paper is the data mining step, in which we used several new Bayesian learning classification methods. The approach we have taken, namely the six-step knowledge discovery process has proven to be very successful in this complex data mining task and as such the process can be extended to other medical data mining projects.

  7. Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology

    Science.gov (United States)

    Erlandsson, Kjell; Kacperski, Krzysztof; van Gramberg, Dean; Hutton, Brian F.

    2009-05-01

    D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a β-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s-1 MBq-1 per head (99mTc, 10 cm) (CS: 72 s-1 MBq-1), and the tomographic sensitivity in the heart region was in the range 647-1107 s-1 MBq-1 (CS: 141 s-1 MBq-1). The count rate increased linearly with increasing activity up to 1.44 M s-1. The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies.

  8. Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology.

    Science.gov (United States)

    Erlandsson, Kjell; Kacperski, Krzysztof; van Gramberg, Dean; Hutton, Brian F

    2009-05-07

    D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a beta-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s(-1) MBq(-1) per head ((99m)Tc, 10 cm) (CS: 72 s(-1) MBq(-1)), and the tomographic sensitivity in the heart region was in the range 647-1107 s(-1) MBq(-1) (CS: 141 s(-1) MBq(-1)). The count rate increased linearly with increasing activity up to 1.44 M s(-1). The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies.

  9. Anatomical-based Partial Volume Correction for Low-dose Dedicated Cardiac SPECT/CT

    OpenAIRE

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-01-01

    Due to the limited spatial resolution, partial volume effect (PVE) has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view (FOV) over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods ...

  10. Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, Kjell; Kacperski, Krzysztof; Van Gramberg, Dean; Hutton, Brian F [Institute of Nuclear Medicine, University College London and UCLH NHS Foundation Trust, London NW1 2BU (United Kingdom)], E-mail: kjell.erlandsson@uclh.nhs.uk

    2009-05-07

    D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a {beta}-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s{sup -1} MBq{sup -1} per head ({sup 99m}Tc, 10 cm) (CS: 72 s{sup -1} MBq{sup -1}), and the tomographic sensitivity in the heart region was in the range 647-1107 s{sup -1} MBq{sup -1} (CS: 141 s{sup -1} MBq{sup -1}). The count rate increased linearly with increasing activity up to 1.44 M s{sup -1}. The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies.

  11. The effect of truncation on very small cardiac SPECT camerasystems

    Energy Technology Data Exchange (ETDEWEB)

    Rohmer, Damien; Eisner, Robert L.; Gullberg, Grant T.

    2006-08-01

    Background: The limited transaxial field-of-view (FOV) of avery small cardiac SPECT camera system causes view-dependent truncationof the projection of structures exterior to, but near the heart. Basictomographic principles suggest that the reconstruction of non-attenuatedtruncated data gives a distortion-free image in the interior of thetruncated region, but the DC term of the Fourier spectrum of thereconstructed image is incorrect, meaning that the intensity scale of thereconstruction is inaccurate. The purpose of this study was tocharacterize the reconstructed image artifacts from truncated data, andto quantify their effects on the measurement of tracer uptake in themyocardial. Particular attention was given to instances where the heartwall is close to hot structures (structures of high activity uptake).Methods: The MCAT phantom was used to simulate a 2D slice of the heartregion. Truncated and non-truncated projections were formed both with andwithout attenuation. The reconstructions were analyzed for artifacts inthe myocardium caused by truncation, and for the effect that attenuationhas relative to increasing those artifacts. Results: The inaccuracy dueto truncation is primarily caused by an incorrect DC component. Forvisualizing theleft ventricular wall, this error is not worse than theeffect of attenuation. The addition of a small hot bowel-like structurenear the left ventricle causes few changes in counts on the wall. Largerartifacts due to the truncation are located at the boundary of thetruncation and can be eliminated by sinogram interpolation. Finally,algebraic reconstruction methods are shown to give better reconstructionresults than an analytical filtered back-projection reconstructionalgorithm. Conclusion: Small inaccuracies in reconstructed images fromsmall FOV camera systems should have little effect on clinicalinterpretation. However, changes in the degree of inaccuracy in countsfrom slice toslice are due to changes in the truncated structures

  12. The usefulness of myocardial SPECT for the preoperative cardiac risk evaluation in noncardiac surgery

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Seok Tae; Lee, Dong Soo; Kang, Won Jon; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    1999-02-01

    We investigated whether myocardial SPECT had additional usefulness to clinical, functional or surgical indices for the preoperative evaluation of cardiac risks in noncardiac surgery. 118 patients ( M: F=66: 52, 62.7{+-}10.5 years) were studied retrospectively. Eighteen underwent vascular surgeries and 100 nonvascular surgeries. Rest Tl-201/ stress Tc-99m-MIBI SPECT was performed before operation and cardiac events (hard event: cardiac death and myocardial infarction; soft event: ischemic ECG change, congestive heat failure and unstable angina) were surveyed through perioperative periods (14.6{+-}5.6 days). Clinical risk indices, functional capacity, surgery procedures and SPECT findings were tested for their predictive values of perioperative cardiac events. Peri-operative cardiac events occurred in 25 patients (3 hard events and 22 soft events). Clinical risk indices, surgical procedure risks and SPECT findings but functional capacity were predictive of cardiac events. Reversible perfusion decrease was a better predictor than persistent decrease. Multivariate analysis sorted out surgical procedure risk (p=0.0018) and SPECT findings (p=0.0001) as significant risk factors. SPECT could re-stratify perioperative cardiac risks in patients ranked with surgical procedures. We conclude that myocardial SPECT provides additional predictive value to surgical type risks as well as clinical indexes or functional capacity for the prediction of preoperative cardiac events in noncardiac surgery.

  13. Patient position alters attenuation effects in multipinhole cardiac SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Timmins, Rachel; Ruddy, Terrence D.; Wells, R. Glenn, E-mail: gwells@ottawaheart.ca [Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7 (Canada)

    2015-03-15

    Purpose: Dedicated cardiac cameras offer improved sensitivity over conventional SPECT cameras. Sensitivity gains are obtained by large numbers of detectors and novel collimator arrangements such as an array of multiple pinholes that focus on the heart. Pinholes lead to variable amounts of attenuation as a source is moved within the camera field of view. This study evaluated the effects of this variable attenuation on myocardial SPECT images. Methods: Computer simulations were performed for a set of nine point sources distributed in the left ventricular wall (LV). Sources were placed at the location of the heart in both an anthropomorphic and a water-cylinder computer phantom. Sources were translated in x, y, and z by up to 5 cm from the center. Projections were simulated with and without attenuation and the changes in attenuation were compared. A LV with an inferior wall defect was also simulated in both phantoms over the same range of positions. Real camera data were acquired on a Discovery NM530c camera (GE Healthcare, Haifa, Israel) for five min in list-mode using an anthropomorphic phantom (DataSpectrum, Durham, NC) with 100 MBq of Tc-99m in the LV. Images were taken over the same range of positions as the simulations and were compared based on the summed perfusion score (SPS), defect width, and apparent defect uptake for each position. Results: Point sources in the water phantom showed absolute changes in attenuation of ≤8% over the range of positions and relative changes of ≤5% compared to the apex. In the anthropomorphic computer simulations, absolute change increased to 20%. The changes in relative attenuation caused a change in SPS of <1.5 for the water phantom but up to 4.2 in the anthropomorphic phantom. Changes were larger for axial than for transverse translations. These results were supported by SPS changes of up to six seen in the physical anthropomorphic phantom for axial translations. Defect width was also seen to significantly increase. The

  14. Diminishing the impact of the partial volume effect in cardiac SPECT perfusion imaging.

    Science.gov (United States)

    Pretorius, P Hendrik; King, Michael A

    2009-01-01

    The partial volume effect (PVE) significantly restricts the absolute quantification of regional myocardial uptake and thereby limits the accuracy of absolute measurement of blood flow and coronary flow reserve by SPECT. The template-projection-reconstruction method has been previously developed for PVE compensation. This method assumes the availability of coregistered high-spatial resolution anatomical information as is now becoming available with commercial dual-modality imaging systems such as SPECT/CTs. The objective of this investigation was to determine the extent to which the impact of the PVE on cardiac perfusion SPECT imaging can be diminished if coregistered high-spatial resolution anatomical information is available. For this investigation the authors introduced an additional parameter into the template-projection-reconstruction compensation equation called the voxel filling fraction (F). This parameter specifies the extent to which structure edge voxels in the emission reconstruction are filled by the structure in question as determined by the higher spatial-resolution imaging modality and the fractional presence of the structure at different states of physiological motion as in combining phases of cardiac motion. During correction the removal of spillover to the cardiac region from the surrounding structures is performed first by using reconstructed templates of neighboring structures (liver, blood pool, lungs) to calculate spillover fractions. This is followed by determining recovery coefficients for all voxels within the heart wall from the reconstruction of the template projections of the left and right ventricles (LV and RV). The emission data are subsequently divided by these recovery coefficients taking into account the filling fraction F. The mathematical cardiac torso phantom was used for investigation correction of PVE for a normal LV distribution, a defect in the inferior wall, and a defect in the anterior wall. PVE correction resulted in a

  15. 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''.

  16. Evaluation of Rigid-Body Motion Compensation in Cardiac Perfusion SPECT Employing Polar-Map Quantification.

    Science.gov (United States)

    Pretorius, P Hendrik; Johnson, Karen L; King, Michael A

    2016-06-01

    We have recently been successful in the development and testing of rigid-body motion tracking, estimation and compensation for cardiac perfusion SPECT based on a visual tracking system (VTS). The goal of this study was to evaluate in patients the effectiveness of our rigid-body motion compensation strategy. Sixty-four patient volunteers were asked to remain motionless or execute some predefined body motion during an additional second stress perfusion acquisition. Acquisitions were performed using the standard clinical protocol with 64 projections acquired through 180 degrees. All data were reconstructed with an ordered-subsets expectation-maximization (OSEM) algorithm using 4 projections per subset and 5 iterations. All physical degradation factors were addressed (attenuation, scatter, and distance dependent resolution), while a 3-dimensional Gaussian rotator was used during reconstruction to correct for six-degree-of-freedom (6-DOF) rigid-body motion estimated by the VTS. Polar map quantification was employed to evaluate compensation techniques. In 54.7% of the uncorrected second stress studies there was a statistically significant difference in the polar maps, and in 45.3% this made a difference in the interpretation of segmental perfusion. Motion correction reduced the impact of motion such that with it 32.8 % of the polar maps were statistically significantly different, and in 14.1% this difference changed the interpretation of segmental perfusion. The improvement shown in polar map quantitation translated to visually improved uniformity of the SPECT slices.

  17. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT

    Science.gov (United States)

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with 99mTc-tetrofosmin, a myocardial perfusion agent, and 99mTc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of 99mTc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both 99mTc-tetrofosmin perfusion imaging and 99mTc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low

  18. Ventricular function following coronary artery bypass grafting: comparison between Gated SPECT and cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Claudio Tinoco [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Pessoa, Maria Carolina Pinheiro [Pro-Echo Hospital Samaritano, Rio de Janeiro, RJ (Brazil); Vasconcelos, Paulo Pontes [Centro de Diagnostico por Imagens (CDPI), Rio de Janeiro, RJ (Brazil); Oliveira Junior, Amarino Carvalho [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil). Servico de Radiologia; Dohmann, Hans Fernando Rocha [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil). Servico de Radiologia; Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Reis, Adair Gomes dos [Nuclear Diagnosticos, SP (Brazil); Fonseca, Lea Mirian Barbosa da [Pro-Echo Hospital Samaritano, Rio de Janeiro, RJ (Brazil); Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2009-04-15

    Background: The assessment of left ventricular function may be impaired by the abnormal interventricular septal motion frequently found after coronary artery bypass grafting (CABG). Studies on the validation of gated SPECT as a tool for the assessment of left ventricular function in this patient group are scarce. Objective: We investigated the agreement and correlation between left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) as obtained using electrocardiogram-gated myocardial perfusion scintigraphy (gated SPECT) and cardiac magnetic resonance imaging in 20 patients undergoing coronary artery bypass grafting. Methods: Correlation was measured using Spearman's correlation coefficient ({rho}). Agreement was assessed using Bland-Altman analysis. Results: A good correlation was found between gated SPECT and cardiac magnetic resonance imaging in patients after CABG with regard to left ventricular ejection fraction ({rho} = 0.85; p =0.0001), moderate correlation for end-diastolic volume ({rho} = 0.51; p = 0.02), and non-significant correlation for end-diastolic volume ({rho} = 0.13; p = 0.5). Agreement ranges for LVEF, ESV and EDV were: -20% to 12%; -38 to 54 ml and; -96 to 100 ml, respectively. Conclusion: A reliable correlation was found for left ventricular ejection fraction as obtained by gated SPECT and magnetic resonance imaging in patients undergoing CABG. For ventricular volumes, however, the correlation is not adequate. (author)

  19. Geometric calibration for a SPECT system dedicated to breast imaging

    Institute of Scientific and Technical Information of China (English)

    WU Li-Wei; WEI Long; CAO Xue-Xiang; WANG Lu; HUANG Xian-Chao; CHAI Pei; YUN Ming-Kai; ZHANG Yu-Bao; ZHANG Long; SHAN Bao-Ci

    2012-01-01

    Geometric calibration is critical to the accurate SPECT reconstruction.In this paper,a geometric calibration method was developed for a dedicated breast SPECT system with a tilted parallel beam (TPB)orbit.The acquisition geometry of the breast SPECT was firstly characterized.And then its projection model was established based on the acquisition geometry.Finally,the calibration results were obtained using a nonlinear optimization method that fitted the measured projections to the model.Monte Carlo data of the breast SPECT were used to verify the calibration method.Simulation results showed that the geometric parameters with reasonable accuracy could be obtained by the proposed method.

  20. Respiratory motion correction in gated cardiac SPECT using quaternion-based, rigid-body registration

    OpenAIRE

    Parker, Jason G.; Mair, Bernard A.; Gilland, David R.

    2009-01-01

    In this article, a new method is introduced for estimating the motion of the heart due to respiration in gated cardiac SPECT using a rigid-body model with rotation parametrized by a unit quaternion. The method is based on minimizing the sum of squared errors between the reference and the deformed frames resulting from the usual optical flow constraint by using an optimized conjugate gradient routine. This method does not require any user-defined parameters or penalty terms, which simplifies i...

  1. Murine cardiac images obtained with focusing pinhole SPECT are barely influenced by extra-cardiac activity

    Science.gov (United States)

    Branderhorst, Woutjan; van der Have, Frans; Vastenhouw, Brendan; Viergever, Max A.; Beekman, Freek J.

    2012-02-01

    Ultra-high-resolution SPECT images can be obtained with focused multipinhole collimators. Here we investigate the influence of unwanted high tracer uptake outside the scan volume on reconstructed tracer distributions inside the scan volume, for 99mTc-tetrofosmin myocardial perfusion scanning in mice. Simulated projections of a digital mouse phantom (MOBY) in a focusing multipinhole SPECT system (U-SPECT-II, MILabs, The Netherlands) were generated. With this system differently sized user-defined scan volumes can be selected, by translating the animal in 3D through the focusing collimators. Scan volume selections were set to (i) a minimal volume containing just the heart, acquired without translating the animal during scanning, (ii) a slightly larger scan volume as is typically applied for the heart, requiring only small XYZ translations during scanning, (iii) same as (ii), but extended further transaxially, and (iv) same as (ii), but extended transaxially to cover the full thorax width (gold standard). Despite an overall negative bias that is significant for the minimal scan volume, all selected volumes resulted in visually similar images. Quantitative differences in the reconstructed myocardium between gold standard and the results from the smaller scan volume selections were small; the 17 standardized myocardial segments of a bull's eye plot, normalized to the myocardial mean of the gold standard, deviated on average 6.0%, 2.5% and 1.9% for respectively the minimal, the typical and the extended scan volume, while maximum absolute deviations were respectively 18.6%, 9.0% and 5.2%. Averaged over ten low-count noisy simulations, the mean absolute deviations were respectively 7.9%, 3.2% and 1.9%. In low-count noisy simulations, the mean and maximum absolute deviations for the minimal scan volume could be reduced to respectively 4.2% and 12.5% by performing a short survey scan of the exterior activity and focusing the remaining scan time at the organ of interest. We

  2. Cardiac ⁹⁹mTc sestamibi SPECT and ¹⁸F FDG PET as viability markers in Takotsubo cardiomyopathy

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Bang, Lia Evi; Holmvang, Lene;

    2014-01-01

    guidelines recommend cardiac SPECT and fluorodeoxyglucose (FDG) PET for viability assessment. Takotsubo cardiomyopathy (TTC) is a disease characterized by acute but reversible HF leaving no scarring. To explore how robust the semi-quantitative viability criteria used in cardiac SPECT and FDG PET stands...

  3. Performance evaluation of advanced industrial SPECT system with diverging collimator.

    Science.gov (United States)

    Park, Jang Guen; Jung, Sung-Hee; Kim, Jong Bum; Moon, Jinho; Yeom, Yeon Soo; Kim, Chan Hyeong

    2014-12-01

    An advanced industrial SPECT system with 12-fold-array diverging collimator was developed for flow visualization in industrial reactors and was discussed in the previous study. The present paper describes performance evaluation of the SPECT system under both static- and dynamic- flow conditions. Under static conditions, the movement of radiotracer inside the test reactor was compared with that of color tracer (blue ink) captured with a high-speed camera. The comparison of the reconstructed images obtained with the radiotracer and the SPECT system showed fairly good agreement with video-frames of the color tracer obtained with the camera. Based on the results of the performance evaluation, it is concluded that the SPECT system is suitable for investigation and visualization of flows in industrial flow reactors.

  4. Examination of the findings on {sup 201}Tl, {sup 123}I-BMIPP dual cardiac SPECT in acute phase of Kawasaki disease

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Yutaka [Matsushita-Kotobuki Electronics Industries Ltd., Ohzu, Ehime (Japan); Ishizuka, Takehiro; Otabe, Hiroyuki; Kori, Takeo; Ota, Toshiko; Suzuki, Kazushige

    1999-02-01

    In 42 cases with acute phase of Kawasaki disease (3-27 days since pathopoiesis), {sup 201}Tl, {sup 123}I-BMIPP dual cardiac SPECT was performed and the reduction of the isotope-uptake was macroscopically assessed. On cardiac SPECT, 28 of 42 cases (67%), and 19 of 30 cases (63%) who were normal on electrocardiogram, echocardiogram and blood CK levels showed abnormal images. In a part of cases showing abnormal cardiac SPECT, coronary arteriography was performed, and constrictive lesions with more than 25% were not observed. In acute phase of Kawasaki disease, the risk of cardiac complication was thought to be low. But these results suggest that there are cardiac complications detectable by {sup 201}Tl, {sup 123}I-BMIPP dual cardiac SPECT. This cardiac lesions were thought to be intramyocardinal microangiitis or abnormal coronary micro circulation cased by myocarditis associating microangiitis. (K.H.)

  5. Examination of the findings on [sup 201]Tl, [sup 123]I-BMIPP dual cardiac SPECT in acute phase of Kawasaki disease

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Yutaka (Matsushita-Kotobuki Electronics Industries Ltd., Ohzu, Ehime (Japan)); Ishizuka, Takehiro; Otabe, Hiroyuki; Kori, Takeo; Ota, Toshiko; Suzuki, Kazushige

    1999-02-01

    In 42 cases with acute phase of Kawasaki disease (3-27 days since pathopoiesis), [sup 201]Tl, [sup 123]I-BMIPP dual cardiac SPECT was performed and the reduction of the isotope-uptake was macroscopically assessed. On cardiac SPECT, 28 of 42 cases (67%), and 19 of 30 cases (63%) who were normal on electrocardiogram, echocardiogram and blood CK levels showed abnormal images. In a part of cases showing abnormal cardiac SPECT, coronary arteriography was performed, and constrictive lesions with more than 25% were not observed. In acute phase of Kawasaki disease, the risk of cardiac complication was thought to be low. But these results suggest that there are cardiac complications detectable by [sup 201]Tl, [sup 123]I-BMIPP dual cardiac SPECT. This cardiac lesions were thought to be intramyocardinal microangiitis or abnormal coronary micro circulation cased by myocarditis associating microangiitis. (K.H.)

  6. The utility of segmental analysis in cardiac I-123 MIBG SPECT in Parkinson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Soo Hyun; Yoon, Joon Kee; Yoon, Jung Han; Lee, Su Jin; Jo, Kyung Soo; Lee, Dong Hyun; An, Young Sil [Ajou University School of Medicine, Suwon (Korea, Republic of)

    2015-12-15

    Cardiac images using I-123 metaiodobenzylguanidine (MIBG) are widely used to evaluate cardiac sympathetic denervation in Parkinson’s disease (PD). The aim of this study was to evaluate the utility of segmental analysis on cardiac MIBG SPECT in PD patients. In total, 36 patients with PD (n = 26) or essential tremor (ET, n = 10) who underwent MIBG cardiac SPECT were enrolled. The heart-to-mediastinum (H/M) ratios of MIBG uptake were acquired on planar images. For the segmental analysis of SPECT images, we evaluated the summed defect score (SDS) using a 17-segment model. The diagnostic abilities of H/M ratios and segmental parameters on MIBG SPECT were assessed by ROC curve analysis. The H/M ratios were significantly lower in PD than in ET patients (p < 0.05). On segmental analysis, SDS was significantly higher in PD patients than in the ET group (7.04 ± 4.09 vs. 2.90 ± 2.80; p = 0.006). The defect score of the anteroseptal region showed a significant difference between the groups (p = 0.002). The ROC analysis suggested only SDS (AUC = 0.785, p = 0.0003) and defect scores in the anteroseptal (AUC = 0.800, p < 0.0001) and inferior (AUC = 0.667, p = 0.013) regions showed significant diagnostic ability to differentiate PD from ET. Segmental parameters from cardiac MIBG SPECT images can provide additional information to differentiate PD from ET patients. Beyond H/M ratios from planar images, we recommend an MIBG SPECT study to evaluate sympathetic denervation in PD.

  7. Respiratory motion correction in gated cardiac SPECT using quaternion-based, rigid-body registration.

    Science.gov (United States)

    Parker, Jason G; Mair, Bernard A; Gilland, David R

    2009-10-01

    In this article, a new method is introduced for estimating the motion of the heart due to respiration in gated cardiac SPECT using a rigid-body model with rotation parametrized by a unit quaternion. The method is based on minimizing the sum of squared errors between the reference and the deformed frames resulting from the usual optical flow constraint by using an optimized conjugate gradient routine. This method does not require any user-defined parameters or penalty terms, which simplifies its use in a clinical setting. Using a mathematical phantom, the method was quantitatively compared to the principal axis method, as well as an iterative method in which the rotation matrix was represented by Euler angles. The quaternion-based method was shown to be substantially more accurate and robust across a wide range of extramyocardial activity levels than the principal axis method. Compared with the Euler angle representation, the quaternion-based method resulted in similar accuracy but a significant reduction in computation times. Finally, the quaternion-based method was investigated using a respiratory-gated cardiac SPECT acquisition of a human subject. The motion-corrected image has increased sharpness and myocardial uniformity compared to the uncorrected image.

  8. Comparison of inferior myocardial defect between planar and SPECT image of {sup 123}I-metaiodobenzylguanidine cardiac scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hideki; Momose, Mitsuru; Kashikura, Kenichi; Matsumoto, Nobusuke; Saito, Katsumi; Asano, Ryuta; Hosoda, Saichi; Kusakabe, Kiyoko [Tokyo Women`s Medical Coll. (Japan)

    1995-02-01

    Discordant findings of inferior MIBG defect between SPECT and planar images were sometimes observed in the clinical studies. In this study, we compared inferior myocardial findings between planar and SPECT image of {sup 123}I-metaiodobenzyl-guanidine (MIBG) cardiac scintigraphy in 29 patients. All patients were estimated as normal in anterior accumulation of MIBG. The patients were divided into 3 groups according to the visual finding of inferior defect in the planar and SPECT image; normal group (normal inferior accumulation of MIBG both in the planar and SPECT image, N=10), discordance group (inferior MIBG defect was only observed in the SPECT image, but was not observed in the planar image, N=7), inferior defect group (inferior MIBG defect was observed both in the planar and SPECT image, N=12). Inferior/anterior count ratio of SPECT and planar image were 0.96{+-}0.11 vs. 0.97{+-}0.05 in normal group, 0.59{+-}0.21 vs. 0.99{+-}0.13 in discordance group, 0.46{+-}0.13 vs. 0.82{+-}0.04 in inferior defect group. Liver/heart count ratio was significantly higher in the discordance group (2.07{+-}0.49) than that in the normal (1.14{+-}0.15) and inferior defect group (1.45{+-}0.39). In phantom study, it has been reported that increased liver accumulation of MIBG causes artifactual inferior defect adjacent to the liver. These data indicate that increased liver/heart count ratio may cause artifactual inferior defect on MIBG SPECT image in the clinical studies. Planar image evaluation may be helpful to distinct the artifactual inferior defect on SPECT image. (author).

  9. 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

  10. The development and initial evaluation of a realistic simulated SPECT dataset with simultaneous respiratory and cardiac motion for gated myocardial perfusion SPECT

    Science.gov (United States)

    Lee, Taek-Soo; Tsui, Benjamin M. W.

    2015-02-01

    We developed a realistic simulation dataset for simultaneous respiratory and cardiac (R&C) gated SPECT/CT using the 4D NURBS-based Cardiac-Torso (NCAT) Phantom and Monte Carlo simulation methods, and evaluated it for a sample application study. The 4D NCAT phantom included realistic respiratory motion and beating heart motion based on respiratory gated CT and cardiac tagged MRI data of normal human subjects. To model the respiratory motion, a set of 24 separate 3D NCAT phantoms excluding the heart was generated over a respiratory cycle. The beating heart motion was modeled separately with 48 frames per cardiac cycle for each of the 24 respiratory phases. The resultant set of 24  ×  48 3D NCAT phantoms provides a realistic model of a normal human subject at different phases of combined R&C motions. An almost noise-free SPECT projection dataset for each of the 1152 3D NCAT phantoms was generated using Monte Carlo simulation techniques and the radioactivity uptake distribution of 99mTc sestamibi in different organs. By grouping and summing the separate projection datasets, separate or simultaneous R&C gated acquired data with different gating schemes could be simulated. In the initial evaluation, we combined the projection datasets into ungated, 6 respiratory-gates only, 8 cardiac-gates only, and combined 6 respiratory-gates & 8 cardiac-gates projection datasets. Each dataset was reconstructed using 3D OS-EM without and with attenuation correction using the averaged and respiratory-gated attenuation maps, and the resulting reconstructed images were compared. These results were used to demonstrate the effects of R&C motions and the reduction of image artifact due to R&C motions by gating and attenuation corrections. We concluded that the realistic 4D NCAT phantom and Monte Carlo simulated SPECT projection datasets with R&C motions are powerful tools in the study of the effects of R&C motions, as well as in the development of R&C gating schemes and motion

  11. Multimodality evaluation of ventricular function: comparison of cardiac magnetic resonance imaging, echocardiography, and planar and SPECT blood pool imaging

    Science.gov (United States)

    Feiglin, David H.; Krol, Andrzej; Tillapaugh-Fay, Gwen M.; Szeverenyi, Nikolaus M.; Thomas, Frank D.

    2001-05-01

    Fifteen patients underwent resting echocardiography (EC), ECG gated cardiac MR ventriculography (MRV) and blood pool planar and SPECT ventriculography (SPV) sequentially on the same day. In addition, 36 patients had sequential ECG gated blood pool and SPV and 20 normal volunteers, age > 18 years, had sequential ECG gated cardiac MRI performed on both Siemens closed, 1.5T, and open, 0.2T, magnets. Echocardiography was performed using a HP 5500 system equipped with an S4 transducer in 2D mode. MRV at 0.2T and 1.5T used a circular polarized body coil. Nuclear Medicine studies used 25 mCi Tc- 99m labeled red blood cells. Gated planar and SPV were acquired on a dual head Siemens E-Cam system. We have found that MRV affords the most accurate measurement of ventricular function. SPV and MRV provide similar estimations of left ventricular function (LVEF). Further, SPV consistently provides higher LVEF, as compared to the planar data simultaneously acquired. Observed significant differences in intermodality measurements indicate that follow up studies in patients, especially in patients whose management is critically dependent on functional measurement changes, should be monitored by one modality only.

  12. Design and evaluation of a mobile bedside PET/SPECT imaging system

    Science.gov (United States)

    Studenski, Matthew Thomas

    Patients confined to an intensive care unit, the emergency room, or a surgical suite are managed without nuclear medicine procedures such as positron emission tomography (PET) or single photon emission computed tomography (SPECT). These studies have diagnostic value which can greatly benefit the physician's treatment of the patient but require that the patient is moved to a scanner. This dissertation examines the feasibility of an economical PET/SPECT system that can be brought to the bedside of an immobile patient for imaging. We chose to focus on cardiac SPECT imaging including perfusion imaging using 99mTc tracers and viability imaging using 18F tracers first because of problems arising from positioning a detector beneath a patient's bed, a requirement for the opposed detector orientation in PET imaging. Second, SPECT imaging acquiring over the anterior 180 degrees of the patient results in reduced attenuation effects due to the heart's location in the anterior portion of the body. Four studies were done to assess the clinical feasibility of the mobile system; 1) the performance of the system was evaluated in SPECT mode at both 140 keV (99mTc tracers) and 511 keV (positron emitting tracers), 2) a dynamic cardiac phantom was used to develop and test image acquisition and processing methods for the system at both energies, 3) a high energy pinhole collimator was designed to reduce the effects of high energy photon penetration through the parallel hole collimator, and 4) we estimated the radiation dose to persons that would be in the vicinity of a patient to ensure that the effective dose is below the regulatory limit. With these studies, we show that the mobile system provides an economical means of bringing nuclear medicine to an immobile patient while staying below the regulatory dose limit to other persons. The system performed well at both 140 keV and 511 keV and provided viable images of a phantom myocardium at both energies. The system does not achieve the

  13. 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.

  14. SVD-based evaluation of multiplexing in multipinhole SPECT systems.

    Science.gov (United States)

    Jorgensen, Aaron K; Zeng, Gengsheng L

    2008-01-01

    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.

  15. Comparison study of temporal regularization methods for fully 5D reconstruction of cardiac gated dynamic SPECT

    Science.gov (United States)

    Niu, Xiaofeng; Yang, Yongyi; King, Michael A.

    2012-09-01

    Temporal regularization plays a critical role in cardiac gated dynamic SPECT reconstruction, of which the goal is to obtain an image sequence from a single acquisition which simultaneously shows both cardiac motion and tracer distribution change over the course of imaging (termed 5D). In our recent work, we explored two different approaches for temporal regularization of the dynamic activities in gated dynamic reconstruction without the use of fast camera rotation: one is the dynamic EM (dEM) approach which is imposed on the temporal trend of the time activity of each voxel, and the other is a B-spline modeling approach in which the time activity is regulated by a set of B-spline basis functions. In this work, we extend the B-spline approach to fully 5D reconstruction and conduct a thorough quantitative comparison with the dEM approach. In the evaluation of the reconstruction results, we apply a number of quantitative measures on two major aspects of the reconstructed dynamic images: (1) the accuracy of the reconstructed activity distribution in the myocardium and (2) the ability of the reconstructed dynamic activities to differentiate perfusion defects from normal myocardial wall uptake. These measures include the mean square error (MSE), bias-variance analysis, accuracy of time-activity curves (TAC), contrast-to-noise ratio of a defect, composite kinetic map of the left ventricle wall and perfusion defect detectability with channelized Hotelling observer. In experiments, we simulated cardiac gated imaging with the NURBS-based cardiac-torso phantom and Tc99m-Teboroxime as the imaging agent, where acquisition with the equivalent of only three full camera rotations was used during the imaging period. The results show that both dEM and B-spline 5D could achieve similar overall accuracy in the myocardium in terms of MSE. However, compared to dEM 5D, the B-spline approach could achieve a more accurate reconstruction of the voxel TACs; in particular, B-spline 5D could

  16. 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

  17. Radiotracers for PET and SPECT studies of neurotransmitter systems

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.

    1991-01-01

    The study of neurotransmitter systems is one of the major thrusts in emission tomography today. The current generation of Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) radiotracers examines neurotransmitter properties from a number of different perspectives including their pre and post synaptic sites and the activity of the enzymes which regulate their concentration. Although the dopamine system has been the most extensively investigated, other neurotransmitter systems including the acetylcholine muscarine, serotonin, benzodiazepine, opiate, NMDA and others are also under intensive development. Enzymes involved in the synthesis and regulation of neurotransmitter concentration, for example monoamine oxidase and amino acid decarboxylase has also been probed in vivo. Medical applications range from the study of normal function and the characterization of neurotransmitter activity in neurological and psychiatric diseases and in heart disease and cancer to the study of the binding of therapeutic drugs and substances of abuse. This chapter will provide an overview of the current generation of radiotracers for PET and SPECT studies of neurotransmitter systems including radiotracer design, synthesis localization mechanisms and applications in emission tomography. 60 refs., 1 tab.

  18. GATE simulation of a new design of pinhole SPECT system for small animal brain imaging

    Science.gov (United States)

    Uzun Ozsahin, D.; Bläckberg, L.; El Fakhri, G.; Sabet, H.

    2017-01-01

    Small animal SPECT imaging has gained an increased interest over the past decade since it is an excellent tool for developing new drugs and tracers. Therefore, there is a huge effort on the development of cost-effective SPECT detectors with high capabilities. The aim of this study is to simulate the performance characteristics of new designs for a cost effective, stationary SPECT system dedicated to small animal imaging with a focus on mice brain. The conceptual design of this SPECT system platform, Stationary Small Animal SSA-SPECT, is to use many pixelated CsI:TI detector modules with 0.4 mm × 0.4 mm pixels in order to achieve excellent intrinsic detector resolution where each module is backed by a single pinhole collimator with 0.3 mm hole diameter. In this work, we present the simulation results of four variations of the SSA-SPECT platform where the number of detector modules and FOV size is varied while keeping the detector size and collimator hole size constant. Using the NEMA NU-4 protocol, we performed spatial resolution, sensitivity, image quality simulations followed by a Derenzo-like phantom evaluation. The results suggest that all four SSA-SPECT systems can provide better than 0.063% system sensitivity and < 1.5 mm FWHM spatial resolution without resolution recovery or other correction techniques. Specifically, SSA-SPECT-1 showed a system sensitivity of 0.09% in combination with 1.1 mm FWHM spatial resolution.

  19. Validation of a new cardiac image fusion software for three-dimensional integration of myocardial perfusion SPECT and stand-alone 64-slice CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver; Schepis, Tiziano; Namdar, Mehdi; Valenta, Ines [University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Kalff, Victor [Alfred Hospital, Department of Nuclear Medicine, Melbourne (Australia); Stefani, Laurent [GE Healthcare Bio-Sciences, Buc Cedex (France); Desbiolles, Lotus; Leschka, Sebastian; Husmann, Lars; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); University of Zurich, Zurich Center for Integrative Human Physiology (ZIHP), Zurich (Switzerland)

    2007-07-15

    Combining the functional information of SPECT myocardial perfusion imaging (SPECT-MPI) and the morphological information of coronary CT angiography (CTA) may allow easier evaluation of the spatial relationship between coronary stenoses and perfusion defects. The aim of the present study was the validation of a novel software solution for three-dimensional (3D) image fusion of SPECT-MPI and CTA. SPECT-MPI with adenosine stress/rest {sup 99m}Tc-tetrofosmin was fused with 64-slice CTA in 15 consecutive patients with a single perfusion defect and a single significant coronary artery stenosis ({>=}50% diameter stenosis). 3D fused SPECT/CT images were analysed by two independent observers with regard to superposition of the stenosed vessel onto the myocardial perfusion defect. Interobserver variability was assessed by recording the X, Y, Z coordinates for the origin of the stenosed coronary artery and the centre of the perfusion defect and measuring the distance between the two landmarks. SPECT-MPI revealed a fixed defect in seven patients, a reversible defect in five patients and a mixed defect in three patients and CTA documented a significant stenosis in the respective subtending coronary artery. 3D fused SPECT/CT images showed a match of coronary lesion and perfusion defect in each patient and the fusion process took less than 15 min. Interobserver variability was excellent for landmark detection (r = 1.00 and r = 0.99, p < 0.0001) and very good for the 3D distance between the two landmarks (r = 0.94, p < 0.001). 3D SPECT/CT image fusion is feasible, reproducible and allows correct superposition of SPECT segments onto cardiac CT anatomy. (orig.)

  20. Evaluation of cardiac function in patients with Duchenne's muscular dystrophy by single photon emission computed tomography (SPECT)

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Takuhisa; Motomura, Masakatsu; Kanazawa, Hajime; Shibuya, Noritoshi (Kawatana Byoin National Sanatorium, Nagasaki (Japan))

    1989-06-01

    The extent of myocardial ischemia was evaluated in 20 patients with Duchenne's muscular dystrophy (DMD) by using Bull's eye method of thallium-201 myocardial SPECT. It was examined in relation to skeletal muscle involvement, age, left ventricular (LV) ejection fraction and ventricular premature contractions (VPCs). Myocardial ischemia was detected in all of patients with DMD. Ischemic lesion was mostly detected in the apical side of the LV lateral wall and interventricular septum, while the extent of myocardial ischemia had no correlations with either the stage of functional disability of skeletal muscle or age. The more ischemic ratio was higher, the more LV ejection fraction decreased. The total number of VPCs was relatively small and it did not have any relation to myocardial ischemic ratio. These results suggest that younger DMD patients having extensive myocardial ischemia and/or ventricular tachycardia will have a high risk of cardiac death. (author).

  1. Lung function assessment using Xe-133 dynamic SPECT in dual-camera system

    Energy Technology Data Exchange (ETDEWEB)

    Sakaji, Katsuyuki; Akiyama, Masayuki; Nakazawa, Yasuo [Showa Univ., Tokyo (Japan). Hospital; Umeda, Hirotaka; Takenaka, Haruki; Shinozuka, Akira

    2001-09-01

    The purpose of this study was to estimate lung regional function using Xe-133 dynamic SPECT. SPECT equipment with a dual camera was used. Fourteen rotation acquisitions were obtained beginning immediately after Xe-133 gas inhalation. The time activity curve of each pixel was obtained, and T{sub 1/2} of the washout phase was calculated and mapped. Residual radioactivity was evaluated. Adequate images could be obtained at 30 seconds per rotation even with the dual-camera system. Mapping of T{sub 1/2} allowed temporal changes on one image. Three-dimensional evaluation could be made on a SPECT system using our method. (author)

  2. 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).

  3. Cardiac Imaging System

    Science.gov (United States)

    1990-01-01

    Although not available to all patients with narrowed arteries, balloon angioplasty has expanded dramatically since its introduction with an estimated further growth to 562,000 procedures in the U.S. alone by 1992. Growth has fueled demand for higher quality imaging systems that allow the cardiologist to be more accurate and increase the chances of a successful procedure. A major advance is the Digital Cardiac Imaging (DCI) System designed by Philips Medical Systems International, Best, The Netherlands and marketed in the U.S. by Philips Medical Systems North America Company. The key benefit is significantly improved real-time imaging and the ability to employ image enhancement techniques to bring out added details. Using a cordless control unit, the cardiologist can manipulate images to make immediate assessment, compare live x-ray and roadmap images by placing them side-by-side on monitor screens, or compare pre-procedure and post procedure conditions. The Philips DCI improves the cardiologist's precision by expanding the information available to him.

  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. Development of an MR-compatible SPECT system (MRSPECT) for simultaneous data acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Hamamura, Mark J; Ha, Seunghoon; Roeck, Werner W; Muftuler, L Tugan; Nalcioglu, Orhan [Tu and Yuen Center for Functional Onco-Imaging, University of California, Irvine, CA (United States); Wagenaar, Douglas J; Meier, Dirk; Patt, Bradley E [Gamma Medica-Ideas, Inc., Northridge, CA (United States)], E-mail: markjham@uci.edu

    2010-03-21

    In medical imaging, single-photon emission computed tomography (SPECT) can provide specific functional information while magnetic resonance imaging (MRI) can provide high spatial resolution anatomical information as well as complementary functional information. In this study, we developed a miniaturized dual-modality SPECT/MRI (MRSPECT) system and demonstrated the feasibility of simultaneous SPECT and MRI data acquisition, with the possibility of whole-body MRSPECT systems through suitable scaling of components. For our MRSPECT system, a cadmium-zinc-telluride (CZT) nuclear radiation detector was interfaced with a specialized radiofrequency (RF) coil and placed within a whole-body 4 T MRI system. Various phantom experiments characterized the interaction between the SPECT and MRI hardware components. The metallic components of the SPECT hardware altered the B{sub 0} field and generated a non-uniform reduction in the signal-to-noise ratio (SNR) of the MR images. The presence of a magnetic field generated a position shift and resolution loss in the nuclear projection data. Various techniques were proposed to compensate for these adverse effects. Overall, our results demonstrate that accurate, simultaneous SPECT and MRI data acquisition is feasible, justifying the further development of MRSPECT for either small-animal imaging or whole-body human systems by using appropriate components.

  6. Hybrid cardiac imaging: SPECT/CT and PET/CT. A joint position statement by the European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC)

    DEFF Research Database (Denmark)

    Flotats, Albert; Gutberlet, Matthias; Knuuti, Juhani

    2011-01-01

    . However, hybrid cardiac imaging has also generated controversy with regard to which patients should undergo such integrated examination for clinical effectiveness and minimization of costs and radiation dose, and if software-based fusion of images obtained separately would be a useful alternative....... The European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC) in this paper want to present a position statement of the institutions on the current roles of SPECT/CT and PET/CT hybrid cardiac imaging in patients...

  7. [Neurological diseases and SPECT--analysis using easy Z-score imaging system (eZIS)].

    Science.gov (United States)

    Matsuda, Hiroshi

    2007-05-01

    We developed a method for automated diagnosis of brain perfusion SPECT and designated this method as an easy Z-score imaging system (eZIS). In this software program, voxel-by-voxel Z-score analysis after voxel normalization to global mean or cerebellar values; Z-score = ( [control mean] - [individual value] )/ (control SD) is performed. These Z-score maps are displayed by overlay on tomographic sections and by projection with averaged Z-score of 14mm thickness to surface rendering of the anatomically standardized MRI template. Anatomical standardization of SPECT images into a stereotactic space is performed using statistical parametric mapping (SPM) 2. This program has an advantage of capability of incorporation of SPM results into automated analysis of Z-score values as a volume of interest (VOI). A specific VOI can be determined by group comparison of SPECT images for patients with a neuropsychiatric disease with those for healthy volunteers using SPM. Even if a center can construct a normal database with good quality comprising a large number of healthy volunteers, other centers have not been able to use this normal database because of differences between the used gamma cameras, collimators and physical correction algorithms. Since SPECT exhibits greater variations in image quality among different centers than PET, conversion of SPECT images may be necessary for sharing a normal database. In this eZIS software, we incorporated a newly developed program for making it possible to share a normal database in SPECT studies. A Hoffman 3-dimensional brain phantom experiment was conducted to determine systematic differences between SPECT scanners. SPECT images for the brain phantom were obtained using two different scanners. Dividing these two phantom images after anatomical standardization by SPM created a 3-dimensional conversion map. The use of a conversion map obtained from SPECT images of the same phantom provided very similar SPECT data despite extreme differences

  8. Quantitative analysis of L-SPECT system for small animal brain imaging

    Science.gov (United States)

    Rahman, Tasneem; Tahtali, Murat; Pickering, Mark R.

    2016-03-01

    This paper aims to investigate the performance of a newly proposed L-SPECT system for small animal brain imaging. The L-SPECT system consists of an array of 100 × 100 micro range diameter pinholes. The proposed detector module has a 48 mm by 48 mm active area and the system is based on a pixelated array of NaI crystals (10×10×10 mm elements) coupled with an array of position sensitive photomultiplier tubes (PSPMTs). The performance of this system was evaluated with pinhole radii of 50 μm, 60 μm and 100 μm. Monte Carlo simulation studies using the Geant4 Application for Tomographic Emission (GATE) software package validate the performance of this novel dual head L-SPECT system where a geometric mouse phantom is used to investigate its performance. All SPECT data were obtained using 120 projection views from 0° to 360° with a 3° step. Slices were reconstructed using conventional filtered back projection (FBP) algorithm. We have evaluated the quality of the images in terms of spatial resolution (FWHM) based on line spread function, the system sensitivity, the point source response function and the image quality. The sensitivity of our newly proposed L- SPECT system was about 4500 cps/μCi at 6 cm along with excellent full width at half-maximum (FWHM) using 50 μm pinhole aperture at several radii of rotation. The analysis results show the combination of excellent spatial resolution and high detection efficiency over an energy range between 20-160 keV. The results demonstrate that SPECT imaging using a pixelated L-SPECT detector module is applicable in a quantitative study of mouse brain imaging.

  9. Cardiac manifestations in systemic sclerosis

    Institute of Scientific and Technical Information of China (English)

    Sevdalina; Lambova

    2014-01-01

    Primary cardiac involvement, which develops as a direct consequence of systemic sclerosis(SSc), may manifest as myocardial damage, fibrosis of the conduction system, pericardial and, less frequently, as valvular disease. In addition, cardiac complications in SSc may develop as a secondary phenomenon due to pulmonary arterial hypertension and kidney pathology. The prevalence of primary cardiac involvement in SSc is variable and difficult to determine because of the diversity of cardiac manifestations, the presence of subclinical periods, the type of diagnostic tools applied, and the diversity of patient populations. When clinically manifested, cardiac involvement is thought to be an important prognostic factor. Profound microvascular disease is a pathognomonic feature of SSc, as both vasospasm and structural alterations are present. Such alterations are thought to predict macrovascular atherosclerosis over time. There are contradictory reports regarding the prevalence of atherosclerosis in SSc. According to some authors, the prevalence of atherosclerosis of the large epicardial coronary arteries is similar to that of the general population, in contrast with other rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus. However, the level of inflammation in SSc is inferior. Thus, the atherosclerotic process may not be as aggressive and not easily detectable in smaller studies. Echocardiography(especially tissue Doppler imaging), single-photon emission computed tomography, magnetic resonance imaging and cardiac computed tomography are sensitive techniques for earlier detection of both structural and functional scleroderma-related cardiac pathologies. Screening for subclinical cardiac involvement via modern, sensitive tools provides an opportunity for early diagnosis and treatment, which is of crucial importance for a positive outcome.

  10. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Lung; Min, Hooney [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Befera, Nicholas; Clark, Darin; Qi, Yi [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Das, Shiva [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Johnson, G. Allan; Badea, Cristian T. [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina (United States)

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches

  11. Estimation of dynamic time activity curves from dynamic cardiac SPECT imaging

    Science.gov (United States)

    Hossain, J.; Du, Y.; Links, J.; Rahmim, A.; Karakatsanis, N.; Akhbardeh, A.; Lyons, J.; Frey, E. C.

    2015-04-01

    Whole-heart coronary flow reserve (CFR) may be useful as an early predictor of cardiovascular disease or heart failure. Here we propose a simple method to extract the time-activity curve, an essential component needed for estimating the CFR, for a small number of compartments in the body, such as normal myocardium, blood pool, and ischemic myocardial regions, from SPECT data acquired with conventional cameras using slow rotation. We evaluated the method using a realistic simulation of 99mTc-teboroxime imaging. Uptake of 99mTc-teboroxime based on data from the literature were modeled. Data were simulated using the anatomically-realistic 3D NCAT phantom and an analytic projection code that realistically models attenuation, scatter, and the collimator-detector response. The proposed method was then applied to estimate time activity curves (TACs) for a set of 3D volumes of interest (VOIs) directly from the projections. We evaluated the accuracy and precision of estimated TACs and studied the effects of the presence of perfusion defects that were and were not modeled in the estimation procedure. The method produced good estimates of the myocardial and blood-pool TACS organ VOIs, with average weighted absolute biases of less than 5% for the myocardium and 10% for the blood pool when the true organ boundaries were known and the activity distributions in the organs were uniform. In the presence of unknown perfusion defects, the myocardial TAC was still estimated well (average weighted absolute bias myocardial uptake (product of defect extent and severity) was ≤5%. This indicates that the method was robust to modest model mismatch such as the presence of moderate perfusion defects and uptake nonuniformities. With larger defects where the defect VOI was included in the estimation procedure, the estimated normal myocardial and defect TACs were accurate (average weighted absolute bias ≈5% for a defect with 25% extent and 100% severity).

  12. Factors affecting the myocardial activity acquired during exercise SPECT with a high-sensitivity cardiac CZT camera as compared with conventional Anger camera

    Energy Technology Data Exchange (ETDEWEB)

    Verger, Antoine; Karcher, Gilles [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947 and Universite de Lorraine, 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); Yagdigul, Yalcine; Roch, Veronique [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep experimental imaging platform, Nancy (France); Fay, Renaud [INSERM, Centre d' Investigation Clinique CIC-P 9501, Nancy (France); Djaballah, Wassila [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); INSERM U947 and Universite de Lorraine, Nancy (France); Rouzet, Francois; Le Guludec, Dominique [AP-HP, Hopital Bichat, Department of Nuclear Medicine, Paris (France); INSERM U 773 and Denis Diderot University, Paris (France); Fourquet, Nicolas [Clinique Pasteur, Toulouse (France); Poussier, Sylvain [INSERM U947 and Universite de Lorraine, Nancy (France); Nancyclotep experimental imaging platform, Nancy (France); Marie, Pierre-Yves [CHU-Nancy, Department of Nuclear Medicine, Nancy (France); Nancyclotep experimental imaging platform, Nancy (France); INSERM U1116 and Universite de Lorraine, Nancy (France); CHU-Nancy, Allee du Morvan, Medecine Nucleaire, Hopital de Brabois, Vandoeuvre-les-Nancy (France)

    2014-03-15

    Injected doses are difficult to optimize for exercise SPECT since they depend on the myocardial fraction of injected activity (MFI) that is detected by the camera. The aim of this study was to analyse the factors affecting MFI determined using a cardiac CZT camera as compared with those determined using conventional Anger cameras. Factors affecting MFI were determined and compared in patients who had consecutive exercise SPECT acquisitions with {sup 201}Tl (84 patients) or {sup 99m}Tc-sestamibi (87 patients) with an Anger or a CZT camera. A predictive model was validated in a group of patients routinely referred for {sup 201}Tl (78 patients) or {sup 99m}Tc-sestamibi (80 patients) exercise CZT SPECT. The predictive model involved: (1) camera type, adjusted mean MFI being ninefold higher for CZT than for Anger SPECT, (2) tracer type, adjusted mean MFI being twofold higher for {sup 201}Tl than for {sup 99m}Tc-sestamibi, and (3) logarithm of body weight. The CZT SPECT model led to a +1 ± 26 % error in the prediction of the actual MFI from the validation group. The mean MFI values estimated for CZT SPECT were more than twofold higher in patients with a body weight of 60 kg than in patients with a body weight of 120 kg (15.9 and 6.8 ppm for {sup 99m}Tc-sestamibi and 30.5 and 13.1ppm for {sup 201}Tl, respectively), and for a 14-min acquisition of up to one million myocardial counts, the corresponding injected activities were only 80 and 186 MBq for {sup 99m}Tc-sestamibi and 39 and 91 MBq for {sup 201}Tl, respectively. Myocardial activities acquired during exercise CZT SPECT are strongly influenced by body weight and tracer type, and are dramatically higher than those obtained using an Anger camera, allowing very low-dose protocols to be planned, especially for {sup 99m}Tc-sestamibi and in non-obese subjects. (orig.)

  13. SPECT imaging with off-set detector system. Comparison of sampling angles 2, 4 and 6 degrees

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yasuyuki; Murase, Kenya [Osaka Medical Coll., Takatsuki (Japan). Graduate School; Higashino, Hiroshi; Kawakami, Hideo [Ehime Prefectural Imabari Hospital (Japan); Kawamata, Isao [Ehime Prefectural Iyo-Mishima Hospital (Japan)

    2002-07-01

    We evaluated an off set reconstruction method for single photon emission computed tomography (SPECT), and compared it with the conventional on set reconstruction method, using sampling angles of 2, 4, and 6 degrees. A triple-detector system was used. In the off-set acquisition, sampling angles of the opposite detector were shifted 1/2 of the sampling angles of 2, 4, and 6 degrees. For example, when projection data were acquired every 6-degrees (sampling angle=6 degrees), the projection angles were at 0 deg, 6 deg, 12 deg and 174 deg with one detector, and 177 deg, 183 deg, 189 deg, and 357 deg with the other, opposite, detector. The conventional on set reconstruction images were compared with an off set reconstruction for a pool phantom of uniform concentration, a hot rods phantom, a myocardial phantom, and a human study. The off set reconstruction method was better at all three sampling angles. FWHM (mm) were 11.02 at off-set versus 11.17 at on-set (sampling angle 2 deg), 11.13 at off-set versus 11.48 at on-set (sampling angle 4 deg), and 11.24 at off-set versus 11.64 at on-set (sampling angle 6 deg), respectively. In human myocardium SPECT, visualization of the interventricular septum and cardiac cavity was improved. Off set reconstruction by means of filtered back projection will be an efficient sampling mode, having a larger number of effective projection angles. (author)

  14. 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

  15. Bayesian reconstruction strategy of fluorescence-mediated tomography using an integrated SPECT-CT-OT system

    Science.gov (United States)

    Cao, Liji; Peter, Jörg

    2010-05-01

    Following the assembly of a triple-modality SPECT-CT-OT small animal imaging system providing intrinsically co-registered projection data of all three submodalities and under the assumption and investigation of dual-labeled probes consisting of both fluorophores and radionuclides, a novel multi-modal reconstruction strategy is presented in this paper aimed at improving fluorescence-mediated tomography (FMT). The following reconstruction procedure is proposed: firstly, standard x-ray CT image reconstruction is performed employing the FDK algorithm. Secondly, standard SPECT image reconstruction is performed using OSEM. Thirdly, from the reconstructed CT volume data the surface boundary of the imaged object is extracted for finite element definition. Finally, the reconstructed SPECT data are used as a priori information within a Bayesian reconstruction framework for optical (FMT) reconstruction. We provide results of this multi-modal approach using phantom experimental data and illustrate that this strategy does suppress artifacts and facilitates quantitative analysis for optical imaging studies.

  16. Microvascular obstruction on delayed enhancement cardiac magnetic resonance imaging after acute myocardial infarction, compared with myocardial {sup 201}Tl and {sup 123}I-BMIPP dual SPECT findings

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Hiroaki [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Cardiology, Kainan Hospital, Yatomi (Japan); Isobe, Satoshi, E-mail: sisobe@med.nagoya-u.ac.jp [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Sakai, Shinichi [Department of Cardiology, Kainan Hospital, Yatomi (Japan); Yamada, Takashi [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Watanabe, Naoki; Miura, Manabu [Department of Cardiology, Kainan Hospital, Yatomi (Japan); Uchida, Yasuhiro; Kanashiro, Masaaki; Ichimiya, Satoshi [Department of Cardiology, Yokkaichi Municipal Hospital, Yokkaichi (Japan); Okumura, Takahiro; Murohara, Toyoaki [Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)

    2015-08-15

    Highlights: • The percentage infarct size (%IS) was significantly greater in the microvascular obstruction (MO) group than in the non-MO group. • The percentage mismatch score (%MMS) on dual scintigraphy significantly correlated with the %IS and the percentage MO. • The %MMS was significantly greater in the non-MO group than in the MO group, and was an independent predictor for MO. - Abstract: Background: The hypo-enhanced regions within the hyper-enhanced infarct areas detected by cardiac magnetic resonance (CMR) imaging reflect microvascular obstruction (MO) after acute myocardial infarction (AMI). The combined myocardial thallium-201 ({sup 201}Tl)/iodine-123-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid ({sup 123}I-BMIPP) dual single-photon emission computed tomography (SPECT) is a useful tool for detecting myocardial reversibility after AMI. We evaluated whether MO could be an early predictor of irreversible myocardial damage in comparison with {sup 201}Tl and {sup 123}I-BMIPP dual SPECT findings in AMI patients. Methods: Sixty-two patients with initial AMI who successfully underwent coronary revascularization were enrolled. MO was defined by CMR imaging. Patients were divided into 2 groups as follows: MO group (n = 32) and non-MO group (n = 30). Scintigraphic defect scores were calculated using a 17-segment model with a 5-point scoring system. The mismatch score (MMS) was calculated as follows: the total sum of (Σ) {sup 123}I-BMIPP defect score minus Σ{sup 201}Tl defect score. The percentage mismatch score (%MMS) was calculated as follows: MMS/(Σ{sup 123}I-BMIPP score) × 100 (%). Results: The percentage infarct size (%IS) was significantly greater in the MO group than in the non-MO group (32.2 ± 13.8% vs. 18.3 ± 12.1%, p < 0.001). The %MMS significantly correlated with the %IS and the percentage MO (r = −0.26, p = 0.03; r = −0.45, p < 0.001, respectively). The %MMS was significantly greater in the non-MO group than in the MO group (45.4

  17. 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...

  18. 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.

  19. 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.

  20. Disappearance of myocardial perfusion defects on prone SPECT imaging: Comparison with cardiac magnetic resonance imaging in patients without established coronary artery disease

    Directory of Open Access Journals (Sweden)

    Hedén Bo

    2009-08-01

    Full Text Available Abstract Background It is of great clinical importance to exclude myocardial infarction in patients with suspected coronary artery disease who do not have stress-induced ischemia. The diagnostic use of myocardial perfusion single-photon emission computed tomography (SPECT in this situation is sometimes complicated by attenuation artifacts that mimic myocardial infarction. Imaging in the prone position has been suggested as a method to overcome this problem. Methods In this study, 52 patients without known prior infarction and no stress-induced ischemia on SPECT imaging were examined in both supine and prone position. The results were compared with cardiac magnetic resonance imaging (CMR with delayed-enhancement technique to confirm or exclude myocardial infarction. Results There were 63 defects in supine-position images, 37 of which disappeared in the prone position. None of the 37 defects were associated with myocardial infarction by CMR, indicating that all of them represented attenuation artifacts. Of the remaining 26 defects that did not disappear on prone imaging, myocardial infarction was confirmed by CMR in 2; the remaining 24 had no sign of ischemic infarction but 2 had other kinds of myocardial injuries. In 3 patients, SPECT failed to detect small scars identified by CMR. Conclusion Perfusion defects in the supine position that disappeared in the prone position were caused by attenuation, not myocardial infarction. Hence, imaging in the prone position can help to rule out ischemic heart disease for some patients admitted for SPECT with suspected but not documented ischemic heart disease. This would indicate a better prognosis and prevent unnecessary further investigations and treatment.

  1. Implementation of strip-area system model for fan-beam collimator SPECT reconstruction

    Science.gov (United States)

    Ye, Hongwei; Krol, Andrzej; Feiglin, David H.; Lipson, Edward D.; Lee, Wei; Coman, Ioana L.

    2006-03-01

    We have implemented a more accurate physical system representation, a strip-area system model (SASM), for improved fan-beam collimator (FBC) SPECT reconstruction. This approach required implementation of modified ray tracing and attenuation compensation in comparison to a line-length system model (LLSM). We have compared performance of SASM with LLSM using Monte Carlo and analytical simulations of FBC SPECT from a thorax phantom. OSEM reconstruction was performed with OS=3 in a 64×64 matrix with attenuation compensation (assuming uniform attenuation of 0.13 cm -1). Scatter correction and smoothing were not applied. We observe overall improvement in SPECT image bias, visual image quality and an improved hot myocardium contrast for SASM vs. LLSM. In contrast to LLSM, the sensitivity pattern artifacts are not present in the SASM reconstruction. In both reconstruction methods, cross-talk image artifacts (e.g. inverse images of the lungs) can be observed, due to the uniform attenuation map used. SASM applied to fan-beam collimator SPECT results in better image quality and improved hot target contrast, as compared to LLSM, but at the expense of 1.5-fold increase in reconstruction time.

  2. Implementation and assessment of an animal management system for small-animal micro-CT / micro-SPECT imaging

    Science.gov (United States)

    Holdsworth, David W.; Detombe, Sarah A.; Chiodo, Chris; Fricke, Stanley T.; Drangova, Maria

    2011-03-01

    Advances in laboratory imaging systems for CT, SPECT, MRI, and PET facilitate routine micro-imaging during pre-clinical investigations. Challenges still arise when dealing with immune-compromised animals, biohazardous agents, and multi-modality imaging. These challenges can be overcome with an appropriate animal management system (AMS), with the capability for supporting and monitoring a rat or mouse during micro-imaging. We report the implementation and assessment of a new AMS system for mice (PRA-3000 / AHS-2750, ASI Instruments, Warren MI), designed to be compatible with a commercial micro-CT / micro-SPECT imaging system (eXplore speCZT, GE Healthcare, London ON). The AMS was assessed under the following criteria: 1) compatibility with the imaging system (i.e. artifact generation, geometric dimensions); 2) compatibility with live animals (i.e. positioning, temperature regulation, anesthetic supply); 3) monitoring capabilities (i.e. rectal temperature, respiratory and cardiac monitoring); 4) stability of co-registration; and 5) containment. Micro-CT scans performed using a standardized live-animal protocol (90 kVp, 40 mA, 900 views, 16 ms per view) exhibited low noise (+/-19 HU) and acceptable artifact from high-density components within the AMS (e.g. ECG pad contacts). Live mice were imaged repeatedly (with removal and replacement of the AMS) and spatial registration was found to be stable to within +/-0.07 mm. All animals tolerated enclosure within the AMS for extended periods (i.e. > one hour) without distress, based on continuous recordings of rectal temperature, ECG waveform and respiratory rate. A sealed AMS system extends the capability of a conventional micro-imaging system to include immune-compromised and biosafety level 2 mouse-imaging protocols.

  3. Targeted multi-pinhole SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Branderhorst, Woutjan; Blezer, Erwin L.A. [University Medical Centre Utrecht, Image Sciences Institute and Rudolf Magnus Institute of Neuroscience, Utrecht (Netherlands); Vastenhouw, Brendan; Have, Frans van der; Beekman, Freek J. [University Medical Centre Utrecht, Image Sciences Institute and Rudolf Magnus Institute of Neuroscience, Utrecht (Netherlands); Molecular Imaging Laboratories BV, Utrecht (Netherlands); Delft University of Technology, Section of Radiation Detection and Medical Imaging, Applied Sciences, Delft (Netherlands); Bleeker, Wim K. [Genmab BV, Utrecht (Netherlands)

    2011-03-15

    Small-animal single photon emission computed tomography (SPECT) with focused multi-pinhole collimation geometries allows scanning modes in which large amounts of photons can be collected from specific volumes of interest. Here we present new tools that improve targeted imaging of specific organs and tumours, and validate the effects of improved targeting of the pinhole focus. A SPECT system with 75 pinholes and stationary detectors was used (U-SPECT-II). An XYZ stage automatically translates the animal bed with a specific sequence in order to scan a selected volume of interest. Prior to stepping the animal through the collimator, integrated webcams acquire images of the animal. Using sliders, the user designates the desired volume to be scanned (e.g. a xenograft or specific organ) on these optical images. Optionally projections of an atlas are overlaid semiautomatically to locate specific organs. In order to assess the effects of more targeted imaging, scans of a resolution phantom and a mouse myocardial phantom, as well as in vivo mouse cardiac and tumour scans, were acquired with increased levels of targeting. Differences were evaluated in terms of count yield, hot rod visibility and contrast-to-noise ratio. By restricting focused SPECT scans to a 1.13-ml resolution phantom, count yield was increased by a factor 3.6, and visibility of small structures was significantly enhanced. At equal noise levels, the small-lesion contrast measured in the myocardial phantom was increased by 42%. Noise in in vivo images of a tumour and the mouse heart was significantly reduced. Targeted pinhole SPECT improves images and can be used to shorten scan times. Scan planning with optical cameras provides an effective tool to exploit this principle without the necessity for additional X-ray CT imaging. (orig.)

  4. Model-based correction for scatter and tailing effects in simultaneous 99mTc and 123I imaging for a CdZnTe cardiac SPECT camera

    Science.gov (United States)

    Holstensson, M.; Erlandsson, K.; Poludniowski, G.; Ben-Haim, S.; Hutton, B. F.

    2015-04-01

    An advantage of semiconductor-based dedicated cardiac single photon emission computed tomography (SPECT) cameras when compared to conventional Anger cameras is superior energy resolution. This provides the potential for improved separation of the photopeaks in dual radionuclide imaging, such as combined use of 99mTc and 123I . There is, however, the added complexity of tailing effects in the detectors that must be accounted for. In this paper we present a model-based correction algorithm which extracts the useful primary counts of 99mTc and 123I from projection data. Equations describing the in-patient scatter and tailing effects in the detectors are iteratively solved for both radionuclides simultaneously using a maximum a posteriori probability algorithm with one-step-late evaluation. Energy window-dependent parameters for the equations describing in-patient scatter are estimated using Monte Carlo simulations. Parameters for the equations describing tailing effects are estimated using virtually scatter-free experimental measurements on a dedicated cardiac SPECT camera with CdZnTe-detectors. When applied to a phantom study with both 99mTc and 123I, results show that the estimated spatial distribution of events from 99mTc in the 99mTc photopeak energy window is very similar to that measured in a single 99mTc phantom study. The extracted images of primary events display increased cold lesion contrasts for both 99mTc and 123I.

  5. 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

  6. 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).

  7. Performance evaluation of a pinhole SPECT system for myocardial perfusion imaging of mice.

    Science.gov (United States)

    Wu, Max C; Hasegawa, Bruce H; Dae, Michael W

    2002-12-01

    The increasing use of transgenic mice as models of human physiology and disease has motivated the development of dedicated in vivo imaging systems for anatomic and functional characterization of mice as an adjunct to or a replacement for established ex vivo techniques. We have developed a pinhole single photon emission computed tomography (SPECT) system for high resolution imaging of mice with cardiovascular imaging as the primary application. In this work, we characterize the system performance through phantom studies. The spatial resolution and sensitivity were measured from images of a line source and point source, respectively, and were reported for a range of object-to-pinhole distances and pinhole diameters. Tomographic images of a uniform cylindrical phantom, Defrise phantom, and grid phantom were used to characterize the image uniformity and spatial linearity. The uniform phantom image did not contain any ring or reconstruction artifacts, but blurring in the axial direction was evident in the Defrise phantom images. The grid phantom images demonstrated excellent spatial linearity. A novel phantom modeling perfusion of the left ventricle of a mouse was designed and built with perfusion defects of varying sizes to evaluate the system performance for myocardial perfusion imaging of mice. The defect volumes were measured from the pinhole SPECT images and correlated to the actual defect volumes calculated according to geometric formulas. Linear regression analysis produced a correlation coefficient of r = 0.995 (p defect size in mice using pinhole SPECT. We have performed phantom studies to characterize the spatial resolution, sensitivity, image uniformity, and spatial linearity of the pinhole SPECT system. Measurement of the perfusion defect size is a valuable phenotypic assessment and will be useful for hypothesis testing in murine models of cardiovascular disease.

  8. Cardiac hybrid imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2014-05-15

    Hybrid cardiac single photon emission computed tomography (SPECT)/CT imaging allows combined assessment of anatomical and functional aspects of cardiac disease. In coronary artery disease (CAD), hybrid SPECT/CT imaging allows detection of coronary artery stenosis and myocardial perfusion abnormalities. The clinical value of hybrid imaging has been documented in several subsets of patients. In selected groups of patients, hybrid imaging improves the diagnostic accuracy to detect CAD compared to the single imaging techniques. Additionally, this approach facilitates functional interrogation of coronary stenoses and guidance with regard to revascularization procedures. Moreover, the anatomical information obtained from CT coronary angiography or coronary artery calcium scores (CACS) adds prognostic information over perfusion data from SPECT. The use of cardiac hybrid imaging has been favoured by the dissemination of dedicated hybrid systems and the release of dedicated image fusion software, which allow simple patient throughput for hybrid SPECT/CT studies. Further technological improvements such as more efficient detector technology to allow for low-radiation protocols, ultra-fast image acquisition and improved low-noise image reconstruction algorithms will be instrumental to further promote hybrid SPECT/CT in research and clinical practice. (orig.)

  9. Performance evaluation of a compact PET/SPECT/CT tri-modality system for small animal imaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qingyang [Department of Electrical Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China); Wang, Shi [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China); Ma, Tianyu, E-mail: maty@tsinghua.edu.cn [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China); Wu, Jing; Liu, Hui; Xu, Tianpeng; Xia, Yan; Fan, Peng; Lyu, Zhenlei; Liu, Yaqiang [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle & Radiation Imaging (Tsinghua University), Ministry of Education, Beijing 100084 (China)

    2015-06-21

    PET, SPECT and CT imaging techniques are widely used in preclinical small animal imaging applications. In this paper, we present a compact small animal PET/SPECT/CT tri-modality system. A dual-functional, shared detector design is implemented which enables PET and SPECT imaging with a same LYSO ring detector. A multi-pinhole collimator is mounted on the system and inserted into the detector ring in SPECT imaging mode. A cone-beam CT consisting of a micro focus X-ray tube and a CMOS detector is implemented. The detailed design and the performance evaluations are reported in this paper. In PET imaging mode, the measured NEMA based spatial resolution is 2.12 mm (FWHM), and the sensitivity at the central field of view (CFOV) is 3.2%. The FOV size is 50 mm (∅)×100 mm (L). The SPECT has a spatial resolution of 1.32 mm (FWHM) and an average sensitivity of 0.031% at the center axial, and a 30 mm (∅)×90 mm (L) FOV. The CT spatial resolution is 8.32 lp/mm @10%MTF, and the contrast discrimination function value is 2.06% with 1.5 mm size cubic box object. In conclusion, a compact, tri-modality PET/SPECT/CT system was successfully built with low cost and high performance.

  10. Simultaneous Tc-99m/I-123 Dual Radionuclide Myocardial Perfusion/Innervation Imaging Using Siemens IQ-SPECT with SMARTZOOM Collimator

    OpenAIRE

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric C.

    2014-01-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region compared to a typical parallel-hole low-energy high-resolution collimator but without the data truncation that can result with conventional converging-beam collimators. Th...

  11. 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

  12. 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

  13. [Research progress of cardiac systems biology].

    Science.gov (United States)

    Wang, Juan; Shang, Tong

    2009-04-01

    Systems Biology is one of the most widely discussed fields among emerging post-genomic disciplines. Medical systems biology is an important component of systems biology. The goals of medical systems biology are gaining a complete understanding of human body in normal and disease states. Driven by the great importance of cardiovascular diseases, cardiac systems biology is improving rapidly. This review provides an overview of major themes in the developing field of cardiac systems biology, including some of the high-throughput experiments and strategies used to integrate the datasets, various types of computational approaches used for developing useful quantitative models, and successful examples, future directions of cardiac systems biology.

  14. Experimental MRI-SPECT insert system with Hybrid Semiconductor detectors Timepix for MR animal scanner Bruker 47/20

    Science.gov (United States)

    Zajicek, J.; Burian, M.; Soukup, P.; Novak, V.; Macko, M.; Jakubek, J.

    2017-01-01

    Multimodal medical imaging based on Magnetic Resonance is mainly combinated with one of the scintigraphic method like PET or SPECT. These methods provide functional information whereas magnetic resonance imaging provides high spatial resolution of anatomical information or complementary functional information. Fusion of imaging modalities allows researchers to obtain complimentary information in a single measurement. The combination of MRI with SPECT is still relatively new and challenging in many ways. The main complication of using SPECT in MRI systems is the presence of a high magnetic field therefore (ferro)magnetic materials have to be eliminated. Furthermore the application of radiofrequency fields within the MR gantry does not allow for the use of conductive structures such as the common heavy metal collimators. This work presents design and construction of an experimental MRI-SPECT insert system and its initial tests. This unique insert system consists of an MR-compatible SPECT setup with CdTe pixelated sensors Timepix tungsten collimators and a radiofrequency coil. Measurements were performed on a gelatine and tissue phantom with an embedded radioisotopic source (57Co 122 keV γ ray) inside the RF coil by the Bruker BioSpec 47/20 (4.7 T) MR animal scanner. The project was performed in the framework of the Medipix Collaboration.

  15. Intrinsic and Tomographic Evaluation of Siemens e.cam® SPECT System at the Korle-Bu Teaching Hospital (Ghana

    Directory of Open Access Journals (Sweden)

    Intrinsic and Tomographic Evaluation of Siemens e.cam® SPECT System at the Korle-Bu Teaching Hospital (Ghana

    2011-10-01

    Full Text Available Intrinsic and tomographic evaluation tests on the Siemens e.cam® Signature Series Single Photon Emission Computed Tomography (SPECT system were conducted to ensure that it meets the specification required by the user and the capabilities claimed by the manufacturer after installation. The tests were performed according to National Electrical Manufacturers Association protocols and various measuring instrument and point sources containing 99 m-Tc were used. Intrinsic tests performed include intrinsic flood uniformity, intrinsic count rate performance in air and intrinsic energy resolution. Whole body scanning, SPECT resolution without scatter, SPECT resolution with inserts, SPECT uniformity and center of rotation were also evaluated. The intrinsic count rate performance measured was 300kcps as against manufactures’ specification of 310 kcps, intrinsic energy resolution was 9.31% whiles manufacturers’ specification was ≤ 9.9% and center of rotation specification is that Max. X-Min. X< 1 pixel and RMS < 0.5 whiles values measured was 0.254 and 0.10 for LEAP and 0.092 and 0.083 for LEHR collimators. The evaluation confirm that the SPECT system met the requirements for clinical medical imagine and also the values obtained could be used as baseline data for future quality control.

  16. Prognostic value of myocardial perfusion single photon emission computed tomography for major adverse cardiac cerebrovascular and renal events in patients with chronic kidney disease: results from first year of follow-up of the Gunma-CKD SPECT multicenter study

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Toyama, Takuji [Department of Cardiovascular Medicine, Gunma Prefectural Cardiovascular Center, Maebashi (Japan); Sato, Makito [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Tatebayashi Kosei Hospital, Department of Internal Medicine, Gunma (Japan); Sano, Hirokazu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Isesaki Municipal Hospital, Department of Cardiovascular Medicine, Isesaki (Japan); Ueda, Tetsuya [Fujioka General Hospital, Division of Cardiology, Fujioka (Japan); Sasaki, Toyoshi [Takasaki General Medical Center, Division of Cardiology, Takasaki (Japan); Nakahara, Takehiro; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Higuchi, Tetsuya; Tsushima, Yoshito [Gunma University Graduate School of Medicine, Department of Diagnostic Radiology and Nuclear Medicine, Maebashi (Japan)

    2016-02-15

    Patients with chronic kidney disease (CKD) have an increased risk of adverse cardio-cerebrovascular events. We examined whether stress myocardial perfusion single photon emission computed tomography (SPECT) provides reliable prognostic markers for these patients. In this multicenter, prospective cohort trial from the Gunma-CKD SPECT study protocol, patients with CKD [estimated glomerular filtration rate (eGFR) < 60 min/ml per 1.73 m{sup 2}] undergoing stress {sup 99m}Tc-tetrofosmin SPECT for suspected or possible ischemic heart disease were initially followed for 1 year, with the following study endpoints: primary, the occurrence of cardiac deaths (CDs), and secondary, major adverse cardiac, cerebrovascular, and renal events (MACCREs). The summed stress score (SSS), summed rest score, and summed difference score (SDS) were estimated with the standard 17-segment, 5-point scoring model. Left ventricular end-diastolic volume, end-systolic volume (ESV), and ejection fraction were measured using electrocardiogram-gated SPECT. During the first year of follow-up, 69 of 299 patients experienced MACCREs (CD, n = 7; non-fatal myocardial infarction, n = 3; hospitalization for heart failure, n = 13; cerebrovascular accident, n = 1; need for revascularization, n = 38; and renal failure, i.e., hemodialysis initiation, n = 7). ESV and SSS were associated with CDs (p < 0.05), and eGFR and SDS were associated with MACCREs (p < 0.05), in multivariate logistic analysis. Patients with high ESV and high SSS had a significantly higher CD rate during the first year than the other CKD patient subgroups (p < 0.05). Patients with low eGFR and high SDS had a significantly higher MACCRE rate than the other subgroups (p < 0.05). Myocardial perfusion SPECT can provide reliable prognostic markers for patients with CKD. (orig.)

  17. Evaluation of myocardial SPECT imaging reconstructed from 270deg projection data. A study using a cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    Kashikura, Kenichi [Japan Science and Technology Corp., Akita (Japan). Akita Lab.; Kobayashi, Hideki; Kashikura, Akemi

    1997-01-01

    SPECT reconstruction is commonly performed using 360deg or 180deg projection data. However, it is also possible to reconstruct SPECT images using other projection data arcs. The purpose of this study was to characterize images obtained by limiting the projection data to 270deg by discarding the projection views with severe attenuation. A series of phantom studies was performed with and without plastic chambers simulating perfusion defects using {sup 201}Tl and {sup 99m}Tc. Images using 270deg, 360deg, and 180deg projection arcs were identically reconstructed from the same data. In the absence of plastic chambers, intraslice uniformity in a given slice was assessed by computing the coefficient of variation (CV) of average counts in 8 ROIs within the slice. Interslice uniformity was assessed by computing the CV of average counts in five short axial slices. With plastic chambers in place, the variability in defect contrasts was assessed by computing the CV of defect contrasts in 4 chambers, located on the anterior, lateral, inferoposterior, and septal walls. The intraslice uniformity of the 270deg images were considerably inferior to those of the 360deg and 180deg images. The interslice uniformity was highest in the 360deg images, and lowest in the 180deg images. The variation in defect contrasts in the 270deg image was higher than those of the other two images. The 270deg images showed a high defect contrast in the septum and high counts in the anterior and anteroseptal wall. Because a large variation in defect contrasts within a segment might result in false positive or negative in diagnosis, 270deg imaging is not recommended over 360deg or 180deg imaging. (author)

  18. A SPECT system simulator built on the SolidWorks (TM) 3D-Design package.

    Science.gov (United States)

    Li, Xin; Furenlid, Lars R

    2014-08-17

    We have developed a GPU-accelerated SPECT system simulator that integrates into instrument-design workflow [1]. This simulator includes a gamma-ray tracing module that can rapidly propagate gamma-ray photons through arbitrary apertures modeled by SolidWorks (TM) -created stereolithography (.STL) representations with a full complement of physics cross sections [2, 3]. This software also contains a scintillation detector simulation module that can model a scintillation detector with arbitrary scintillation crystal shape and light-sensor arrangement. The gamma-ray tracing module enables us to efficiently model aperture and detector crystals in SolidWorks (TM) and save them as STL file format, then load the STL-format model into this module to generate list-mode results of interacted gamma-ray photon information (interaction positions and energies) inside the detector crystals. The Monte-Carlo scintillation detector simulation module enables us to simulate how scintillation photons get reflected, refracted and absorbed inside a scintillation detector, which contributes to more accurate simulation of a SPECT system.

  19. Design of a high-resolution small-animal SPECT-CT system sharing a CdTe semiconductor detector

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Hyun-Ju; Lee, Young-Jin; Lee, Seung-Wan; Cho, Hyo-Min; Choi, Yu-Na; Kim, Hee-Joung [Yonsei University, Wonju (Korea, Republic of)

    2012-07-15

    A single photon emission computed tomography (SPECT) system with a co-registered X-y computed tomography (CT) system allows the convergence of functional information and morphologic information. The localization of radio pharmaceuticals on a SPECT can be enhanced by combining the SPECT with an anatomical modality, such as X-ray CT. Gamma-ray imaging for nuclear medicine devices and X-ray imaging systems for diagnostics has recently been developed based on semiconductor detectors, and semiconductor detector materials such as cadmium telluride (CdTe) or cadmium zinc telluride (CZT) are available for both X-ray and gamma-ray systems for small animal imaging. CdTe or CZT detectors provide strong absorption and high detection efficiency of high energy X-ray and gamma-ray photons because of their large atomic numbers. In this study, a pinhole collimator SPECT system sharing a cadmium telluride (CdTe) detector with a CT was designed. The GEANT4 application for tomographic emission (GATE) v.6.1 was used for the simulation. The pinhole collimator was designed to obtain a high spatial resolution of the SPECT system. The acquisition time for each projection was 40 seconds, and 60 projections were obtained for tomographic image acquisition. The reconstruction was performed using ordered subset expectation maximization (OS-EM) algorithms. The sensitivity and the spatial resolution were measured on the GATE simulation to evaluate the system characteristics. The spatial resolution of the system calculated from the FWHM of Gaussian fitted PSF curve was 0.69 mm, and the sensitivity of the system was measured to be 0.354 cps/kBq by using a Tc-99m point source of 1 MBq for 800 seconds. A phantom study was performed to verify the design of the dual imaging modality system. The system will be built as designed, and it can be applied as a pre-clinical imaging system.

  20. The feasibility of using CT-guided ROI for semiquantifying striatal dopamine transporter availability in a hybrid SPECT/CT system.

    Science.gov (United States)

    Hsu, Chien-Chin; Chang, Yen-Hsiang; Lin, Wei-Che; Tang, Shu-Wen; Wang, Pei-Wen; Huang, Yung-Cheng; Chiu, Nan-Tsing

    2014-01-01

    A hybrid SPECT/CT system provides accurate coregistration of functional and morphological images. CT-guided region of interest (ROI) for semiquantifying striatal dopamine transporter (DAT) availability may be a feasible method. We therefore assessed the intra- and interobserver reproducibility of manual SPECT and CT-guided ROI methods and compared their semiquantitative data with data from MRI-guided ROIs. We enrolled twenty-eight patients who underwent Tc-99m TRODAT-1 brain SPECT/CT and brain MRI. ROIs of the striatal, caudate, putamen, and occipital cortex were manually delineated on the SPECT, CT, and MRI. ROIs from CT and MRI were transferred to the coregistered SPECT for semiquantification. The striatal, caudate, and putamen nondisplaceable binding potential (BPND) were calculated. Using CT-guided ROIs had higher intra- and interobserver concordance correlation coefficients, closer Bland-Altman biases to zero, and narrower limits of agreement than using manual SPECT ROIs. The correlation coefficients of striatal, caudate, and putamen BPND were good between manual SPECT and MRI-guided ROI methods and even better between CT-guided and MRI-guided ROI methods. Conclusively, CT-guided ROI delineation for semiquantifying striatal DAT availability in a hybrid SPECT/CT system is highly reproducible, and the semiquantitative data correlate well with data from MRI-guided ROIs.

  1. The Feasibility of Using CT-Guided ROI for Semiquantifying Striatal Dopamine Transporter Availability in a Hybrid SPECT/CT System

    Directory of Open Access Journals (Sweden)

    Chien-Chin Hsu

    2014-01-01

    Full Text Available A hybrid SPECT/CT system provides accurate coregistration of functional and morphological images. CT-guided region of interest (ROI for semiquantifying striatal dopamine transporter (DAT availability may be a feasible method. We therefore assessed the intra- and interobserver reproducibility of manual SPECT and CT-guided ROI methods and compared their semiquantitative data with data from MRI-guided ROIs. We enrolled twenty-eight patients who underwent Tc-99m TRODAT-1 brain SPECT/CT and brain MRI. ROIs of the striatal, caudate, putamen, and occipital cortex were manually delineated on the SPECT, CT, and MRI. ROIs from CT and MRI were transferred to the coregistered SPECT for semiquantification. The striatal, caudate, and putamen nondisplaceable binding potential (BPND were calculated. Using CT-guided ROIs had higher intra- and interobserver concordance correlation coefficients, closer Bland-Altman biases to zero, and narrower limits of agreement than using manual SPECT ROIs. The correlation coefficients of striatal, caudate, and putamen BPND were good between manual SPECT and MRI-guided ROI methods and even better between CT-guided and MRI-guided ROI methods. Conclusively, CT-guided ROI delineation for semiquantifying striatal DAT availability in a hybrid SPECT/CT system is highly reproducible, and the semiquantitative data correlate well with data from MRI-guided ROIs.

  2. Computer-assisted diagnostic system for neurodegenerative dementia using brain SPECT and 3D-SSP

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Kazunari; Kanda, Tomonori; Uemura, Takafumi; Miyamoto, Naokazu; Yoshikawa, Toshiki [Hyogo Brain and Heart Center, Department of Radiology and Nuclear Medicine, Himeji, Hyogo (Japan); Shimada, Kenichi; Ohkawa, Shingo [Hyogo Brain and Heart Center, Institute for Aging Brain and Cognitive Disorders, Himeji, Hyogo (Japan); Minoshima, Satoshi [University of Washington, Radiology and Bioengineering, Department of Radiology, Seattle, WA (United States)

    2009-05-15

    To develop a computer-assisted automated diagnostic system to distinguish among Alzheimer disease (AD), dementia with Lewy bodies (DLB), and other degenerative disorders in patients with mild dementia. Single photon emission computed tomography (SPECT) images with injection of N-Isopropyl-p-[{sup 123}I]iodoamphetamine (IMP) were obtained from patients with mild degenerative dementia. First, datasets from 20 patients mild AD, 15 patients with dementia with DLB, and 17 healthy controls were used to develop an automated diagnosing system based on three-dimensional stereotactic surface projections (3D-SSP). AD- and DLB-specific regional templates were created using 3D-SSP, and critical Z scores in the templates were established. Datasets from 50 AD patients, 8 DLB patients, and 10 patients with non-AD/DLB type degenerative dementia (5 with frontotemporal dementia and 5 with progressive supranuclear palsy) were then used to test the diagnostic accuracy of the optimized automated system in comparison to the diagnostic interpretation of conventional IMP-SPECT images. These comparisons were performed to differentiate AD and DLB from non-AD/DLB and to distinguish AD from DLB. A receiver operating characteristic (ROC) analysis was performed. The area under the ROC curve (Az) and the accuracy of the automated diagnosis system were 0.89 and 82%, respectively, for AD/DLB vs. non-AD/DLB patients, and 0.70 and 65%, respectively, for AD vs. DLB patients. The mean Az and the accuracy of the visual inspection were 0.84 and 77%, respectively, for AD/DLB vs. non-AD/DLB patients, and 0.70 and 65%, respectively, for AD vs. DLB patients. The mean Az and the accuracy of the combination of visual inspection and this system were 0.96 and 91%, respectively, for AD/DLB vs. non-AD/DLB patients, and 0.70 and 66%, respectively, for AD vs. DLB patients. The system developed in the present study achieved as good discrimination of AD, DLB, and other degenerative disorders in patients with mild

  3. Iterative deconvolution of simultaneous {sup 99m}Tc and {sup 201}Tl projection data measured on a CdZnTe-based cardiac SPECT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Kacperski, Krzysztof; Erlandsson, Kjell; Ben-Haim, Simona; Hutton, Brian F, E-mail: k.kacperski@zfm.coi.pl [Institute of Nuclear Medicine, University College London, London (United Kingdom)

    2011-03-07

    We present a method of correcting self-scatter and crosstalk effects in simultaneous technetium-99m/thallium-201 stress/rest myocardial perfusion (single photon emission computed tomography) SPECT scans. The method, which is in essence a hybrid between the triple energy window method and scatter modelling, is based on a model of spatial and spectral distribution of projection counts in several selected energy windows. The parameters of the model are determined from measurements of thin rod sources in air when no in-object scatter or attenuation effects are present. The model equations are solved using the iterative maximum likelihood expectation maximization algorithm in the projection space to find estimates of the primary photopeak counts of both radionuclides. The method has been developed particularly for a novel dedicated cardiac camera based on CdZnTe pixellated detectors, although it can also be adapted to a conventional scintillator camera. The method has been validated in anthropomorphic phantom experiments. Significant improvement in defect contrast has been observed with only moderate increase in image noise. The application of the method to patient data is illustrated.

  4. Iterative deconvolution of simultaneous 99mTc and 201Tl projection data measured on a CdZnTe-based cardiac SPECT scanner

    Science.gov (United States)

    Kacperski, Krzysztof; Erlandsson, Kjell; Ben-Haim, Simona; Hutton, Brian F.

    2011-03-01

    We present a method of correcting self-scatter and crosstalk effects in simultaneous technetium-99m/thallium-201 stress/rest myocardial perfusion (single photon emission computed tomography) SPECT scans. The method, which is in essence a hybrid between the triple energy window method and scatter modelling, is based on a model of spatial and spectral distribution of projection counts in several selected energy windows. The parameters of the model are determined from measurements of thin rod sources in air when no in-object scatter or attenuation effects are present. The model equations are solved using the iterative maximum likelihood expectation maximization algorithm in the projection space to find estimates of the primary photopeak counts of both radionuclides. The method has been developed particularly for a novel dedicated cardiac camera based on CdZnTe pixellated detectors, although it can also be adapted to a conventional scintillator camera. The method has been validated in anthropomorphic phantom experiments. Significant improvement in defect contrast has been observed with only moderate increase in image noise. The application of the method to patient data is illustrated.

  5. Evaluation of regional work from ECG-gated SPECT images through solution of equations of continuity for fluids-mechanical cardiac work calculated using thin wall model.

    Science.gov (United States)

    Maeda, Hisatoshi

    2012-03-01

    Regional contraction work (RCW) of left ventricle (LV) was evaluated from cardiac perfusion images of ECG-gated single photon emission computed tomography (ECG-SPECT). The mechanical work was computed as a product of force and displaced distance. Force was determined from Laplace's law under a rectangle pressure. Deformation of wireframe representing LV was calculated from equations of continuity for two-dimensional fluids. Experiments were performed with homemade life-sized cardiac models. Total contraction work (TCW) and stroke work (SW) were 524.0 ± 166.1 mJ/beat and 709.8 ± 169.5 mJ/beat, respectively, in normal subjects (n = 23). Moderate correlation was seen between TCW and SW (y = -43.4 + 0.779 x, r = 0.815). The regional contraction amplitude (RCA), synchronous contraction index and RCW were 35.4 ± 3.5%, 95.4 ± 3.1% and 5.58 ± 0.97 mJ cm(-2)/beat in normal subjects, whereas those in patients with decreased ejection raction (EF) ≤ 30% (n = 6) were 19.6 ± 7.7%, 64.4 ± 32.2% and 2.58 ± 0.82 mJ cm(-2)/beat (p < 0.0001, Student's t-test). There was a poor correlation between RCW and RCA (y = 1.648 ± 0.116 x, r = 0.501) in normal subjects, suggesting that it might not be suitable to use RCA as an alternative to evaluate RCW.

  6. Usefulness of three-phase bone scintigraphy and SPECT/CT for the diagnosis of bone lesions of systemic sarcoidosis

    Directory of Open Access Journals (Sweden)

    Shigeaki Higashiyama

    2014-05-01

    The findings of the three-phase bone scintigraphy and SPECT/CT suggested the presence of systemic sarcoidosis; however, a subsequent 18Ffluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT could not exclude the possibility of multiple metastases from testicular tumors. Therefore, testicular enucleation was performed, and the pathological examination confirmed the presence of sarcoidosis.

  7. Assessment of cardiac function using myocardial perfusion imaging technique on SPECT with 99mTc sestamibi

    Science.gov (United States)

    Gani, M. R. A.; Nazir, F.; Pawiro, S. A.; Soejoko, D. S.

    2016-03-01

    Suspicion on coronary heart disease can be confirmed by observing the function of left ventricle cardiac muscle with Myocardial Perfusion Imaging techniques. The function perfusion itself is indicated by the uptake of radiopharmaceutical tracer. The 31 patients were studied undergoing the MPI examination on Gatot Soebroto Hospital using 99mTc-sestamibi radiopharmaceutical with stress and rest conditions. Stress was stimulated by physical exercise or pharmacological agent. After two hours, the patient did rest condition on the same day. The difference of uptake percentage between stress and rest conditions will be used to determine the malfunction of perfusion due to ischemic or infarct. Degradation of cardiac function was determined based on the image-based assessment of five segments of left ventricle cardiac. As a result, 8 (25.8%) patients had normal myocardial perfusion and 11 (35.5%) patients suspected for having partial ischemia. Total ischemia occurred to 8 (25.8%) patients with reversible and irreversible ischemia and the remaining 4 (12.9%) patients for partial infarct with characteristic the percentage of perfusion ≤50%. It is concluded that MPI technique of image-based assessment on uptake percentage difference between stress and rest conditions can be employed to predict abnormal perfusion as complementary information to diagnose the cardiac function.

  8. 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)

  9. Systems biology and cardiac arrhythmias.

    Science.gov (United States)

    Grace, Andrew A; Roden, Dan M

    2012-10-27

    During the past few years, the development of effective, empirical technologies for treatment of cardiac arrhythmias has exceeded the pace at which detailed knowledge of the underlying biology has accumulated. As a result, although some clinical arrhythmias can be cured with techniques such as catheter ablation, drug treatment and prediction of the risk of sudden death remain fairly primitive. The identification of key candidate genes for monogenic arrhythmia syndromes shows that to bring basic biology to the clinic is a powerful approach. Increasingly sophisticated experimental models and methods of measurement, including stem cell-based models of human cardiac arrhythmias, are being deployed to study how perturbations in several biologic pathways can result in an arrhythmia-prone heart. The biology of arrhythmia is largely quantifiable, which allows for systematic analysis that could transform treatment strategies that are often still empirical into management based on molecular evidence.

  10. Diagnosis of myocardial involvement in patients with systemic myopathies with 15-(p-[I-123]iodophenyl) pentadecanoic acid (IPPA) SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kropp, J.; Briele, B.; Smekal, A.V.; Hotze, A.L.; Biersack, H.J.; Koehler, U.; Zierz, St. [Bonn Univ. (Germany); Knapp, F.F. [Oak Ridge National Lab., TN (United States)

    1992-03-01

    Involvement of the myocardium in non-infectious myopathies presents in most cases as systolic dysfunction or a disturbed cardiac rhythm. We are interested in exploring how often cardiac involvement can be evaluated with various diagnostic techniques in patients with proven myopathy. We investigated 41 patients with myopathies of various etiology, including mitochondrial and congenital myopathies, Curshmann-Steinert disease, muscular dystrophy, and others. Myopathy was proven by muscular biopsy usually from the bicep. Fatty acid imaging was performed with 15-(p-[I-123]iodophenyl)pentadecanoic acid (IP-PA) and sequential SPECT-scintigraphy with a 180 deg. rotation starting at the 45 deg. RAO position. 190 MBq were injected at the maximal stage of a submaximal exercise. Filtered backprojection and reorientation of the slices were achieved by standard techniques. The quantitative comparison of the oblique slices (bulls-eye technique) of the SPECT-studies revealed turnover-rates as a qualitative measure of {beta}-oxidation. Serum levels of lactate (L), pyruvate (P), glucose (G) and triglycerides (TG) were measured at rest and stress. Ventricular function was investigated by radionuclide ventriculography (MUGA) at rest and under stress with Tc-99m labeled red blood cells. In addition, ECG, 24 hour-ECG, and echocardiography were also performed with standard techniques.

  11. Diagnosis of myocardial involvement in patients with systemic myopathies with 15-(p-(I-123)iodophenyl) pentadecanoic acid (IPPA) SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kropp, J.; Briele, B.; Smekal, A.V.; Hotze, A.L.; Biersack, H.J.; Koehler, U.; Zierz, St. (Bonn Univ. (Germany)); Knapp, F.F. (Oak Ridge National Lab., TN (United States))

    1992-01-01

    Involvement of the myocardium in non-infectious myopathies presents in most cases as systolic dysfunction or a disturbed cardiac rhythm. We are interested in exploring how often cardiac involvement can be evaluated with various diagnostic techniques in patients with proven myopathy. We investigated 41 patients with myopathies of various etiology, including mitochondrial and congenital myopathies, Curshmann-Steinert disease, muscular dystrophy, and others. Myopathy was proven by muscular biopsy usually from the bicep. Fatty acid imaging was performed with 15-(p-(I-123)iodophenyl)pentadecanoic acid (IP-PA) and sequential SPECT-scintigraphy with a 180 deg. rotation starting at the 45 deg. RAO position. 190 MBq were injected at the maximal stage of a submaximal exercise. Filtered backprojection and reorientation of the slices were achieved by standard techniques. The quantitative comparison of the oblique slices (bulls-eye technique) of the SPECT-studies revealed turnover-rates as a qualitative measure of {beta}-oxidation. Serum levels of lactate (L), pyruvate (P), glucose (G) and triglycerides (TG) were measured at rest and stress. Ventricular function was investigated by radionuclide ventriculography (MUGA) at rest and under stress with Tc-99m labeled red blood cells. In addition, ECG, 24 hour-ECG, and echocardiography were also performed with standard techniques.

  12. Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system.

    Science.gov (United States)

    Zeraatkar, Navid; Sajedi, Salar; Farahani, Mohammad Hossein; Arabi, Hossein; Sarkar, Saeed; Ghafarian, Pardis; Rahmim, Arman; Ay, Mohammad Reza

    2014-11-01

    The small-animal High-Resolution SPECT (HiReSPECT) is a dedicated dual-head gamma camera recently designed and developed in our laboratory for imaging of murine models. Each detector is composed of an array of 1.2 × 1.2 mm(2) (pitch) pixelated CsI(Na) crystals. Two position-sensitive photomultiplier tubes (H8500) are coupled to each head's crystal. In this paper, we report on a resolution-recovery-embedded image reconstruction code applicable to the system and present the experimental results achieved using different phantoms and mouse scans. Collimator-detector response functions (CDRFs) were measured via a pixel-driven method using capillary sources at finite distances from the head within the field of view (FOV). CDRFs were then fitted by independent Gaussian functions. Thereafter, linear interpolations were applied to the standard deviation (σ) values of the fitted Gaussians, yielding a continuous map of CDRF at varying distances from the head. A rotation-based maximum-likelihood expectation maximization (MLEM) method was used for reconstruction. A fast rotation algorithm was developed to rotate the image matrix according to the desired angle by means of pre-generated rotation maps. The experiments demonstrated improved resolution utilizing our resolution-recovery-embedded image reconstruction. While the full-width at half-maximum (FWHM) radial and tangential resolution measurements of the system were over 2 mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5 mm in some locations, they fell below 1.8 mm everywhere within the FOV using the resolution-recovery algorithm. The noise performance of the system was also acceptable; the standard deviation of the average counts per voxel in the reconstructed images was 6.6% and 8.3% without and with resolution recovery, respectively.

  13. Evaluation of reconstruction arc in myocardial SPECT imaging using a cardiac phantom. Comparison between 360deg and 180deg arcs

    Energy Technology Data Exchange (ETDEWEB)

    Kashikura, Kenichi [Japan Science and Technology Corp., Tokyo (Japan); Kashikura, Akemi; Terada, Shinichirou; Kobayashi, Hideki

    1996-10-01

    In order to investigate the effect of reconstruction arc on myocardial SPECT images, a series of phantom studies was performed with and without plastic chambers simulating perfusion defects using {sup 201}Tl and {sup 99m}Tc. Coefficient of variations (CV) of the counts among the ROIs and defect contrast were evaluated in 360deg and 180deg images reconstructed from the same 360deg projection data. Reconstruction processes were identical for all images. In the absence of defects, the CV of the counts were approximately the same in 360deg and 180deg images. The CV of the counts in the 360deg {sup 201}Tl image, among 4 defects located on the anterior, lateral, inferoposterior, and septal walls, was superior to those in the 180deg images. In contrast, in the {sup 99m}Tc images, the CV of the counts among the 4 defects in the 180deg image was superior to those of the 360deg image. The defect contrast was changed both by the location of the defect and by the reconstruction arc ({sup 201}Tl, {sup 99m}Tc). The defect contrast of the 180deg images, in both {sup 201}Tl and {sup 99m}Tc experiments, was closer to the true contrast value as calculated by the count ratio between myocardium and defect. Although the defect contrast in the anterior, lateral and septal walls was more emphasized in the 180deg images, the defect contrast in the inferoposterior wall was less emphasized in the 180deg images compared to the 360deg ({sup 201}Tl, {sup 99m}Tc). (author)

  14. SPECT detectors: the Anger Camera and beyond

    Science.gov (United States)

    Peterson, Todd E.; Furenlid, Lars R.

    2011-09-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous sodium iodide scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic.

  15. Gated SPECT evaluation of left ventricular function using a CZT camera and a fast low-dose clinical protocol: comparison to cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giorgetti, Assuero; Masci, Pier Giorgio; Marras, Gavino; Gimelli, Alessia; Genovesi, Dario; Lombardi, Massimo [Fondazione CNR/Regione Toscana ' ' G. Monasterio' ' , Pisa (Italy); Rustamova, Yasmine K. [Azerbaijan Medical University, Department of internal medicine Central Customs Hospital, Baku (Azerbaijan); Marzullo, Paolo [Istituto di Fisiologia Clinica del CNR, Pisa (Italy)

    2013-12-15

    CZT technology allows ultrafast low-dose myocardial scintigraphy but its accuracy in assessing left ventricular function is still to be defined. The study group comprised 55 patients (23 women, mean age 63 {+-} 9 years) referred for myocardial perfusion scintigraphy. The patients were studied at rest using a CZT camera (Discovery NM530c; GE Healthcare) and a low-dose {sup 99m}Tc-tetrofosmin clinical protocol (mean dose 264 {+-} 38 MBq). Gated SPECT imaging was performed as a 6-min list-mode acquisition, 15 min after radiotracer injection. Images were reformatted (8-frame to 16-frame) using Lister software on a Xeleris workstation (GE Healthcare) and then reconstructed with a dedicated iterative algorithm. Analysis was performed using Quantitative Gated SPECT (QGS) software. Within 2 weeks patients underwent cardiac magnetic resonance imaging (cMRI, 1.5-T unit CVi; GE Healthcare) using a 30-frame acquisition protocol and dedicated software for analysis (MASS 6.1; Medis). The ventricular volumes obtained with 8-frame QGS showed excellent correlations with the cMRI volumes (end-diastolic volume (EDV), r = 0.90; end-systolic volume (ESV), r = 0.94; p < 0.001). However, QGS significantly underestimated the ventricular volumes (mean differences: EDV, -39.5 {+-} 29 mL; ESV, -15.4 {+-} 22 mL; p < 0.001). Similarly, the ventricular volumes obtained with 16-frame QGS showed an excellent correlations with the cMRI volumes (EDV, r = 0.92; ESV, r = 0.95; p < 0.001) but with significant underestimations (mean differences: EDV, -33.2 {+-} 26 mL; ESV, -17.9 {+-} 20 mL; p < 0.001). Despite significantly lower values (47.9 {+-} 16 % vs. 51.2 {+-} 15 %, p < 0.008), 8-frame QGS mean ejection fraction (EF) was closely correlated with the cMRI values (r = 0.84, p < 0.001). The mean EF with 16-frame QGS showed the best correlation with the cMRI values (r = 0.91, p < 0.001) and was similar to the mean cMRI value (49.6 {+-} 16 %, p not significant). Regional analysis showed a good

  16. Cerebral hypoperfusion detected by SPECT in patients with systemic lupus erythematosus is related to clinical activity and cumulative tissue damage.

    Science.gov (United States)

    López-Longo, F J; Carol, N; Almoguera, M I; Olazarán, J; Alonso-Farto, J C; Ortega, A; Monteagudo, I; González, C Manuel; Carreño, L

    2003-01-01

    Cerebral single-photon emission computed tomography (SPECT) is a sensitive technique for the detection of central nervous system (CNS) involvement in systemic lupus erythematosus (SLE). The objective was to determine whether a relationship exists between cerebral hypoperfusion as detected by cerebral SPECT, cumulative tissue damage and the clinical activity of SLE. Cerebral technetium-99m-L,L-ethyl cysteinate dimer (99mTc-ECD) SPECT was performed in two groups of patients: 10 women with SLE (Group A) who had no previous history of major neuropsychiatric (NPS) manifestations and no minor NPS symptoms in the last six months, and 57 unselected women with SLE (Group B). In the same week that SPECT was performed, the SLE disease activity index (SLEDAI), SLICC/ACR damage index, native anti-DNA antibodies (ELISA) and erythrocyte sedimentation rate (ESR) were determined. In Group A, cerebral SPECT showed moderate or severe hypoperfusion (abnormal SPECT) in five patients without NPS symptoms, unrelated to age (mean 24.8 versus 27.8 years) or disease duration (mean 6.8 versus 9 years). Patients with significant cerebral hypoperfusion had greater clinical disease activity (mean SLEDAI 13.6 versus 7.6) (SLEDAI > 7 in 5/5 versus 1/5; Fisher: 0.023; OR: 33; 95% CI: 2.3-469.8) and ESR (mean 43.6 versus 9.8; P < 0.05). In Group B, the mean age of the 57 unselected women with SLE was 37 years (SD 6.3) and the mean duration of the disease was 9.7 years (SD 6.3). Cerebral SPECT revealed normal perfusion or mild hypoperfusion (normal SPECT) in 30 patients (52.6%), and moderate or severe hypoperfusion in 27 (47.4%). Hypoperfusion was unrelated to age, duration of SLE or concentrations of anti-DNA antibodies and C3 and C4 fractions. Patients with significant cerebral hypoperfusion had more active clinical disease (mean SLEDAI 13.92; SD 8.44 versus 4.56; SD 4.15) (Mann-Whitney, P < 0.005), more cumulative tissue damage (mean SLICC 2.66; SD 2.84 versus 1.03; SD 1.51) (Mann-Whitney, P = 0

  17. 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

  18. Development of a fully 3D system model in iterative expectation-maximization reconstruction for cone-beam SPECT

    Science.gov (United States)

    Ye, Hongwei; Vogelsang, Levon; Feiglin, David H.; Lipson, Edward D.; Krol, Andrzej

    2008-03-01

    In order to improve reconstructed image quality for cone-beam collimator SPECT, we have developed and implemented a fully 3D reconstruction, using an ordered subsets expectation maximization (OSEM) algorithm, along with a volumetric system model - cone-volume system model (CVSM), a modified attenuation compensation, and a 3D depth- and angle-dependent resolution and sensitivity correction. SPECT data were acquired in a 128×128 matrix, in 120 views with a single circular orbit. Two sets of numerical Defrise phantoms were used to simulate CBC SPECT scans, and low noise and scatter-free projection datasets were obtained using the SimSET Monte Carlo package. The reconstructed images, obtained using OSEM with a line-length system model (LLSM) and a 3D Gaussian post-filter, and OSEM with FVSM and a 3D Gaussian post-filter were quantitatively studied. Overall improvement in the image quality has been observed, including better transaxial resolution, higher contrast-to-noise ratio between hot and cold disks, and better accuracy and lower bias in OSEM-CVSM, compared with OSEM-LLSM.

  19. Exprerimental Evaluation of a Dedicated Pinhole SPECT System for Small Animal Imaging and Scintimammography

    Directory of Open Access Journals (Sweden)

    G. Loudos

    2011-02-01

    Full Text Available Nuclear medicine (SPECT and PET provides functional information, which is complementary to the structural. In cancer imaging radiopharmaceuticals allow visualization of cancer cells functionality, thus small cell population can be imaged. This allows early diagnosis, as well as fast assessment of response to therapy. Our system is a single head gamma camera based on an R3292 position sensitive photomultiplier tube (PSPMT, coupled to a 10cm in diameter CsI:Tl crystal. We have assessed two CsI:Tl crystals with pixel size of 2x2mm2 and 3x3mm2 respectively. Three collimators were tested: a a hexagonal, 1.1mm in diameter, general purpose parallel hole collimator b a 1mm pinhole and c a 2mm pinhole. Systems were tested using capillary phantoms. All measurements were carried out in photon counting mode with gamma radiation produced by 99mTc. Using the 2x2mm2 crystal and the 1mm pinhole collimator - a resolution better than 1mm was achieved. This allows very detailed imaging of small animals. Using the 3x3mm2 and the 2mm pinhole collimator a resolution of 1.3mm was possible with suitable sensitivity for breast imaging. Those results indicate that this system is suitable for animal and breast studies. The next step will be clinical evaluation of the camera.

  20. 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.

  1. Evaluation of the channelized Hotelling observer with an internal-noise model in a train-test paradigm for cardiac SPECT defect detection

    Science.gov (United States)

    Brankov, Jovan G.

    2013-10-01

    The channelized Hotelling observer (CHO) has become a widely used approach for evaluating medical image quality, acting as a surrogate for human observers in early-stage research on assessment and optimization of imaging devices and algorithms. The CHO is typically used to measure lesion detectability. Its popularity stems from experiments showing that the CHO's detection performance can correlate well with that of human observers. In some cases, CHO performance overestimates human performance; to counteract this effect, an internal-noise model is introduced, which allows the CHO to be tuned to match human-observer performance. Typically, this tuning is achieved using example data obtained from human observers. We argue that this internal-noise tuning step is essentially a model training exercise; therefore, just as in supervised learning, it is essential to test the CHO with an internal-noise model on a set of data that is distinct from that used to tune (train) the model. Furthermore, we argue that, if the CHO is to provide useful insights about new imaging algorithms or devices, the test data should reflect such potential differences from the training data; it is not sufficient simply to use new noise realizations of the same imaging method. Motivated by these considerations, the novelty of this paper is the use of new model selection criteria to evaluate ten established internal-noise models, utilizing four different channel models, in a train-test approach. Though not the focus of the paper, a new internal-noise model is also proposed that outperformed the ten established models in the cases tested. The results, using cardiac perfusion SPECT data, show that the proposed train-test approach is necessary, as judged by the newly proposed model selection criteria, to avoid spurious conclusions. The results also demonstrate that, in some models, the optimal internal-noise parameter is very sensitive to the choice of training data; therefore, these models are prone

  2. Evaluation of the channelized Hotelling observer with an internal-noise model in a train-test paradigm for cardiac SPECT defect detection.

    Science.gov (United States)

    Brankov, Jovan G

    2013-10-21

    The channelized Hotelling observer (CHO) has become a widely used approach for evaluating medical image quality, acting as a surrogate for human observers in early-stage research on assessment and optimization of imaging devices and algorithms. The CHO is typically used to measure lesion detectability. Its popularity stems from experiments showing that the CHO's detection performance can correlate well with that of human observers. In some cases, CHO performance overestimates human performance; to counteract this effect, an internal-noise model is introduced, which allows the CHO to be tuned to match human-observer performance. Typically, this tuning is achieved using example data obtained from human observers. We argue that this internal-noise tuning step is essentially a model training exercise; therefore, just as in supervised learning, it is essential to test the CHO with an internal-noise model on a set of data that is distinct from that used to tune (train) the model. Furthermore, we argue that, if the CHO is to provide useful insights about new imaging algorithms or devices, the test data should reflect such potential differences from the training data; it is not sufficient simply to use new noise realizations of the same imaging method. Motivated by these considerations, the novelty of this paper is the use of new model selection criteria to evaluate ten established internal-noise models, utilizing four different channel models, in a train-test approach. Though not the focus of the paper, a new internal-noise model is also proposed that outperformed the ten established models in the cases tested. The results, using cardiac perfusion SPECT data, show that the proposed train-test approach is necessary, as judged by the newly proposed model selection criteria, to avoid spurious conclusions. The results also demonstrate that, in some models, the optimal internal-noise parameter is very sensitive to the choice of training data; therefore, these models are prone

  3. Cardiac autonomic nervous system activity in obesity.

    Science.gov (United States)

    Liatis, Stavros; Tentolouris, Nikolaos; Katsilambros, Nikolaos

    2004-08-01

    The development of obesity is caused by a disturbance of energy balance, with energy intake exceeding energy expenditure. As the autonomic nervous system (ANS) has a role in the regulation of both these variables, it has become a major focus of investigation in the fields of obesity pathogenesis. The enhanced cardiac sympathetic drive shown in most of the studies in obese persons might be due to an increase in their levels of circulating insulin. The role of leptin needs further investigation with studies in humans. There is a blunted response of the cardiac sympathetic nervous system (SNS) activity in obese subjects after consumption of a carbohydrate-rich meal as well as after insulin administration. This might be due to insulin resistance. It is speculated that increased SNS activity in obesity may contribute to the development of hypertension in genetically susceptible individuals. It is also speculated that the increase in cardiac SNS activity under fasting conditions in obesity may be associated with high cardiovascular morbidity and mortality.

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

    Directory of Open Access Journals (Sweden)

    J. Mejia

    2010-12-01

    Full Text Available 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.

  5. 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)

  6. Development and evaluation of Monte Carlo-based SPECT reconstruction

    NARCIS (Netherlands)

    Xiao, J.

    2009-01-01

    Single Photon Emission Computed Tomography (SPECT) is one of the most applied molecular imaging techniques to diagnose human diseases, e.g., of the heart, the brain or in oncology. For example, cardiac SPECT imaging plays a central role in diagnosing coronary heart diseases by providing clinicians w

  7. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous {sup 99m}Tc/{sup 201}Tl SPECT imaging: A Monte Carlo simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Heidary, Saeed, E-mail: saeedheidary@aut.ac.ir; Setayeshi, Saeed, E-mail: setayesh@aut.ac.ir

    2015-01-11

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous {sup 99m}Tc/{sup 201}Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of {sup 201}Tl (77±10% keV) and {sup 99m}Tc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results.

  8. Evaluation of Multiple System Atrophy and Early Parkinson's Disease Using {sup 123}I-FP-CIT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Oh, So Won; Kim, Yu Kyeong; Lee, Byung Chul; Kim, Bom Sahn; Kim, Ji Sun; Kim, Jong Min; Kim, Sang Eun [Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2009-02-15

    We investigated quantification of dopaminergic transporter (DAT) and serotonergic transporter (SERT) on {sup 123}I-FP-CIT SPECT for differentiating between multiple systemic atrophy (MSA) and idiopathic Parkinson's disease (IPD). N.fluoropropyl-2{beta}-carbomethoxy-3{beta}-4-[{sup 123}I]-iodophenylnortropane SPECT ({sup 123}I-FP-CIT SPECT) was performed in 8 patients with MSA (mean age: 64.0{+-}4.5yrs, m:f=6:2), 13 with early IPD (mean age: 65.5{+-}5.3yrs, m:f=9:4), and 12 healthy controls (mean age: 63.3{+-}5.7yrs, m:f=8:4). Standard regions of interests (ROIs) of striatum to evaluate DAT, and hypothalamus and midbrain for SERT were drawn on standard template images and applied to each image taken 4 hours after radiotracer injection. Striatal specific binding for DAT and hypothalamic and midbrain specific binding for SERT were calculated using region/reference ratio based on the transient equilibrium method. Group differences were tested using ANOVA with the postHoc analysis. DAT in the whole striatum and striatal subregions were significantly decreased in both patient groups with MSA and early IPD, compared with healthy control (p<0.05 in all). In early IPD, a significant increase in the uptake ratio in anterior and posterior putamen and a trend of increase in caudate to putamen ratio was observed. In MSA, the decrease of DAT was accompanied with no difference in the striatal uptake pattern compared with healthy controls. Regarding the brain regions where {sup 123}I-FP-CIT binding was predominant by SERT, MSA patients showed a decrease in the binding of {sup 123}I-FP-CIT in the pons compared with controls as well as early IPD patients (MSA: 0.22{+-}0.1 healthy controls: 0.33{+-}0.19, IPD: 0.29{+-}0.19), however, it did not reach the statistical significance. In this study, the differential patterns in the reduction of DAT in the striatum and the reduction of pontine {sup 123}I- FP-CIT binding predominant by SERT could be observed in MSA patients on {sup 123

  9. Evaluation of a novel integrated sensor system for synchronous measurement of cardiac vibrations and cardiac potentials.

    Science.gov (United States)

    Chuo, Yindar; Tavakolian, Kouhyar; Kaminska, Bozena

    2011-08-01

    The measurement of human body vibrations as a result of heart beating, simultaneously with cardiac potentials have been demonstrated in past studies to bring additional value to diagnostic cardiology through the detection of irregularities in the mechanical movement of the heart. The equipment currently available to the medical community is either large and bulky or difficult to synchronize. To address this problem, a novel integrated sensor system has been developed to record cardiac vibration and cardiac potential simultaneously and synchronously from a single compact site on the chest. The developed sensor system is lightweight, small in size, and suitable for mounting on active moving patients. The sensor is evaluated for its adequacy in measuring cardiac vibrations and potentials. In this evaluation, 45 independent signal recording are studied from 15 volunteers, and the morphology of the recorded signals are analyzed qualitatively (by visual inspection) and quantitatively (by computational methods) against larger devices used in established cardiac vibration studies (reference devices). It is found that the cardiac vibration signals acquired by the integrated sensor has 92.37% and 81.76% identically identifiable systolic and diastolic cardiac complexes, respectively, when compared to the cardiac vibration signals recorded simultaneously from the reference device. Further, the cardiac potential signals acquired by the integrated sensor show a high correlation coefficient of 0.8912 and a high estimated signal-to-noise-ratio of 22.00 dB when compared to the reference electrocardiograph (non-standard leads) acquired through a common clinical machine. The results suggest that the tiny, wearable, integrated sensor system that synchronously measures cardiac vibrations and cardiac potentials may be practical for use as an alternative or assistive cardiac diagnostic tool.

  10. 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

    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 tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic 94Tc-methoxyisobutylisonitrile (94Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K1 for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K1. For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from 94Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of 99mTc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The spatiotemporal maximum

  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

    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 tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic (94)Tc-methoxyisobutylisonitrile ((94)Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K(1) for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K(1). For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from (94)Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of (99m)Tc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The

  12. Implementation of a fully 3D system model for brain SPECT with fan- beam-collimator OSEM reconstruction with 3D total variation regularization

    Science.gov (United States)

    Ye, Hongwei; Krol, Andrzej; Lipson, Edward D.; Lu, Yao; Xu, Yuesheng; Lee, Wei; Feiglin, David H.

    2007-03-01

    In order to improve tomographically reconstructed image quality, we have implemented a fully 3D reconstruction, using an ordered subsets expectation maximization (OSEM) algorithm for fan-beam collimator (FBC) SPECT, along with a volumetric system model-fan-volume system model (FVSM), a modified attenuation compensation, a 3D depth- and angle-dependent resolution and sensitivity correction, and a 3D total variation (TV) regularization. SPECT data were acquired in a 128x64 matrix, in 120 views with a circular orbit. The numerical Zubal brain phantom was used to simulate a FBC HMPAO Tc-99m brain SPECT scan, and a low noise and scatter-free projection dataset was obtained using the SimSET Monte Carlo package. A SPECT scan for a mini-Defrise phantom and brain HMPAO SPECT scans for five patients were acquired with a triple-head gamma camera (Triad 88) equipped with a low-energy high-resolution (LEHR) FBC. The reconstructed images, obtained using clinical filtered back projection (FBP), OSEM with a line-length system model (LLSM) and 3D TV regularization, and OSEM with FVSM and 3D TV regularization were quantitatively studied. Overall improvement in the image quality has been observed, including better axial and transaxial resolution, better integral uniformity, higher contrast-to-noise ration between the gray matter and the white matter, and better accuracy and lower bias in OSEM-FVSM, compared with OSEM-LLSM and clinical FBP.

  13. Função ventricular após cirurgia de revascularização: Gated SPECT comparado à ressonância cardíaca Función ventricular tras cirugía de revascularización: Gated SPECT comparado a la resonancia cardiaca Ventricular function following coronary artery bypass grafting: comparison between Gated SPECT and cardiac magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Cláudio Tinoco Mesquita

    2009-05-01

    scintigraphy (gated SPECT and cardiac magnetic reso

  14. Optimizing and Evaluating an Integrated SPECT-CmT System Dedicated to Improved 3-D Breast Cancer Imaging

    Science.gov (United States)

    2010-05-01

    M. P. Tornai, "Pilot Patient Studies Using a Dedicated Dual-Modality SPECT-CT System for Breast Imaging " 2008 AAPM (2008). 3M. J. Butson, P. K. N...for Breast Imaging " in 2008 AAPM , (Houston TX, 2008). 16. M. P. Tornai, R. L. McKinley, C. N. Brzymialkiewicz, P. Madhav, S. J. Cutler, D. J...S. Meigooni, R. Nath, J. E. Rodgers and C. G. Soares, "Radiochromic film dosimetry: recommendations of AAPM Radiation Therapy Committee Task Group

  15. MO-G-17A-02: Computer Simulation Studies for On-Board Functional and Molecular Imaging of the Prostate Using a Robotic Multi-Pinhole SPECT System

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, L [University of Heifelberg, Mannheim (Germany); Duke University Medical Center, Durham, NC (United States); Fudan University Shanghai Cancer Center, Shanghai (China); Bowsher, J; Yin, F [Duke University Medical Center, Durham, NC (United States); Duke University Medical Physics Graduate Program, Durham, NC (United States); Yan, S [Duke University Medical Physics Graduate Program, Durham, NC (United States)

    2014-06-15

    Purpose: To investigate prostate imaging onboard radiation therapy machines using a novel robotic, 49-pinhole Single Photon Emission Computed Tomography (SPECT) system. Methods: Computer-simulation studies were performed for region-of-interest (ROI) imaging using a 49-pinhole SPECT collimator and for broad cross-section imaging using a parallel-hole SPECT collimator. A male XCAT phantom was computersimulated in supine position with one 12mm-diameter tumor added in the prostate. A treatment couch was added to the phantom. Four-minute detector trajectories for imaging a 7cm-diameter-sphere ROI encompassing the tumor were investigated with different parameters, including pinhole focal length, pinhole diameter and trajectory starting angle. Pseudo-random Poisson noise was included in the simulated projection data, and SPECT images were reconstructed by OSEM with 4 subsets and up to 10 iterations. Images were evaluated by visual inspection, profiles, and Root-Mean- Square-Error (RMSE). Results: The tumor was well visualized above background by the 49-pinhole SPECT system with different pinhole parameters while it was not visible with parallel-hole SPECT imaging. Minimum RMSEs were 0.30 for 49-pinhole imaging and 0.41 for parallelhole imaging. For parallel-hole imaging, the detector trajectory from rightto- left yielded slightly lower RMSEs than that from posterior to anterior. For 49-pinhole imaging, near-minimum RMSEs were maintained over a broader range of OSEM iterations with a 5mm pinhole diameter and 21cm focal length versus a 2mm diameter pinhole and 18cm focal length. The detector with 21cm pinhole focal length had the shortest rotation radius averaged over the trajectory. Conclusion: On-board functional and molecular prostate imaging may be feasible in 4-minute scan times by robotic SPECT. A 49-pinhole SPECT system could improve such imaging as compared to broadcross-section parallel-hole collimated SPECT imaging. Multi-pinhole imaging can be improved by

  16. Clinical usefulness of {sup 123}I-BMIPP myocardial SPECT in collagen disease

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kazuki; Zen, Kan [Asahi Univ., Gifu (Japan). Murakami Memorial Hospital; Sugihara, Hiroki (and others)

    2000-07-01

    This study was designed to evaluate the clinical usefulness of {sup 123}I-BMIPP myocardial SPECT for detecting cardiac involvement in patients with collagen disease. We studied 12 patients with systemic lupus erythematosus (SLE), 8 with progressive systemic sclerosis (PSS), 6 with polymyositis/dermatomyositis (PM/DM) and 3 with allergic granulomatosis and angiitis (AGA). A 111 MBq of {sup 123}I-BMIPP was intravenously injected at rest, and SPECT images were obtained at 15 min after the injection. Seven of 12 SLE, 6 of 8 PSS, 3 of 6 PM/DM and all 3 AGA patients showed an abnormal tracer uptake. The left ventricular ejection fraction was inversely correlated with a BMIPP abnormality. The regional wall motion abnormality was reduced in regions with reduced tracer uptake. These findings suggest that {sup 123}I-BMIPP imaging could be useful for assessment of cardiac involvement in patients with collagen disease. (author)

  17. Quantification of perfusion and risk stratification by myocardial perfusion SPECT; Quantifizierung der Perfusion und Risikostratifizierung durch die Myokardperfusions-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Bernd [Ueberoertliche Gemeinschaft (GbR) fuer diagnostische und interventionelle Radiologie und Nuklearmedizin (DIRANUK), Bielefeld (Germany); Klinikum Bielefeld-Mitte (Germany). Klinik fuer Nuklearmedizin; Schaefer, W.M. [Kliniken Maria Hilf GmbH, Krankenhaus St. Franziskus, Moenchengladbach (Germany). Klinik fuer Nuklearmedizin

    2010-06-15

    Myocardial perfusion SPECT detects flow-limiting coronary artery disease with high sensitivity and specificity, enables semiquantification of severity and extensiveness of myocardial ischemia, and furthermore enables reliable assessment of future cardiac events independently of other clinical and diagnostic parameters. A normal myocardial perfusion SPECT is associated with a favorable prognosis and warrants restrictive patient management. Cardiac risk increases in relation to the severity of perfusion abnormalities. Differentiated analysis of quantitative parameters derived from myocardial perfusion SPECT provides effective risk stratification of patients with a large variety of risk factors. (orig.)

  18. Cardiac tamponade as an initial manifestation of systemic lupus erythematosus.

    Science.gov (United States)

    Carrion, Diego M; Carrion, Andres F

    2012-06-12

    Clinical manifestations of pericardial disease may precede other signs and symptoms associated with systemic lupus erythematosus. Although pericardial effusion is one of the most common cardiac problems in patients with systemic lupus erythematosus, haemodynamically significant effusions manifesting as cardiac tamponade are rare and require prompt diagnosis and treatment.

  19. 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

  20. Determining the minimum number of detectable cardiac-transplanted 111In-tropolone-labelled bone-marrow-derived mesenchymal stem cells by SPECT

    Science.gov (United States)

    Jin, Yuan; Kong, Huafu; Stodilka, Rob Z.; Wells, R. Glenn; Zabel, Pamela; Merrifield, Peter A.; Sykes, Jane; Prato, Frank S.

    2005-10-01

    In this work, we determined the minimum number of detectable 111In-tropolone-labelled bone-marrow-derived stem cells from the maximum activity per cell which did not affect viability, proliferation and differentiation, and the minimum detectable activity (MDA) of 111In by SPECT. Canine bone marrow mesenchymal cells were isolated, cultured and expanded. A number of samples, each containing 5 × 106 cells, were labelled with 111In-tropolone from 0.1 to 18 MBq, and cell viability was measured afterwards for each sample for 2 weeks. To determine the MDA, the anthropomorphic torso phantom (DataSpectrum Corporation, Hillsborough, NC) was used. A point source of 202 kBq 111In was placed on the surface of the heart compartment, and the phantom and all compartments were then filled with water. Three 111In SPECT scans (duration: 16, 32 and 64 min; parameters: 128 × 128 matrix with 128 projections over 360°) were acquired every three days until the 111In radioactivity decayed to undetectable quantities. 111In SPECT images were reconstructed using OSEM with and without background, scatter or attenuation corrections. Contrast-to-noise ratio (CNR) in the reconstructed image was calculated, and MDA was set equal to the 111In activity corresponding to a CNR of 4. The cells had 100% viability when incubated with no more than 0.9 MBq of 111In (80% labelling efficiency), which corresponded to 0.14 Bq per cell. Background correction improved the detection limits for 111In-tropolone-labelled cells. The MDAs for 16, 32 and 64 min scans with background correction were observed to be 1.4 kBq, 700 Bq and 400 Bq, which implies that, in the case where the location of the transplantation is known and fixed, as few as 10 000, 5000 and 2900 cells respectively can be detected.

  1. 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.)

  2. Simulation of the expected performance of INSERT: A new multi-modality SPECT/MRI system for preclinical and clinical imaging

    Science.gov (United States)

    Busca, P.; Fiorini, C.; Butt, A. D.; Occhipinti, M.; Peloso, R.; Quaglia, R.; Schembari, F.; Trigilio, P.; Nemeth, G.; Major, P.; Erlandsson, K.; Hutton, B. F.

    2014-01-01

    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 such as 3 T MRI with 59 cm bore diameter. 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 will be developed, one dedicated to preclinical imaging, the second one dedicated to clinical imaging. The basic building block of the SPECT detector ring is a small 5 cm×5 cm gamma camera, based on the well-established Anger architecture with a continuous scintillator readout by an array of silicon photodetectors. Silicon Drift Detectors (SDDs) and Silicon PhotoMultipliers (SiPM) are being considered as possible scintillator readout, considering that the detector choice plays a predominant role for the final performance of the system, such as energy and spatial resolution, as well as the useful field of view of the camera. Both solutions are therefore under study to evaluate their performances in terms of field of view (FOV), spatial and energy resolution. Preliminary simulations for both the preclinical and clinical systems have been carried out to evaluate resolution and sensitivity.

  3. SU-E-I-79: Effect of Number of Pinholes in Onboard Robotic Multi-Pinhole SPECT System

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

    Purpose: To study the effect of number of pinholes for a novel Single Photon Emission Computed Tomography (SPECT) system for onboard molecular and functional imaging. Methods: Comparison studies were performed using simulation for the 49-pinhole SPECT system and a series of reductions in number of pinholes. Trajectories about the breast of a supine patient were considered. Minimum distances, radii of rotation (RORs), were determined by requirements to fully view the region of interest (ROI) and to avoid collision between the detector and the patient. Reductions in RORs translate into improvements in sensitivity. Starting from the 49-pinhole system, pinholes were removed pod by pod. The furthest two end pods in the Sup-Inf direction were removed first for their higher likelihood of alleviating the collision avoidance criteria. After iterating through different combinations of pinhole pods, and selecting three combinations, the corresponding RORs were used to analytically calculate sensitivities. Results: Based on the Methods procedure, 3 combination of pods removal were identified: 1) Superior peripheral pod 2) Inferior peripheral pod 3) both pods. RORs were reduced at only one multi-pinhole stop. Analytic calculation showed that sensitivities were reduced from 0.032 for the 49-pinhole system to 0.028 for 42-pinhole and to 0.023 for 39-pinhole system respectively. The sensitivity per pinhole detector was approximately the same for all three cases. Conclusion: For the trajectories considered, only minimal improvements in RORs were identified by removing pinhole pods. Consequently, sensitivities decreased in proportion to the number of pinholes. Studies of other anatomical sites are needed to determine if in some cases sensitivity per pinhole can be improved by removing some pinholes. PHS/NIH/NCI grant R21-CA156390-01A1.

  4. 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.

  5. 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...

  6. MediSPECT: Single photon emission computed tomography system for small field of view small animal imaging based on a CdTe hybrid pixel detector

    Science.gov (United States)

    Accorsi, R.; Autiero, M.; Celentano, L.; Chmeissani, M.; Cozzolino, R.; Curion, A. S.; Frallicciardi, P.; Laccetti, P.; Lanza, R. C.; Lauria, A.; Maiorino, M.; Marotta, M.; Mettivier, G.; Montesi, M. C.; Riccio, P.; Roberti, G.; Russo, P.

    2007-02-01

    We describe MediSPECT, a new scanner developed at University and INFN Napoli, for SPECT studies on small animals with a small field of view (FOV) and high spatial resolution. The CdTe pixel detector (a 256×256 matrix of 55 μm square pixels) operating in single photon counting for detection of gamma-rays with low and medium energy (e.g. 125I, 27-35 keV, 99mTc, 140 keV), is bump bonded to the Medipix2 readout chip. The FOV of the MediSPECT scanner with a coded aperture mask collimator ranges from 6.3 mm (system spatial resolution 110 μm at 27-35 keV) to 24.3 mm. With a 0.30 mm pinhole the FOV ranges from 2.4 to 29 mm (where the system spatial resolution is 1.0 mm at 27-35 keV and 2.0 mm at 140 keV). MediSPECT will be used for in vivo imaging of small organs or tissue structures in mouse, e.g., brain, thyroid, heart or tumor.

  7. A smartphone based cardiac coherence biofeedback system.

    Science.gov (United States)

    De Jonckheere, J; Ibarissene, I; Flocteil, M; Logier, R

    2014-01-01

    Cardiac coherence biofeedback training consist on slowing one's breathing to 0.1 Hz in order to simulate the baroreflex sensitivity and increase the respiratory sinus arrhythmia efficiency. Several studies have shown that these breathing exercises can constitute an efficient therapy in many clinical contexts like cardiovascular diseases, asthma, fibromyalgia or post-traumatic stress. Such a non-intrusive therapeutic solution needs to be performed on an 8 to 10 weeks period. Even if some heart rate variability based solutions exist, they presented some mobility constrain rendering these cardiac / respiratory control technologies more difficult to perform on a daily used. In this paper, we present a new simplified smartphone based solution allowing people to process efficient cardiac coherence biofeedback exercises. Based on photo-plethysmographic imaging through the smartphone camera, this sensor-less technology allows controlling cardiac coherence biofeedback exercises through a simplified heart rate variability algorithm.

  8. Is there an association between Fahr′s disease and cardiac conduction system disease?: A case report

    Directory of Open Access Journals (Sweden)

    Prashanth Panduranga

    2012-01-01

    Full Text Available Background: Fahr′s disease is a rare neurodegenerative disorder of unknown cause characterized by idiopathic basal ganglia calcification that is associated with neuropsychiatric and cognitive impairment. No case of Fahr′s disease with associated cardiac conduction disease has been described in the literature to date. The objective of this case report was to describe a young female with various cardiac conduction system abnormalities and bilateral basal ganglia calcifica-tion suggestive of Fahr′s disease. Case Report: A 19-year-old female was transferred to our hospital for a pacemaker insertion. Her past medical history included cognitive impairment and asymptomatic congenital complete heart block since birth. Her manifestations in-cluded cognitive impairment, tremors, rigidity, ataxia, bilateral basal ganglia calcification without clinical manifesta-tions of mitochondrial cytopathy. She also had right bundle branch block, left anterior fascicular block, intermittent complete heart block, atrial arrhythmias with advanced atrioventricular blocks and ventricular asystole manifested by Stokes-Adams seizures, which was diagnosed as epilepsy. Conclusions: According to our knowledge, this was the first case report of a su spected association between Fahr′s disease and isolated cardiac conduction system disease. In addition, this case illustrated that in patients with heart blocks and seizures, a diagnosis of epilepsy needs to be made with caution and such patients need further evaluations by a cardiologist or electrophysiologist to consider pacing and prevent future catastrophic events.

  9. Simulation of the expected performance of INSERT: A new multi-modality SPECT/MRI system for preclinical and clinical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Busca, P., E-mail: busca@elet.polimi.it [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano (Italy); Fiorini, C., E-mail: carlo.fiorini@polimi.it [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano (Italy); Butt, A.D.; Occhipinti, M.; Peloso, R.; Quaglia, R.; Schembari, F.; Trigilio, P. [Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, 20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano (Italy); Nemeth, G.; Major, P. [Mediso Medical Imaging Systems, Alsotorokvesz 14, H-1022 Budapest (Hungary); Erlandsson, K. [University College London, Gower Street, WC1E 6BT London (United Kingdom); Hutton, B.F. [University College London, Gower Street, WC1E 6BT London (United Kingdom); Centre for Medical Radiation Physics, University of Wollongong, NSW 2522 (Australia)

    2014-01-11

    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 such as 3 T MRI with 59 cm bore diameter. 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 will be developed, one dedicated to preclinical imaging, the second one dedicated to clinical imaging. The basic building block of the SPECT detector ring is a small 5 cm×5 cm gamma camera, based on the well-established Anger architecture with a continuous scintillator readout by an array of silicon photodetectors. Silicon Drift Detectors (SDDs) and Silicon PhotoMultipliers (SiPM) are being considered as possible scintillator readout, considering that the detector choice plays a predominant role for the final performance of the system, such as energy and spatial resolution, as well as the useful field of view of the camera. Both solutions are therefore under study to evaluate their performances in terms of field of view (FOV), spatial and energy resolution. Preliminary simulations for both the preclinical and clinical systems have been carried out to evaluate resolution and sensitivity. -- Highlights: • We introduce INSERT, a new multi-modality SPECT/MRI instrument. • We propose two possible photodetectors (SDD, SiPM) for the scintillators readout. • We show possible results for INSERT, based on simulations.

  10. Evaluation of the effects of methylprednisolone pulse therapy in patients with systemic lupus erythematosus with brain involvement by Tc-99m HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Sun, S.S.; Kao, C.H. [Department of Nuclear Medicine, China Medical University Hospital, Taichung (Taiwan); Huang, W.S. [Department of Nuclear Medicine, National Defense Medical Center, Tri-Service General Hospital, Taipei (Taiwan); Chen, J.J.H. [Section of Rheumatology, Department of Internal Medicine, China Medicine University Hospital, Taichung (Taiwan); Chang, C.P. [Division of Allergy, Immunology and Rheumatology, Changhua Christian Hospital, Changhua (Taiwan); Wang, J.J. [Department of Medical Research, Chi-Mei Medical Center, Tainan (Taiwan)

    2004-07-01

    Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in patients with systemic lupus erythematosus (SLE) with brain manifestations; however, the efficacy of MPT in SLE patients with brain involvement is still uncertain and needs to be objectively evaluated. We enrolled 15 female SLE patients with neuropsychiatric manifestations in this study. All patients had normal brain MRI and abnormal brain HMPAO-SPECT findings. Follow-up HMPAO-SPECT studies were conducted 2 weeks after MPT. Serum levels of anticardiolipin antibodies (ACA) and anti-ribosomal P antibodies (anti-P) were measured before and after MPT. Before MPT, 7 patients were positive for ACA and 7 patients were positive for anti-P. After MPT, none of the 15 patients demonstrated positive serologic findings or neuropsychiatric manifestations. Based on the follow up brain HMPAO-SPECT images following MPT, 13 patients showed disappearance of the perfusion defects and 2 patients showed partial recovery of rCBF. Brain HMPAO-SPECT imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by determining of changes in rCBF. (orig.)

  11. No evidence of myocardial restoration following transplantation of mononuclear bone marrow cells in coronary bypass grafting surgery patients based upon cardiac SPECT and 18F-PET

    Directory of Open Access Journals (Sweden)

    Ünal Nermin

    2006-07-01

    Full Text Available Abstract Background We tested the hypothesis, that intramyocardial injection of mononuclear bone marrow cells combined with coronary artery bypass grafting (CABG surgery improves tissue viability or function in infarct regions with non-viable myocardium as assessed by nuclear imaging techniques. Methods Thus far, 7 patients (60 ± 10 [SD] years undergoing elective CABG surgery after a myocardial infarction were included in this study. Prior to sternotomy, bone marrow was harvested by sternal puncture. Mononuclear bone marrow cells were isolated by gradient centrifugation and resuspended in 2 ml volume of Hank's buffered salt solution. At the end of CABG surgery 10 injections of 0.2 ml each were applied to the core area and borderzones of the infarct. Global and regional perfusion and viability were evaluated by ECG-gated 99mTc-tetrofosmin myocardial single-photon emission computed tomograph (SPECT imaging and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET in all study patients Results Non-viable segments indicating transmural defects were identified in 5 patients. Two patients were found to have non-transmural defects before surgery. Concomitant surgical revascularisation and bone marrow cell injection was performed in all patients without major complications. The median total injected mononuclear cell number was 7.0 × 107 (range: 0.8–20.4. At 3 months 99mTc-tetrofosmin SPECT and 18F-FDG-PET scanning showed in 5 patients (transmural defect n = 4; non-transmural defect n = 1 no change in myocardial viability and in two patients (transmural defect n = 1, non-transmural defect n = 1 enhanced myocardial viability by 75%. Overall, global and regional LV ejection fraction was not significantly increased after surgery compared with the preoperative value. Conclusion In CABG surgery patients with non-viable segments the concurrent use of intramyocardial cell transfer did not show any clear improvement in tissue viability or function by

  12. Simultaneous Tc-99m/I-123 dual-radionuclide myocardial perfusion/innervation imaging using Siemens IQ-SPECT with SMARTZOOM collimator

    Science.gov (United States)

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric C.

    2014-06-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about the mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region, compared to a typical parallel-hole low-energy high-resolution collimator, but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator-detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulations and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single-radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter

  13. Simultaneous Tc-99m/I-123 Dual Radionuclide Myocardial Perfusion/Innervation Imaging Using Siemens IQ-SPECT with SMARTZOOM Collimator

    Science.gov (United States)

    Du, Yong; Bhattacharya, Manojeet; Frey, Eric. C.

    2014-01-01

    Simultaneous dual-radionuclide myocardial perfusion/innervation SPECT imaging can provide important information about mismatch between scar tissue and denervated regions. The Siemens IQ-SPECT system developed for cardiac imaging uses a multifocal SMARTZOOM collimator to achieve a four-fold sensitivity for the cardiac region compared to a typical parallel-hole low-energy high-resolution collimator but without the data truncation that can result with conventional converging-beam collimators. The increased sensitivity allows shorter image acquisition times or reduced patient dose, making IQ-SPECT ideal for simultaneous dual-radionuclide SPECT, where reduced administrated activity is desirable in order to reduce patient radiation exposure. However, crosstalk is a major factor affecting the image quality in dual-radionuclide imaging. In this work we developed a model-based method that can estimate and compensate for the crosstalk in IQ-SPECT data. The crosstalk model takes into account interactions in the object and collimator-detector system. Scatter in the object was modeled using the effective source scatter estimation technique (ESSE), previously developed to model scatter with parallel-hole collimators. The geometric collimator detector response was analytically modeled in the IQ-SPECT projector. The estimated crosstalk was then compensated for in an iterative reconstruction process. The new method was validated with data from both Monte Carlo simulation and physical phantom experiments. The results showed that the estimated crosstalk was in good agreement with simulated and measured results. After model-based compensation the images from simultaneous dual-radionuclide acquisitions were similar in quality to those from single radionuclide acquisitions that did not have crosstalk contamination. The proposed model-based method can be used to improve simultaneous dual-radionuclide images acquired using IQ-SPECT. This work also demonstrates that ESSE scatter modeling

  14. 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.)

  15. Electrical stimulation systems for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, Nina; Cannizzaro, Christopher; Chao, Pen-Hsiu Grace; Maidhof, Robert; Marsano, Anna; Au, Hoi Ting Heidi; Radisic, Milica; Vunjak-Novakovic, Gordana

    2009-01-01

    We describe a protocol for tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cells with the application of pulsatile electrical fields designed to mimic those present in the native heart. Tissue culture is conducted in a customized chamber built to allow for cultivation of (i) engineered three-dimensional (3D) cardiac tissue constructs, (ii) cell monolayers on flat substrates or (iii) cells on patterned substrates. This also allows for analysis of the individual and interactive effects of pulsatile electrical field stimulation and substrate topography on cell differentiation and assembly. The protocol is designed to allow for delivery of predictable electrical field stimuli to cells, monitoring environmental parameters, and assessment of cell and tissue responses. The duration of the protocol is 5 d for two-dimensional cultures and 10 d for 3D cultures.

  16. Cardiac conductive system excitation maps using intracardiac tissue Doppler imaging

    Institute of Scientific and Technical Information of China (English)

    尹立雪; 郑昌琼; 蔡力; 郑翊; 李春梅; 邓燕; 罗芸; 李德玉; 赵树魁

    2003-01-01

    Objective To precisely visualize cardiac anatomic structures and simultaneously depict ele ctro-mechanical events for the purpose of precise underblood intervention. Methods Intracardiac high-resolution tissue Doppler imaging was used to map realt imemyocardial contractions in response to electrical activation within the anat omic structure of the cardiac conductive system using a canine open-chest model . Results The detailed inner anatomic structure of the cardiac conductive system at differ entsites (i.e., sino-atrial, atrial wall, atrial-ventricular node and ventr icular wall) with the inside onset and propagation of myocardial velocity and ac celeration induced by electrical activation was clearly visualized and quan titatively evaluated.Conclusion The simultaneous single modality visualization of the anatomy, function and electrical events of the cardiac conductive system will foster target pacing and pre cision ablation.

  17. e-Health prototype system for cardiac telemonitoring.

    Science.gov (United States)

    Vargas Escobar, Laura Juliana; Salinas, Sergio Alexander

    2016-08-01

    This paper presents the approach of an e-health system for cardiac telemonitoring which uses the development board LinkIt ONE as a monitoring system. Such board was adapted to measure the cardiac pulse, analyze it and determine whether a person is having a cardiac arrhythmia or not. When an arrhythmia appears, the prototype activates an alarm in order to report the patient's condition and its location to a caregiver or a close healthcare center. The data of the cardiac pulse is originated in an e-health sensor platform connected to an Arduino. Location data comes from a GPS module in the aforementioned board which is connected by WiFi with the virtual platform UBIDOTS. It provides visual information about the variables measured, the patient's location and the alarms; keeping the patient's caregiver or the healthcare center constantly informed.

  18. 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

  19. Genetic and physiologic dissection of the vertebrate cardiac conduction system.

    Directory of Open Access Journals (Sweden)

    Neil C Chi

    2008-05-01

    Full Text Available Vertebrate hearts depend on highly specialized cardiomyocytes that form the cardiac conduction system (CCS to coordinate chamber contraction and drive blood efficiently and unidirectionally throughout the organism. Defects in this specialized wiring system can lead to syncope and sudden cardiac death. Thus, a greater understanding of cardiac conduction development may help to prevent these devastating clinical outcomes. Utilizing a cardiac-specific fluorescent calcium indicator zebrafish transgenic line, Tg(cmlc2:gCaMP(s878, that allows for in vivo optical mapping analysis in intact animals, we identified and analyzed four distinct stages of cardiac conduction development that correspond to cellular and anatomical changes of the developing heart. Additionally, we observed that epigenetic factors, such as hemodynamic flow and contraction, regulate the fast conduction network of this specialized electrical system. To identify novel regulators of the CCS, we designed and performed a new, physiology-based, forward genetic screen and identified for the first time, to our knowledge, 17 conduction-specific mutations. Positional cloning of hobgoblin(s634 revealed that tcf2, a homeobox transcription factor gene involved in mature onset diabetes of the young and familial glomerulocystic kidney disease, also regulates conduction between the atrium and the ventricle. The combination of the Tg(cmlc2:gCaMP(s878 line/in vivo optical mapping technique and characterization of cardiac conduction mutants provides a novel multidisciplinary approach to further understand the molecular determinants of the vertebrate CCS.

  20. 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.

  1. Conceptual Foundations of Systems Biology Explaining Complex Cardiac Diseases

    Directory of Open Access Journals (Sweden)

    George E. Louridas

    2017-02-01

    Full Text Available Systems biology is an important concept that connects molecular biology and genomics with computing science, mathematics and engineering. An endeavor is made in this paper to associate basic conceptual ideas of systems biology with clinical medicine. Complex cardiac diseases are clinical phenotypes generated by integration of genetic, molecular and environmental factors. Basic concepts of systems biology like network construction, modular thinking, biological constraints (downward biological direction and emergence (upward biological direction could be applied to clinical medicine. Especially, in the field of cardiology, these concepts can be used to explain complex clinical cardiac phenotypes like chronic heart failure and coronary artery disease. Cardiac diseases are biological complex entities which like other biological phenomena can be explained by a systems biology approach. The above powerful biological tools of systems biology can explain robustness growth and stability during disease process from modulation to phenotype. The purpose of the present review paper is to implement systems biology strategy and incorporate some conceptual issues raised by this approach into the clinical field of complex cardiac diseases. Cardiac disease process and progression can be addressed by the holistic realistic approach of systems biology in order to define in better terms earlier diagnosis and more effective therapy.

  2. Conceptual Foundations of Systems Biology Explaining Complex Cardiac Diseases.

    Science.gov (United States)

    Louridas, George E; Lourida, Katerina G

    2017-02-21

    Systems biology is an important concept that connects molecular biology and genomics with computing science, mathematics and engineering. An endeavor is made in this paper to associate basic conceptual ideas of systems biology with clinical medicine. Complex cardiac diseases are clinical phenotypes generated by integration of genetic, molecular and environmental factors. Basic concepts of systems biology like network construction, modular thinking, biological constraints (downward biological direction) and emergence (upward biological direction) could be applied to clinical medicine. Especially, in the field of cardiology, these concepts can be used to explain complex clinical cardiac phenotypes like chronic heart failure and coronary artery disease. Cardiac diseases are biological complex entities which like other biological phenomena can be explained by a systems biology approach. The above powerful biological tools of systems biology can explain robustness growth and stability during disease process from modulation to phenotype. The purpose of the present review paper is to implement systems biology strategy and incorporate some conceptual issues raised by this approach into the clinical field of complex cardiac diseases. Cardiac disease process and progression can be addressed by the holistic realistic approach of systems biology in order to define in better terms earlier diagnosis and more effective therapy.

  3. Evaluation of cardiac blood blow, metabolism and sympathetic nerve function in patients with cardiac failure using PET and SPECT. Prognostic diagnosis based on the analysis of aggravating factors of the disease

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Shimozu, Junko; Yasumura, Yoshio; Nagatani, Kenzo; Miyatake, Kunio [National Cardiovascular Center, Suita, Osaka (Japan)

    1998-02-01

    Focusing on the failure of energy metabolism, which is assumed to be attributed to the cardiac muscle disorder of a patient with cardiac failure, the characteristics and diagnostic significance of the metabolic disorders of cadiac muscles were investigated in those patients. The diagnostic efficacy of {beta}-methyl iodophenyl pentadecanoic acid (BMIPP) which is a imaging agent for lipid metabolism in the cardiac muscle was assessed in the clinical states of cardiac failure due to pulmonary hypertension. Even if there was a considerable increase in the mean pulmonary arterial pressure (mPAP), the initial accumulation of BMIPP linearly increased, similarly to the increase in the accumulation of MIBI, a blood flow agent. The initial accumulation of BMIPP was thought to reflect a thicken cardiac muscle and/or increased blood flow. Also, its washing-out rate was suggested to be usable as an clinical indicator to estimate the loading of ventricular pressure. (M.N.)

  4. A recirculating cooling system for improved topical cardiac hypothermia.

    Science.gov (United States)

    Rosenfeldt, F L; Fambiatos, A; Pastoriza-Pinol, J; Stirling, G R

    1981-10-01

    A simple system is described that recirculates cooling fluid for topical cardiac hypothermia. This disposable system can produce a flow of 1,500 ml/min at 2 degrees to 4 degrees C. The recirculating cooler produced significantly lower myocardial temperatures than a conventional fluid-discard system in 22 patients having coronary operation. This system has been used as part of the technique of hypothermic cardioplegia in more than 600 patients. During various cardiac procedures, septal temperatures were maintained well below 20 degrees C for 60 minutes or more without the need to reinfuse the cardioplegic solution.

  5. A phantom study for the evaluation of the effect of the high uptake in the liver on technetium-99m myocardial perfusion SPECT images

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Hideo; Masuda, Kazutaka; Takada, Masahiko; Yamamoto, Itsuo; Morita, Rikushi [Shiga Univ., Otsu (Japan). Hospital

    1998-07-01

    The purpose of this study was to evaluate influences of the high hepatic uptake on parameters such as filtering, attenuation coefficient, and scatter correction at reconstructing of the myocardial SPECT images. Hepatic and cardiac spaces of a myocardial phantom (RH-2, Kyoto Kagaku), were filled with technetium-99m and a three-detector SPECT system (GCA 9300-DI, TOSHIBA) was used. The hepatic activity`s influence was estimated from a qualitative percent regional scattering and the effects of attenuation and scatter correction were evaluated by a circumferential profile curve. Percent regional scattering increased in reverse to hepato-cardiac distance (HCD) and in proportion to hepatic to cardiac activity ratio (HCR). This tendency was observed the most significantly in the inferior region, followed by in the lateral, anterior and septal regions, declining in this order. An artifactual defect adjacent to the liver was observed when HCR is three and HCD is zero. However, when the Butterworth filter was used with small filtering-sizes and lower orders in combination with attenuation and scatter correction, the defects were decreased up to 15% at counts in the inferior region. This study showed that the hepatic to cardiac activity ratio, and the hepato-cardiac distance should be considered for reconstruction of the SPECT images. (author)

  6. Hybrid pixel-waveform CdTe/CZT detector for use in an ultrahigh resolution MRI compatible SPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Liang, E-mail: cai7@illinois.edu [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana Champaign, 216 Talbot Laboratory, 104 S Wrig, Urbana, Urbana, Illinois 61801 (United States); Meng, Ling-Jian [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana Champaign, 216 Talbot Laboratory, 104 S Wrig, Urbana, Urbana, Illinois 61801 (United States)

    2013-02-21

    In this paper, we will present a new small pixel CdTe/CZT detector for sub-500 μm resolution SPECT imaging application inside MR scanner based on a recently developed hybrid pixel-waveform (HPWF) readout circuitry. The HPWF readout system consists of a 2-D multi-pixel circuitry attached to the anode pixels to provide the X–Y positions of interactions, and a high-speed digitizer to read out the pulse-waveform induced on the cathode. The digitized cathode waveform could provide energy deposition information, precise timing and depth-of-interaction information for gamma ray interactions. Several attractive features with this HPWF detector system will be discussed in this paper. To demonstrate the performance, we constructed several prototype HPWF detectors with pixelated CZT and CdTe detectors of 2–5 mm thicknesses, connected to a prototype readout system consisting of energy-resolved photon-counting ASIC for readout anode pixels and an Agilent high-speed digitizer for digitizing the cathode signals. The performances of these detectors based on HPWF are discussed in this paper.

  7. Hybrid pixel-waveform CdTe/CZT detector for use in an ultrahigh resolution MRI compatible SPECT system

    Science.gov (United States)

    Cai, Liang; Meng, Ling-Jian

    2013-02-01

    In this paper, we will present a new small pixel CdTe/CZT detector for sub-500 μm resolution SPECT imaging application inside MR scanner based on a recently developed hybrid pixel-waveform (HPWF) readout circuitry. The HPWF readout system consists of a 2-D multi-pixel circuitry attached to the anode pixels to provide the X-Y positions of interactions, and a high-speed digitizer to read out the pulse-waveform induced on the cathode. The digitized cathode waveform could provide energy deposition information, precise timing and depth-of-interaction information for gamma ray interactions. Several attractive features with this HPWF detector system will be discussed in this paper. To demonstrate the performance, we constructed several prototype HPWF detectors with pixelated CZT and CdTe detectors of 2-5 mm thicknesses, connected to a prototype readout system consisting of energy-resolved photon-counting ASIC for readout anode pixels and an Agilent high-speed digitizer for digitizing the cathode signals. The performances of these detectors based on HPWF are discussed in this paper.

  8. [Evaluation of reconstruction arc in myocardial SPECT imaging using a cardiac phantom--comparison between 360 degrees and 180 degrees arcs].

    Science.gov (United States)

    Kashikura, K; Kashikura, A; Terada, S; Kobayashi, H

    1996-10-01

    In order to investigate the effect of reconstruction arc on myocardial SPECT images, a series of phantom studies was performed with and without plastic chambers simulating perfusion defects using 201Tl and 99mTc. Coefficient of variations (CV) of the counts among the ROIs and defect contrast were evaluated in 360 degrees and 180 degrees images reconstructed from the same 360 degrees projection data. Reconstruction processes were identical for all images. In the absence of defects, the CV of the counts were approximately the same in 360 degrees and 180 degrees images. The CV of the counts in the 360 degrees 201Tl image, among 4 defects located on the anterior, lateral, inferoposterior, and septal walls, was superior to those in the 180 degrees images. In contrast, in the 99mTc images, the CV of the counts among the 4 defects in the 180 degrees image was superior to those of the 360 degrees image. The defect contrast was changed both by the location of the defect and by the reconstruction arc (201Tl, 99mTc). The defect contrast of the 180 degrees images, in both 201Tl and 99mTc experiments, was closer to the true contrast value as calculated by the count ratio between myocardium and defect. Although the defect contrast in the anterior, lateral and septal walls was more emphasized in the 180 degrees images, the defect contrast in the inferoposterior wall was less emphasized in the 180 degrees images compared to the 360 degrees (201Tl, 99mTc).

  9. Single photon emission computed tomography of technetium-99m tetrofosmin myocardial perfusion imaging in patients with systemic lupus erythematosus-A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Jen-Jhy; Hsu, Hsiu-Bao; Sun, Shung-Shung; Kao, Chia-Hung [China Medical Coll., Taichung, Taiwan (China). Hospital; Wang, Jhi-Joung [Chi-Mei Medical Center, Tainan, Taiwan (China); Ho, Shung-Tai [National Defense Medical Center, Taipei, Taiwan (China). School of Medicine

    2003-01-01

    The purpose of this study was to evaluate the utility of single-photon emission computed tomography (SPECT) of technetium-99m tetrofosmin (Tc-99m TF) myocardial perfusion imaging to detect myocardial involvement in patients with systemic lupus erythematosus (SLE). Three groups of subjects-group 1: 25 SLE female patients with non-specific cardiac symptoms and signs, group 2: 25 female SLE patients without any cardiac symptoms and signs, and group 3: 25 female healthy controls-were evaluated by comparing rest and dipyridamole-stress Tc-99m TF myocardial perfusion SPECT. Tc-99m TF myocardial perfusion SPECT revealed perfusion defects in 88% and 40% of the cases in groups 1 and 2, respectively. However, no cases in group 3 demonstrated myocardial perfusion defects. Tc-99m TF myocardial perfusion SPECT is a useful noninvasive imaging modality to detect cardiac involvement in SLE patients with or without cardiac symptoms and signs. (author)

  10. Rapid radiotracer washout from the heart: effect on image quality in SPECT performed with a single-headed gamma camera system.

    Science.gov (United States)

    O'Connor, M K; Cho, D S

    1992-06-01

    Technetium-99m-teboroxime demonstrates high extraction and rapid washout from the myocardium. To evaluate the feasibility of performing SPECT with this agent using a single-headed gamma camera system, a series of phantom studies were performed that simulated varying degrees of washout from normal and "ischemic" regions of the myocardium. In the absence of ischemic regions, short axis profiles were relatively unaffected by washout of less than 50% of activity over the duration of a SPECT acquisition. However, significant corruption of the SPECT data was observed when large (greater than a factor of 2) differences existed in the washout of activity from normal and "ischemic" myocardium. This corruption was observed with 30%-40% washout of activity from normal regions of the heart. Based on published washout rates, these results indicate that clinical studies with 99mTc-teboroxime may need to be completed within 2-4 min to order to prevent degradation of image quality due to differential washout effects.

  11. Design Optimization of a Small-animal SPECT System Using LGSO Continuous Crystal and a Micro Parallel-hole Collimator

    CERN Document Server

    Kim, Joong Hyun; Kim, Soo Mee; Hong, Seong Jong; Lee, Jae Sung

    2015-01-01

    The aim of this study was to optimize the design of a monolithic LGSO scintillation crystal and micro parallel-hole collimator for the development of a small-animal single photon emission computed tomography (SPECT) system with compact size, low-cost and reasonable performance through Monte Carlo simulation. L0.9GSO crystals with surface area of 50 mm X 50 mm were investigated for the design optimization. The intrinsic detection efficiency, intrinsic spatial resolution, and intrinsic energy resolution of crystals were estimated for different crystal thicknesses and photon energies (using I-125 and Tc-99m sources). Two kinds of surface treatments (providing polished and rough surfaces) were compared by optical photon simulation. The standard deviation of the angle between a micro-facet and the mean surface was set to 0.1 and 6.0 for polished and rough surfaces, respectively. For comparison, the intrinsic performance of NaI(Tl) was also investigated. A multi-photomultiplier tube was designed with 16 X 16 anode ...

  12. Recovery of the cardiac frequency to the minute post effort as early indicator of myocardial ischemia; Recuperacion de la frecuencia cardiaca al minuto postesfuerzo como indicador temprano de isquemia miocardica

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez M, L. [Centro Medico Nacional 20 de Noviembre, Mexico D.F. (Mexico)

    2007-07-01

    The objective of the work was to evaluate the recovery cardiac frequency like ischemia indicator, due to the immediate reactivity of the parasympathetic nervous system in the post-effort. It is obtained as conclusion that a slow descent of the cardiac frequency to the first minute of the post-effort is a predictor ischemia index when correlating it with the risk evaluated by cardiac SPECT with a high specificity; being this a marker of simple calculating in the daily practice. (Author)

  13. Development of the cardiac conduction system and cardiac anatomy in relation to genesis and treatment of arrhythmias

    NARCIS (Netherlands)

    Jongbloed, Monica Reina Maria

    2006-01-01

    Clinical mapping studies demonstrate that cardiac arrhythmias are often encountered at specific anatomical sites. The anatomical development of the heart and the cardiac conduction system are narrowly related. The thesis starts with a Chapter 1 that provides a general overview of the basics of cardi

  14. Simulation, construction and application of focused pinhole small animal SPECT

    NARCIS (Netherlands)

    Vastenhouw, B.

    2008-01-01

    New developments in molecular imaging techniques like small animal SPECT systems are important tools to analyze mouse models of human diseases. The main subjects of this thesis are simulation, construction and image reconstruction algorithms needed for the development of a small-animal SPECT system

  15. Cardiac and systemic haemodynamic complications of liver cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Møller, Søren

    2009-01-01

    by physical and pharmacological strain. Cardiac failure is an important cause of mortality after liver transplantation and stressful procedures as insertions of transjugular intrahepatic portal systemic shunt (TIPS), peritoneal venous shunting, and other types of surgery. Improvement of liver function has...... been shown to reverse the cardiovascular complications. The clinical significance is an important topic for future research. At present, no specific treatment can be recommended, and the cardiac failure in cirrhosis should be treated as in non-cirrhotic patients with sodium restriction, diuretics......Cardiovascular complications of liver cirrhosis include cardiac dysfunction and abnormalities in the central-, splanchnic,- and peripheral circulation. Vasodilatation prevails, but vascular beds with various degrees of reduced and increased haemodynamic resistance are the results of massive...

  16. A Visualization System for Interactive Exploration of the Cardiac Anatomy.

    Science.gov (United States)

    Zhang, Lei; Wang, Kuanquan; Yang, Fei; Lu, Wenjing; Wang, Kechao; Zhang, Yue; Liang, Xiaoqing; Han, Dongchen; Zhu, Ying Julie

    2016-06-01

    Because of the complex and fine structure, visualization of the heart still remains a challenging task, which makes it an active research topic. In this paper, we present a visualization system for medical data, which takes advantage of the recent graphics processing unit (GPU) and can provide real-time cardiac visualization. This work focuses on investigating the anatomical structure visualization of the human heart, which is fundamental to the cardiac visualization, medical training and diagnosis assistance. Several state-of-the-art cardiac visualization methods are integrated into the proposed system and a task specified visualization method is proposed. In addition, auxiliary tools are provided to generate user specified visualization results. The contributions of our work lie in two-fold: for doctors and medical staff, the system can provide task specified visualization with interactive visualization tools; for researchers, the proposed platform can serve as a baseline for comparing different rendering methods and can easily incorporate new rendering methods. Experimental results show that the proposed system can provide favorable cardiac visualization results in terms of both effectiveness and efficiency.

  17. A system model for pinhole SPECT simulating edge penetration, detector, and pinhole response and non-uniform attenuation

    Science.gov (United States)

    Wietholt, Christian; Hsiao, Ing-Tsung; Chen, Chin-Tu

    2007-03-01

    Small animal SPECT using low energy photons of I-125 and approaching resolutions of microscopic levels, imaging parameters such as pinhole edge penetration, detector blur, geometric response, detector and pinhole misalignment, and gamma photon attenuation and scatter can have increasingly noticeable and/or adverse effects on reconstructed image quality. Iterative reconstruction algorithms, the widelyaccepted standard for emission tomography, allow modeling of such parameters through a system matrix. For this Monte Carlo simulation study, non-uniform attenuation correction was added to the existing system model. The model was constructed using ray-tracing and further included corrections for edge penetration, detector blur, and geometric aperture response. For each ray passing through different aperture locations, this method attenuates a voxel's contribution to a detector element along the photon path, which is then weighted according to a pinhole penetration model. To lower the computational and memory expenses, symmetry along the detector axes and an incremental storage scheme for the system model were used. For evaluating the nonuniform attenuation correction method, 3 phantoms were designed of which projection images were simulated using Monte Carlo methods. The first phantom was used to examined skin artifacts, the second to simulate attenuation by bone, and the third to generate artifacts of an air-filled space surrounded by soft tissue. In reconstructions without attenuation correction, artifacts were observed with up to a 40% difference in activity. These could be corrected using the implemented method, although in one case overcorrection occurred. Overall, attenuation correction improved reconstruction accuracy of the radioisotope distribution in the presence of structural differences.

  18. PET and SPET tracers for mapping the cardiac nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Halldin, Christer [Department of Clinical Neuroscience, Psychiatry Section, Karolinska Institute, Karolinska Hospital, 17176 Stockholm (Sweden)

    2002-03-01

    The human cardiac nervous system consists of a sympathetic and a parasympathetic branch with (-)-norepinephrine and acetylcholine as the respective endogenous neurotransmitters. Dysfunction of the cardiac nervous system is implicated in various types of cardiac disease, such as heart failure, myocardial infarction and diabetic autonomic neuropathy. In vivo assessment of the distribution and function of cardiac sympathetic and parasympathetic neurones with positron emission tomography (PET) and single-photon emission tomography (SPET) can be achieved by means of a number of carbon-11-, fluorine-18-, bromine-76- and iodine-123-labelled tracer molecules. Available tracers for mapping sympathetic neurones can be divided into radiolabelled catecholamines, such as 6-[{sup 18}F]fluorodopamine, (-)-6-[{sup 18}F]fluoronorepinephrine and (-)-[{sup 11}C]epinephrine, and radiolabelled catecholamine analogues, such as [{sup 123}I]meta-iodobenzylguanidine, [{sup 11}C]meta-hydroxyephedrine, [{sup 18}F]fluorometaraminol, [{sup 11}C]phenylephrine and meta-[{sup 76}Br]bromobenzylguanidine. Resistance to metabolism by monoamine oxidase and catechol-O-methyl transferase simplifies the myocardial kinetics of the second group. Both groups of compounds are excellent agents for an overall assessment of sympathetic innervation. Biomathematical modelling of tracer kinetics is complicated by the complexity of the steps governing neuronal uptake, retention and release of these agents as well as by their high neuronal affinity, which leads to partial flow dependence of uptake. Mapping of cardiac parasympathetic neurones is limited by a low density and focal distribution pattern of these neurones in myocardium. Available tracers are derivatives of vesamicol, a molecule that binds to a receptor associated with the vesicular acetylcholine transporter. Compounds like (-)-[{sup 18}F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility

  19. [A phantom study for the evaluation of the effect of the high uptake in the liver on technetium-99m myocardial perfusion SPECT images].

    Science.gov (United States)

    Ohnishi, H; Masuda, K; Takada, M; Yamamoto, I; Morita, R

    1998-07-01

    The purpose of this study was to evaluate influences of the high hepatic uptake on parameters such as filtering, attenuation coefficient, and scatter correction at reconstructing of the myocardial SPECT images. Hepatic and cardiac spaces of a myocardial phantom (RH-2, Kyoto Kagaku), were filled with technetium-99m and a three-detector SPECT system (GCA 9300-DI, TOSHIBA) was used. The hepatic activity's influence was estimated from a qualitative percent regional scattering and the effects of attenuation and scatter correction were evaluated by a circumferential profile curve. Percent regional scattering increased in reverse to hepato-cardiac distance (HCD) and in proportion to hepatic to cardiac activity ratio (HCR). This tendency was observed the most significantly in the inferior region, followed by in the lateral, anterior and septal regions, declining in this order. An artifactual defect adjacent to the liver was observed when HCR is three and HCD is zero. However, when the Butterworth filter was used with small filtering-sizes and lower orders in combination with attenuation and scatter correction, the defects were decreased up to 15% at counts in the inferior region. This study showed that the hepatic to cardiac activity ratio, and the hepatocardiac distance should be considered for reconstruction of the SPECT images.

  20. Quantification of dopaminergic neurotransmission SPECT studies with {sup 123}I-labelled radioligands. A comparison between different imaging systems and data acquisition protocols using Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Crespo, Cristina; Aguiar, Pablo [Universitat de Barcelona - IDIBAPS, Unitat de Biofisica i Bioenginyeria, Departament de Ciencies Fisiologiques I, Facultat de Medicina, Barcelona (Spain); Gallego, Judith [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); Institut de Bioenginyeria de Catalunya, Barcelona (Spain); Cot, Albert [Universitat de Barcelona - IDIBAPS, Unitat de Biofisica i Bioenginyeria, Departament de Ciencies Fisiologiques I, Facultat de Medicina, Barcelona (Spain); Universitat Politecnica de Catalunya, Seccio d' Enginyeria Nuclear, Departament de Fisica i Enginyeria Nuclear, Barcelona (Spain); Falcon, Carles; Ros, Domenec [Universitat de Barcelona - IDIBAPS, Unitat de Biofisica i Bioenginyeria, Departament de Ciencies Fisiologiques I, Facultat de Medicina, Barcelona (Spain); CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); Bullich, Santiago [Hospital del Mar, Center for Imaging in Psychiatry, CRC-MAR, Barcelona (Spain); Pareto, Deborah [CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); PRBB, Institut d' Alta Tecnologia, Barcelona (Spain); Sempau, Josep [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); Lomena, Francisco [IDIBAPS, Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain); Calvino, Francisco [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); Universitat Politecnica de Catalunya, Seccio d' Enginyeria Nuclear, Departament de Fisica i Enginyeria Nuclear, Barcelona (Spain); Pavia, Javier [CIBER en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Barcelona (Spain); IDIBAPS, Servei de Medicina Nuclear, Hospital Clinic, Barcelona (Spain)

    2008-07-15

    {sup 123}I-labelled radioligands are commonly used for single-photon emission computed tomography (SPECT) imaging of the dopaminergic system to study the dopamine transporter binding. The aim of this work was to compare the quantitative capabilities of two different SPECT systems through Monte Carlo (MC) simulation. The SimSET MC code was employed to generate simulated projections of a numerical phantom for two gamma cameras equipped with a parallel and a fan-beam collimator, respectively. A fully 3D iterative reconstruction algorithm was used to compensate for attenuation, the spatially variant point spread function (PSF) and scatter. A post-reconstruction partial volume effect (PVE) compensation was also developed. For both systems, the correction for all degradations and PVE compensation resulted in recovery factors of the theoretical specific uptake ratio (SUR) close to 100%. For a SUR value of 4, the recovered SUR for the parallel imaging system was 33% for a reconstruction without corrections (OSEM), 45% for a reconstruction with attenuation correction (OSEM-A), 56% for a 3D reconstruction with attenuation and PSF corrections (OSEM-AP), 68% for OSEM-AP with scatter correction (OSEM-APS) and 97% for OSEM-APS plus PVE compensation (OSEM-APSV). For the fan-beam imaging system, the recovered SUR was 41% without corrections, 55% for OSEM-A, 65% for OSEM-AP, 75% for OSEM-APS and 102% for OSEM-APSV. Our findings indicate that the correction for degradations increases the quantification accuracy, with PVE compensation playing a major role in the SUR quantification. The proposed methodology allows us to reach similar SUR values for different SPECT systems, thereby allowing a reliable standardisation in multicentric studies. (orig.)

  1. SPECT/NIRF Dual Modality Imaging for Detection of Intraperitoneal Colon Tumor with an Avidin/Biotin Pretargeting System.

    Science.gov (United States)

    Dong, Chengyan; Yang, Sujuan; Shi, Jiyun; Zhao, Huiyun; Zhong, Lijun; Liu, Zhaofei; Jia, Bing; Wang, Fan

    2016-01-06

    We describe herein dual-modality imaging of intraperitoneal colon tumor using an avidin/biotin pretargeting system. A novel dual-modality probe, (99m)Tc-HYNIC-lys(Cy5.5)-PEG4-biotin, was designed, synthesized and characterized. Single-photon emission computed tomography/ computed tomography (SPECT/CT) imaging and near infrared fluorescence (NIRF) imaging were developed using intraperitoneal LS180 human colon adenocarcinoma xenografts. Following avidin preinjection for 4 hours, (99m)Tc-HYNIC-lys(Cy5.5)-PEG4-biotin could successfully detect colon tumors of different sizes inside the abdominal region using both modalities, and the imaging results showed no differences. Biodistribution studies demonstrated that the tumors had a very high uptake of the probe (99m)Tc-HYNIC-lys(Cy5.5)-PEG4-biotin (12.74 ± 1.89% ID/g at 2 h p.i.), and the clearance from blood and other normal tissues occured very fast. The low tumor uptake in the non-pretargeted mice (1.63 ± 0.50% ID/g at 2 h p.i.) and tumor cell staining results showed excellent tumor binding specificity of the pretargeting system. The ability of the novel probe to show excellent imaging quality with high tumor-to-background contrast, a high degree of binding specificity with tumors and excellent in vivo biodistribution pharmacokinetics should prove that the avidin/biotin based dual-modality pretargeting probe is a promising imaging tool during the entire period of tumor diagnosis and treatment.

  2. Calibration of gamma camera systems for a multicentre European ¹²³I-FP-CIT SPECT normal database

    DEFF Research Database (Denmark)

    Tossici-Bolt, Livia; Dickson, John C; Sera, Terez

    2011-01-01

    A joint initiative of the European Association of Nuclear Medicine (EANM) Neuroimaging Committee and EANM Research Ltd. aimed to generate a European database of [(123)I]FP-CIT single photon emission computed tomography (SPECT) scans of healthy controls. This study describes the characterization...

  3. SPECT-CT Hybrid cardiac imaging synchronized to Ecg for the mouse after myocardium infarction; Imagerie cardiaque hybride TEMP-TDM synchronisee a l'ECG chez la souris apres infarctus du myocarde

    Energy Technology Data Exchange (ETDEWEB)

    Choquet, P.; Goetz, C.; Aubertin, G.; Hubele, F. [HUS Strasbourg, Service de biophysique et medecine nucleaire, 67 (France); El-Fertak, L.; Monassier, L. [Laboratoire de pharmacologie cardiovasculaire, 67 - Strasbourg (France)

    2010-07-01

    The preclinical SPECT-CT imaging synchronized to electrocardiogram among mice allows to acquire isotropic morphological and functional data, data of high spatial and temporal resolutions with relatively short acquisition times. (N.C.)

  4. U-SPECT-II: An Ultra-High-Resolution Device for Molecular Small-Animal Imaging

    NARCIS (Netherlands)

    Van der Have, F.; Vastenhouw, B.; Ramakers, R.M.; Branderhorst, W.; Krah, J.O.; Ji, C.; Staelens, S.G.; Beekman, F.J.

    2009-01-01

    We present a new rodent SPECT system (U-SPECT-II) that enables molecular imaging of murine organs down to resolutions of less than half a millimeter and high-resolution total-body imaging. Methods: The U-SPECT-II is based on a triangular stationary detector set-up, an XYZ stage that moves the animal

  5. Role of the autonomic nervous system in modulating cardiac arrhythmias.

    Science.gov (United States)

    Shen, Mark J; Zipes, Douglas P

    2014-03-14

    The autonomic nervous system plays an important role in the modulation of cardiac electrophysiology and arrhythmogenesis. Decades of research has contributed to a better understanding of the anatomy and physiology of cardiac autonomic nervous system and provided evidence supporting the relationship of autonomic tone to clinically significant arrhythmias. The mechanisms by which autonomic activation is arrhythmogenic or antiarrhythmic are complex and different for specific arrhythmias. In atrial fibrillation, simultaneous sympathetic and parasympathetic activations are the most common trigger. In contrast, in ventricular fibrillation in the setting of cardiac ischemia, sympathetic activation is proarrhythmic, whereas parasympathetic activation is antiarrhythmic. In inherited arrhythmia syndromes, sympathetic stimulation precipitates ventricular tachyarrhythmias and sudden cardiac death except in Brugada and J-wave syndromes where it can prevent them. The identification of specific autonomic triggers in different arrhythmias has brought the idea of modulating autonomic activities for both preventing and treating these arrhythmias. This has been achieved by either neural ablation or stimulation. Neural modulation as a treatment for arrhythmias has been well established in certain diseases, such as long QT syndrome. However, in most other arrhythmia diseases, it is still an emerging modality and under investigation. Recent preliminary trials have yielded encouraging results. Further larger-scale clinical studies are necessary before widespread application can be recommended.

  6. Evaluation of myocardial viability with cardiac PET before and after CABG and the study of hibernating myocardium

    Energy Technology Data Exchange (ETDEWEB)

    Adachi, Masahiro; Sakamoto, Shigeru [Kanazawa Medical Univ., Uchinada, Ishikawa (Japan); Seki, Hiroyasu

    1997-09-01

    This study included 28 patients in whom graft patency after coronary artery bypass graft (CABG) was confirmed by coronary angiography. Diagnosis included angina pectoris following myocardial infarction and severe angina pectoris accompanied by stenosis at the left main trunk region or lesion involving multiple branches. As a rule, cardiac PET ({sup 13}NH{sub 3}, {sup 18}FDG) was performed in fasted patients before and 1 to 2 months after surgery. Myocardial blood flow and glucose metabolism in the bypass site were mainly investigated. Furthermore, {sup 201}Tl-SPECT was concurrently performed. The effect of CABG was examined by the two procedures, and redistribution was compared between PET and {sup 201}Tl-SPECT. Preoperative PET with {sup 13}NH{sub 3} revealed reduced blood flow in the ischemic site in all patients. However, preoperative {sup 201}Tl-SPECT showed redistribution in 16 (57.1%) of 28 patients, while there was no redistribution in 12 patients (42.9%). In 10 (83.3%) of 12 patients evaluated as having no myocardial viability on {sup 201}Tl-SPECT, PET showed accumulation of {sup 18}FDG. However, in 21 (75%) of 28 patients, accumulation of {sup 18}FDG was reduced postoperatively, suggesting improvement of aerobic metabolism in cardiac muscle. These patients also showed improvement in regional wall motion. The energy source of cardiac muscle consists mainly of free fatty acid and glucose. Fasting healthy cardiac muscle depends on fatty acid for approximately 60% of its energy source. However, ischemic cardiac muscle depends on the glycolytic system, utilizing glucose. Progression of ischemia causes myocardial necrosis without metabolism. Therefore, ischemic cardiac muscle can be differentiated from infarcted cardiac muscle by cardiac PET. We evaluated myocardial viability before and after CABG for ischemic heart disease, and confirmed that cardiac PET is more useful than standard myocardial scan with {sup 201}Tl for evaluating myocardial viability. (K.H.)

  7. Ultra-high-resolution small-animal SPECT imaging

    NARCIS (Netherlands)

    Have, F. van der

    2007-01-01

    The main subject of this thesis is the development of the first two in a series of dedicated ultra-high resolution Single Photon Emission Computed Tomography (SPECT) systems (U-SPECT-I and II) for the imaging of distributions of radio-isotope labeled tracers in small laboratory animals such as mice

  8. First determination of the heart-to-mediastinum ratio using cardiac dual isotope ({sup 123}I-MIBG/{sup 99m}Tc-tetrofosmin) CZT imaging in patients with heart failure: the ADRECARD study

    Energy Technology Data Exchange (ETDEWEB)

    Bellevre, Dimitri; Desmonts, Cedric [CHU Cote de Nacre, Department of Nuclear Medicine, Caen (France); Manrique, Alain; Agostini, Denis [CHU Cote de Nacre, Department of Nuclear Medicine, Caen (France); EA 4650, Normandie Universite, Caen (France); Legallois, Damien [EA 4650, Normandie Universite, Caen (France); CHU Cote de Nacre, Cardiology Department, Caen (France); Bross, Samy; Baavour, Rafael; Roth, Nathaniel [Spectrum Dynamics, Biosensors, Caesarea (Israel); Blaire, Tanguy; Bailliez, Alban [EA 4650, Normandie Universite, Caen (France); IRIS, Polyclinique du Bois, Nuclear Medicine Department, Lille (France)

    2015-11-15

    Cardiac innervation is assessed using the heart-to-mediastinum ratio (HMR) of metaiodobenzylguanidine (MIBG) on planar imaging using Anger single photon emission computed tomography (A-SPECT). The aim of the study was to determine the HMR of MIBG obtained using a CZT-based camera (D-SPECT; Spectrum Dynamics, Israel) in comparison with that obtained using conventional planar imaging. The ADRECARD study prospectively evaluated 44 patients with heart failure. They underwent planar acquisition using the A-SPECT camera 4 h after {sup 123}I-MIBG injection (236.4 ± 39.7 MBq). To localize the heart using D-SPECT, {sup 99m}Tc-tetrofosmin (753 ± 133 MBq) was administered and dual isotope acquisition was performed using the D-SPECT system. HMR was calculated using both planar A-SPECT imaging and front view D-SPECT cine data. In a phantom study, we estimated a model fitting the A-SPECT and the D-SPECT data that was further applied to correct for differences between the cameras. A total of 44 patients (39 men and 5 women, aged 60 ± 11 years) with ischaemic (31 patients) and nonischaemic (13 patients) cardiomyopathy completed the study. Most patients (28 of 44) were NYHA class II, and the mean left ventricular ejection fraction was 33 ± 7 %. The mean HMR values were 1.34 ± 0.15 and 1.45 ± 0.27 from A-SPECT and D-SPECT, respectively (p < 0.0001). After correction, Lin's concordance correlation showed an almost perfect concordance between corrected D-SPECT HMR and A-SPECT HMR, and Bland-Altman analysis demonstrated a high agreement between the two measurements. The ADRECARD study demonstrated that determination of late HMR during cardiac MIBG imaging using dual isotope ({sup 123}I and {sup 99m}Tc) acquisition on a CZT camera (D-SPECT) is feasible in patients with heart failure. A linear correction based on the phantom study yielded a high agreement between {sup 123}I MIBG HMR obtained using a CZT camera and that from conventional planar imaging. (orig.)

  9. Tumors of the cardiac conduction system: are they an explanation for otherwise unexplained sudden cardiac death?

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Cardiac tumors are well described in the literature. The first reports of cardiac tumors date back hundreds of years.The prevalence of primary cardiac tumors at autopsy ranges from 0.001% to 0.3% with secondary tumors more common than in primary tumors.

  10. 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.)

  11. SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

    Science.gov (United States)

    We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

  12. An ultrahigh resolution SPECT system for I-125 mouse brain imaging studies

    Energy Technology Data Exchange (ETDEWEB)

    Meng, L.J. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana-Champaign (United States)], E-mail: ljmeng@umich.edu; Fu, G. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana-Champaign (United States); Roy, E.J.; Suppe, B. [Department of Pathology, University of Illinois, Urbana-Champaign (United States); Chen, C.T. [Department of Radiology, University of Chicago (United States)

    2009-03-01

    This paper presents some initial experimental results obtained with a dual-head prototype single photon emission microscope system (SPEM) that is dedicated to mouse brain studies using I-125 labeled radiotracers. In particular, this system will be used for in vivo tacking of radiolabeled T cells in mouse brain. This system is based on the use of the intensified electron multiplying charge-coupled device (I-EMCCD) camera that offers the combination of an excellent intrinsic spatial resolution, a good signal-to-noise ratio, a large active area and a reasonable detection efficiency over an energy range between 27-140 keV. In this study, the dual-head SPEM system was evaluated using both resolution phantoms and a mouse with locally injected T cells labeled with I-125. It was demonstrated that for a relatively concentrated source object, the current dual-head SPEM system is capable of visualizing the tiny amount of radioactivity ({approx}12 nCi) carried by a very small number (<1000) of T cells. The current SPEM system design allows four or six camera heads to be installed in a stationary system configuration that offers a doubled or tripled sensitivity at a spatial resolution similar to that obtained with the dual-head system. This development would provide a powerful tool for in vivo and non-invasive tracking of radiolabeled T cells in mouse brain and potentially for other rodent brain imaging studies.

  13. An ultrahigh resolution SPECT system for I-125 mouse brain imaging studies

    Science.gov (United States)

    Meng, L. J.; Fu, G.; Roy, E. J.; Suppe, B.; Chen, C. T.

    2009-03-01

    This paper presents some initial experimental results obtained with a dual-head prototype single photon emission microscope system (SPEM) that is dedicated to mouse brain studies using I-125 labeled radiotracers. In particular, this system will be used for in vivo tacking of radiolabeled T cells in mouse brain. This system is based on the use of the intensified electron multiplying charge-coupled device (I-EMCCD) camera that offers the combination of an excellent intrinsic spatial resolution, a good signal-to-noise ratio, a large active area and a reasonable detection efficiency over an energy range between 27-140 keV. In this study, the dual-head SPEM system was evaluated using both resolution phantoms and a mouse with locally injected T cells labeled with I-125. It was demonstrated that for a relatively concentrated source object, the current dual-head SPEM system is capable of visualizing the tiny amount of radioactivity (˜12 nCi) carried by a very small number (<1000) of T cells. The current SPEM system design allows four or six camera heads to be installed in a stationary system configuration that offers a doubled or tripled sensitivity at a spatial resolution similar to that obtained with the dual-head system. This development would provide a powerful tool for in vivo and non-invasive tracking of radiolabeled T cells in mouse brain and potentially for other rodent brain imaging studies.

  14. 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

  15. Cardiac effects of 3-iodothyronamine: a new aminergic system modulating cardiac function.

    Science.gov (United States)

    Chiellini, Grazia; Frascarelli, Sabina; Ghelardoni, Sandra; Carnicelli, Vittoria; Tobias, Sandra C; DeBarber, Andrea; Brogioni, Simona; Ronca-Testoni, Simonetta; Cerbai, Elisabetta; Grandy, David K; Scanlan, Thomas S; Zucchi, Riccardo

    2007-05-01

    3-Iodothyronamine T1AM is a novel endogenous thyroid hormone derivative that activates the G protein-coupled receptor known as trace anime-associated receptor 1 (TAAR1). In the isolated working rat heart and in rat cardiomyocytes, T1AM produced a reversible, dose-dependent negative inotropic effect (e.g., 27+/-5, 51+/-3, and 65+/-2% decrease in cardiac output at 19, 25, and 38 microM concentration, respectively). An independent negative chronotropic effect was also observed. The hemodynamic effects of T1AM were remarkably increased in the presence of the tyrosine kinase inhibitor genistein, whereas they were attenuated in the presence of the tyrosine phosphatase inhibitor vanadate. No effect was produced by inhibitors of protein kinase A, protein kinase C, calcium-calmodulin kinase II, phosphatidylinositol-3-kinase, or MAP kinases. Tissue cAMP levels were unchanged. In rat ventricular tissue, Western blot experiments with antiphosphotyrosine antibodies showed reduced phosphorylation of microsomal and cytosolic proteins after perfusion with synthetic T1AM; reverse transcriptase-polymerase chain reaction experiments revealed the presence of transcripts for at least 5 TAAR subtypes; specific and saturable binding of [125I]T1AM was observed, with a dissociation constant in the low micromolar range (5 microM); and endogenous T1AM was detectable by tandem mass spectrometry. In conclusion, our findings provide evidence for the existence of a novel aminergic system modulating cardiac function.

  16. Nuclear imaging in cardiac amyloidosis

    Energy Technology Data Exchange (ETDEWEB)

    Glaudemans, A.W.J.M.; Slart, R.H.J.A.; Veltman, N.C.; Dierckx, R.A.J.O. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Hanzeplein 1, P.O. Box 30001, Groningen (Netherlands); Zeebregts, C.J. [University Medical Center Groningen, Department of Surgery (Division of Vascular Surgery), Groningen (Netherlands); Tio, R.A. [University Medical Center Groningen, Department of Cardiology, Groningen (Netherlands); Hazenberg, B.P.C. [University Medical Center Groningen, Department of Rheumatology and Clinical Immunology, Groningen (Netherlands)

    2009-04-15

    Amyloidosis is a disease characterized by depositions of amyloid in organs and tissues. It can be localized (in just one organ) or systemic. Cardiac amyloidosis is a debilitating disease and can lead to arrhythmias, deterioration of heart function and even sudden death. We reviewed PubMed/Medline, without time constraints, on the different nuclear imaging modalities that are used to visualize myocardial amyloid involvement. Several SPECT tracers have been used for this purpose. The results with these tracers in the evaluation of myocardial amyloidosis and their mechanisms of action are described. Most clinical evidence was found for the use of {sup 123}I-MIBG. Myocardial defects in MIBG activity seem to correlate well with impaired cardiac sympathetic nerve endings due to amyloid deposits. {sup 123}I-MIBG is an attractive option for objective evaluation of cardiac sympathetic level and may play an important role in the indirect measurement of the effect of amyloid myocardial infiltration. Other, less sensitive, options are {sup 99m}Tc-aprotinin for imaging amyloid deposits and perhaps {sup 99m}Tc-labelled phosphate derivatives, especially in the differential diagnosis of the aetiology of cardiac amyloidosis. PET tracers, despite the advantage of absolute quantification and higher resolution, are not yet well evaluated for the study of cardiac amyloidosis. Because of these advantages, there is still the need for further research in this field. (orig.)

  17. Cardiac tamponade as initial presentation in systemic lupus erythematosus.

    Science.gov (United States)

    Jawaid, Ambreen; Almas, Aysha

    2014-05-01

    Systemic Lupus Erythematosus (SLE) is one of the many diseases known as 'the great imitators' because it can have diverse presentations and so is misunderstood for other illnesses. This case illustrates a 19 years old girl with SLE who presented as cardiac tamponade which is a rare feature of lupus pericarditis requiring medical and surgical treatment. Even after pericardiocentesis and steroid therapy there was a re-accumulation of the pericardial fluid resulting in cardiac tamponade which led to pericardial window formation. This case draws attention to the need to consider the diagnosis of tamponade in patients with connective tissue disease and dyspnea or hemodynamic compromise. It also outlines the treatment options available so that surgical referral, if needed, can be done timely for this rare but life threatening manifestation of SLE.

  18. Integrative systems models of cardiac excitation-contraction coupling.

    Science.gov (United States)

    Greenstein, Joseph L; Winslow, Raimond L

    2011-01-07

    Excitation-contraction coupling in the cardiac myocyte is mediated by a number of highly integrated mechanisms of intracellular Ca²(+) transport. The complexity and integrative nature of heart cell electrophysiology and Ca²(+) cycling has led to an evolution of computational models that have played a crucial role in shaping our understanding of heart function. An important emerging theme in systems biology is that the detailed nature of local signaling events, such as those that occur in the cardiac dyad, have important consequences at higher biological scales. Multiscale modeling techniques have revealed many mechanistic links between microscale events, such as Ca²(+) binding to a channel protein, and macroscale phenomena, such as excitation-contraction coupling gain. Here, we review experimentally based multiscale computational models of excitation-contraction coupling and the insights that have been gained through their application.

  19. Global and regional left ventricular function: a comparison between gated SPECT, 2D echocardiography and multi-slice computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Henneman, Maureen M.; Bax, Jeroen J.; Holman, Eduard R. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Schuijf, Joanne D.; Jukema, J.W.; Wall, Ernst E. van der [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands); Stokkel, Marcel P.M. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Lamb, Hildo J.; Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands)

    2006-12-15

    Global and regional left ventricular (LV) function are important indicators of the cardiac status in patients with coronary artery disease (CAD). Therapy and prognosis are to a large extent dependent on LV function. Multi-slice computed tomography (MSCT) has already earned its place as an imaging modality for non-invasive assessment of the coronary arteries, but since retrospective gating to the patient's ECG is performed, information on LV function can be derived. In 49 patients with known or suspected CAD, coronary angiography with MSCT imaging was performed, in addition to gated SPECT and 2D echocardiography. LV end-diastolic and LV end-systolic volumes and LV ejection fraction were analysed with dedicated software (CMR Analytical Software System, Medis, Leiden, The Netherlands for MSCT; gated SPECT by QGS, Cedars-Sinai Medical Center, Los Angeles, CA, USA), and by the biplane Simpson's rule for 2D echocardiography. Regional wall motion was evaluated according to a 17-segment model and a three-point score system. Correlations were fairly good between gated SPECT and MSCT (LVEDV: r=0.65; LVESV: r=0.63; LVEF: r=0.60), and excellent between 2D echocardiography and MSCT (LVEDV: r=0.92; LVESV: r=0.93; LVEF: r=0.80). Agreement for regional wall motion was 95% ({kappa}=0.66) between gated SPECT and MSCT, and 96% ({kappa}=0.73) between 2D echocardiography and MSCT. Global and regional LV function and LV volumes can be adequately assessed with MSCT. Correlations with 2D echocardiography are stronger than with gated SPECT. (orig.)

  20. 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.

  1. 21 CFR 862.1163 - Cardiac allograft gene expression profiling test system.

    Science.gov (United States)

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1163 Cardiac allograft gene expression profiling test system....

  2. SPECT using asymmetric pinholes with truncated projections

    Energy Technology Data Exchange (ETDEWEB)

    Lin Jianyu; Meikle, Steven R, E-mail: jianyu.lin@curtin.edu.au [Ramaciotti Imaging Centre, Brain and Mind Research Institute, University of Sydney (Australia)

    2011-07-07

    Tomographic systems employing truncated projections have been developed for parallel and fan beam collimation and for cone beam CT but the idea has not been extensively explored in pinhole single photon emission computed tomography (SPECT). In this paper, we explore the sampling requirements and system performance of SPECT systems with asymmetric pinhole collimators and truncated projections. We demonstrate that complete 3D sampling can be achieved by using multiple detectors with truncated asymmetric pinholes, offset axially from each other, and a spiral orbit. The use of truncated projections can be exploited in the design of pinhole SPECT systems by moving the pinholes closer to the subject, resulting in increased sensitivity and improved spatial resolution. Truncated and untruncated pinhole systems were evaluated using the contrast-to-noise ratio (CNR) calculated from the linearized local impulse response as a figure of merit. The CNR for the truncated pinhole system was up to 60% greater than that for the untruncated system at matched resolution for a source voxel near the centre of a uniform phantom and 30% greater at the edge. We conclude that an object can be reconstructed from asymmetric pinholes with truncated projections, which leads to potentially important design considerations and applications in single- and multi-pinhole SPECT.

  3. [The Optimal Reconstruction Parameters by Scatter and Attenuation Corrections Using Multi-focus Collimator System in Thallium-201 Myocardial Perfusion SPECT Study].

    Science.gov (United States)

    Shibutani, Takayuki; Onoguchi, Masahisa; Funayama, Risa; Nakajima, Kenichi; Matsuo, Shinro; Yoneyama, Hiroto; Konishi, Takahiro; Kinuya, Seigo

    2015-11-01

    The aim of this study was to reveal the optimal reconstruction parameters of ordered subset conjugates gradient minimizer (OSCGM) by no correction (NC), attenuation correction (AC), and AC+scatter correction (ACSC) using IQ-single photon emission computed tomography (SPECT) system in thallium-201 myocardial perfusion SPECT. Myocardial phantom acquired two patterns, with or without defect. Myocardial images were performed 5-point scale visual score and quantitative evaluations using contrast, uptake, and uniformity about the subset and update (subset×iteration) of OSCGM and the full width at half maximum (FWHM) of Gaussian filter by three corrections. We decided on optimal reconstruction parameters of OSCGM by three corrections. The number of subsets to create suitable images were 3 or 5 for NC and AC, 2 or 3 for ACSC. The updates to create suitable images were 30 or 40 for NC, 40 or 60 for AC, and 30 for ACSC. Furthermore, the FWHM of Gaussian filters were 9.6 mm or 12 mm for NC and ACSC, 7.2 mm or 9.6 mm for AC. In conclusion, the following optimal reconstruction parameters of OSCGM were decided; NC: subset 5, iteration 8 and FWHM 9.6 mm, AC: subset 5, iteration 8 and FWHM 7.2 mm, ACSC: subset 3, iteration 10 and FWHM 9.6 mm.

  4. Cardiac troponin testing in idiopathic inflammatory myopathies and systemic sclerosis-spectrum disorders: biomarkers to distinguish between primary cardiac involvement and low-grade skeletal muscle disease activity.

    Science.gov (United States)

    Hughes, Michael; Lilleker, James B; Herrick, Ariane L; Chinoy, Hector

    2015-05-01

    Primary cardiac involvement, an under-recognised manifestation of the idiopathic inflammatory myopathies (IIM) and systemic sclerosis (SSc)-spectrum disorders, is associated with significant mortality. Within these two conditions, traditional skeletal muscle enzyme testing may not effectively distinguish between skeletal and cardiac muscle involvement, especially in patients with subclinical cardiac disease. Accurate biomarkers are thus required to screen for cardiac disease, to better inform both therapeutic decision-making and treatment response. The widespread uptake of cardiac troponin testing has revolutionised the management of acute coronary syndromes. While cardiac troponin I (cTnI) appears specific to the myocardium, cardiac troponin T (cTnT) is also expressed by skeletal muscle, including regenerating skeletal muscle tissue. There is increasing interest about the role of cardiac troponins as a putative biomarker of primary cardiac involvement in IIM and SSc-spectrum disorders. Herewith we discuss subclinical cardiac disease in IIM and SSc-spectrum disorders, the respective roles of cTnI and cTnT testing, and the re-expression of cTnT within regenerating skeletal muscle tissue. There remains wide variation in access to cardiac troponin testing nationally and internationally. We propose two pragmatic clinical pathways using cardiac troponins, preferably measuring concomitant cTnT followed by confirmatory (cardiac) cTnI to screen patients for subclinical cardiac disease and/or low-grade skeletal muscle disease activity, and also an agenda for future research.

  5. Abnormal cardiac enzymes in systemic sclerosis: a report of four patients and review of the literature.

    Science.gov (United States)

    Vasta, B; Flower, V; Bucciarelli-Ducci, C; Brown, S; Korendowych, E; McHugh, N J; Pauling, J D

    2014-03-01

    Cardiac involvement in systemic sclerosis (SSc) is heterogeneous and can include primary involvement of the myocardium, pericardium and coronary arteries or be secondary to cardiac complications of pulmonary and renal disease. Primary cardiac involvement in SSc is uncommon but can result in ventricular dysfunction, organ failure, arrhythmias and death. It can remain clinically silent and the prevalence is likely to be under-reported. We report four cases of SSc associated with a raised serum troponin T (TnT), in a proportion of whom cardiac MRI myocardial abnormalities were detected. These cases highlight the heterogeneity of cardiac involvement in SSc, the role of cardiac MRI and promising biochemical responses to immunosuppression. Cardiac biomarkers such as TnT may be useful screening tools to identify subclinical cardiac disease and assess response to therapeutic intervention.

  6. SPECT心肌灌注显像和超声心动图对糖尿病性心肌病心功能的评估价值%The role of SPECT myocardial perfusion imaging and echocardiography in assessing cardiac function of patients with diabetic cardiomyopathy

    Institute of Scientific and Technical Information of China (English)

    孙涛; 严金川; 陈小节; 梁仪; 赵建伟; 张朝普; 李璇

    2011-01-01

    目的 研究单光子发射计算机断层(SPECT)心肌灌注显像和二维超声心动图(2DE)对糖尿病性心肌病(DCM)心功能的评估价值.方法 使用SPECT心肌灌注显像与2DE对56例DCM患者分别进行左心室容积及功能检查,其中纽约心脏病学会(NYHA)心功能分级Ⅰ~Ⅱ级21例,Ⅲ级17例,Ⅳ级18例.SPECT心肌灌注显像采用QGS软件处理,2DE采用Simpson法测算.结果 两种检查方法的舒张末期容量(EDV)、收缩末期容量(ESV)和射血分数(EF)值差异均有统计学意义(P<0.05),对三项指标测值的相关性较好(r值分别为0.892、0.732、0.856,P<0.01),两种检查方法均显示心功能Ⅲ、Ⅳ级EDV、ESV和EF值与心功能Ⅰ~Ⅱ级者差异有统计学意义(P<0.01).结论 SPECT心肌灌注显像能较好的评估心功能指标,2DE低估了左心室容积;两种检查方法均能较好的反映NYHA心功能分级.%Objective To study the significance of single photon emission computed tomography(SPECT) myocardial perfusion imaging and two-dimensional echocardiography(2DE) in assessing cardiac function of patients with diabetic cardiomyopathy ( DCM). Methods SPECT myocardial perfusion imaging and 2DE were performed in 56 patients with diabetic cardiomyopathy, who were NYHA class I-II in 21 cases,class III in 17 cases and class ]V in 18 cases. Left ventricular (LV) volumes and function were measured using QGS software for SPECT myocardial perfusion imaging and Simpson's method for 2DE. Results There was a significant difference between SPECT myocardial perfusion imaging and 2DE in the estimation of end diastolic volume ( EDV), end systolic volume(ESV) and ejection fraction (EF) (P<0. 05). The correlation between SPECT myocardial perfusion imaging and 2DE was good for the assessment of EDV, ESV and EF (r=0. 892, 0. 732, 0. 856, respectively, P<0. 01). EDV.ESV and EF were significantly different among NYHA class III, IV and I - II graded by two methods(P<0. 01). Conclusion SPECT

  7. Reproducibility of area at risk assessment in acute myocardial infarction by T1- and T2-mapping sequences in cardiac magnetic resonance imaging in comparison to Tc99m-sestamibi SPECT.

    Science.gov (United States)

    Langhans, Birgit; Nadjiri, Jonathan; Jähnichen, Christin; Kastrati, Adnan; Martinoff, Stefan; Hadamitzky, Martin

    2014-10-01

    Area at risk (AAR) is an important parameter for the assessment of the salvage area after revascularization in acute myocardial infarction (AMI). By combining AAR assessment by T2-weighted imaging and scar quantification by late gadolinium enhancement imaging cardiovascular magnetic resonance (CMR) offers a promising alternative to the "classical" modality of Tc99m-sestamibi single photon emission tomography (SPECT). Current T2 weighted sequences for edema imaging in CMR are limited by low contrast to noise ratios and motion artifacts. During the last years novel CMR imaging techniques for quantification of acute myocardial injury, particularly the T1-mapping and T2-mapping, have attracted rising attention. But no direct comparison between the different sequences in the setting of AMI or a validation against SPECT has been reported so far. We analyzed 14 patients undergoing primary coronary revascularization in AMI in whom both a pre-intervention Tc99m-sestamibi-SPECT and CMR imaging at a median of 3.4 (interquartile range 3.3-3.6) days after the acute event were performed. Size of AAR was measured by three different non-contrast CMR techniques on corresponding short axis slices: T2-weighted, fat-suppressed turbospin echo sequence (TSE), T2-mapping from T2-prepared balanced steady state free precession sequences (T2-MAP) and T1-mapping from modified look locker inversion recovery (MOLLI) sequences. For each CMR sequence, the AAR was quantified by appropriate methods (absolute values for mapping sequences, comparison with remote myocardium for other sequences) and correlated with Tc99m-sestamibi-SPECT. All measurements were performed on a 1.5 Tesla scanner. The size of the AAR assessed by CMR was 28.7 ± 20.9 % of left ventricular myocardial volume (%LV) for TSE, 45.8 ± 16.6 %LV for T2-MAP, and 40.1 ± 14.4 %LV for MOLLI. AAR assessed by SPECT measured 41.6 ± 20.7 %LV. Correlation analysis revealed best correlation with SPECT for T2-MAP at a T2-threshold of 60 ms

  8. Brain {sup 18}F-FDG, {sup 18}F-florbtaben PET/CT, {sup 123}I-FP-CIT SPECT and cardiac {sup 123}I-MBG imaging for diagnosis of a 'cerebral type' of Lewy Body disease

    Energy Technology Data Exchange (ETDEWEB)

    Gucht, Axel Van Der; Bélissant, Ophélie; Rabu, Corenti; Cottereau, Anne-Ségolène; Evangelista, Eva; Chalaye, Julia; Bonnot-Lours, Sophie; Fénelon, Gilles; Itti, Emmanuel [Dept. of Nuclear Medicine, AP-HP, Henri-Mondor Teaching Hospital, Crteil (France); De Langavant, Laurent Cleret [Cognitive Neurology Unit, H. Mondor Hospital, Creteil (France)

    2016-09-15

    A 67-year-old man was referred for fluctuating neuropsychiatric symptoms, featuring depression, delirious episodes, recurrent visual hallucinations and catatonic syndrome associated with cognitive decline. No parkinsonism was found clinically even under neuroleptic treatment. {sup 18}F-FDG PET/CT showed hypometabolism in the posterior associative cortex including the occipital cortex, suggesting Lewy body dementia, but {sup 123}I-FP-CIT SPECT was normal and cardiac {sup 123}I-MIBG imaging showed no signs of sympathetic denervation. Alzheimer's disease was excluded by a normal {sup 18}F-florbetaben PET/CT. This report suggests a rare case of α-synucleinopathy without brainstem involvement, referred to as 'cerebral type' of Lewy body disease.

  9. Design for a high-resolution small-animal spect system usingpixellated Si(Li) detectors for in vivo Iodine-125 imaging

    Energy Technology Data Exchange (ETDEWEB)

    Choong, Woon-Seng; Moses, William W.; Tindall, Craig S.; Luke,Paul N.

    2004-08-01

    We propose a design for a high-resolution single-photon emission computed tomography (SPECT) system for in vivo {sup 125}I imaging in small animal using pixellated lithium-drifted silicon (Si(Li)) detectors. The proposed detectors are expected to have high interaction probability (>90%), good energy resolution (<15% FWHM), and good intrinsic spatial resolution ({approx}1 mm FWHM). The SPECT system will consist of a dual head detector geometry with the distance between the detectors ranging 30-50 mm to minimize the imaging distance between the mouse and the detectors. The detectors, each with an active area of 64 mm x 40 mm (64 x 40 array of 1 mm{sup 2} pixels and a 6 mm thick Si(Li) detector), will be mounted on a rotating gantry with an axial field-of-view of 64 mm. The detector signals will be read out by custom application-specific integrated circuits (ASICs). Using a high-resolution parallel-hole collimator, the expected spatial resolution is 1.6 mm FWHM at an imaging distance of 20 mm, and sensitivity is 6.7 cps/{micro}Ci. {sup 125}I is a readily available radioisotope with a long half-life of 59.4 days and it is commonly used to label biological compounds in molecular biology. Conventional gamma cameras are not optimized to detect the low emission energies (27 to 35 keV) of {sup 125}I. However, Si(Li) detector provides an ideal solution for detecting the low-energy emissions of {sup 125}I. In addition to presenting the design of the system, this paper presents a feasibility study of using Si(Li) detectors to detect the emissions of {sup 125}I.

  10. Combination of European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Cardiac Surgery Score (CASUS) to Improve Outcome Prediction in Cardiac Surgery.

    Science.gov (United States)

    Doerr, Fabian; Heldwein, Matthias B; Bayer, Ole; Sabashnikov, Anton; Weymann, Alexander; Dohmen, Pascal M; Wahlers, Thorsten; Hekmat, Khosro

    2015-08-17

    BACKGROUND We hypothesized that the combination of a preoperative and a postoperative scoring system would improve the accuracy of mortality prediction and therefore combined the preoperative 'additive EuroSCORE' (European system for cardiac operative risk evaluation) with the postoperative 'additive CASUS' (Cardiac Surgery Score) to form the 'modified CASUS'. MATERIAL AND METHODS We included all consecutive adult patients after cardiac surgery during January 2007 and December 2010 in our prospective study. Our single-centre study was conducted in a German general referral university hospital. The original additive and the 'modified CASUS' were tested using calibration and discrimination statistics. We compared the area under the curve (AUC) of the receiver characteristic curves (ROC) by DeLong's method and calculated overall correct classification (OCC) values. RESULTS The mean age among the total of 5207 patients was 67.2 ± 10.9 years. Whilst the ICU mortality was 5.9% we observed a mean length of ICU stay of 4.6 ± 7.0 days. Both models demonstrated excellent discriminatory power (mean AUC of 'modified CASUS': ≥ 0.929; 'additive CASUS': ≥ 0.920), with no significant differences according to DeLong. Neither model showed a significant p-value (cardiac surgery by combining a preoperative and a postoperative scoring system. A separate calculation of the two individual elements is therefore recommended.

  11. 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

  12. Morphological observations of tumors in cardiac conduction system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Tumors of the cardiac conduction system (CCS) have rarely been reported. The CCS from 198 cardiac-related deaths (GroupⅠ),and 838 deaths from non-cardiovascular diseases or trauma (Group Ⅱ ), were studied. Sampling was done of the sinoatrial node (SAN)and atrio-ventricular node (AVN) along their long axis of each node as a single block and the His bundle (HB) perpendicular to its long axis in 2-4 blocks. Five-micron serial sections were made; tissue slices were taken intermittently, every 20th from the SAN, every 10th from the AVN, and every 30th from the HB and bundle branches (BB), by continuous slices three times. Tumors in the CCS were found in 12 cases (1.155 %), where 10 (0.965%) were primary tumors, and 2 (0.193%) were metastatic tumors. The primary tumors included 4 fibromata compressing the HB (0.386 %), 4 hemangiomata (0.386%), 1 AVN tumor (0.097 %), and 1 rhabdomyoma (0.097 %). In 8 of the 10 cases, the tumors were located in the AVN or HB. The metastatic tumors originated from lymphocytic leukemia and malignant lymphoma (histiocytic type) in lung, and were all found in the SAN. Of the 12 cases, 2 were from the group Ⅰ. Tumors in the CCS are the smallest tumors in different parts of the body, which can cause sudden death.

  13. Brain renin angiotensin system in cardiac hypertrophy and failure

    Directory of Open Access Journals (Sweden)

    Luciana eCampos

    2012-01-01

    Full Text Available Brain renin-angiotensin system (RAS is significantly involved in the roles of the endocrine RAS in cardiovascular regulation. Our studies indicate that the brain RAS participates in the development of cardiac hypertrophy and fibrosis through sympathetic activation. Inhibition of sympathetic hyperactivity after myocardial infarction through suppression of the brain RAS appears beneficial. The brain RAS is involved in the modulation of circadian rhythms of arterial pressure, contributing to nondipping hypertension. We conclude that the brain RAS in pathophysiological states interacts synergistically with the chronically overactive RAS through a positive biofeedback in order to maintain a state of alert diseased conditions, such as cardiac hypertrophy and failure. Therefore, targeting brain RAS with drugs such as angiotensin converting inhibitors or receptor blockers having increased brain penetrability could be of advantage. These RAS-targeting drugs are first-line therapy for all heart failure patients. Since the RAS has both endocrine and local tissue components, RAS drugs are being developed to attain increased tissue penetrability and volume of distribution and consequently an efficient inhibition of both RAS components.

  14. 2D and 3D multimodality cardiac imagery: application for the coronarography/SPECT/PET-CT; Imagerie cardiaque multimodalites 2D et 3D: application a la coronarographie/tomoscintigraphie/TEP-CT

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Hernandez, J.M

    2006-06-15

    Coronarography and tomo-scintigraphy (SPECT, Single Photon Emission Tomography) are two imaging techniques used broadly for the diagnosis of cardiovascular diseases. The first modality consists of X-ray image sequences visualizing each, in a same plane, the coronary arteries located on the front and the back side of the heart. The X-ray images give anatomical information relating to the arterial tree and highlight eventual artery narrowing (stenoses). The SPECT modality (nuclear imaging) provide a 3-dimensional (3D) representation of the myocardial volume perfusion. This functional information authorizes the visualization of myocardial regions suffering from irrigation defaults. The aim of the presented work is to superimpose (in the 3D space) the functional and anatomical information in order to establish the visual link between arterial lesions and their consequence in terms of irrigation defaults. In the 3D representation chosen to facilitate the diagnosis, the structure of a schematic arterial tree and the stenoses are placed onto the perfusion volume. The initial data consist of a list of points representative for the arterial tree (start and end points of arterial segments, bifurcations, stenoses, etc) and marked by coronary-graphs on the X-ray images of the different incidences. The perfusion volume is then projected under the incidences of the coronary-graphic images. A registration algorithm superimposing the X-ray images and the corresponding SPECT projections provides the parameters of the geometrical transformations bringing the points marked in the X rays images in equivalent positions in the 2-dimensional SPECT images. A 3D reconstruction algorithm is then used to place the arterial points and the stenoses on the perfusion volume and build a schematic tree acting as landmark for the clinician. A 28 patient database was used to realize 40 3D superimposition of anatomical-functional data. These reconstructions have shown that the 3D representation is

  15. Optogenetic control of the cardiac conduction system (Conference Presentation)

    Science.gov (United States)

    Crocini, Claudia; Ferrantini, Cecilia; Coppini, Raffaele; Loew, Leslie M.; Cerbai, Elisabetta; Poggesi, Corrado; Pavone, Francesco S.; Sacconi, Leonardo

    2016-03-01

    Fatal cardiac arrhythmias are a major medical and social issue in Western countries. Current implantable pacemaker/defibrillators have limited effectiveness and are plagued by frequent malfunctions and complications. Here, we aim at setting up a new method to map and control the electrical activity of whole isolated mouse hearts. We employ a transgenic mouse model expressing Channel Rhodopsin-2 (ChR2) in the heart coupled with voltage optical mapping to monitor and control action potential propagation. The whole heart is loaded with the fluorinated red-shifted voltage sensitive dye (di-4-ANBDQPQ) and imaged with the central portion (128 x 128 pixel) of sCMOS camera operating at frame rate of 1.6 kHz. The wide-field imaging system is implemented with a random access ChR2 activation developed using two orthogonally-mounted acousto-optical deflectors (AODs). AODs rapidly scan different sites of the sample with a commutation time of 4 μs, allowing us to design ad hoc ChR2-stimulation pattern. First, we demonstrate the capability of our system in manipulating the conduction system of the whole mouse heart by changing the electrical propagation features. Then, we explore the efficacy of the random access ChR2 stimulation in inducing arrhythmias as well as to restore the cardiac sinus rhythm during an arrhythmic event. This work shows the potentiality of this new method for studying the mechanisms of arrhythmias and reentry in healthy and diseased hearts, as well as the basis of intra-ventricular dyssynchrony.

  16. Cardiac transplant in young female patient diagnosed with diffuse systemic sclerosis.

    Science.gov (United States)

    Bennasar, Guillermo; Carlevaris, Leandro; Secco, Anastasia; Romanini, Felix; Mamani, Marta

    2016-01-01

    Systemic sclerosis (SS) in a multifactorial and systemic, chronic, autoimmune disease that affects the connective tissue. We present this clinical case given the low prevalence of diffuse SS with early and progressive cardiac compromise in a young patient, and treatment with cardiac transplantation.

  17. Brain pertechnetate SPECT in perinatal asphyxia

    Energy Technology Data Exchange (ETDEWEB)

    Sfakianakis, G.; Curless, R.; Goldberg, R.; Clarke, L.; Saw, C.; Sfakianakis, E.; Bloom, F.; Bauer, C.; Serafini, A.

    1984-01-01

    Single photon emission computed tomography of the brain was performed in 6 patients with perinatal asphyxis aged 8-26 days. A single-head (LFOV) commercial SPECT system (Picker) was used and data were acquired 2-3 hr after an IV injection of 1-2 mCi Tc-99m-pertechnetate (360/sup 0/ rotation, 60 views, 64 x 64 matrix, 50K cts/view). Reconstruction in three planes was performed using MDS software (Hanning medium resolution filter, with or without attenuation correction using Sorenson's technique). For each clinical study, a ring type phantom source was used to identify the level of reconstruction noise in the tomographic planes. Abnormalities were found in all patients studied, 3 central (moderate intensity), 2 peripheral (1 severe, 1 moderate) and 1 diffuse (mild intensity). Despite use of oral perchlorate (50 mg) in one patient the choroid plexus was visible. Since attenuation correction tended to amplify noise, the clinical studies were interpreted both with and without this correction. All 3 patients with central lesions were found abnormal on early (1-4 mo) neurologic follow-up examination, whereas the others were normal. No correlation was found between SPECT and 24 hr blood levels of CPK, ammonia, base excess, or the Apgar scores. Ct scans were reported abnormal (3 diffuse, 1 peripheral, 1 central and 1 questionable). Planar scintigrams obtained immediately after SPECT were normal (2), questionable (2) and abnormal (2). Follow-up SPECT brain scintigrams in two of the patients showed partial resolution. SPECT of the brain appears promising in perinatal asphyxia but long-term correlation with patient development is necessary.

  18. High-resolution SPECT for small-animal imaging

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article presents a brief overview of the development of high-resolution SPECT for small-animal imaging. A pinhole collimator has been used for high-resolution animal SPECT to provide better spatial resolution and detection efficiency in comparison with a parallel-hole collimator. The theory of imaging characteristics of the pinhole collimator is presented and the designs of the pinhole aperture are discussed. The detector technologies used for the development of small-animal SPECT and the recent advances are presented. The evolving trend of small-animal SPECT is toward a multi-pinhole and a multi-detector system to obtain a high resolution and also a high detection efficiency.

  19. Cardiac arrest during gamete release in chum salmon regulated by the parasympathetic nerve system.

    Directory of Open Access Journals (Sweden)

    Yuya Makiguchi

    Full Text Available Cardiac arrest caused by startling stimuli, such as visual and vibration stimuli, has been reported in some animals and could be considered as an extraordinary case of bradycardia and defined as reversible missed heart beats. Variability of the heart rate is established as a balance between an autonomic system, namely cholinergic vagus inhibition, and excitatory adrenergic stimulation of neural and hormonal action in teleost. However, the cardiac arrest and its regulating nervous mechanism remain poorly understood. We show, by using electrocardiogram (ECG data loggers, that cardiac arrest occurs in chum salmon (Oncorhynchus keta at the moment of gamete release for 7.39+/-1.61 s in females and for 5.20+/-0.97 s in males. The increase in heart rate during spawning behavior relative to the background rate during the resting period suggests that cardiac arrest is a characteristic physiological phenomenon of the extraordinarily high heart rate during spawning behavior. The ECG morphological analysis showed a peaked and tall T-wave adjacent to the cardiac arrest, indicating an increase in potassium permeability in cardiac muscle cells, which would function to retard the cardiac action potential. Pharmacological studies showed that the cardiac arrest was abolished by injection of atropine, a muscarinic receptor antagonist, revealing that the cardiac arrest is a reflex response of the parasympathetic nerve system, although injection of sotalol, a beta-adrenergic antagonist, did not affect the cardiac arrest. We conclude that cardiac arrest during gamete release in spawning release in spawning chum salmon is a physiological reflex response controlled by the parasympathetic nervous system. This cardiac arrest represents a response to the gaping behavior that occurs at the moment of gamete release.

  20. New concepts in cardiac imaging 1985

    Energy Technology Data Exchange (ETDEWEB)

    Pohost, G.M.; Higgins, C.B.; Morganroth, J.; Ritchie, J.L.; Schelbert, H.R.

    1985-01-01

    This book presents 5 specialists work on reviewing and editing the area of applications for cardiac imaging: Contents: Ultrasound Methods; 1. Echocardiography in Valvular Heart Disease, 2. Echocardiography in Ischemic Heart Disease, 3. Current Status of Doppler Ultrasound for Assessing Regurgitant Valvular Lesions, Radionuclide Methods; 4. Cardiovascular Nuclear Medicine, 5. Single Photon Emission Computed Tomography (SPECT): Validation and Application for Myocardial Perfusion Imaging, 6. Assessment of Regional Myocardial Perfusion with Positron Emission Tomography, 7. Assessment of Regional Myocardial Substrate Metabolism with Positron Emission Tomography, X-Ray Imaging Techniques; 8. The Evaluation of Left Ventricular Function in Ischemic Heart Disease by Digital Subtraction Angigraphy, 9. Digital Angiography in the Assessment of Coronary Artery Disease, 10. Cardiac Computed Tomography: Its Potential Use in Evaluation of Ischemic Heart Disease, Magnetic Methods; 11. NMR Evaluation of the Cardiovascular System, 12. Magnetic Resonance Imaging of the Heart.

  1. Identification of systems failures in successful paediatric cardiac surgery.

    Science.gov (United States)

    Catchpole, K R; Giddings, A E B; de Leval, M R; Peek, G J; Godden, P J; Utley, M; Gallivan, S; Hirst, G; Dale, T

    Patient safety will benefit from an approach to human error that examines systemic causes, rather than blames individuals. This study describes a direct observation methodology, based on a threat and error model, prospectively to identify types and sources of systems failures in paediatric cardiac surgery. Of substantive interest were the range, frequency and types of failures that could be identified and whether minor failures could accumulate to form more serious events, as has been the case in other industries. Check lists, notes and video recordings were employed to observe 24 successful operations. A total of 366 failures were recorded. Coordination and communication problems, equipment problems, a relaxed safety culture, patient-related problems and perfusion-related problems were most frequent, with a smaller number of skill, knowledge and decision-making failures. Longer and more risky operations were likely to generate a greater number of minor failures than shorter and lower risk operations, and in seven higher-risk cases frequently occurring minor failures accumulated to threaten the safety of the patient. Non-technical errors were more prevalent than technical errors and task threats were the most prevalent systemic source of error. Adverse events in surgery are likely to be associated with a number of recurring and prospectively identifiable errors. These may be co-incident and cumulative human errors predisposed by threats embedded in the system, rather than due to individual incompetence or negligence. Prospectively identifying and reducing these recurrent failures would lead to improved surgical standards and enhanced patient safety.

  2. Comparison between a dual-head and a brain-dedicated SPECT system in the measurement of the loss of dopamine transporters with [{sup 123}I]FP-CIT

    Energy Technology Data Exchange (ETDEWEB)

    Varrone, Andrea [University Federico II, Biostructure and Bioimaging Institute, National Research Council/Department of Biomorphological and Functional Sciences, Napoli (Italy); Karolinska Institutet, Department of Clinical Neuroscience, Stockholm (Sweden); Sansone, Valeria; Pappata, Sabina; Salvatore, Marco [University Federico II, Biostructure and Bioimaging Institute, National Research Council/Department of Biomorphological and Functional Sciences, Napoli (Italy); Pellecchia, Maria T.; Salvatore, Elena; de Michele, Giuseppe; Filla, Alessandro; Barone, Paolo [University Federico II, Department of Neurological Sciences, Napoli (Italy); Amboni, Marianna [University Federico II, Department of Neurological Sciences, Napoli (Italy); IDC-Hermitage, Capodimonte, Napoli (Italy)

    2008-07-15

    Dual-head SPECT systems are used by many clinical departments for [{sup 123}I]FP-CIT SPECT imaging, while triple-head or brain-dedicated systems with better imaging performance are more commonly used by research institutions. There are limited data comparing the capability of the two types of system to measure dopamine transporter (DAT) loss in vivo. The aim of this study was to compare the ability of a dual-head and a brain-dedicated SPECT system to estimate the degree of DAT loss in different movement disorders with variable nigrostriatal impairment, with [{sup 123}I]FP-CIT. Four patients with essential tremor, 24 with Parkinson's disease (PD), six with spinocerebellar ataxia type 2 and six controls were studied with [{sup 123}I]FP-CIT. SPECT scans were performed on a dual-head (E.CAM - Siemens) and subsequently on a brain-dedicated system (Ceraspect - DSI). Striatal DAT outcome measures on the E.CAM and the Ceraspect were strongly correlated and the putamen-to-caudate ratios were almost identical. Although the measured values were lower by 52 {+-} 25% in caudate and by 51 {+-} 31% in putamen on the E.CAM (p < 0.0001), the average striatal DAT decrease in each patient group compared with controls was similar for both systems. In PD patients, similar correlations (p < 0.05) were found between motor UPDRS or Hoehn and Yahr stage and striatal DAT density. Despite underestimation of striatal DAT outcome measures, the E.CAM showed similar capability as the Ceraspect in measuring the degree of nigrostriatal dopaminergic deficit and assessing the correlation between DAT outcome measures and clinical variables of PD severity and stage. (orig.)

  3. 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; Proffitt, James

    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.

  4. ACR testing of a dedicated head SPECT unit.

    Science.gov (United States)

    Sensakovic, William F; Hough, Matthew C; Kimbley, Elizabeth A

    2014-07-08

    Physics testing necessary for program accreditation is rigorously defined by the ACR. This testing is easily applied to most conventional SPECT systems based on gamma camera technology. The inSPira HD is a dedicated head SPECT system based on a rotating dual clamshell design that acquires data in a dual-spiral geometry. The unique geometry and configuration force alterations of the standard ACR physics testing protocol. Various tests, such as intrinsic planar uniformity and/or resolution, do not apply. The Data Spectrum Deluxe Phantom used for conventional SPECT testing cannot fit in the inSPira HD scanner bore, making (currently) unapproved use of the Small Deluxe SPECT Phantom necessary. Matrix size, collimator type, scanning time, reconstruction method, and attenuation correction were all varied from the typically prescribed ACR instructions. Visible spheres, sphere contrast, visible rod groups, uniformity, and root mean square (RMS) noise were measured. The acquired SPECT images surpassed the minimum ACR requirements for both spatial resolution (9.5 mm spheres resolved) and contrast (6.4 mm rod groups resolved). Sphere contrast was generally high. Integral uniformity was 4% and RMS noise was 1.7%. Noise appeared more correlated than in images from a conventional SPECT scanner. Attenuation-corrected images produced from direct CT scanning of the phantom and a manufacturer supplied model of the phantom demonstrated negligible differences.

  5. Reducing multiplexing artifacts in multi-pinhole SPECT with a stacked silicon-germanium system: a simulation study.

    Science.gov (United States)

    Johnson, Lindsay C; Shokouhi, Sepideh; Peterson, Todd E

    2014-12-01

    In pinhole single photon emission computed tomography (SPECT), multi-pinhole collimators can increase sensitivity but may lead to projection overlap, or multiplexing, which can cause image artifacts. In this work, we explore whether a stacked-detector configuration with a germanium and a silicon detector, used with 123I (27-32, 159 keV), where little multiplexing occurs in the Si projections, can reduce image artifacts caused by highly-multiplexed Ge projections. Simulations are first used to determine a reconstruction method that combines the Si and Ge projections to maximize image quality. Next, simulations of different pinhole configurations (varying projection multiplexing) in conjunction with digital phantoms are used to examine whether additional Si projections mitigate artifacts from the multiplexing in the Ge projections. Reconstructed images using both Si and Ge data are compared to those using Ge data alone. Normalized mean-square error and normalized standard deviation provide a quantitative evaluation of reconstructed images' error and noise, respectively, and are used to evaluate the impact of the additional nonmultiplexed data on image quality. For a qualitative comparison, the differential point response function is used to examine multiplexing artifacts. Results show that in cases of highly-multiplexed Ge projections, the addition of low-multiplexed Si projections helps to reduce image artifacts both quantitatively and qualitatively.

  6. Contribution of the SPECT-CT in the diagnosis of systemic osteonecrosis: about one case;Apport de la TEMP-TDM dans le diagnostic des osteonecroses systemiques: a propos d'un cas

    Energy Technology Data Exchange (ETDEWEB)

    Thelu-Vanysacker, M.; Blanc, D.; Huglo, D.; Steinling, M. [CHRU de Lille, Service de medecine nucleaire, hopital Huriez, 59 - Lille (France); Sivova, N.; Launay, D. [CHRU de Lille, service de medecine interne, hopital Huriez, 59 - Lille (France)

    2010-05-15

    Systemic osteonecrosis remains currently a very bad bone disease due to its poor functional prognosis. The multiple locations are frequent, but undervalued. We report a case illustrating the contribution of morpho SPECT (SPECT-CT) in screening for this complication. This case illustrates the potential of hybrid imaging to differentiate in a D.P.D. {sup 99m}Tc ({sup 99m}Tc 2,3-di-carboxy propane-1,1-diphosphonate) a bone and joint damage associated with peri-arteritis of systemic osteonecrosis. In addition, through its whole body study, bone scan allows an exhaustive site of necrosis knowing that the description of the extent and topography of the site of osteonecrosis is an important prognostic factor. (N.C.)

  7. Silicon Detectors for PET and SPECT

    Science.gov (United States)

    Cochran, Eric R.

    Silicon detectors use state-of-the-art electronics to take advantage of the semiconductor properties of silicon to produce very high resolution radiation detectors. These detectors have been a fundamental part of high energy, nuclear, and astroparticle physics experiments for decades, and they hold great potential for significant gains in both PET and SPECT applications. Two separate prototype nuclear medicine imaging systems have been developed to explore this potential. Both devices take advantage of the unique properties of high resolution pixelated silicon detectors, designed and developed as part of the CIMA collaboration and built at The Ohio State University. The first prototype is a Compton SPECT imaging system. Compton SPECT, also referred to as electronic collimation, is a fundamentally different approach to single photon imaging from standard gamma cameras. It removes the inherent coupling of spatial resolution and sensitivity in mechanically collimated systems and provides improved performance at higher energies. As a result, Compton SPECT creates opportunities for the development of new radiopharmaceuticals based on higher energy isotopes as well as opportunities to expand the use of current isotopes such as 131I due to the increased resolution and sensitivity. The Compton SPECT prototype consists of a single high resolution silicon detector, configured in a 2D geometry, in coincidence with a standard NaI scintillator detector. Images of point sources have been taken for 99mTc (140 keV), 131I (364keV), and 22Na (511 keV), demonstrating the performance of high resolution silicon detectors in a Compton SPECT system. Filtered back projection image resolutions of 10 mm, 7.5 mm, and 6.7 mm were achieved for the three different sources respectively. The results compare well with typical SPECT resolutions of 5-15 mm and validate the claims of improved performance in Compton SPECT imaging devices at higher source energies. They also support the potential of

  8. Excitation model of pacemaker cardiomyocytes of cardiac conduction system

    Science.gov (United States)

    Grigoriev, M.; Babich, L.

    2015-11-01

    Myocardium includes typical and atypical cardiomyocytes - pacemakers, which form the cardiac conduction system. Excitation from the atrioventricular node in normal conditions is possible only in one direction. Retrograde direction of pulses is impossible. The most important prerequisite for the work of cardiomyocytes is the anatomical integrity of the conduction system. Changes in contractile force of the cardiomyocytes, which appear periodically, are due to two mechanisms of self-regulation - heterometric and homeometric. Graphic course of the excitation pulse propagation along the heart muscle more accurately reveals the understanding of the arrhythmia mechanism. These models have the ability to visualize the essence of excitation dynamics. However, they do not have the proper forecasting function for result estimation. Integrative mathematical model enables further investigation of general laws of the myocardium active behavior, allows for determination of the violation mechanism of electrical and contractile function of cardiomyocytes. Currently, there is no full understanding of the topography of pacemakers and ionic mechanisms. There is a need for the development of direction of mathematical modeling and comparative studies of the electrophysiological arrangement of cells of atrioventricular connection and ventricular conduction system.

  9. A real-time cardiac surface tracking system using Subspace Clustering.

    Science.gov (United States)

    Singh, Vimal; Tewfik, Ahmed H; Gowreesunker, B

    2010-01-01

    Catheter based radio frequency ablation of atrial fibrillation requires real-time 3D tracking of cardiac surfaces with sub-millimeter accuracy. To best of our knowledge, there are no commercial or non-commercial systems capable to do so. In this paper, a system for high-accuracy 3D tracking of cardiac surfaces in real-time is proposed and results applied to a real patient dataset are presented. Proposed system uses Subspace Clustering algorithm to identify the potential deformation subspaces for cardiac surfaces during the training phase from pre-operative MRI scan based training set. In Tracking phase, using low-density outer cardiac surface samples, active deformation subspace is identified and complete inner & outer cardiac surfaces are reconstructed in real-time under a least squares formulation.

  10. Cardiac repolarization during hypoglycaemia and hypoxaemia in healthy males: impact of renin-angiotensin system activity

    DEFF Research Database (Denmark)

    Due-Andersen, Rikke; Høi-Hansen, Thomas; Olsen, Niels Vidiendal;

    2008-01-01

    AIMS: Activity in the renin-angiotensin system (RAS) may influence the susceptibility to cardiac arrhythmia. To study the effect of basal RAS activity on cardiac repolarization during myocardial stress induced by hypoglycaemia or hypoxaemia in healthy humans. METHODS AND RESULTS: Ten subjects...

  11. Angiotensin II dependent cardiac remodeling in the eel Anguilla anguilla involves the NOS/NO system

    DEFF Research Database (Denmark)

    Filice, Mariacristina; Amelio, Daniela; Garofalo, Filippo

    2017-01-01

    Angiotensin II (AngII), the principal effector of the Renin-Angiotensin System (RAS), plays an important role in controlling mammalian cardiac morpho-functional remodelling. In the eel Anguilla anguilla, one month administration of AngII improves cardiac performance and influences the expression...

  12. SPECT检查放射性水污染智能防护系统的研制与应用%Development and utility of intelligent protection system for SPECT radioactive water pollution

    Institute of Scientific and Technical Information of China (English)

    李祥林; 殷志杰; 李建平; 董艳军; 邓大平; 刘泉源; 张迪; 王静

    2011-01-01

    目的 研制一种SPECT检查放射性水污染智能防护系统.方法 根据《医院污水处理技术指南》中对放射性废水的处理标准,应用计算机技术和电离辐射传感技术自主研制一种智能化的SPECT放射性水污染防护系统.结果 智能防护系统无需人工干预,可实时防护SPECT放射性水污染,排放废水的放射性浓度低于3.7×102 Bq/L.结论 SPECT放射性水污染智能防护系统可实现放射性废水排放的智能化、自动化,排放废水的放射性浓度符合国家标准要求.%Objective To develop an intelligent protection system, in order to protect the radioactive water pollution of SPECT. Methods According to the radioactive sewage processing standards of the hospital waste water treatment technology guide, using computer technology and ionizing radiation sensing technology, an intelligent protection system for SPECT radioactive water pollution was self-developed. Results Without manual intervention, the intelligent protection system could real-time protect the radioactive pollution of SPECT. The radioactive concentration of the discharge sewage was below 3. 7×102 Bq/L. Conclusion The intelligent protection system for SPECT radioactive pollution ensures the automatic discharge of radioactive sewage, and the radioactive concentration of the discharged sewage conforms to the state standards.

  13. 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.

  14. Human cardiac systems electrophysiology and arrhythmogenesis: iteration of experiment and computation.

    Science.gov (United States)

    Holzem, Katherine M; Madden, Eli J; Efimov, Igor R

    2014-11-01

    Human cardiac electrophysiology (EP) is a unique system for computational modelling at multiple scales. Due to the complexity of the cardiac excitation sequence, coordinated activity must occur from the single channel to the entire myocardial syncytium. Thus, sophisticated computational algorithms have been developed to investigate cardiac EP at the level of ion channels, cardiomyocytes, multicellular tissues, and the whole heart. Although understanding of each functional level will ultimately be important to thoroughly understand mechanisms of physiology and disease, cardiac arrhythmias are expressly the product of cardiac tissue-containing enough cardiomyocytes to sustain a reentrant loop of activation. In addition, several properties of cardiac cellular EP, that are critical for arrhythmogenesis, are significantly altered by cell-to-cell coupling. However, relevant human cardiac EP data, upon which to develop or validate models at all scales, has been lacking. Thus, over several years, we have developed a paradigm for multiscale human heart physiology investigation and have recovered and studied over 300 human hearts. We have generated a rich experimental dataset, from which we better understand mechanisms of arrhythmia in human and can improve models of human cardiac EP. In addition, in collaboration with computational physiologists, we are developing a database for the deposition of human heart experimental data, including thorough experimental documentation. We anticipate that accessibility to this human heart dataset will further human EP computational investigations, as well as encourage greater data transparency within the field of cardiac EP.

  15. Continuous measurement of cardiac output using stochastic system identification techniques.

    Science.gov (United States)

    Yelderman, Mark

    2004-01-01

    Indicator dilutions techniques offer the most reliable methods of determining clinical cardiac output because of the elastic nature of the cardiac vessels. A catheter-mounted beating filament affords a simple means of supplying "heat" indicator, but is power and temperature limited because of possible patient injury. A stochastic signal processing method using pseudorandom binary infusion of heat offers a process of enhancing the signal to noise sufficiently to facilitate a computation of cardiac output over a reasonable time period (5 min) with a clinically acceptable error.

  16. Rapid Circular Tomography System Suitable For Cardiac Imaging

    Science.gov (United States)

    Kruger, R. A.; Sorensor, J. A.; Boye, J. R.; Conrad, J.; Ric, S. P. D.; Yih, B. C.; Liu, P.

    1985-06-01

    Tomographic DSA (digital subtraction angiography) can be used to improve the image quality that results from intravenous angiographic studies of relatively stationary arterial anatomy. While DSA removes much of the non-opacified anatomy, tomographic blurring reduces both the severity of patient motion artefacts and the confusion introduced by overlapping vascular anatomy. For this purpose a conventional longitudinal tomography device to which an image intensifier and television has been added can be used. However, such an apparatus is inadequate for cardiac imaging due to the slow speed of the tomographic motion. A tomographic system consisting of a rotating focal spot x-ray tube and an image intensifier, modified to allow electronic image scanning, is proposed. After this device is constructed it will be possible to acquire tomographic images of the beating heart in as little as .005-.010 seconds. When combined with image subtraction it is anticipated that the quality of intravenous coronary angiograms will be improved in much the same way that tomographic DSA improves image quality in many of the other arteries of the body.

  17. Progression of dopamine transporter decline in patients with the Parkinson variant of multiple system atrophy: a voxel-based analysis of [{sup 123}I]{beta}-CIT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Nocker, Michael; Seppi, Klaus; Wenning, Gregor K.; Poewe, Werner; Scherfler, Christoph [Innsbruck Medical University, Department of Neurology, Innsbruck (Austria); Donnemiller, Eveline; Virgolini, Irene [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria)

    2012-06-15

    We characterized the progression of dopamine transporter (DAT) decline in the striatum and extrastriatal regions including the midbrain and pons of patients with the Parkinson variant of multiple system atrophy (MSA-P) and compared longitudinally collected SPECT results with those in a cohort of patients with Parkinson's disease (PD). Eight patients with MSA-P (age 60.4 {+-} 7.7 years, disease duration 2.4 {+-} 1 years, UPDRS-III motor score 39.7 {+-} 4.7), and 11 patients with PD (age 61.2 {+-} 6.4 years, disease duration 2.4 {+-} 1.1 years, UPDRS-III motor score 18.9 {+-} 7.6) underwent a baseline and follow-up [{sup 123}I]{beta}-CIT SPECT investigation within a time period of 1.3 years. Statistical parametric mapping (SPM) and a repetitive ANOVA design were used to objectively localize the decline in DAT availability without having to make an a priori hypothesis as to its location. SPM localized significant reductions in [{sup 123}I]{beta}-CIT uptake in the dorsal brainstem of MSA-P patients compared to PD patients (p < 0.001) at baseline. Additional reductions in the DAT signal were localized in the caudate and anterior putamen of patients with MSA-P patients compared to PD patients at the follow-up examination (p < 0.001). Relative decline in tracer binding was evident in the caudate and anterior putamen of MSA-P patients compared to PD patients in the longitudinal analysis (p < 0.05), whereas no significant relative signal alteration was observed in the brainstem. In contrast to PD, the relatively higher rate of signal reduction in the caudate and anterior putamen is consistent with the faster disease progression reported in MSA-P. At baseline, the tracer uptake in the brainstem was already at very low levels in the MSA-P patients compared to that in healthy control subjects and did not progress any further, suggesting that the degeneration of monoaminergic neurons is almost complete early in the disease course. (orig.)

  18. 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.)

  19. Expression of L amino acid transport system 1 and analysis of iodine-123-methyltyrosine tumor uptake in a pancreatic xenotransplantation model using fused high-resolution-micro-SPECT-MRI

    Institute of Scientific and Technical Information of China (English)

    Corinna von Forstner; Maaz Zuhayra; Ole Ammerpohl; Yi Zhao; Sanjay Tiwari; Olav Jansen; Holger Kalthoff; Eberhard Henze; Jan-Hendrik Egberts

    2011-01-01

    BACKGROUND: The specificity in discriminating pancreatitis is limited in the positron emission tomography (PET) using Fluorine-18-fluorodeoxyglucose.Furthermore,PETisnot widely available compared to the single photon emission computed tomography (SPECT). Since amino acids play a minor role in metabolism of inflammatory cells, the potential of the SPECT tracer, 3-[123I]iodo-L-α-methyltyrosine (123I-IMT), for detecting pancreatic cancer was examined in xenotransplantation models of humanpancreaticcarcinomainmice. METHODS:  123I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors. Fused high-resolution-micro-SPECT (Hi-SPECT) and magnetic resonance imaging were performed. The gene expression level of L amino acid transport-system 1 (LAT1) was analyzed and correlated with tumor uptake of 123I-IMT. RESULTS: A high uptake of 123I-IMT was detected in all tumor-bearing mice. The median tumor-to-background ratio (T/B) was 12.1 (2.0-13.2) for orthotopic and 8.4 (1.8-11.1) for subcutaneous xenotransplantation, respectively. Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls. CONCLUSIONS: Our mouse model could show a high 123I-IMT uptake in pancreatic cancer. Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest. Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells. Since amino acids play a minor role in the metabolism of inflammatory cells, the potential for application of 123I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.

  20. Impact of the renin-angiotensin system on cardiac energy metabolism in heart failure.

    Science.gov (United States)

    Mori, Jun; Zhang, Liyan; Oudit, Gavin Y; Lopaschuk, Gary D

    2013-10-01

    The renin-angiotensin system (RAS) plays a key pathogenic role in heart failure. The adverse effects of angiotensin II (Ang II), a major player of the RAS, contributes to the development of heart failure. Heart failure is accompanied by significant perturbations in cardiac energy metabolism that can both decrease cardiac energy supply and decrease cardiac efficiency. Recent evidence suggests that Ang II might be involved in these perturbations in cardiac energy metabolism. Furthermore, new components of the RAS, such as angiotensin converting enzyme 2 and Ang1-7, have been reported to exert beneficial effects on cardiac energy metabolism. As a result, a further understanding of the relationship between the RAS and cardiac energy metabolism has the potential to improve the control of heart failure, and may lead to the development of new therapies to treat heart failure. This review summarizes what effects the RAS has on cardiac energy metabolism, highlighting how Ang II can induce cardiac insulin resistance and mitochondrial damage, and what role reactive oxygen species and sirtuins have on these processes.

  1. 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

  2. Accelerated GPU based SPECT Monte Carlo simulations

    Science.gov (United States)

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

    2016-06-01

    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, 111In and 131I, 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 efficiency

  3. 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.)

  4. Medical Devices; Cardiovascular Devices; Classification of the Steerable Cardiac Ablation Catheter Remote Control System. Final order.

    Science.gov (United States)

    2015-09-30

    The Food and Drug Administration (FDA) is classifying the steerable cardiac ablation catheter remote control system into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the steerable cardiac ablation catheter remote control system's classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

  5. The dopaminergic system in patients with functional dyspepsia analysed by single photon emission computed tomography (SPECT) and an alpha-methyl-para-tyrosine (AMPT) challenge test

    Energy Technology Data Exchange (ETDEWEB)

    Braak, Breg; Klooker, Tamira K. [Academic Medical Center, Department of Gastroenterology and Hepatology, Amsterdam (Netherlands); Booij, Jan [Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Wijngaard, Rene M.J. van den [Academic Medical Center, Tytgat Institute of Liver and Intestinal Research, Amsterdam (Netherlands); Boeckxstaens, Guy E.E. [Academic Medical Center, Department of Gastroenterology and Hepatology, Amsterdam (Netherlands); University Hospital Leuven, Catholic University Leuven, Department of Gastroenterology, Leuven (Belgium)

    2012-04-15

    Functional dyspepsia (FD) is a chronic condition characterized by upper abdominal symptoms without an identifiable cause. While the serotonergic system is thought to play a key role in the regulation of gut physiology, the role of the dopaminergic system, which is important in the regulation of visceral pain and stress, is under-studied. Therefore, this study investigated the dopaminergic system and its relationship with drinking capacity and symptoms in FD patients. In FD patients and healthy volunteers (HV) the dopaminergic system was investigated by in-vivo assessment of central dopamine D2 receptors (D2Rs) with [{sup 123}I]IBZM SPECT and by an acute, but reversible, dopamine depletion alpha-methyl-para-tyrosine (AMPT) challenge test. A nutrient drink test was performed to investigate the association between maximal ingested volume, evoked symptoms, and D2Rs. The HV subjects comprised 12 women and 8 men (mean age 31 {+-} 3 years), and the FD patients comprised 5 women and 3 men (mean age 39 {+-} 5 years). The FD patients had a lower left plus right average striatal binding potential (BP{sub NP}) for the caudate nucleus (p = 0.02), but not for putamen (p = 0.15), which in the FD patients was correlated with maximal ingested volume (r = 0.756, p = 0.03). The D2R BP{sub NP} in the putamen was correlated with nausea (r = 0.857, p = 0.01). The acute dopamine depletion test, however, failed to reveal differences in prolactin release between the FD patients and the HV subjects. These preliminary data suggest that chronic rather than acute alterations in the dopaminergic system may be involved in the pathogenesis of FD. Further studies are required to reproduce our novel findings and to evaluate to what extent the dopaminergic changes may be secondary to abnormalities in serotonergic pathways. (orig.)

  6. 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.

  7. A new scoring system for the triage of cardiac tamponade.

    Science.gov (United States)

    Imazio, Massimo; Adler, Yehuda; Ristić, Arsen D; Charron, Philippe

    2015-03-01

    Prompt recognition of cardiac tamponade is critical since the underlying hemodynamic disorder can lead to death if not resolved by percutaneous or surgical drainage of the pericardium. Nevertheless, the management of cardiac tamponade can be challenging because of the lack of the validated criteria for the risk stratification that should guide clinicians in the decision-making process. The Working Group on Myocardial and Pericardial Diseases issued this position statement in order to reply to specific questions: Which patients need immediate drainage of the pericardial effusion?; Is echocardiography sufficient for guidance of pericardiocentesis or should patient be taken to the cardiac catheterization laboratory?; Who should be transferred to specialized/tertiary institution or surgical service?; What type of medical support is necessary during transportation? Current European guidelines published in 2004 do not cover these issues and no additional guidelines are available from major medical and cardiology societies.

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

    Science.gov (United States)

    Grova, C.; Jannin, P.; Biraben, A.; Buvat, I.; Benali, H.; Bernard, A. M.; Scarabin, J. M.; Gibaud, B.

    2003-12-01

    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 found within

  9. Cardiac Sarcoidosis.

    Science.gov (United States)

    Birnie, David; Ha, Andrew C T; Gula, Lorne J; Chakrabarti, Santabhanu; Beanlands, Rob S B; Nery, Pablo

    2015-12-01

    Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.

  10. NOTE: Implementation of angular response function modeling in SPECT simulations with GATE

    Science.gov (United States)

    Descourt, P.; Carlier, T.; Du, Y.; Song, X.; Buvat, I.; Frey, E. C.; Bardies, M.; Tsui, B. M. W.; Visvikis, D.

    2010-05-01

    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.

  11. 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)

  12. Systems and methods for remote long standoff biometric identification using microwave cardiac signals

    Science.gov (United States)

    McGrath, William R. (Inventor); Talukder, Ashit (Inventor)

    2012-01-01

    Systems and methods for remote, long standoff biometric identification using microwave cardiac signals are provided. In one embodiment, the invention relates to a method for remote biometric identification using microwave cardiac signals, the method including generating and directing first microwave energy in a direction of a person, receiving microwave energy reflected from the person, the reflected microwave energy indicative of cardiac characteristics of the person, segmenting a signal indicative of the reflected microwave energy into a waveform including a plurality of heart beats, identifying patterns in the microwave heart beats waveform, and identifying the person based on the identified patterns and a stored microwave heart beats waveform.

  13. Evaluation of early cardiac dysfunction in patients with systemic lupus erythematosus with or without anticardiolipin antibodies.

    Science.gov (United States)

    Barutcu, A; Aksu, F; Ozcelik, F; Barutcu, C A E; Umit, G E; Pamuk, O N; Altun, A

    2015-09-01

    The aim of this study was to use transthoracic Doppler echocardiographic (TTE) imaging methods to identify cardiac dysfunction, an indicator of subclinical atherosclerosis in asymptomatic systemic lupus erythematosus (SLE) patients in terms of cardiac effects. This study involved 80 patients: a study group (n = 50) and control group (n = 30). They were categorized into four subgroups: anticardiolipin antibodies (aCL) (+) (n = 14) and aCL (-) (n = 36); systemic lupus erythematosus disease activity index (SLEDAI) ≥ 6 (n = 15) and SLEDAI 5 years group compared with the disease period <5 years group (p < 0.01, p < 0.05, respectively). Carrying out regular scans with TTE image of SLE patients is important in order to identify early cardiac involvement during monitoring and treatment. Identifying early cardiac involvement in SLE may lead to a reduction in mortality and morbidity rates.

  14. SPECT Imaging of patients with parkinsonian syndromes; SPECT-Untersuchungen bei Patienten mit Parkinson-Syndromen

    Energy Technology Data Exchange (ETDEWEB)

    Tatsch, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Univ. Muenchen-Grosshardern (Germany)

    2002-09-01

    Stimulated by the commercial availability of specific radioligands in vivo characterization of the dopaminergic system with single-photon emission tomography (SPECT) has gained clinical importance in the diagnostic work-up of patiens with parkinsonism. Currently interest is focused on two aspects of the dopaminergic neurotransmission: Cocaine analogues bind to the presynaptically located striatal dopamine transporter and herewith allow to assess the structural integrity of the presynaptic terminals which are the striatal projections of neurons originating in the substantia nigra. For functional assessment of the postsynaptic aspect of the dopaminergic synapse binding of specific receptor antagonists to postsynaptically located D2 receptors is analyzed. Depending on the clinical question and the pathology expected both methods - either each one alone or a combination of both - provide valuable diagnostic information. Currently those SPECT methods are applied to confirm or exclude a Parkinsonian syndrome, in the early and differential diagnosis of Parkinsonian syndromes, to assess disease severity and measure disease progression, and to monitor the effects of therapy e.g. with potentially neuroprotective drugs. This paper offers a comprehensive summary of the SPECT results reported in the literature dealing with the mentioned clinical applications. (orig.) [German] Stimuliert durch die kommerzielle Verfuegbarkeit spezifischer Radioliganden gewinnt die In-vivo-Charakterisierung des dopaminergen Systems mit der single-photon-emissions-computertomographie (SPECT) bei der diagnostischen Abklaerung von Parkinson-Syndromen zunehmend an Bedeutung. Hierbei stehen zwei Aspekte der dopaminergen Neurotransmission im Blickpunkt des Interesses: Die Bindung von Kokainanaloga an den praesynaptischen Dopamintransporter laesst Rueckschluesse auf die Integritaet von Neuronen der Substantia nigra mit ihren zum Corpus striatum projizierenden Axonen (praesynaptische Nervenfasern) zu. Die

  15. Molecular imaging agents for SPECT (and SPECT/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Gnanasegaran, Gopinath [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); Ballinger, James R. [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

    2014-05-15

    The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

  16. Activation of the Cardiac Renin-Angiotensin System in High Oxygen-Exposed Newborn Rats: Angiotensin Receptor Blockade Prevents the Developmental Programming of Cardiac Dysfunction.

    Science.gov (United States)

    Bertagnolli, Mariane; Dios, Anne; Béland-Bonenfant, Sarah; Gascon, Gabrielle; Sutherland, Megan; Lukaszewski, Marie-Amélie; Cloutier, Anik; Paradis, Pierre; Schiffrin, Ernesto L; Nuyt, Anne Monique

    2016-04-01

    Newborn rats exposed to high oxygen (O2), mimicking preterm birth-related neonatal stress, develop later in life cardiac hypertrophy, dysfunction, fibrosis, and activation of the renin-angiotensin system. Cardiac renin-angiotensin system activation in O2-exposed adult rats is characterized by an imbalance in angiotensin (Ang) receptors type 1/2 (AT1/2), with prevailing AT1 expression. To study the role of renin-angiotensin system in the developmental programming of cardiac dysfunction, we assessed Ang receptor expression during neonatal high O2 exposure and whether AT1 receptor blockade prevents cardiac alterations in early adulthood. Sprague-Dawley newborn rats were kept with their mother in 80% O2 or room air (control) from days 3 to 10 (P3-P10) of life. Losartan or water was administered by gavage from P8 to P10 (n=9/group). Rats were studied at P3 (before O2 exposure), P5, P10 (end of O2), and P28. Losartan treatment had no impact on growth or kidney development. AT1 and Ang type 2 receptors were upregulated in the left ventricle by high O2 exposure (P5 and P10), which was prevented by Losartan treatment at P10. Losartan prevented the cardiac AT1/2 imbalance at P28. Losartan decreased cardiac hypertrophy and fibrosis and improved left ventricle fraction of shortening in P28 O2-exposed rats, which was associated with decreased oxidation of calcium/calmodulin-dependent protein kinase II, inhibition of the transforming growth factor-β/SMAD3 pathway, and upregulation of cardiac angiotensin-converting enzyme 2. In conclusion, short-term Ang II blockade during neonatal high O2 prevents the development of cardiac alterations later in life in rats. These findings highlight the key role of neonatal renin-angiotensin system activation in the developmental programming of cardiac dysfunction induced by deleterious neonatal conditions.

  17. [{sup 123}I]β-CIT SPECT imaging of dopamine and serotonin transporters in Parkinson's disease and multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Berding, G.; Gielow, P.; Harke, H.; Knoop, B.O.; Knapp, W.H. [Dept. of Nuclear Medicine, Univ. School of Medicine, Hannover (Germany); Bruecke, Th. [Univ. Clinic of Neurology and Nuclear Medicine, Vienna (Austria); Odin, P. [Dept. of Neurology, Zentralkrankenhaus Reinkenheide, Bremerhaven (Germany); Brooks, D.J. [MRC Clinical Sciences Centre and Div. of Neuroscience, Faculty of Medicine, Imperial Coll., Hammersmith Hospital, London (United Kingdom); Kolbe, H.; Dengler, R. [Dept. of Neurology, Univ. School of Medicine, Hannover (Germany)

    2003-02-01

    Aims: Definition of the regional pattern of dopamine transporter (DAT) dysfunction in advanced Parkinson's disease (PD) and evaluation of a potential correlation between DAT binding and symptoms; elucidation of the role of DAT imaging in the differential diagnosis of PD and multiple system atrophy (MSA); assessment and comparison of serotonin transporter (SERT) binding in PD and MSA. Methods: [{sup 123}I]β-CIT SPECT was performed in 14 patients with advanced PD, 10 with moderate MSA and 20 healthy persons. Specific to non-specific tracer binding ratios (V{sub 3}{sup ''}) were calculated via ROI analysis of uptake images at 4 h (SERT binding) and 24 h (DAT binding) p. i. Results: In PD bilateral reduction of striatal DAT binding (63-70%) was seen. The caudate ipsilateral to the clinically predominantly affected side showed relatively the least impairment. Significant correlations (r = -0.54 to -0.64) between DAT binding and Hoehn and Yahr stage, UPDRS-scores and duration of disease were found. In MSA DAT binding was less reduced (40-48%) targeting the putamen contralateral to the side of clinical predominance. Significantly lower SERT binding was observed in PD midbrain and MSA hypothalamus compared to controls - and in MSA relative to PD mesial frontal cortex. Conclusions: In advanced PD striatal DAT binding is markedly reduced with the least reduction in caudate ipsilateral to the clinically predominantly affected side. In moderate MSA with asymmetrical symptoms DAT dysfunction is predominant in the contralateral putamen, a pattern seen in early PD. The reduction of SERT in the midbrain area of PD patients suggests additional tegmental degeneration while in MSA the serotonergic system seems to be more generally affected. (orig.)

  18. Prognostic Value of Normal Perfusion but Impaired Left Ventricular Function in the Diabetic Heart on Quantitative Gated Myocardial Perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hwanjeong; Choi, Sehun; Han, Yeonhee [Research Institute of Chonbuk National Univ. Medical School and Hospitial, Jeonju (Korea, Republic of); Lee, Dong Soo; Lee, Hoyoung; Chung, Junekey [Seoul National Univ., Seoul (Korea, Republic of)

    2013-09-15

    This study aimed at identifying the predictive parameters on quantitative gated myocardial perfusion single-photon emission computed tomography (QG-SPECT) in diabetic patients with normal perfusion but impaired function. Methods Among the 533 consecutive diabetic patients, 379 patients with normal perfusion on rest Tl-201/dipyridamole-stress Tc-{sup 99m} sestamibi Gated SPECT were enrolled. Patients were grouped into those with normal post-stress left ventricular function (Group I) and those with impaired function (EF <50 or impaired regional wall motion, Group II). We investigated cardiac events and cause of death by chart review and telephone interview. Survival analysis and Cox proportional hazard model analysis were performed. Between the Group I and II, cardiac events as well as chest pain symptoms, smoking, diabetic complications were significantly different (P<0.05). On survival analysis, event free survival rate in Group II was significantly lower than in Group I (P=0.016). In univariate Cox proportional hazard analysis on overall cardiac event, Group (II over I), diabetic nephropathy, summed motion score (SMS), summed systolic thickening score (STS), numbers of abnormal segmental wall motion and systolic thickening predicted more cardiac events (P<0.05). Multivariate analysis showed that STS was the only independent predictor cardiac event. The functional parameter, especially summed systolic thickening score on QG-SPECT had prognostic values, despite normal perfusion, in predicting cardiac events in diabetic patients, and QG-SPECT provides clinically useful risk stratification in diabetic patients with normal perfusion.

  19. Application of Quantitative Analysis in Brain SPECT Imaging of Neuropsychiatric in Systemic Lupus Erythematosus%定量分析在系统性红斑狼疮脑病SPECT脑显像中的应用

    Institute of Scientific and Technical Information of China (English)

    许守林; 冯雪凤; 施鸣

    2013-01-01

    Objective: To elucidate a method for the quantitative analysis in 99mTc-ECD brain SPECT imaging of neuropsychiatric in systemic lupus erythematosus and the correlation of visual and quantitative analysis. Methods: 99mTc-ECD SPECT imaging was performed in 33 SLE patients and 29 controls. The results were analyzed by visual and quantitative comparison. The images were analyzed with brain search (BS). Results: The change of cerebral blood flow, especially decreases in regional cerebral blood flow were associated with serious neuropsychiatric SLE presentations. Cingulate gyrus and temporal- parietal were most involved areas under unpaired t-test. The positive rate of SPECT imaging by visual and quantitative analysis was respectively 51.51%, and 57.57%. The method of quantitative and visual analysis had high correlation. Conclusions: 99mTc-ECD SPECT could easily demonstrate metabolic, functional lesions and cerebral blood flow change without structural abnormalities. The sensitivity of cerebral blood flow perfusion SPECT imaging was high, but lack of specificity. The combination of brain perfusion SPECT and brain search (BS) was a convenient and shortcut method to align the disfunctional areas of the brain. 99Tcm-ECD SPECT was a useful and objective method for detecting perfusion abnormalities in SLE patients.%目的:探讨定量分析在SPECT脑99mTc-ECD显像检测系统性红斑狼疮(SLE)脑病中的应用价值和目测分析与定量分析方法的相关性.方法:选择年龄匹配的健康人作比较,分别对33例SLE患者和29例正常对照进行SPECT脑血流灌注显像,采用肉眼读片分析及定量分析进行评价,BS软件进行分析.结果:狼疮脑病患者99mTc-ECD显像有脑血流改变,多表现为局部脑血流降低.肉眼读片分析SPECT诊断的SLE脑部受损的阳性率为51.51%,定量分析的阳性率达57.57%.成组t检验示扣带回、颞顶叶等部位最常受累.结论:SPECT脑血流灌注显像可探查到脑组织代谢

  20. Molecular imaging of angiogenesis with SPECT.

    NARCIS (Netherlands)

    Dijkgraaf, I.; Boerman, O.C.

    2010-01-01

    Single-photon emission computed tomography (SPECT) and position emission tomography (PET) are the two main imaging modalities in nuclear medicine. SPECT imaging is more widely available than PET imaging and the radionuclides used for SPECT are easier to prepare and usually have a longer half-life th

  1. Predicting the onset of period-doubling bifurcations in noisy cardiac systems.

    Science.gov (United States)

    Quail, Thomas; Shrier, Alvin; Glass, Leon

    2015-07-28

    Biological, physical, and social systems often display qualitative changes in dynamics. Developing early warning signals to predict the onset of these transitions is an important goal. The current work is motivated by transitions of cardiac rhythms, where the appearance of alternating features in the timing of cardiac events is often a precursor to the initiation of serious cardiac arrhythmias. We treat embryonic chick cardiac cells with a potassium channel blocker, which leads to the initiation of alternating rhythms. We associate this transition with a mathematical instability, called a period-doubling bifurcation, in a model of the cardiac cells. Period-doubling bifurcations have been linked to the onset of abnormal alternating cardiac rhythms, which have been implicated in cardiac arrhythmias such as T-wave alternans and various tachycardias. Theory predicts that in the neighborhood of the transition, the system's dynamics slow down, leading to noise amplification and the manifestation of oscillations in the autocorrelation function. Examining the aggregates' interbeat intervals, we observe the oscillations in the autocorrelation function and noise amplification preceding the bifurcation. We analyze plots--termed return maps--that relate the current interbeat interval with the following interbeat interval. Based on these plots, we develop a quantitative measure using the slope of the return map to assess how close the system is to the bifurcation. Furthermore, the slope of the return map and the lag-1 autocorrelation coefficient are equal. Our results suggest that the slope and the lag-1 autocorrelation coefficient represent quantitative measures to predict the onset of abnormal alternating cardiac rhythms.

  2. Comparison of ultra-high-resolution parallel-hole collimator materials based on the CdTe pixelated semiconductor SPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Jin; Ryu, Hyun-Ju; Lee, Seung-Wan; Park, Su-Jin; Kim, Hee-Joung, E-mail: hjk1@yonsei.ac.kr

    2013-06-11

    Recently, many studies have sought to improve the sensitivity and spatial resolution of pixelated semiconductor detectors. Spatial resolution can be improved by using a pinhole or pixelated parallel-hole collimator with equal hole and pixel sizes. We compared a pinhole to a pixelated parallel-hole collimator and found that the pixelated parallel-hole collimator had higher sensitivity. Additionally, collimator materials with high absorption efficiency are often used because of their high spatial resolution. The purpose of this study was to compare the quality of images generated using a pixelated semiconductor single photon emission computed tomography (SPECT) system simulated with pixelated parallel-hole collimators of lead, tungsten, gold, and depleted uranium. We performed a simulation study of the PID 350 (Ajat Oy Ltd., Finland) CdTe pixelated semiconductor detector, which consists of small pixels (0.35×0.35 mm{sup 2}), using a Geant4 Application for Tomographic Emission (GATE) simulation. Sensitivities and spatial resolutions were measured for the four collimator materials. To evaluate overall image performance, a hot-rod phantom was designed using GATE simulation. The results showed that with lead, sensitivity was 4.25%, 6.53%, and 10.28% higher than with tungsten, gold, and depleted uranium, respectively. Spatial resolution using depleted uranium was 3.19%, 4.19%, and 8.01% better than that of gold, tungsten, and lead, respectively. Sensitivity and spatial resolution showed little difference among the four types of collimator materials tested. It was difficult to visually distinguish between the reconstructed images of the hot-rod phantom for different collimator materials. The results are promising for notable cost reductions in collimator manufacturing while avoiding impractical and rare materials.

  3. Hotspot quantification of myocardial focal tracer uptake from molecular targeted SPECT/CT images: experimental validation

    Science.gov (United States)

    Liu, Yi-Hwa; Sahul, Zakir; Weyman, Christopher A.; Ryder, William J.; Dione, Donald P.; Dobrucki, Lawrence W.; Mekkaoui, Choukri; Brennan, Matthew P.; Hu, Xiaoyue; Hawley, Christi; Sinusas, Albert J.

    2008-03-01

    We have developed a new single photon emission computerized tomography (SPECT) hotspot quantification method incorporating extra cardiac activity correction and hotspot normal limit estimation. The method was validated for estimation accuracy of myocardial tracer focal uptake in a chronic canine model of myocardial infarction (MI). Dogs (n = 4) at 2 weeks post MI were injected with Tl-201 and a Tc-99m-labeled hotspot tracer targeted at matrix metalloproteinases (MMPs). An external point source filled with Tc-99m was used for a reference of absolute radioactivity. Dual-isotope (Tc-99m/Tl-201) SPECT images were acquired simultaneously followed by an X-ray CT acquisition. Dogs were sacrificed after imaging for myocardial gamma well counting. Images were reconstructed with CT-based attenuation correction (AC) and without AC (NAC) and were quantified using our quantification method. Normal limits for myocardial hotspot uptake were estimated based on 3 different schemes: maximum entropy, meansquared-error minimization (MSEM) and global minimization. Absolute myocardial hotspot uptake was quantified from SPECT images using the normal limits and compared with well-counted radioactivity on a segment-by-segment basis (n = 12 segments/dog). Radioactivity was expressed as % injected dose (%ID). There was an excellent correlation (r = 0.78-0.92) between the estimated activity (%ID) derived using the SPECT quantitative approach and well-counting, independent of AC. However, SPECT quantification without AC resulted in the significant underestimation of radioactivity. Quantification using SPECT with AC and the MSEM normal limit yielded the best results compared with well-counting. In conclusion, focal myocardial "hotspot" uptake of a targeted radiotracer can be accurately quantified in vivo using a method that incorporates SPECT imaging with AC, an external reference, background scatter compensation, and a suitable normal limit. This hybrid SPECT/CT approach allows for the serial

  4. 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.

  5. Strategies to Study Desmin in Cardiac Muscle and Culture Systems.

    Science.gov (United States)

    Diokmetzidou, Antigoni; Tsikitis, Mary; Nikouli, Sofia; Kloukina, Ismini; Tsoupri, Elsa; Papathanasiou, Stamatis; Psarras, Stelios; Mavroidis, Manolis; Capetanaki, Yassemi

    2016-01-01

    Intermediate filament (IF) cytoskeleton comprises the fine-tuning cellular machinery regulating critical homeostatic mechanisms. In skeletal and cardiac muscle, deficiency or disturbance of the IF network leads to severe pathology, particularly in the latter. The three-dimensional scaffold of the muscle-specific IF protein desmin interconnects key features of the cardiac muscle cells, including the Z-disks, intercalated disks, plasma membrane, nucleus, mitochondria, lysosomes, and potentially sarcoplasmic reticulum. This is crucial for the highly organized striated muscle, in which effective energy production and transmission as well as mechanochemical signaling are tightly coordinated among the organelles and the contractile apparatus. The role of desmin and desmin-associated proteins in the biogenesis, trafficking, and organelle function, as well as the development, differentiation, and survival of the cardiac muscle begins to be enlightened, but the precise mechanisms remain elusive. We propose a set of experimental tools that can be used, in vivo and in vitro, to unravel crucial new pathways by which the IF cytoskeleton facilitates proper organelle function, homeostasis, and cytoprotection and further understand how its disturbance and deficiency lead to disease.

  6. [A hardware-software system for monitoring the characteristics of the cardiac conduction system].

    Science.gov (United States)

    Fedotov, N M; Oferkin, A I; Zharyĭ, S V

    2008-01-01

    A new hardware-software system for monitoring and treatment of the cardiac conduction system abnormalities is described. The system can also be used to test non-X-ray devices for detection and imaging of endocardial electrodes. The system uses a reliable position measurement method based on biplane fluoroscopy. The system consists of standard units for electrophysiological examination of the heart. The system can operate using a preset model stored in the system database or a model constructed from X-ray imaging data. The preset mathematical model provides fast detection of the abnormal excitation site and effective electrode navigation based on the iteration procedure. On the other hand, the constructed model is more specific: it provides an opportunity to reconstruct the excitation front and store the electrode and site positions.

  7. STUDY AND APPLICATION ABOUT COMPUTED SYSTEM FOR EXTERNAL CARDIAC MASSAGE,MONITOR OF HEART AND BODY TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To make and study computed system for external cardiac massage, monitor of heart and body temperature and observe its clinical effect. Method: The system was made and applied. Result: The effect of system was obvious. Conclusion: The system was an effective clinical equipment in treatment of patient with cardiac arrest.

  8. Determination of Three-Dimensional Left Ventricle Motion to Analyze Ventricular Dyssyncrony in SPECT Images

    DEFF Research Database (Denmark)

    de Sá Rebelo, Marina; Aarre, Ann Kirstine Hummelgaard; Clemmesen, Karen-Louise;

    2010-01-01

    A method to compute three-dimension (3D) left ventricle (LV) motion and its color coded visualization scheme for the qualitative analysis in SPECT images is proposed. It is used to investigate some aspects of Cardiac Resynchronization Therapy (CRT). The method was applied to 3D gated-SPECT images...... sets from normal subjects and patients with severe Idiopathic Heart Failure, before and after CRT. Color coded visualization maps representing the LV regional motion showed significant difference between patients and normal subjects. Moreover, they indicated a difference between the two groups...

  9. Interaction of the renin-angiotensin system and the endothelin system in cardiac hypertrophy.

    Science.gov (United States)

    Stula, M; Pinto, Y M; Gschwend, S; Teisman, A C; van Gilst, W H; Böhm, M; Dietz, R; Paul, M

    1998-01-01

    It has been suggested that the renin-angiotensin system (RAS) interacts with the endothelin system in the pathogenesis of cardiac remodeling. We examined endothelin system regulation in a model of chronic RAS dysfunction, which is believed to be an important factor in cardiac remodeling. We used the transgenic rat line TGR(mRen2)27, which overexpresses the mouse Renin-2 gene and shows hypertension and left ventricular hypertrophy compared to Sprague-Dawley (SD) rats. Ren-2 rats (n = 24) received either losartan (LOS), quniapril (QIN), or carvedilol (CARV) for 11 weeks, or no treatment. After 11 weeks left (LV) and right ventricular (RV) weights were determined and total RNA extracted. Ren-2 rats showed a mean systolic blood pressure of 190 mm (+/- SEM), which could be normalized to 110 +/- mm (+/- SEM) by treatment with LOS or QIN. CARV also reduced blood pressure but did not normalize it. LV end-diastolic pressure was normal in both SD and Ren-2 rats. LV weight was increased in the Ren-2 rats compared to SD rats, and was significantly reduced to normal in the LOS and QIN but not in the CARV group. RV weight was normal in all groups. Northern blot analysis of preproendothelin-1 (preproET-1) and endothelin-converting enzyme-1 (ECE-1) expression revealed a significant (p < 0.05) 20% decrease in preproET-1 mRNA in the mRen2 rats in the RV and in the LV, compared to SD rats. ECE-1 mRNA was unchanged. Treatment with LOS, but not with QIN or CARV, induced preproET-1 transcription by threefold (p < 0.01) over baseline in both the LV and RV. ECE-1 mRNA was unaltered in the CARV and LOS group and was decreased by 20% in the QIN group. Similar changes in LV and RV indicated a direct influence of a dysregulated RAS on the endothelin system. In conclusion, the activated RAS downregulates the endothelin system in this model of cardiac hypertrophy. This suggests that in chronic RAS activated, the endothelin system may have a different pathophysiologic impact as a co

  10. 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

  11. Fetal cardiac activity analysis during twin pregnancy using a multi-channel SQUID system

    Science.gov (United States)

    Costa Monteiro, E.; Schleussner, E.; Kausch, S.; Grimm, B.; Schneider, A.; Hall Barbosa, C.; Haueisen, J.

    2001-05-01

    The use of SQUID magnetometers for non-invasive in utero assessment of cardiac electrical disturbances has already been shown to be a valuable clinical tool. In this way, its applicability also for the complicated case of twin pregnancy, in which the proximity of the cardiac magnetic source of each fetus can hamper the individual analysis of cardiac electrical activity, is of clinical interest. In this paper, we present fetal magnetocardiography performed on a mother pregnant of twins with 26 weeks gestational age, measured inside a magnetically shielded room, by using two identical 31-channel low- Tc SQUID magnetometer systems. Each sensor array has been positioned over one of the fetuses, according to its heart position previously assessed with the aid of ultrasound measurements. The raw data is initially averaged in time and, afterwards, analyzed by means of time plots and isofield maps. The time recordings allow the study of the morphology of each fetus’ cardiac signal and the cardiac time intervals. The resultant equivalent dipole obtained from the isofield maps indicates the position and orientation of each fetus heart. The results agree with the ultrasound analysis performed immediately before the measurements and used to obtain the approximate location of the fetuses’ hearts. Since a distinct analysis of the cardiac electrical activity of each fetus could be achieved, the results indicate the potential of the fetal magnetocardiography in the individual antenatal diagnosis of each one of the fetuses of a twin pregnancy.

  12. Cardiac arrhythmias and conduction defects in systemic sclerosis.

    Science.gov (United States)

    Vacca, Alessandra; Meune, Christophe; Gordon, Jessica; Chung, Lorinda; Proudman, Susanna; Assassi, Shervin; Nikpour, Mandana; Rodriguez-Reyna, Tatiana S; Khanna, Dinesh; Lafyatis, Robert; Matucci-Cerinic, Marco; Distler, Oliver; Allanore, Yannick

    2014-07-01

    Signs and symptoms of arrhythmias or conduction defects are frequently reported in patients with SSc. These rhythm disorders may have several origins (i.e., related to primary heart involvement, pericardial disease, valvular regurgitation or pulmonary arterial hypertension) and may negatively affect the overall prognosis of these patients. It is therefore important to identify patients at high risk for cardiac arrhythmias with a complete cardiological evaluation and to identify the underlying heart disease, including SSc-related myocardial involvement. In addition, some therapeutic options in SSc patients may differ from those recommended in other populations.

  13. Modeling cardiac mechano-electrical feedback using reaction-diffusion-mechanics systems

    Science.gov (United States)

    Keldermann, R. H.; Nash, M. P.; Panfilov, A. V.

    2009-06-01

    In many practically important cases, wave propagation described by the reaction-diffusion equation initiates deformation of the medium. Mathematically, such processes are described by coupled reaction-diffusion-mechanics (RDM) systems. RDM systems were recently used to study the effects of deformation on wave propagation in cardiac tissue, so called mechano-electrical feedback (MEF). In this article, we review the results of some of these studies, in particular those relating to the effects of deformation on pacemaker activity and spiral wave dynamics in the heart. We also provide brief descriptions of the numerical methods used, and the underlying cardiac physiology.

  14. CALOR87: HETC87, MICAP, EGS4, and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, T.A.; Alsmiller, F.S.; Alsmiller, R.G. Jr.; Bishop, B.L.; Hermann, O.W.; Johnson, J.O.

    1987-01-01

    A brief history of CALOR (HETC, EGS, MICAP, SPECT) is presented to indicate the evolution of this code system. Details concerning the current modifications and additions to the high-energy transport code, HETC, are also presented and new comparisons with experimental data are included to verify the new physics improvements. 27 refs., 5 figs.

  15. 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...

  16. Cost-effectiveness of exercise {sup 201}Tl myocardial SPECT in patients with chest pain assessed by decision-tree analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kosuda, Shigeru; Momiyama, Yukihiko; Ohsuzu, Fumitaka; Kusano, Shoichi [National Defense Medical Coll., Tokorozawa, Saitama (Japan); Ichihara, Kiyoshi

    1999-09-01

    To evaluate the potential cost-effectiveness of exercise {sup 201}Tl myocardial SPECT in outpatients with angina-like chest pain, we developed a decision-tree model which comprises three 1000-patients groups, i.e., a coronary arteriography (CAG) group, a follow-up group, and a SPECT group, and total cost and cardiac events, including cardiac deaths, were calculated. Variables used for the decision-tree analysis were obtained from references and the data available at out hospital. The sensitivity and specificity of {sup 201}Tl SPECT for diagnosing angina pectoris, and its prevalence were assumed to be 95%, 85%, and 33%, respectively. The mean costs were 84.9 x 10{sup 4} yen/patient in the CAG group, 30.2 x 10{sup 4} yen/patient in the follow-up group, and 71.0 x 10{sup 4} yen/patient in the SPECT group. The numbers of cardiac events and cardiac deaths were 56 and 15, respectively in the CAG group, 264 and 81 in the follow-up group, and 65 and 17 in the SPECT group. SPECT increases cardiac events and cardiac deaths by 0.9% and 0.2%, but it reduces the number of CAG studies by 50.3%, and saves 13.8 x 10{sup 4} yen/patient, as compared to the CAG group. In conclusion, the exercise {sup 201}Tl myocardial SPECT strategy for patients with chest pain has the potential to reduce health care costs in Japan. (author)

  17. 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

    Purpose: Brain single photon emission computed tomography (SPECT) imaging is an important clinical tool, with unique tracers for studying neurological diseases. Nowadays, most commercial SPECT systems are combined with x-ray computed tomography (CT) in so-called SPECT/CT systems to obtain an anatomical background for the functional information. However, while CT images have a high spatial resolution, they have a low soft-tissue contrast, which is an important disadvantage for brain imaging. Magnetic resonance imaging (MRI), on the other hand, has a very high soft-tissue contrast and does not involve extra ionizing radiation. Therefore, the authors designed a brain SPECT insert that can operate inside a clinical MRI. Methods: The authors designed and simulated a compact stationary multipinhole SPECT insert based on digital silicon photomultiplier detector modules, which have shown to be MR-compatible and have an excellent intrinsic resolution (0.5 mm) when combined with a monolithic 2 mm thick LYSO crystal. First, the authors optimized the different parameters of the SPECT system to maximize sensitivity for a given target resolution of 7.2 mm in the center of the field-of-view, given the spatial constraints of the MR system. Second, the authors performed noiseless simulations of two multipinhole configurations to evaluate sampling and reconstructed resolution. Finally, the authors performed Monte Carlo simulations and compared the SPECT insert with a clinical system with ultrahigh-resolution (UHR) fan beam collimators, based on contrast-to-noise ratio and a visual comparison of a Hoffman phantom with a 9 mm cold lesion. Results: The optimization resulted in a stationary multipinhole system with a collimator radius of 150.2 mm and a detector radius of 172.67 mm, which corresponds to four rings of 34 diSPM detector modules. This allows the authors to include eight rings of 24 pinholes, which results in a system volume sensitivity of 395 cps/MBq. Noiseless simulations

  18. A critical role of cardiac fibroblast-derived exosomes in activating renin angiotensin system in cardiomyocytes.

    Science.gov (United States)

    Lyu, Linmao; Wang, Hui; Li, Bin; Qin, Qingyun; Qi, Lei; Nagarkatti, Mitzi; Nagarkatti, Prakash; Janicki, Joseph S; Wang, Xing Li; Cui, Taixing

    2015-12-01

    Chronic activation of the myocardial renin angiotensin system (RAS) elevates the local level of angiotensin II (Ang II) thereby inducing pathological cardiac hypertrophy, which contributes to heart failure. However, the precise underlying mechanisms have not been fully delineated. Herein we report a novel paracrine mechanism between cardiac fibroblasts (CF)s and cardiomyocytes whereby Ang II induces pathological cardiac hypertrophy. In cultured CFs, Ang II treatment enhanced exosome release via the activation of Ang II receptor types 1 (AT1R) and 2 (AT2R), whereas lipopolysaccharide, insulin, endothelin (ET)-1, transforming growth factor beta (TGFβ)1 or hydrogen peroxide did not. The CF-derived exosomes upregulated the expression of renin, angiotensinogen, AT1R, and AT2R, downregulated angiotensin-converting enzyme 2, and enhanced Ang II production in cultured cardiomyocytes. In addition, the CF exosome-induced cardiomyocyte hypertrophy was blocked by both AT1R and AT2R antagonists. Exosome inhibitors, GW4869 and dimethyl amiloride (DMA), inhibited CF-induced cardiomyocyte hypertrophy with little effect on Ang II-induced cardiomyocyte hypertrophy. Mechanistically, CF exosomes upregulated RAS in cardiomyocytes via the activation of mitogen-activated protein kinases (MAPKs) and Akt. Finally, Ang II-induced exosome release from cardiac fibroblasts and pathological cardiac hypertrophy were dramatically inhibited by GW4869 and DMA in mice. These findings demonstrate that Ang II stimulates CFs to release exosomes, which in turn increase Ang II production and its receptor expression in cardiomyocytes, thereby intensifying Ang II-induced pathological cardiac hypertrophy. Accordingly, specific targeting of Ang II-induced exosome release from CFs may serve as a novel therapeutic approach to treat cardiac pathological hypertrophy and heart failure.

  19. Prognostic value of normal stress-only myocardial perfusion imaging: a comparison between conventional and CZT-based SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

    Single photon emission computed tomography (SPECT) myocardial perfusion imaging has proven to have prognostic importance in patients with suspected stable coronary artery disease (CAD). The recently introduced ultrafast cadmium zinc telluride (CZT)-based gamma cameras have been associated with less equivocal findings and more normal interpretations, allowing stress-only imaging to be performed more often. However, it is yet unclear whether normal stress-only CZT SPECT has comparable prognostic value as normally interpreted stress-only conventional SPECT. The study population consisted of 1,650 consecutive patients without known CAD with normal stress-only myocardial perfusion results with either conventional (n = 362) or CZT SPECT (n = 1,288). The incidence of major adverse cardiac events (MACE, all-cause death, non-fatal myocardial infarction and/or coronary revascularization) was compared between the conventional SPECT and CZT SPECT groups. Multivariable analyses using the Cox model were used to adjust for differences in baseline variables. Patients scanned with CZT were less often male (33 vs 39 %), had less often hypercholesterolaemia (41 vs 50 %) and had more often a family history of CAD (57 vs 49 %). At a median follow-up time of 37 months (interquartile range 28-45 months) MACE occurred in 68 patients. The incidence of MACE was 1.5 %/year in the CZT group, compared to 2.0 %/year in the conventional group (p = 0.08). After multivariate analyses, there was a trend to a lower incidence of MACE in the CZT SPECT group (hazard ratio 0.61, 95 % confidence interval 0.35-1.04, p = 0.07). The prognostic value of normal stress-only CZT SPECT is at least comparable and may be even better than that of normal conventional stress SPECT. (orig.)

  20. Optimizing and Evaluating an Integrated SPECT-CmT System Dedicated to Improved 3-D Breast Cancer Imaging

    Science.gov (United States)

    2009-05-01

    the imaging system’s required clinica l performance. This evidence ranged from the ability of the CmT system to image close to the chest wall (see...year old woman undergoing dual-view screening mammograph y of her remaining int act breast seven years after a mastectomy) to completing a medica ...Telluride (CZT) gamma camera (model LumaGEM 3200S, Gamma Medica , Inc., Northridge, CA) with discretized crystals, each 2.3x2.3x5mm3 on a 2.5mm

  1. 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

  2. Left ventricular dyssynchrony assessed by gated SPECT phase analysis is an independent predictor of death in patients with advanced coronary artery disease and reduced left ventricular function not undergoing cardiac resynchronization therapy

    Energy Technology Data Exchange (ETDEWEB)

    Uebleis, Christopher; Hellweger, Stefan; Lehner, Sebastian; Haug, Alexander; Bartenstein, Peter; Cumming, Paul; Hacker, Marcus [Ludwig-Maximilians University, Department of Nuclear Medicine, Munich (Germany); Laubender, Ruediger Paul [Ludwig-Maximilians University, Institute of Medical Informatics, Biometry, and Epidemiology (IBE), Munich (Germany); Becker, Alexander [Ludwig-Maximilians University, Medical Department I, Munich (Germany); Sohn, Hae-Young [Ludwig-Maximilians University, Medical Department Innenstadt, Munich (Germany); Van Kriekinge, Serge D.; Slomka, Piotr J. [Cedars-Sinai Medical Center, Los Angeles, CA (United States); UCLA, David Geffen School of Medicine, Los Angeles, CA (United States)

    2012-10-15

    Left ventricular (LV) mechanical dyssynchrony (LVMD) was assessed by gated single-photon emission CT myocardial perfusion imaging (MPI) as an independent predictor of death from any cause in patients with known coronary artery disease (CAD) and reduced LV function. Between 2001 and 2010, 135 patients (64 {+-} 11 years of age, 84 % men) with known CAD, reduced LV ejection fraction (LVEF, 38 {+-} 15 %) and without an implanted cardiac resynchronization therapy device underwent gated MPI at rest. LV functional evaluation, which included phase analysis, was conducted to identify patients with LVMD. Kaplan-Meier survival curves were calculated for death of any cause during a mean follow-up of 2.0 {+-} 1.7 years. Uni- and multivariate Cox proportional hazards regression models were calculated to identify independent predictors of death from any cause. Of the 135 patients, 30 (22 %) died during follow-up (18 cardiac deaths and 12 deaths from other causes). Kaplan-Meier curves showed a significantly shorter survival time in the patients with severely reduced LVEF (<30 %, n = 45) or with LVMD (n = 81, log-rank test P <0.005). Cox models identified LVMD, LVEF <30 % and a total perfusion deficit at rest of {>=}20 % as independent predictors of death from any cause. While patients with LVEF <30 % in conjunction with LVMD had similar survival times irrespective of whether they had early revascularization or medical therapy, those patients with LVEF {>=}30% and LVMD who underwent revascularization had significantly longer survival. In patients with known CAD and reduced LV function, dyssynchrony of the LV is an independent predictor of death from any cause. (orig.)

  3. New SPECT and PET Radiopharmaceuticals for Imaging Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Oyebola O. Sogbein

    2014-01-01

    Full Text Available Nuclear cardiology has experienced exponential growth within the past four decades with converging capacity to diagnose and influence management of a variety of cardiovascular diseases. Single photon emission computed tomography (SPECT myocardial perfusion imaging (MPI with technetium-99m radiotracers or thallium-201 has dominated the field; however new hardware and software designs that optimize image quality with reduced radiation exposure are fuelling a resurgence of interest at the preclinical and clinical levels to expand beyond MPI. Other imaging modalities including positron emission tomography (PET and magnetic resonance imaging (MRI continue to emerge as powerful players with an expanded capacity to diagnose a variety of cardiac conditions. At the forefront of this resurgence is the development of novel target vectors based on an enhanced understanding of the underlying pathophysiological process in the subcellular domain. Molecular imaging with novel radiopharmaceuticals engineered to target a specific subcellular process has the capacity to improve diagnostic accuracy and deliver enhanced prognostic information to alter management. This paper, while not comprehensive, will review the recent advancements in radiotracer development for SPECT and PET MPI, autonomic dysfunction, apoptosis, atherosclerotic plaques, metabolism, and viability. The relevant radiochemistry and preclinical and clinical development in addition to molecular imaging with emerging modalities such as cardiac MRI and PET-MR will be discussed.

  4. N-13 ammonia myocardial positron computed tomography, (1). Comparative study with thallium-201 SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Nagara; Senda, Michio; Yonekura, Yoshiharu

    1985-02-01

    Myocardial positron computed tomography (PCT) was obtained in 11 cases and the images were compared with thallium-201 single-photon emission computed tomography (SPECT). The myocardial PCT was performed at rest after 10-20 mCi of N-13 labeled ammonia injection using whole-body multislice PCT device (Positologica III). The PCT clearly delineated 2.5-3.0 mm hot spots while the SPECT barely showed 5.0 mm hot spots of Derenzo phantom. The myocardial images looked better in PCT because of the better spatial resolution and count statistics. The myocardium looked thinner and the papillary muscle was visualized by PCT. The PCT also showed the right ventricle in each case. Furthermore, PCT detected increased lung uptake of ammonia in 2 of the 8 cases with myocardial infarction, suggesting presence of pulmonary congestion. Perfusion defect was clearly seen by PCT as well as SPECT. However, the cardiac short-axis and long-axis sections which were easily obtained by SPECT were useful for the localization of the lesion. We conclude that both PCT and SPECT were valuable for the assessment of coronary artery disease. (author).

  5. A single CdZnTe detector for simultaneous CT/SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Barber, W.C. E-mail: bill@barber.uscf.edu; Iwata, Koji; Hasegawa, B.H.; Bennett, P.R.; Cirignano, L.J.; Shah, K.S

    2003-06-01

    Clinical CT/SPECT systems acquire CT and SPECT data sequentially using different detectors in close proximity to minimise patient movement and interscan delay. We have developed a prototype simultaneous CT/SPECT imager, using a single CdZnTe detector, with the goal of improving image coregistration and decreasing scan time. A 16-pixel CdZnTe detector was operated in pulse-counting mode with 50 ns shaping time. Energy discrimination is used to separate the CT and SPECT data. Simultaneous SPECT and CT images were obtained for a phantom with the X-ray flux limited to reduce pulse pile-up in the radionuclide energy window. At 140 keV, the efficiency and energy resolution are 70% and 10%, respectively, and were constant for fluence rates up to 10{sup 3} cps per detector element for 140 keV gamma rays, but degrade rapidly at higher fluence rates. In pulse-counting mode, the maximum count rate of 10{sup 3} cps per element from the CdZnTe detector is sufficient for SPECT imaging, but is considerably lower than the fluence rates encountered in CT. The smallest lesion visually detectable in SPECT is 9 mm and the CT spatial resolution is smaller than 4.5 mm. Image registration is intrinsic because the data can be acquired simultaneously with a single detector with the same reconstruction geometry.

  6. Non-sedating antihistamine drugs and cardiac arrhythmias : biased risk estimates from spontaneous reporting systems?

    NARCIS (Netherlands)

    De Bruin, M L; van Puijenbroek, E P; Egberts, A C G; Hoes, A W; Leufkens, H G M

    2002-01-01

    AIMS: This study used spontaneous reports of adverse events to estimate the risk for developing cardiac arrhythmias due to the systemic use of non-sedating antihistamine drugs and compared the risk estimate before and after the regulatory action to recall the over-the-counter status of some of these

  7. Time-resolved cardiac cone beam CT using an interventional C-arm system

    NARCIS (Netherlands)

    Schomberg, H.

    2012-01-01

    It is both desirable and challenging to make interventional C-arm systems fit for cardiac cone beam CT. A number of methods towards thisgoal have been proposed, some of which even attempt to generate 4Dimages of the beating heart. A promising candidate of this type, proposed earlier by this author,

  8. A new automated method for analysis of gated-SPECT images based on a three-dimensional heart shaped model

    DEFF Research Database (Denmark)

    Lomsky, Milan; Richter, Jens; Johansson, Lena

    2005-01-01

    A new automated method for quantification of left ventricular function from gated-single photon emission computed tomography (SPECT) images has been developed. The method for quantification of cardiac function (CAFU) is based on a heart shaped model and the active shape algorithm. The model...

  9. Improvement of tomographic reconstruction in bone SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Schuenemann, M.; Sahlmann, C.O.; Siefker, U.; Luig, H.; Meller, J. [Abteilungen fuer Nuklearmedizin, Georg-August-Univ. Goettingen (Germany); Heidrich, G. [Abteilungen fuer Diagnostische Radiologie, Georg-August-Univ., Goettingen (Germany); Werner, C.; Brunner, E. [Abteilungen fuer Medizinische Statistik, Georg-August-Univ., Goettingen (Germany)

    2006-07-01

    Aim: the comparison between iterative reconstruction and filtered backprojection in the reconstruction of bone SPECT in the diagnosis of skeletal metastases. Patients, methods: 47 consecutive patients (vertebral segments: n = 435), with suspected malignancy of the vertebral column, were examined by bone scintigraphy and MRI (maximal interval between the two procedures {+-} 5 weeks). The SPECT-data were reconstructed with an iterative algorithm (ISA) and with filtered backprojection. We defined semiquantitative criteria in order to assess the quality of the tomograms. Conventional reconstruction was performed both by a Wiener-filter and a low-pass-filter. Iterative reconstruction was performed by the ISA algorithm. The clinical evaluation of the different reconstruction algorithms was performed by MRI as the gold-standard. Results: sensitivity (%): 87.3 (ISA), 86.4 (low-pass), 79.7 (Wiener); specificity (%): 95.3 (ISA), 95 (low-pass), 85.4 (Wiener). The sensitivity of iterative reconstructed SPECT and low-pass reconstructed SPECT was significantly higher (p < 0.05) compared with the sensitivity of SPECT reconstructed by the Wiener-filter. The specificity of iterative reconstruction ISA and low-pass-filter reconstructed SPECT were significantly higher compared with the SPECT data reconstructed by the Wiener-filter. ISA was significantly superior to the Wiener-SPECT relating to all criteria of quality. Iterative reconstruction was significantly superior to the low-pass-SPECT relating to 2 of 3 criteria. In addition the Wiener-SPECT was significantly inferior to the low-pass-SPECT regarding to 2 of 3 criteria. Conclusion: in our series the iterative algorithm ISA was the method of choice in the reconstruction of bone SPECT data. In comparison with conventional algorithms ISA offers a significantly higher quality of the tomograms and yields a high diagnostic accuracy. (orig.)

  10. Systemic and Cardiac Depletion of M2 Macrophage through CSF-1R Signaling Inhibition Alters Cardiac Function Post Myocardial Infarction

    OpenAIRE

    Anne-Laure Leblond; Kerstin Klinkert; Kenneth Martin; Turner, Elizebeth C.; Arun H Kumar; Tara Browne; Caplice, Noel M.

    2015-01-01

    The heart hosts tissue resident macrophages which are capable of modulating cardiac inflammation and function by multiple mechanisms. At present, the consequences of phenotypic diversity in macrophages in the heart are incompletely understood. The contribution of cardiac M2-polarized macrophages to the resolution of inflammation and repair response following myocardial infarction remains to be fully defined. In this study, the role of M2 macrophages was investigated utilising a specific CSF-1...

  11. Na/K pump regulation of cardiac repolarization: insights from a systems biology approach

    KAUST Repository

    Bueno-Orovio, Alfonso

    2013-05-15

    The sodium-potassium pump is widely recognized as the principal mechanism for active ion transport across the cellular membrane of cardiac tissue, being responsible for the creation and maintenance of the transarcolemmal sodium and potassium gradients, crucial for cardiac cell electrophysiology. Importantly, sodium-potassium pump activity is impaired in a number of major diseased conditions, including ischemia and heart failure. However, its subtle ways of action on cardiac electrophysiology, both directly through its electrogenic nature and indirectly via the regulation of cell homeostasis, make it hard to predict the electrophysiological consequences of reduced sodium-potassium pump activity in cardiac repolarization. In this review, we discuss how recent studies adopting the systems biology approach, through the integration of experimental and modeling methodologies, have identified the sodium-potassium pump as one of the most important ionic mechanisms in regulating key properties of cardiac repolarization and its rate dependence, from subcellular to whole organ levels. These include the role of the pump in the biphasic modulation of cellular repolarization and refractoriness, the rate control of intracellular sodium and calcium dynamics and therefore of the adaptation of repolarization to changes in heart rate, as well as its importance in regulating pro-arrhythmic substrates through modulation of dispersion of repolarization and restitution. Theoretical findings are consistent across a variety of cell types and species including human, and widely in agreement with experimental findings. The novel insights and hypotheses on the role of the pump in cardiac electrophysiology obtained through this integrative approach could eventually lead to novel therapeutic and diagnostic strategies. © 2013 Springer-Verlag Berlin Heidelberg.

  12. Autonomic Dysfunction Predicts Early Cardiac Affection in Patients with Systemic Sclerosis

    Directory of Open Access Journals (Sweden)

    Khaled M. Othman

    2010-05-01

    Full Text Available Objective: To detect the early preclinical alterations in cardiac autonomic control as well as altered cardiac function in systemic sclerosis (SSc patients and their relevance to the clinical features of the disease using noninvasive methods. Methods: 30 SSc patients and 15 healthy controls matched for age and sex underwent clinical examination, serological analysis, and echocardiographic assessment including Doppler flow imaging to evaluate cardiac function, and 24-hour Holter monitoring analyzed for arrhythmia and heart rate variability (HRV in the time and frequency domains. Results: The trans-mitral Doppler of early to atrial wave (E/A ratio was reversed in five patients (16.6% and the tricuspid E/A ratio was reversed in 10 patients (33.3%. Holter analysis for SSc patients revealed an increased prevalence of premature ventricular contractions (PVC $ 10/h (P = 0.02, supra-ventricular tachycardias (SVTs (P = 0.2, and total PVC count (P = 0.0000. Highly significant (P = 0.000 impairment in all HRV parameters was demonstrated in the SSc patients. Total skin thickness score (TSS, Raynaud’s phenomenon and anti-scleroderma 70 (anti-SCL70 showed significant positive correlations with all arrhythmia parameters, while showing a significant negative correlation with the impaired ventricular diastolic function and various HRV parameters. No correlation was found between arrhythmia and HRV parameters and disease duration, disease type, or presence of anti-centromere antibodies. Conclusion: Low heart rate variability, increased TSS and the presence of anti-SCL70 are correlated with preclinical cardiac involvement in SSc patients and may predict the likelihood of malignant arrhythmia and sudden cardiac death. Therefore, noninvasive HRV evaluation before clinical cardiac involvement in these patients might be beneficial when added to the clinical and laboratory assessments in detecting high-risk patients, and may allow for implementation of preventive

  13. 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.

  14. 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.).

  15. Cardiac sympathetic nervous system imaging with (123)I-meta-iodobenzylguanidine: Perspectives from Japan and Europe.

    Science.gov (United States)

    Nakajima, Kenichi; Scholte, Arthur J H A; Nakata, Tomoaki; Dimitriu-Leen, Aukelien C; Chikamori, Taishiro; Vitola, João V; Yoshinaga, Keiichiro

    2017-03-13

    Cardiac sympathetic nervous system dysfunction is closely associated with risk of serious cardiac events in patients with heart failure (HF), including HF progression, pump-failure death, and sudden cardiac death by lethal ventricular arrhythmia. For cardiac sympathetic nervous system imaging, (123)I-meta-iodobenzylguanidine ((123)I-MIBG) was approved by the Japanese Ministry of Health, Labour and Welfare in 1992 and has therefore been widely used since in clinical settings. (123)I-MIBG was also later approved by the Food and Drug Administration (FDA) in the United States of America (USA) and it was expected to achieve broad acceptance. In Europe, (123)I-MIBG is currently used only for clinical research. This review article is based on a joint symposium of the Japanese Society of Nuclear Cardiology (JSNC) and the American Society of Nuclear Cardiology (ASNC), which was held in the annual meeting of JSNC in July 2016. JSNC members and a member of ASNC discussed the standardization of (123)I-MIBG parameters, and clinical aspects of (123)I-MIBG with a view to further promoting (123)I-MIBG imaging in Asia, the USA, Europe, and the rest of the world.

  16. Part and Parcel of the Cardiac Autonomic Nerve System: Unravelling Its Cellular Building Blocks during Development

    Directory of Open Access Journals (Sweden)

    Anna M. D. Végh

    2016-09-01

    Full Text Available The autonomic nervous system (cANS is essential for proper heart function, and complications such as heart failure, arrhythmias and even sudden cardiac death are associated with an altered cANS function. A changed innervation state may underlie (part of the atrial and ventricular arrhythmias observed after myocardial infarction. In other cardiac diseases, such as congenital heart disease, autonomic dysfunction may be related to disease outcome. This is also the case after heart transplantation, when the heart is denervated. Interest in the origin of the autonomic nerve system has renewed since the role of autonomic function in disease progression was recognized, and some plasticity in autonomic regeneration is evident. As with many pathological processes, autonomic dysfunction based on pathological innervation may be a partial recapitulation of the early development of innervation. As such, insight into the development of cardiac innervation and an understanding of the cellular background contributing to cardiac innervation during different phases of development is required. This review describes the development of the cANS and focuses on the cellular contributions, either directly by delivering cells or indirectly by secretion of necessary factors or cell-derivatives.

  17. SPECT/CT in neuroendocrine cancers; SPECT/CT bei neuroendokrinen Tumoren

    Energy Technology Data Exchange (ETDEWEB)

    Miederer, M. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik; Mainz Univ. (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Castrop, C.; Scheidhauer, K. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik; Buck, A.K. [Universitaetsklinikum Wuerzburg (Germany). Nuklearmedizinische Klinik und Poliklinik

    2011-03-15

    The accuracy of functional SPECT imaging has been significantly improved by addition of CT. This is especially relevant for functional imaging of neuroendocrine tumors using highly specific radiopharmaceuticals. Parathyroid adenomas can be detected by {sup 99m}Tc-MIBI SPECT/CT with very high sensitivity and specificity, playing an important role especially when minimally invasive techniques are used for surgical resection. With SPECT/CT, extra-adrenal manifestations of pheochromocytomas and tumors of the adrenal cortex can be detected with high accuracy. Because of the availability of PET radiopharmaceuticals such as {sup 68}Ga-DOTATOC, the clinical relevance of {sup 111}In-Octreotide SPECT for detection of neuroendocrine cancers has been recently reduced. Because of the better availability, SPECT and SPECT/CT still represent standard tools for imaging neuroendocrine cancers. SPECT/CT represents the superior imaging modality for monitoring radiopeptide based therapies, which are now increasingly used for treatment of neuroendocrine cancers. (orig.)

  18. 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.

  19. Comparison of arbutamine stress and treadmill exercise thallium-201 SPECT: Hemodynamics, safety profile and diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Kiat, H.; Berman, D.S. [Cedars-Sinai Medical Centre, Los Angeles, California, LA (United States)

    1998-02-01

    Full text: Arbutamine (ARB), a new pharmacologic stress agent with enhanced chronotropic property compared to dobutamine, was compared with treadmill (TM) exercise testing (Ex) in a multicenter study using thallium-201 (Tl) SPECT. Of the total of 184 patients who underwent ARB, 69 also had TM stress and quantitative coronary angiography. Fifty-eight patients with a low pretest likelihood of CAD also underwent ARB study for evaluation of test specificity (normalcy rate). Tl scans were scored by a central laboratory using a 20 segment (seg)/scan visual analysis (5 point system: 0=normal, 4-absent uptake). Maximum heart rate (HR) by ARB and Ex was 122 vs 141 bpm (p<0.05). Mean %HR change from baseline was similar (79% vs 82%, respectively, p=ns). Maximum systolic BP for ARB and Ex was 173 vs 175 mmHg, and mean % change from baseline was 24% vs 28% (p=ns). Sensitivity for detecting CAD (270% stenosis) by ARB Tl was 94% and 97% by Ex Tl (p=ns). Stress Tl SPECT segmental agreement for presence of defect between ARB and Ex was 92% (kappa=0.8, p<0.001). Exact segmental stress Tl score (0-4 grading) agreement was 83 % (kappa=0.7, p<0.001). Among 346 segs with stress defects by both ARB and Ex defect reversibility agreement was 86% (kappa=0.7, p<0.001). The normalcy rate for ARB TI-SPECT among patients with a low likelihood of CAD was 90%. Adverse events were mostly mild (tremor: 23%, flushing: 10%, headache: 10%, paraesthesia: 8%, dizziness: 8%, hot flushes: 4%). Arrhythimia of clinical concern occurred in 8% (10/122) of ARB patients who had cardiac catheterisation and in 1.4% (1/69) of patients who had stress Tl. Of all 184 patients with ARB stress, ARB was discontinued due to arrhythmia in 7(5%) and 1 patient had IV Metoprolol for frequent ventricular couplets. Sustained arrhythmias were not observed

  20. Diagnostic value of SPECT in bone scintigraphy; Bedeutung der SPECT bei der Knochenszintigraphie

    Energy Technology Data Exchange (ETDEWEB)

    Gratz, S.; Becker, W. [Goettingen Univ. (Germany). Abt. fuer Nuklearmedizin

    2000-05-01

    Single Photon Emission Computed Tomography (SPECT) reflects the realization of its ability to remove unwanted activity from bone structures with greater contrast. Especially in the spine SPECT improves the diagnostic accuracy compared with planar bone scintigraphy, because smaller structures of single vertebral bodies can be diagnosed with better anatomic resolution due to SPECT with consequently higher sensitivities and specificities. With SPECT, alterations of the lateral part of the vertebral body, pars interacticularis and smaller facet joints can be correctly diagnosed as spondylarthrotic degenerative alterations. In patients with suspected spine malignancies SPECT did not demonstrate to be a reliable instrument for diagnosing malignancy. We recommend to perform SPECT in case of patients with back pain and suspected spine pathologies seen on planar bone scans, since a correct diagnosis of especially benign spondylarthrotic spine lesions is possible with SPECT. With SPECT, a reduction of radiological examinations of 23% should be possible. (orig.) [German] Die Single-Photonenemissionscomputertomographie (SPECT) erlaubt bei der Knochenszintigraphie eine ueberlagerungsfreie Darstellung von Knochenstrukturen mit hoher Kontrastgenauigkeit. Insbesondere bei Wirbelsaeulenerkrankungen ermoeglicht SPECT einen deutlichen diagnostischen Zugewinn gegenueber planaren Aufnahmen, da kleinere Strukturen einzelner Wirbelkoerper aufgrund des hohen anatomischen Aufloesungsvermoegens mit SPECT sehr sensitiv und spezifisch dargestellt werden. Veraenderungen, die sich auf den lateralen Anteil des Wirbelkoerpers, die Pars interarticularis und die kleinen Facettengelenke projizieren, koennen mit SPECT als spondylarthrotisch degenerative Laesionen eingestuft werden. Zwingende SPECT-szintigraphische Kriterien, die eine Laesion als eindeutig maligne nachweisen, gibt es dagegen nicht. Wir denken, dass SPECT bei allen Patienten mit Rueckenschmerzen und planarszintigraphisch suspekten

  1. Modulation of Cardiac Autonomic Dysfunction in Ischemic Stroke following Ayurveda (Indian System of Medicine) Treatment.

    Science.gov (United States)

    Jaideep, Sriranjini Sitaram; Nagaraja, Dindagur; Pal, Pramod Kumar; Sudhakara, D; Talakad, Sathyaprabha N

    2014-01-01

    Objectives. Cardiac autonomic dysfunction in stroke has implications on morbidity and mortality. Ayurveda (Indian system of medicine) describes stroke as pakshaghata. We intended to study the effect of Ayurveda therapies on the cardiac autonomic dysfunction. Methods. Fifty patients of ischemic stroke (middle cerebral artery territory) (mean age 39.26 ± 9.88 years; male 43, female 7) were recruited within one month of ictus. All patients received standard allopathic medications as advised by neurologist. In addition, patients were randomized to receive physiotherapy (Group I) or Ayurveda treatment (Group II) for 14 days. Continuous electrocardiogram and finger arterial pressure were recorded for 15 min before and after treatments and analyzed offline to obtain heart rate and blood pressure variability and baroreflex sensitivity (BRS). Results were analysed by RMANOVA. Results. Patients in Group II showed statistically significant improvement in cardiac autonomic parameters. The standard deviation of normal to normal intervals,and total and low frequency powers were significantly enhanced (F = 8.16, P = 0.007, F = 9.73, P = 0.004, F = 13.51, and P = 0.001, resp.). The BRS too increased following the treatment period (F = 10.129, P = 0.004). Conclusions. The current study is the first to report a positive modulation of cardiac autonomic activity after adjuvant Ayurveda treatment in ischemic stroke. Further long term studies are warranted.

  2. Modulation of Cardiac Autonomic Dysfunction in Ischemic Stroke following Ayurveda (Indian System of Medicine Treatment

    Directory of Open Access Journals (Sweden)

    Sriranjini Sitaram Jaideep

    2014-01-01

    Full Text Available Objectives. Cardiac autonomic dysfunction in stroke has implications on morbidity and mortality. Ayurveda (Indian system of medicine describes stroke as pakshaghata. We intended to study the effect of Ayurveda therapies on the cardiac autonomic dysfunction. Methods. Fifty patients of ischemic stroke (middle cerebral artery territory (mean age 39.26 ± 9.88 years; male 43, female 7 were recruited within one month of ictus. All patients received standard allopathic medications as advised by neurologist. In addition, patients were randomized to receive physiotherapy (Group I or Ayurveda treatment (Group II for 14 days. Continuous electrocardiogram and finger arterial pressure were recorded for 15 min before and after treatments and analyzed offline to obtain heart rate and blood pressure variability and baroreflex sensitivity (BRS. Results were analysed by RMANOVA. Results. Patients in Group II showed statistically significant improvement in cardiac autonomic parameters. The standard deviation of normal to normal intervals,and total and low frequency powers were significantly enhanced (F=8.16, P=0.007, F=9.73, P=0.004, F=13.51, and P=0.001, resp.. The BRS too increased following the treatment period (F=10.129, P=0.004. Conclusions. The current study is the first to report a positive modulation of cardiac autonomic activity after adjuvant Ayurveda treatment in ischemic stroke. Further long term studies are warranted.

  3. 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...... 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...

  4. Cardiac autonomic profile in rheumatoid arthritis and systemic lupus erythematosus.

    Science.gov (United States)

    Aydemir, M; Yazisiz, V; Basarici, I; Avci, A B; Erbasan, F; Belgi, A; Terzioglu, E

    2010-03-01

    Neurological involvement is a well-documented issue in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). However, little is known about the involvement of the autonomic nervous system. This study was conducted to investigate autonomic nervous system dysfunction in patients with RA and SLE. Twenty-six RA patients, 38 SLE patients and 40 healthy controls were recruited from our in- and out-patient departments. Heart rate variability (HRV) parameters (the power of the high- [HF] and low-frequency [LF] band of haemodynamic time series, the ratio between low- and high-frequency components [LF/HF ratio], the power spectral density), baroreflex sensitivity (BRS) and beat-to-beat blood pressures were assessed by a novel non-invasive haemodynamic monitoring tool (Task Force Monitor [TFM], CNSystems Medizintechnik GmbH, Graz, Austria). Autonomic nervous system dysfunction was determined according to classical Ewing autonomic test battery. Furthermore, we implemented a secondary autonomic test score by modifying the Ewing test battery with additional criteria. Both the classical and modified Ewing test batteries have revealed that the frequencies of autonomic neuropathy were significantly higher in patient groups compared with controls (p disease duration, disease activity and autoantibody positivity. Consequently, we believe that further large-scale studies investigating cardiovascular autonomic neuropathy in rheumatic diseases should be carried out to verify our findings and manifest clinical consequences beyond these results.

  5. Radiation risk and protection of patients in clinical SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Brix, Gunnar; Nekolla, Elke A.; Nosske, Dietmar [Federal Office for Radiation Protection, Department of Medical and Occupational Radiation Protection, Oberschleissheim (Germany); Borowski, Markus [Klinikum Braunschweig, Institute of Radiation Diagnostics and Nuclear Medicine, Braunschweig (Germany)

    2014-05-15

    Clinical studies have demonstrated that hybrid single photon emission computed tomography (SPECT)/CT for various diagnostic issues has an added value as compared to SPECT alone. However, the combined acquisition of functional and anatomical images can substantially increase radiation exposure to patients, in particular when using a hybrid system with diagnostic CT capabilities. It is, therefore, essential to carefully balance the diagnostic needs and radiation protection requirements. To this end, the evidence on health effects induced by ionizing radiation is outlined. In addition, the essential concepts for estimating radiation doses and lifetime attributable cancer risks associated with SPECT/CT examinations are presented taking into account both the new recommendations of the International Commission on Radiological Protection (ICRP) as well as the most recent radiation risk models. Representative values of effective dose and lifetime attributable risk are reported for ten frequently used SPECT radiopharmaceuticals and five fully diagnostic partial-body CT examinations. A diagnostic CT scan acquired as part of a combined SPECT/CT examination contributes considerably to, and for some applications even dominates, the total patient exposure. For the common SPECT and CT examinations considered in this study, the lifetime attributable risk of developing a radiation-related cancer is less than 0.27 %/0.37 % for men/women older than 16 years, respectively, and decreases markedly with increasing age at exposure. Since there is no clinical indication for a SPECT/CT examination unless an emission scan has been indicated, the issue on justification comes down to the question of whether it is necessary to additionally acquire a low-dose CT for attenuation correction and anatomical localization of tracer uptake or even a fully diagnostic CT. In any case, SPECT/CT studies have to be optimized, e.g. by adapting dose reduction measures from state-of-the-art CT practice, and

  6. OptoDyCE: Automated system for high-throughput all-optical dynamic cardiac electrophysiology

    Science.gov (United States)

    Klimas, Aleksandra; Yu, Jinzhu; Ambrosi, Christina M.; Williams, John C.; Bien, Harold; Entcheva, Emilia

    2016-02-01

    In the last two decades, drugs withdrawals from the market were due to cardiac toxicity, where unintended interactions with ion channels disrupt the heart's normal electrical function. Consequently, all new drugs must undergo preclinical testing for cardiac liability, adding to an already expensive and lengthy process. Recognition that proarrhythmic effects often result from drug action on multiple ion channels demonstrates a need for integrative and comprehensive measurements. Additionally, patient-specific therapies relying on emerging technologies employing stem-cell derived cardiomyocytes (e.g. induced pluripotent stem-cell-derived cardiomyocytes, iPSC-CMs) require better screening methods to become practical. However, a high-throughput, cost-effective approach for cellular cardiac electrophysiology has not been feasible. Optical techniques for manipulation and recording provide a contactless means of dynamic, high-throughput testing of cells and tissues. Here, we consider the requirements for all-optical electrophysiology for drug testing, and we implement and validate OptoDyCE, a fully automated system for all-optical cardiac electrophysiology. We demonstrate the high-throughput capabilities using multicellular samples in 96-well format by combining optogenetic actuation with simultaneous fast high-resolution optical sensing of voltage or intracellular calcium. The system can also be implemented using iPSC-CMs and other cell-types by delivery of optogenetic drivers, or through the modular use of dedicated light-sensitive somatic cells in conjunction with non-modified cells. OptoDyCE provides a truly modular and dynamic screening system, capable of fully-automated acquisition of high-content information integral for improved discovery and development of new drugs and biologics, as well as providing a means of better understanding of electrical disturbances in the heart.

  7. A universal system for highly efficient cardiac differentiation of human induced pluripotent stem cells that eliminates interline variability.

    Directory of Open Access Journals (Sweden)

    Paul W Burridge

    Full Text Available BACKGROUND: The production of cardiomyocytes from human induced pluripotent stem cells (hiPSC holds great promise for patient-specific cardiotoxicity drug testing, disease modeling, and cardiac regeneration. However, existing protocols for the differentiation of hiPSC to the cardiac lineage are inefficient and highly variable. We describe a highly efficient system for differentiation of human embryonic stem cells (hESC and hiPSC to the cardiac lineage. This system eliminated the variability in cardiac differentiation capacity of a variety of human pluripotent stem cells (hPSC, including hiPSC generated from CD34(+ cord blood using non-viral, non-integrating methods. METHODOLOGY/PRINCIPAL FINDINGS: We systematically and rigorously optimized >45 experimental variables to develop a universal cardiac differentiation system that produced contracting human embryoid bodies (hEB with an improved efficiency of 94.7±2.4% in an accelerated nine days from four hESC and seven hiPSC lines tested, including hiPSC derived from neonatal CD34(+ cord blood and adult fibroblasts using non-integrating episomal plasmids. This cost-effective differentiation method employed forced aggregation hEB formation in a chemically defined medium, along with staged exposure to physiological (5% oxygen, and optimized concentrations of mesodermal morphogens BMP4 and FGF2, polyvinyl alcohol, serum, and insulin. The contracting hEB derived using these methods were composed of high percentages (64-89% of cardiac troponin I(+ cells that displayed ultrastructural properties of functional cardiomyocytes and uniform electrophysiological profiles responsive to cardioactive drugs. CONCLUSION/SIGNIFICANCE: This efficient and cost-effective universal system for cardiac differentiation of hiPSC allows a potentially unlimited production of functional cardiomyocytes suitable for application to hPSC-based drug development, cardiac disease modeling, and the future generation of clinically

  8. [The state of sympathetic-adrenal system in patients with chronic cardiac insufficiency].

    Science.gov (United States)

    Nigmatullin, R R; Kirillova, V V; Dzhordzhikiia, R K; Kudrin, V S; Klodt, P M

    2009-01-01

    Activation of sympato-adrenal system plays an important role in the development of chronic cardiac failure (CCF). However, its relation to morpho-functional state of myocardium in CCF patients is virtually unknown. HPLC with electrochemical detection was used to determine plasma noradrenalin, adrenalin, and their precursors, 3,4-dioxyphenylalanine (DOPA) and dopamine, in patients with different morpho-functional changes in myocardium. The study demonstrated enhanced activity of sympato-adrenal system in patients with CCF. It showed for the first time that activity of sympato-adrenal system in CCF patients depends on the morpho-functional status of myocardium.

  9. Cardiac echinococcosis

    Directory of Open Access Journals (Sweden)

    Ivanović-Krstić Branislava A.

    2002-01-01

    Full Text Available Cardiac hydatid disease is rare. We report on an uncommon hydatid cyst localized in the right ventricular wall, right atrial wall tricuspid valve left atrium and pericard. A 33-year-old woman was treated for cough, fever and chest pain. Cardiac echocardiograpic examination revealed a round tumor (5.8 x 4 cm in the right ventricular free wall and two smaller cysts behind that tumor. There were cysts in right atrial wall and tricuspidal valve as well. Serologic tests for hydatidosis were positive. Computed tomography finding was consistent with diagnosis of hydatid cyst in lungs and right hylar part. Surgical treatment was rejected due to great risk of cardiac perforation. Medical treatment with albendazole was unsuccessful and the patient died due to systemic hydatid involvement of the lungs, liver and central nervous system.

  10. Continuous measurement of cardiac output with the use of stochastic system identification techniques.

    Science.gov (United States)

    Yelderman, M

    1990-10-01

    The limitations of developing a technique to measure cardiac output continuously are given. Logical explanations are provided for the economic, technical, and physiologic benefits of a stochastic system identification technique for measuring cardiac output. Heat is supplied by a catheter-mounted filament driven according to a pseudorandom binary sequence. Volumetric fluid flow is derived by a cross-correlation algorithm written in the C language. In vitro validation is performed with water in a flow bench. The computed flow (y) compared with the in-line-measured flow (x) yields the linear regression y = 1.024x - 0.157 (r = 0.99). The average coefficient of variation is less than 2% over a volumetric fluid flow range of 2 to 10 L/min.

  11. Systems analysis of the mechanisms of cardiac diastolic function changes after microgravity exposure

    Science.gov (United States)

    Summers, Richard; Coleman, Thomas; Steven, Platts; Martin, David

    Detailed information concerning cardiac function was collected by two-dimensional and M-mode echocardiography at 10 days before flight and 3h after landing in astronauts returning from shuttle missions. A comparative analysis of this data suggests that cardiac diastolic function is reduced after microgravity exposure with little or no change in systolic function as measured by ejection fraction However, the mechanisms responsible for these adaptations have not been determined. In this study, an integrative computer model of human physiology that forms the framework for the Digital Astronaut Project (Guyton/Coleman/Summers Model) was used in a systems analysis of the echocardiographic data in the context of general cardiovascular physiologic functioning. The physiologic mechanisms involved in the observed changes were then determined by a dissection of model interrelationships. The systems analysis of possible physiologic mechanisms involved reveals that a loss of fluid from the myocardial interstitial space may lead to a stiffening of the myocardium and could potentially result in some of the cardiac diastolic dysfunction seen postflight. The cardiovascular dynamics may be different during spaceflight.

  12. Cardiac tamponade preceding skin involvement in systemic sclerosis

    Directory of Open Access Journals (Sweden)

    L. Bozzola

    2011-09-01

    Full Text Available The frequency of pericardial involvement in Systemic Sclerosis (SSc is high on autoptic or echocardiographic studies, but the clinical recognition of pericarditis with or without effusion is rare. We describe a case of a 71-year-old female with no previous history of heart disease, who presented with a large pericardial effusion and tamponade that required pericardial drain. She had suffered from Raynaud’s phenomenon since 25 years. Six weeks after hospital discharge she complained of skin hardening on left leg. Pericardial tamponade is a very rare manifestation of SSc and occurs both early or late in the course of the disease, but in our case it preceded the recognition of scleroderma. We have only identified two other cases of pericardial effusion preceding cutaneous involvement in scleroderma.

  13. Myocardial Perfusion SPECT Imaging in Patients after Percutaneous Coronary Intervention.

    Science.gov (United States)

    Georgoulias, Panagiotis; Valotassiou, Varvara; Tsougos, Ioannis; Demakopoulos, Nikolaos

    2010-05-01

    Coronary artery disease (CAD) is the most prevalent form of cardiovascular disease affecting about 13 million Americans, while more than one million percutaneous transluminal intervention (PCI) procedures are performed annually in the USA. The relative high occurrence of restenosis, despite stent implementation, seems to be the primary limitation of PCI. Over the last decades, single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), has proven an invaluable tool for the diagnosis of CAD and patients' risk stratification, providing useful information regarding the decision about revascularization and is well suited to assess patients after intervention. Information gained from post-intervention MPI is crucial to differentiate patients with angina from those with exo-cardiac chest pain syndromes, to assess peri-intervention myocardial damage, to predict-detect restenosis after PCI, to detect CAD progression in non-revascularized vessels, to evaluate the effects of intervention if required for occupational reasons and to evaluate patients' long-term prognosis. On the other hand, chest pain and exercise electrocardiography are largely unhelpful in identifying patients at risk after PCI.Although there are enough published data demonstrating the value of myocardial perfusion SPECT imaging in patients after PCI, there is still debate on whether or not these tests should be performed routinely.

  14. A SPECT imager with synthetic collimation

    Science.gov (United States)

    Havelin, Ronan J.; Miller, Brian W.; Barrett, Harrison H.; Furenlid, Lars R.; Murphy, J. M.; Foley, Mark J.

    2013-09-01

    This work outlines the development of a multi-pinhole SPECT system designed to produce a synthetic-collimator image of a small field of view. The focused multi-pinhole collimator was constructed using rapid-prototyping and casting techniques. The collimator projects the field of view through forty-six pinholes when the detector is adjacent to the collimator. The detector is then moved further from the collimator to increase the magnification of the system. The amount of pinhole-projection overlap increases with the system magnification. There is no rotation in the system; a single tomographic angle is used in each system configuration. The maximum-likelihood expectation-maximization (MLEM) algorithm is implemented on graphics processing units to reconstruct the object in the field of view. Iterative reconstruction algorithms, such as MLEM, require an accurate model of the system response. For each system magnification, a sparsely-sampled system response is measured by translating a point source through a grid encompassing the field of view. The pinhole projections are individually identified and associated with their respective apertures. A 2D elliptical Gaussian model is applied to the pinhole projections on the detector. These coefficients are associated with the object-space location of the point source, and a finely-sampled system matrix is interpolated. Simulations with a hot-rod phantom demonstrate the efficacy of combining low-resolution non-multiplexed data with high-resolution multiplexed data to produce high-resolution reconstructions.

  15. Molecular imaging of angiogenesis with SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Dijkgraaf, Ingrid; Boerman, Otto C. [Radboud University Nijmegen Medical Center, Department of Nuclear Medicine, P.O. Box 9101, HB Nijmegen (Netherlands)

    2010-08-15

    Single-photon emission computed tomography (SPECT) and position emission tomography (PET) are the two main imaging modalities in nuclear medicine. SPECT imaging is more widely available than PET imaging and the radionuclides used for SPECT are easier to prepare and usually have a longer half-life than those used for PET. In addition, SPECT is a less expensive technique than PET. Commonly used gamma emitters are: {sup 99m}Tc (E{sub max} 141 keV, T{sub 1/2} 6.02 h), {sup 123}I (E{sub max} 529 keV, T{sub 1/2} 13.0 h) and {sup 111}In (E{sub max} 245 keV, T{sub 1/2} 67.2 h). Compared to clinical SPECT, PET has a higher spatial resolution and the possibility to more accurately estimate the in vivo concentration of a tracer. In preclinical imaging, the situation is quite different. The resolution of microSPECT cameras (<0.5 mm) is higher than that of microPET cameras (>1.5 mm). In this report, studies on new radiolabelled tracers for SPECT imaging of angiogenesis in tumours are reviewed. (orig.)

  16. Influence of respiratory gating, image filtering, and animal positioning on high-resolution electrocardiography-gated murine cardiac single-photon emission computed tomography

    NARCIS (Netherlands)

    Wu, Chao; Vaissier, Pieter E. B.; Vastenhouw, Brendan; de Jong, Johan R.; Slart, Riemer H. J. A.; Beekman, Freek J.

    2015-01-01

    Cardiac parameters obtained from single-photon emission computed tomographic (SPECT) images can be affected by respiratory motion, image filtering, and animal positioning. We investigated the influence of these factors on ultra-high-resolution murine myocardial perfusion SPECT. Five mice were inject

  17. Detection of Left Ventricular Regional Dysfunction and Myocardial Abnormalities Using Complementary Cardiac Magnetic Resonance Imaging in Patients with Systemic Sclerosis without Cardiac Symptoms: A Pilot Study.

    Science.gov (United States)

    Kobayashi, Yasuyuki; Kobayashi, Hitomi; T Giles, Jon; Yokoe, Isamu; Hirano, Masaharu; Nakajima, Yasuo; Takei, Masami

    2016-01-01

    Objective We sought to detect the presence of left ventricular regional dysfunction and myocardial abnormalities in systemic sclerosis (SSc) patients without cardiac symptoms using a complementary cardiac magnetic resonance (CMR) imaging approach. Methods Consecutive patients with SSc without cardiac symptoms and healthy controls underwent CMR on a 1.5 T scanner. The peak systolic regional function in the circumferential and radial strain (Ecc, % and Err, %) were calculated using a feature tracking analysis on the mid-left ventricular slices obtained with cine MRI. In addition, we investigated the myocardial characteristics by contrast MRI. Pharmacological stress and rest perfusion scans were performed to assess perfusion defect (PD) due to micro- or macrovascular impairment, and late gadolinium enhancement (LGE) images were obtained for the assessment of myocarditis and/or fibrosis. Results We compared 15 SSc patients with 10 healthy controls. No statistically significant differences were observed in the baseline characteristics between the patients and healthy controls. The mean peak Err and Ecc of all segments was significantly lower in the patients than the controls (p=0.011 and p=0.003, respectively). Four patients with LGE (28.6%) and seven patients with PD (50.0%) were observed. PD was significantly associated with digital ulcers (p=0.005). Utilizing a linear regression model, the presence of myocardial LGE was significantly associated with the peak Ecc (p=0.024). After adjusting for age, the association between myocardial LGE and the peak Ecc was strengthened. Conclusion A subclinical myocardial involvement, as detected by CMR, was prevalent in the SSc patients without cardiac symptoms. Regional dysfunction might predict the myocardial abnormalities observed in SSc patients without cardiac symptoms.

  18. Systemic and Cardiac Depletion of M2 Macrophage through CSF-1R Signaling Inhibition Alters Cardiac Function Post Myocardial Infarction.

    Science.gov (United States)

    Leblond, Anne-Laure; Klinkert, Kerstin; Martin, Kenneth; Turner, Elizebeth C; Kumar, Arun H; Browne, Tara; Caplice, Noel M

    2015-01-01

    The heart hosts tissue resident macrophages which are capable of modulating cardiac inflammation and function by multiple mechanisms. At present, the consequences of phenotypic diversity in macrophages in the heart are incompletely understood. The contribution of cardiac M2-polarized macrophages to the resolution of inflammation and repair response following myocardial infarction remains to be fully defined. In this study, the role of M2 macrophages was investigated utilising a specific CSF-1 receptor signalling inhibition strategy to achieve their depletion. In mice, oral administration of GW2580, a CSF-1R kinase inhibitor, induced significant decreases in Gr1lo and F4/80hi monocyte populations in the circulation and the spleen. GW2580 administration also induced a significant depletion of M2 macrophages in the heart after 1 week treatment as well as a reduction of cardiac arginase1 and CD206 gene expression indicative of M2 macrophage activity. In a murine myocardial infarction model, reduced M2 macrophage content was associated with increased M1-related gene expression (IL-6 and IL-1β), and decreased M2-related gene expression (Arginase1 and CD206) in the heart of GW2580-treated animals versus vehicle-treated controls. M2 depletion was also associated with a loss in left ventricular contractile function, infarct enlargement, decreased collagen staining and increased inflammatory cell infiltration into the infarct zone, specifically neutrophils and M1 macrophages. Taken together, these data indicate that CSF-1R signalling is critical for maintaining cardiac tissue resident M2-polarized macrophage population, which is required for the resolution of inflammation post myocardial infarction and, in turn, for preservation of ventricular function.

  19. Status report of the neutron lifetime experiment tau-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Karch, Jan Peter; Beck, Marcus; Dragisic, Simo; Haak, Jan; Heil, Werner; Kories, Fabian; Kunz, Simon; Stepanow, Dietmar [Institut fuer Physik, University of Mainz (Germany); Geppert, Christopher; Karpuk, Sergei [Institut fuer Kernchemie, University of Mainz (Germany); Sobolev, Yury [Institut fuer Physik, University of Mainz (Germany); Institut fuer Kernchemie, University of Mainz (Germany)

    2015-07-01

    The decay of the free neutron into a proton, electron and antineutrino is the prototype of the semi-leptonic weak decay and plays a key role in particle physics and astrophysics. Nowadays, the accuracy achieved is limited by systematic errors, mainly caused by anomalous losses during storage of neutrons (ultracold neutrons) in material vessels. The magnetic storage of neutrons aims to avoid these systematic limitations and is expected to reach an accuracy of 0.1-0.3 s in the lifetime of the neutron. In this talk, the magnetic spectrometer tau-SPECT is presented, which uses a combination of magnetic multipole fields for radial storage and the field configuration of the superconducting aSPECT magnet for longitudinal storage of ultracold neutrons. This storage experiment benefits greatly from the new ultracold neutron source at the pulsable TRIGA reactor Mainz. The talk gives an overview of the experimental status: Proton detection system and adiabatic fast passages device.

  20. Accuracy of quantitative reconstructions in SPECT/CT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shcherbinin, S; Celler, A [Department of Radiology, University of British Columbia, 366-828 West 10th Avenue, Vancouver BC, V5Z 1L8 (Canada); Belhocine, T; Vanderwerf, R; Driedger, A [Department of Nuclear Medicine, London Health Sciences Centre, 375 South Street, PO Box 5375, London ON, N6A 4G5 (Canada)], E-mail: shcher2@interchange.ubc.ca

    2008-09-07

    The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition protocols. Two radioactive sources were centrally and peripherally placed inside an anthropometric Thorax phantom filled with non-radioactive water. Corrections for attenuation, scatter, collimator blurring and collimator septal penetration were applied and their contribution to the overall accuracy of the reconstruction was evaluated. Reconstruction with the most comprehensive set of corrections resulted in activity estimation with error levels of 3-5% for all the isotopes.

  1. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    Science.gov (United States)

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions.

  2. Sympathoadrenal and hypophyseal-adrenal systems in preoperative irradiation of patients with esophageal and cardiac cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tarutinov, V.I.; Starosel' skij, I.V.; Gol' dshmidt, B.Ya.; Shmal' ko, Yu.P.; Levchenko, A.M. (Nauchno-Issledovatel' skij Rentgeno-Radiologicheskij i Onkologicheskij Inst., Kiev (Ukrainian SSR))

    1983-11-01

    A study was made of 74 patients with esophageal and cardiac cancer, Stages 3 and 4. The excretion of catecholamines, corticosteroids and their precursors was studied, tests with adrenalin before and after preoperative irradiation at a summary dose of 30 Gy were done. It has been shown that before the start of radiation therapy the excretion of catecholamines and corticosteroids is lowered, the reaction to adrenalin administration is negative in most patients, the phase syndrome of cardiac hypodynamics associated with disturbed function of the sympathoadrenal system was revealed. Preoperative irradiation in patients with esophageal and cardiac cancer results in an increased excretion of 17-ketosteroids (17-KS) and 17-ketogenic steroids, however 17-KS excretion does not reach the normal level. For better tolerance of irradiation and for a radiosensitization effect testenate is administered to patients before and during radiation therapy. The administration of testenate 7-10 days before the start and during radiotherapy proved to be effective which was confirmed by noticeable necrobiotic and necrotic changes of cancer cells.

  3. A Real-Time Cardiac Arrhythmia Classification System with Wearable Sensor Networks

    Science.gov (United States)

    Hu, Sheng; Wei, Hongxing; Chen, Youdong; Tan, Jindong

    2012-01-01

    Long term continuous monitoring of electrocardiogram (ECG) in a free living environment provides valuable information for prevention on the heart attack and other high risk diseases. This paper presents the design of a real-time wearable ECG monitoring system with associated cardiac arrhythmia classification algorithms. One of the striking advantages is that ECG analog front-end and on-node digital processing are designed to remove most of the noise and bias. In addition, the wearable sensor node is able to monitor the patient's ECG and motion signal in an unobstructive way. To realize the real-time medical analysis, the ECG is digitalized and transmitted to a smart phone via Bluetooth. On the smart phone, the ECG waveform is visualized and a novel layered hidden Markov model is seamlessly integrated to classify multiple cardiac arrhythmias in real time. Experimental results demonstrate that the clean and reliable ECG waveform can be captured in multiple stressed conditions and the real-time classification on cardiac arrhythmia is competent to other workbenches. PMID:23112746

  4. A Real-Time Cardiac Arrhythmia Classification System with Wearable Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jindong Tan

    2012-09-01

    Full Text Available Long term continuous monitoring of electrocardiogram (ECG in a free living environment provides valuable information for prevention on the heart attack and other high risk diseases. This paper presents the design of a real-time wearable ECG monitoring system with associated cardiac arrhythmia classification algorithms. One of the striking advantages is that ECG analog front-end and on-node digital processing are designed to remove most of the noise and bias. In addition, the wearable sensor node is able to monitor the patient’s ECG and motion signal in an unobstructive way. To realize the real-time medical analysis, the ECG is digitalized and transmitted to a smart phone via Bluetooth. On the smart phone, the ECG waveform is visualized and a novel layered hidden Markov model is seamlessly integrated to classify multiple cardiac arrhythmias in real time. Experimental results demonstrate that the clean and reliable ECG waveform can be captured in multiple stressed conditions and the real-time classification on cardiac arrhythmia is competent to other workbenches.

  5. [Usefulness of attenuation correction with transmission source in myocardial SPECT].

    Science.gov (United States)

    Murakawa, Keizo; Katafuchi, Tetsuro; Nishimura, Yoshihiro; Enomoto, Naoyuki; Sago, Masayoshi; Oka, Hisashi

    2006-01-20

    Attenuation correction in SPECT has been used for uniformly absorptive objects like the head. On the other hand, it has seldom been applied to nonuniform absorptive objects like the heart and surrounding lungs because of the difficulty and inaccuracy of data processing. However, since attenuation correction using a transmission source recently became practical, we were able to apply this method to a nonuniform absorptive object. Therefore, we evaluated the usefulness of this attenuation correction system with a transmission source in myocardial SPECT. The dose linearity, defect/normal ratio using a myocardial phantom, and myocardial count distribution in clinical cases was examined with and without the attenuation correction system. We found that all data processed with attenuation correction were better than those without attenuation correction. For example, in myocardial count distribution, while there was a difference between men and women without attenuation correction, which was considered to be caused by differences in body shape, after processing with attenuation correction, myocardial count distribution was almost the same in all cases. In conclusion, these results suggested that attenuation correction with a transmission source was useful in myocardial SPECT.

  6. First use of mini gamma cameras for intra-operative robotic SPECT reconstruction.

    Science.gov (United States)

    Matthies, Philipp; Sharma, Kanishka; Okur, Ash; Gardiazabal, José; Vogel, Jakob; Lasserl, Tobias; Navab, Nassir

    2013-01-01

    Different types of nuclear imaging systems have been used in the past, starting with pre-operative gantry-based SPECT systems and gamma cameras for 2D imaging of radioactive distributions. The main applications are concentrated on diagnostic imaging, since traditional SPECT systems and gamma cameras are bulky and heavy. With the development of compact gamma cameras with good resolution and high sensitivity, it is now possible to use them without a fixed imaging gantry. Mounting the camera onto a robot arm solves the weight issue, while also providing a highly repeatable and reliable acquisition platform. In this work we introduce a novel robotic setup performing scans with a mini gamma camera, along with the required calibration steps, and show the first SPECT reconstructions. The results are extremely promising, both in terms of image quality as well as reproducibility. In our experiments, the novel setup outperformed a commercial fhSPECT system, reaching accuracies comparable to state-of-the-art SPECT systems.

  7. Noninvasive cardiac assessment in children of women with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Monteitro Pereira Leite

    2003-11-01

    Full Text Available OBJECTIVE: Noninvasive cardiac assessment of newborns and infants of women with systemic lupus erythematosus. The children had no congenital total atrioventricular block and were compared with the children of healthy women. METHODS: We prospectively assessed 13 newborns and infants aged 1 to 60 days, children of women with systemic lupus erythematosus and without congenital total atrioventricular block. These children were compared with 30 children of women who had no lupus or anti-Ro/SSA antibodies, and no risk factors for congenital heart disease either. Their age groups matched. The following examinations were performed: cardiological physical examination, electrocardiography, echocardiography, and signal-averaged electrocardiography. RESULTS: The statistical analysis showed no significant difference in ventricular function or in the cardiac conduction system between the groups. CONCLUSION: In regard to the conduction system and ventricular function in the absence of total atrioventricular block, no statistically significant difference was observed between the children of women with systemic lupus erythematosus and children of healthy women.

  8. Imaging of the autonomic nervous system: focus on cardiac sympathetic innervation.

    Science.gov (United States)

    Goldstein, David S

    2003-12-01

    Symptoms or signs of abnormal autonomic nervous system function occur commonly in several neurological disorders. Clinical evaluations have depended on physiological, pharmacological, and neurochemical approaches. Recently, imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used the radiolabeled sympathomimetic amine, (123)I-metaiodobenzylguanidine. Decreased uptake or increased "washout" of (123)I-metaiodobenzylguanidine-derived radioactivity is associated with worse prognosis or more severe disease in hypertension, congestive heart failure, arrhythmias, and diabetes mellitus. This pattern may reflect a high rate of postganglionic sympathetic nerve traffic to the heart. Many recent studies have agreed on the remarkable finding that all patients with Parkinson's disease and orthostatic hypotension have a loss of cardiac sympathetic innervation, whereas all patients with multiple system atrophy, often difficult to distinguish clinically from Parkinson's disease, have intact cardiac sympathetic innervation. Because Parkinson's disease entails a postganglionic sympathetic noradrenergic lesion, the disease appears to be not only a movement disorder, with dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, with noradrenaline loss in the sympathetic nervous system of the heart. As new ligands are developed, one may predict further discoveries of involvement of components of the autonomic nervous system in neurological diseases.

  9. Systematic morphology and evolutionary anatomy of the autonomic cardiac nervous system in the lesser apes, gibbons (hylobatidae).

    Science.gov (United States)

    Kawashima, Tomokazu; Thorington, Richard W; Kunimatsu, Yutaka; Whatton, James F

    2008-08-01

    We examined the morphology of the autonomic cardiac nervous system (ACNS) on 20 sides of 10 gibbons (Hylobatidae) of three genera, and we have inferred the evolution of the anatomy of the primate ACNS. We report the following. (1) Several trivial intraspecific and interspecific variations are present in gibbons, but the general arrangement of the ACNS in gibbons is consistent. (2) Although the parasympathetic vagal cardiac nervous system is extremely consistent, the sympathetic cardiac nervous system, such as the composition of the sympathetic ganglia and the range of origin of the sympathetic cardiac nerves, exhibit topographical differences among primates. (3) The vertebral ganglion, seldom observed in the Old World monkeys (Cercopithecidae), was consistently present in gibbons as well as in humans. (4) There are fewer thoracic ganglia contributing to the cervicothoracic ganglion in humans than in gibbons and in gibbons than in Old World monkeys. (5) The superior cardiac nerve originating from the superior cervical ganglion, rarely observed in Old World monkeys but commonly observed in humans, was present in 13 of 20 sides (65%), mostly on the left. Accordingly, the ACNS morphology exhibits evolutionary changes within the primate lineage. These evolutionary differences between Old World monkeys, gibbons, and humans are most parsimoniously interpreted as resulting from regular changes in the lineages leading from their common ancestor to the extant species that we dissected. They include the reduction in the number of thoracic ganglia contributing to the cervicothoracic ganglion and the expansion of the range of the cardiac nervous origin.

  10. Effects of voxel size and iterative reconstruction parameters on the spatial resolution of 99mTc SPECT/CT

    OpenAIRE

    Kappadath, S. Cheenu

    2011-01-01

    The purpose of this study was to evaluate the effects of voxel size and iterative reconstruction parameters on the radial and tangential resolution for 99mTc SPECT as a function of radial distance from isocenter. SPECT/CT scans of eight coplanar point sources of size smaller than 1 mm3 containing high concentration 99mTc solution were acquired on a SPECT/CT system with 5/8 inch NaI(Tl) detector and low-energy, high-resolution collimator. The tomographic projection images were acquired in step...

  11. Tissue Doppler echocardiography reveals impaired cardiac function in patients with reversible ischaemia

    DEFF Research Database (Denmark)

    Hoffmann, Søren; Mogelvang, Rasmus; Sogaard, Peter;

    2011-01-01

    = 30) or without (false-positive SPECT, n= 12) significant coronary stenoses assessed by CAG. Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates...... of the cardiac function was even more evident in patients with a true-positive SPECT with reduced average s' (5.5 ± 0.8 vs. 6.1 ± 1.1 cm/s; P... velocities could be demonstrated in patients with a false-positive SPECT compared with controls. CONCLUSION: In patients with stable angina pectoris, preserved ejection fraction, and reversible ischaemia assessed by SPECT, echocardiographic colour TDI performed at rest reveals impaired cardiac function...

  12. Ictal SPECT in Sturge-Weber syndrome

    OpenAIRE

    O. Bilgin; Vollmar, C.; Peraud, A.; la Fougere, C.; Beleza, P; Noachtar, S.

    2008-01-01

    We report on a patient with right-sided Sturge-Weber syndrome (SWS), in whom earlier functional hemispherectomy failed. Subtraction of ictal and interictal single-photon-emission-computed-tomography (SPECT) superimposed on individual MRI showed a right fronto-orbital hyperperfusion, with a left-sided EEG seizure pattern. Ictal SPECT supported our assumption that right frontal originated seizure pattern propagated to left hemisphere via the remaining right frontal bridge. Right orbito-frontal ...

  13. Normal cerebral perfusion of {sup 99m}Tc-ECD brain SPECT. Evaluation by an anatomical standardization technique

    Energy Technology Data Exchange (ETDEWEB)

    Kawashima, Ryuta; Koyama, Masamichi; Ito, Hiroshi; Yoshioka, Seiro; Sato, Kazunori; Ono, Shuichi; Goto, Ryoi; Sato, Tachio; Fukuda, Hiroshi [Tohoku Univ., Sendai (Japan). Inst. of Development, Aging and Cancer

    1996-01-01

    A single photon emitter labeled tracer, {sup 99m}Tc-ethyl cysteinate dimer ({sup 99m}Tc-ECD), has now been used for rCBF studies with SPECT. However, normal distribution pattern of this agent in the brain still remains unclear. Therefore, the specific purpose of this study was to investigate the normal distribution pattern of {sup 99m}Tc-ECD SPECT image. Regional cerebral distribution was measured with SPECT and 984{+-}17 MBq of {sup 99m}Tc-ECD in ten normal subjects. During the SPECT measurement, subjects were placed comfortably in a supine position with their eyes closed. Each SPECT image was anatomically standardized using a computerized brain atlas system of Roland et al. (HBA: Human Brain Atlas) and X-CT image. Anatomically standardized SPECT images were globally normalized to 100 count/voxel. Then, the mean and SD images of brain SPECT were calculated voxel-by-voxel basis. The highest radioactivity was found in the medial aspect of the occipital lobe. The results indicate that the normal distribution pattern of {sup 99m}Tc-ECD in the human brain may be not simply reflect the regional cerebral blood flow. (author).

  14. Cardiac system bioenergetics: metabolic basis of the Frank-Starling law.

    Science.gov (United States)

    Saks, Valdur; Dzeja, Petras; Schlattner, Uwe; Vendelin, Marko; Terzic, Andre; Wallimann, Theo

    2006-03-01

    The fundamental principle of cardiac behaviour is described by the Frank-Starling law relating force of contraction during systole with end-diastolic volume. While both work and respiration rates increase linearly with imposed load, the basis of mechano-energetic coupling in heart muscle has remained a long-standing enigma. Here, we highlight advances made in understanding of complex cellular and molecular mechanisms that orchestrate coupling of mitochondrial oxidative phosphorylation with ATP utilization for muscle contraction. Cardiac system bioenergetics critically depends on an interrelated metabolic infrastructure regulating mitochondrial respiration and energy fluxes throughout cellular compartments. The data reviewed indicate the significance of two interrelated systems regulating mitochondrial respiration and energy fluxes in cells: (1) the creatine kinase, adenylate kinase and glycolytic pathways that communicate flux changes generated by cellular ATPases within structurally organized enzymatic modules and networks; and (2) a secondary system based on mitochondrial participation in cellular calcium cycle, which adjusts substrate oxidation and energy-transducing processes to meet increasing cellular energy demands. By conveying energetic signals to metabolic sensors, coupled phosphotransfer reactions provide a high-fidelity regulation of the excitation-contraction cycle. Such integration of energetics with calcium signalling systems provides the basis for 'metabolic pacing', synchronizing the cellular electrical and mechanical activities with energy supply processes.

  15. Components of the interleukin-33/ST2 system are differentially expressed and regulated in human cardiac cells and in cells of the cardiac vasculature.

    Science.gov (United States)

    Demyanets, Svitlana; Kaun, Christoph; Pentz, Richard; Krychtiuk, Konstantin A; Rauscher, Sabine; Pfaffenberger, Stefan; Zuckermann, Andreas; Aliabadi, Arezu; Gröger, Marion; Maurer, Gerald; Huber, Kurt; Wojta, Johann

    2013-07-01

    Interleukin-33 (IL-33) is a recently described member of the IL-1 family of cytokines, which was identified as a ligand for the ST2 receptor. Components of the IL-33/ST2 system were shown to be expressed in normal and pressure overloaded human myocardium, and soluble ST2 (sST2) has emerged as a prognostic biomarker in myocardial infarction and heart failure. However, expression and regulation of IL-33 in human adult cardiac myocytes and fibroblasts was not tested before. In this study we found that primary human adult cardiac fibroblasts (HACF) and human adult cardiac myocytes (HACM) constitutively express nuclear IL-33 that is released during cell necrosis. Tumor necrosis factor (TNF)-α, interferon (IFN)-γ and IL-1β significantly increased both IL-33 protein and IL-33 mRNA expression in HACF and HACM as well as in human coronary artery smooth muscle cells (HCASMC). The nuclear factor-κB (NF-κB) inhibitor dimethylfumarate inhibited TNF-α- and IL-1β-induced IL-33 production as well as nuclear translocation of p50 and p65 NF-κB subunits in these cells. Mitogen-activated protein/extracellular signal-regulated kinase inhibitor U0126 abrogated TNF-α-, IFN-γ-, and IL-1β-induced and Janus-activated kinase inhibitor I reduced IFN-γ-induced IL-33 production. We detected IL-33 mRNA in human myocardial tissue from patients undergoing heart transplantation (n=27) where IL-33 mRNA levels statistically significant correlated with IFN-γ (r=0.591, p=0.001) and TNF-α (r=0.408, p=0.035) mRNA expression. Endothelial cells in human heart expressed IL-33 as well as ST2 protein. We also reveal that human cardiac and vascular cells have different distribution patterns of ST2 isoforms (sST2 and transmembrane ST2L) mRNA expression and produce different amounts of sST2 protein. Both human macrovascular (aortic and coronary artery) and heart microvascular endothelial cells express specific mRNA for both ST2 isoforms (ST2L and sST2) and are a source for sST2 protein, whereas

  16. 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.)

  17. Mechanisms of electrical activation and conduction in the gastrointestinal system: lessons from cardiac electrophysiology

    Directory of Open Access Journals (Sweden)

    Gary eTse

    2016-05-01

    Full Text Available The gastrointestinal (GI tract is an electrically excitable organ system containing multiple cell types, which coordinate electrical activity propagating through this tract. Disruption in its normal electrophysiology is observed in a number of GI motility disorders. However, this is not well characterized and the field of GI electrophysiology is much less developed compared to the cardiac field. The aim of this article is to use the established knowledge of cardiac electrophysiology to shed light on the mechanisms of electrical activation and propagation along the GI tract, and how abnormalities in these processes lead to motility disorders and suggest better treatment options based on this improved understanding. In the first part of the article, the ionic contributions to the generation of GI slow wave and the cardiac action potential (AP are reviewed. Propagation of these electrical signals can be described by the core conductor theory in both systems. However, specifically for the GI tract, the following unique properties are observed: changes in slow wave frequency along its length, periods of quiescence, synchronization in short distances and desynchronization over long distances. These are best described by a coupled oscillator theory. Other differences include the diminished role of gap junctions in mediating this conduction in the GI tract compared to the heart. The electrophysiology of conditions such as gastroesophageal reflux disease and gastroparesis, and functional problems such as irritable bowel syndrome are discussed in detail, with reference to ion channel abnormalities and potential therapeutic targets. A deeper understanding of the molecular basis and physiological mechanisms underlying GI motility disorders will enable the development of better diagnostic and therapeutic tools and the advancement of this field.

  18. Nontraumatic femoral head necrosis. Classification of bone scintigraphic findings and diagnostic value of SPECT following planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Minoshima, Satoshi; Uchida, Yoshitaka; Anzai, Yoshimi; Uno, Kimiichi; Arimizu, Noboru (Chiba Univ. (Japan). School of Medicine)

    1994-09-01

    This study was conducted to determine bone scintigraphic findings in nontraumatic femoral head avascular necrosis and diagnostic value of SPECT imaging following a conventional planar imaging. Forty-three femoral heads in twenty-six cases with idiopathic femoral head necrosis (n=2), systemic lupus erythematosus (n=22), aplastic anemia (n=1), and renal transplantation (n=1) were studied. The diagnosis for femoral head necrosis was based on magnetic resonance imaging as well as other diagnostic studies in all cases. Scintigraphic findings of planar and SPECT images were classified into six categories: normal (N); cold or decrease (C); partial increase with cold or decrease (PH+C); ring-like increase with a cold center (RH+C); partial increase (PH); diffuse and/or irregular increase (DH). Avascular necrosis was confirmed in twenty-four femoral heads, in which planar and SPECT images showed scintigraphic findings of N (n=3, 2), C (n=1, 3), PH+C (n=2, 8), RH+C (n=2, 3), PH (n=9, 2), and DH (n=7, 6), respectively. Femoral heads without avascular necrosis demonstrated planar and SPECT findings of N (n=16, 12), C (n=0, 6), and DH (n=3, 1), respectively. When considering C, PH+C, and RH+C as diagnostic findings for avascular necrosis, sensitivities of planar and SPECT images were 21% and 58%, and specificities were 100% and 68%, respectively. In nineteen femoral heads with normal planar findings (N), SPECT correctly identified avascular necrosis in two femoral heads and misidentified six normal femoral heads as avascular necrosis. In nineteen femoral heads with nondiagnostic abnormalities (PH, DH), SPECT correctly identified avascular necrosis in seven femoral heads and showed no false positive. Diagnostic planar findings in five femoral heads were concordant with SPECT diagnosis. These results indicate that SPECT imaging is most valuable when planar images show nondiagnostic abnormalities based on the proposed classification of scintigraphic findings. (author).

  19. Clinical evaluation of stress thallium spect in ischemic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Osamu; Kimura, Nazuna; Soeki; Takeshi; Takeichi, Naoki; Shinohara, Hisanori; Tamura, Yoshiyuki; Fukuda, Nobuo [Zentsuji National Hospital, Kagawa (Japan)

    1997-05-01

    Thallium SPECT was performed in patients with significant coronary artery stenosis, 67 cases were after maximal exercise and 74 cases were during coronary vasodilation induced by ATP (adenosine triphosphate) infusion. In patients suspected of angina pectoris, the sensitivity, specificity and predictive accuracy for detection of coronary artery disease (CAD) were 88%, 78% and 82% for exercise SPECT, and 100%, 72% and 84% for ATP SPECT studies, respectively. In patients with old myocardial infarction, these were 73%, 100% and 88% for exercise SPECT and 71%, 100% and 81% for ATP SPECT. These were 75%, 49% and 60% for treadmill exercise test in the patient group including both angina and myocardial infarction. For detection of diseased vessels, the diagnostic accuracy for left anterior descending artery and right coronary artery lesions was almost equal for ATP and exercise SPECT study, but ATP SPECT study was more sensitive than exercise SPECT study in detection of left circumflex artery lesions. ATP as well as exercise SPECT studies occasionally gave false positive results in patients with single-vessel disease. ATP as well as exercise SPECT studies underestimated the severity of multi-vessel disease. In general, the results of ATP SPECT imaging were highly concordant with the results of exercise SPECT imaging. ATP stress thallium SPECT imaging provided a safe and highly accurate diagnostic tool for detection of CAD. (author)

  20. 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.

  1. Diagnostic impact of SPECT-CT in the assessment of endocrine tumors; Impact diagnostique de la TEMP-TDM dans l'exploration des tumeurs endocrines

    Energy Technology Data Exchange (ETDEWEB)

    El Badaoui, A.; Clermont, H. de; Valli, N.; Caignon, J.M.; Fernandez, P.; Allard, M.; Barat, J.L.; Ducassou, D. [CHU de Bordeaux, Service de Medecine Nucleaire, 33 - Bordeaux (France); Clermont, H. de; Valli, N.; Caignon, J.M.; Fernandez, P.; Allard, M.; Barat, J.L.; Ducassou, D. [Universite Victor-Segalen, 33 - Bordeaux (France); Clermont, H. de; Allard, M. [UMR-CNRS 5231, 33 - Bordeaux (France)

    2008-02-15

    Image fusion using single photon emission computed tomography - computed tomography (SPECT - CT) associates functional and morphological images. This study evaluates the added value of SPECT- CT, obtained with a hybrid SPECT- CT gamma camera, on anatomic localization and diagnostic impact in assessment of endocrine tumours and pheochromocytomas. Method: Six months prospective study was undertaken including 33 consecutive exams encompassing 20 Somatostatin Receptor Scintigraphies (S.R.S.) and 13 {sup 123}I-meta-iodo-benzyl-guanidine (Mibg) scans. Two experienced nuclear medicine physicians independently analysed independently planar and SPECT images in a first time, then, SPECT- CT fused images in a second time. They evaluated two parameters: SPECT- CT impact on anatomic localization (L.A.) and its diagnostic impact (I.D.). Each parameter was scored according three levels of evaluation. Results: An added value of SPECT- CT images was evidenced in 55% of cases on the anatomic localization and in 41% of the patients on the diagnostic impact. Therefore, a more important benefit was noted when SPECT was positive (L.A.: 90%; I.D.: 70%) than when it was negative (L.A.: 15%; I.D.: 8%). Furthermore, the added value proved higher for the S;R.S. compared to Mibg scans. Conclusion: SPECT- CT fusion images obtained by a hybrid system is more relevant to determine anatomic localization and more accurate than SPECT alone, particularly in the assessment of endocrine tumours. The added value of SPECT- CT seems to be lower for Mibg scans in the assessment of pheochromocytomas. (authors)

  2. Brain SPECT in childhood; Temp cerebrale chez l'enfant

    Energy Technology Data Exchange (ETDEWEB)

    Tranquart, F.; Saliba, E.; Prunier, C.; Baulieu, F.; Besnard, J.C.; Guilloteau, D.; Baulieu, J.L. [Hopital Bretonneau, Service de Medecine Nucleaire, Unite Inserm 316, 37 - Tours (France)

    2001-04-01

    The modalities and the indications of perfusion and neurotransmission SPECT in childhood are presented. The perfusion as well as neurotransmission tracers have not yet authorization for use in children; they have to be used by prescription of magistral preparation or in research protocols. The radioprotection rules have to be strictly respected. The most frequent indication of perfusion SPECT is pharmacologically resistant epilepsy; the ictal SPECT before surgery allows the localization of the epileptogenic focus. Other indications are relevant in the prognosis of neonatal anoxia and encephalitis. In psychiatric disorders, especially in autism, the interest is the physiopathological approach of the brain dysfunctions. The neurotransmission SPECT is emerging as a consequence of the development of new radiotracer, as the dopaminergic system ligands. The decrease of the dopamine D2 receptors in the striatum can be imaged and quantified in the neonate. The lesions of dopamine system seem to be a consequence of the neonatal hypoxia-ischemia and it is predictive of motor sequelae. Brain SPECT should become a routine examination in child neurologic and psychiatric disorders. (authors)

  3. High Sensitivity SPECT for Small Animals and Plants

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Gregory S. [UC Davis

    2015-02-28

    Imaging systems using single gamma-ray emitting radioisotopes typically implement collimators in order to form the images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (<0.3%). We have built a collimator-less system, which can reach sensitivity of 40% for 99mTc imaging, while still producing images of sufficient spatial resolution for certain applications in thin objects such as mice, small plants, and well plates used for in vitro experiments.

  4. (Non-invasive evaluation of the cardiac autonomic nervous system by PET)

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The proposed research addresses the development, validation and application of cardiac PET imaging techniques to characterize the autonomic nervous system of the heart. PET technology has significantly matured over the last two decades. Instrument design, image processing and production of radiochemical compounds have formed an integrative approach to provide a powerful and novel imaging modality for the quantitative in vivo evaluation of the autonomic nervous system of the heart. Animal studies using novel tracers for the sympathetic and parasympathetic nerve terminals will be employed to characterize the functional integrity of nerve terminals. This work will be complemented by the development of agents which bind to postsynaptic receptor sites. The combined evaluation of presynaptic and postsynaptic neuronal function will allow a unique characterization of neuronal function. Initial development in animal studies will be followed by feasibility studies in humans. These studies are designed to test sophisticated imaging protocols in the human heart and validate the scintigraphic findings with independent markers of autonomic innervation. Subsequent clinical application in various cardiac diseases is expected to provide new insights into the neuropathophysiology of the heart.

  5. Imaging system for cardiac planar imaging using a dedicated dual-head gamma camera

    Science.gov (United States)

    Majewski, Stanislaw; Umeno, Marc M.

    2011-09-13

    A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159 keV and at a rate of up to 500kHz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.

  6. Comparison of myocardial function between post-menopausal and pre-menopausal women: evaluation by gated myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, K. H.; Choa, Won Sick; Yoon, Min Ki [Gachon Medical School, Gil Hospital, Incheon (Korea, Republic of)

    2005-07-01

    In addition to inhibiting coronary atherosclerosis, estrogen is expected to have protective effects on cardiac myocytes. We investigated the difference in myocardial functional parameters evaluated by gated myocardial SPECT after adenosine-stress between post-menopausal and pre-menopausal healthy women. This study included 22 healthy post-menopausal women (mean age: 53.0 yr) and 20 pre-menopausal women (mean age: 43.0 yr) who performed Tc-99m tetrofosmin gated myocardial SPECT after adenosine-stress. Measured hemodynamic parameters, EDV, ESV, stroke volume, EF, cardiac output and cardiac index were compared between the two groups. For comparison, similar-aged two male groups with matched numbers were also studied. There was no significant difference in hemodynamic parameters. EDV, ESV, stroke volume, EF, or cardiac output between the post-menopausal and pre-menopausal women. However, post-menopausal women have a smaller cardiac index (mean: 1.95 L/min/m2 vs 2.20 L/min/m2; p=0.045) and adenosine-induced HR increase (mean : 80.5/min vs 89.7/min ; p=0.03), compared to the pre-menopausal women. On the contrary, the two male groups of the same age range and numbers with the women groups showed no significant difference in any myocardial parameters. These results suggest that menopause may be correlated with reduced increase in cardiac index and HR increase after adenosine-stress.

  7. A realistic 3-D gated cardiac phantom for quality control of gated myocardial perfusion SPET: the Amsterdam gated (AGATE) cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    Visser, Jacco J.N.; Busemann Sokole, Ellinor; Verberne, Hein J.; Habraken, Jan B.A.; Eck-Smit, Berthe L.F. van [Department of Nuclear Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Stadt, Huybert J.F. van de; Jaspers, Joris E.N.; Shehata, Morgan; Heeman, Paul M. [Department of Medical Technological Development, Academic Medical Center, Amsterdam (Netherlands)

    2004-02-01

    A realistic 3-D gated cardiac phantom with known left ventricular (LV) volumes and ejection fractions (EFs) was produced to evaluate quantitative measurements obtained from gated myocardial single-photon emission tomography (SPET). The 3-D gated cardiac phantom was designed and constructed to fit into the Data Spectrum anthropomorphic torso phantom. Flexible silicone membranes form the inner and outer walls of the simulated left ventricle. Simulated LV volumes can be varied within the range 45-200 ml. The LV volume curve has a smooth and realistic clinical shape that is produced by a specially shaped cam connected to a piston. A fixed 70-ml stroke volume is applied for EF measurements. An ECG signal is produced at maximum LV filling by a controller unit connected to the pump. This gated cardiac phantom will be referred to as the Amsterdam 3-D gated cardiac phantom, or, in short, the AGATE cardiac phantom. SPET data were acquired with a triple-head SPET system. Data were reconstructed using filtered back-projection following pre-filtering and further processed with the Quantitative Gated SPECT (QGS) software to determine LV volume and EF values. Ungated studies were performed to measure LV volumes ranging from 45 ml to 200 ml. The QGS-determined LV volumes were systematically underestimated. For different LV combinations, the stroke volumes measured were consistent at 60-61 ml for 8-frame studies and 63-65 ml for 16-frame studies. QGS-determined EF values were slightly overestimated between 1.25% EF units for 8-frame studies and 3.25% EF units for 16-frame studies. In conclusion, the AGATE cardiac phantom offers possibilities for quality control, testing and validation of the whole gated cardiac SPET sequence, and testing of different acquisition and processing parameters and software. (orig.)

  8. 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

  9. Cardiac Mean Electrical Axis in Thoroughbreds—Standardization by the Dubois Lead Positioning System

    Science.gov (United States)

    da Costa, Cássia Fré; Samesima, Nelson; Pastore, Carlos Alberto

    2017-01-01

    Background Different methodologies for electrocardiographic acquisition in horses have been used since the first ECG recordings in equines were reported early in the last century. This study aimed to determine the best ECG electrodes positioning method and the most reliable calculation of mean cardiac axis (MEA) in equines. Materials and Methods We evaluated the electrocardiographic profile of 53 clinically healthy Thoroughbreds, 38 males and 15 females, with ages ranging 2–7 years old, all reared at the São Paulo Jockey Club, in Brazil. Two ECG tracings were recorded from each animal, one using the Dubois lead positioning system, the second using the base-apex method. QRS complex amplitudes were analyzed to obtain MEA values in the frontal plane for each of the two electrode positioning methods mentioned above, using two calculation approaches, the first by Tilley tables and the second by trigonometric calculation. Results were compared between the two methods. Results There was significant difference in cardiac axis values: MEA obtained by the Tilley tables was +135.1° ± 90.9° vs. -81.1° ± 3.6° (p<0.0001), and by trigonometric calculation it was -15.0° ± 11.3° vs. -79.9° ± 7.4° (p<0.0001), base-apex and Dubois, respectively. Furthermore, Dubois method presented small range of variation without statistical or clinical difference by either calculation mode, while there was a wide variation in the base-apex method. Conclusion Dubois improved centralization of the Thoroughbreds' hearts, engendering what seems to be the real frontal plane. By either calculation mode, it was the most reliable methodology to obtain cardiac mean electrical axis in equines. PMID:28095442

  10. Effects of voxel size and iterative reconstruction parameters on the spatial resolution of 99mTc SPECT/CT.

    Science.gov (United States)

    Kappadath, S Cheenu

    2011-11-15

    The purpose of this study was to evaluate the effects of voxel size and iterative reconstruction parameters on the radial and tangential resolution for 99mTc SPECT as a function of radial distance from isocenter. SPECT/CT scans of eight coplanar point sources of size smaller than 1 mm3 containing high concentration 99mTc solution were acquired on a SPECT/CT system with 5/8 inch NaI(Tl) detector and low-energy, high-resolution collimator. The tomographic projection images were acquired in step-and-shoot mode for 360 views over 360° with 250,000 counts per view, a zoom of 2.67, and an image matrix of 256 × 256 pixels that resulted in a 0.9 × 0.9 × 0.9 mm3 SPECT voxel size over 230 mm field-of-view. The projection images were also rebinned to image matrices of 128 × 128 and 64 × 64 to yield SPECT voxel sizes of 1.8 × 1.8 × 1.8 and 3.6 × 3.6 × 3.6 mm3, respectively. The SPECT/CT datasets were reconstructed using the vendor-supplied iterative reconstruction software that incorporated collimator-specific resolution recovery, CT-based attenuation correction, and dual-energy window-based scatter correction using different combinations of iterations and subsets. SPECT spatial resolution was estimated as the full width at half maximum of the radial and tangential profiles through the center of each point source in reconstructed SPECT images. Both radial and tangential resolution improved with higher iterations and subsets, and with smaller voxel sizes. Both radial and tangential resolution also improved with radial distance further away from isocenter. The magnitude of variation decreased for smaller voxel sizes and for higher number of iterations and subsets. Tangential resolution was found not to be equal to the radial resolution, and the nature of the anisotropy depended on the distribution of the radionuclide and on the reconstruction parameters used. The tangential resolution converged faster than the radial resolution, with higher iterations and subsets

  11. SPECT/CT workflow and imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, Catherine [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Hustinx, Roland [University Hospital of Liege, Division of Nuclear Medicine and Oncological Imaging, Department of Medical Physics, Liege (Belgium); Domaine Universitaire du Sart Tilman, Service de Medecine Nucleaire et Imagerie Oncologique, CHU de Liege, Liege (Belgium)

    2014-05-15

    Introducing a hybrid imaging method such as single photon emission computed tomography (SPECT)/CT greatly alters the routine in the nuclear medicine department. It requires designing new workflow processes and the revision of original scheduling process and imaging protocols. In addition, the imaging protocol should be adapted for each individual patient, so that performing CT is fully justified and the CT procedure is fully tailored to address the clinical issue. Such refinements often occur before the procedure is started but may be required at some intermediate stage of the procedure. Furthermore, SPECT/CT leads in many instances to a new partnership with the radiology department. This article presents practical advice and highlights the key clinical elements which need to be considered to help understand the workflow process of SPECT/CT and optimise imaging protocols. The workflow process using SPECT/CT is complex in particular because of its bimodal character, the large spectrum of stakeholders, the multiplicity of their activities at various time points and the need for real-time decision-making. With help from analytical tools developed for quality assessment, the workflow process using SPECT/CT may be separated into related, but independent steps, each with its specific human and material resources to use as inputs or outputs. This helps identify factors that could contribute to failure in routine clinical practice. At each step of the process, practical aspects to optimise imaging procedure and protocols are developed. A decision-making algorithm for justifying each CT indication as well as the appropriateness of each CT protocol is the cornerstone of routine clinical practice using SPECT/CT. In conclusion, implementing hybrid SPECT/CT imaging requires new ways of working. It is highly rewarding from a clinical perspective, but it also proves to be a daily challenge in terms of management. (orig.)

  12. Impact of right-ventricular apical pacing on the optimal left-ventricular lead positions measured by phase analysis of SPECT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Changhua (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Huang, Jin-Long [Taichung Veterans General Hospital, Cardiovascular Center, Taichung (China); School of Medicine, National Yang-Ming University, Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, Taipei (China); Chung-Shan Medical University, Department of Medicine, School of Medicine, Taichung (China); Lin, Wan-Yu; Tsai, Shih-Chung [Taichung Veterans General Hospital, Department of Nuclear Medicine, Taichung (China); Wang, Kuo-Yang [Taichung Veterans General Hospital, Cardiovascular Center, Taichung (China); Chung-Shan Medical University, Department of Medicine, School of Medicine, Taichung (China); Chen, Shih-Ann [School of Medicine, National Yang-Ming University, Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, Taipei (China); Taipei Veterans General Hospital, Division of Cardiology, Department of Medicine, Taipei (China); Lloyd, Michael S.; Chen, Ji [Emory University, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)

    2014-06-15

    The use of SPECT phase analysis to optimize left-ventricular (LV) lead positions for cardiac resynchronization therapy (CRT) was performed at baseline, but CRT works as simultaneous right ventricular (RV) and LV pacing. The aim of this study was to assess the impact of RV apical (RVA) pacing on optimal LV lead positions measured by SPECT phase analysis. This study prospectively enrolled 46 patients. Two SPECT myocardial perfusion scans were acquired under sinus rhythm with complete left bundle branch block and RVA pacing, respectively, following a single injection of {sup 99m}Tc-sestamibi. LV dyssynchrony parameters and optimal LV lead positions were measured by the phase analysis technique and then compared between the two scans. The LV dyssynchrony parameters were significantly larger with RVA pacing than with sinus rhythm (p ∝0.01). In 39 of the 46 patients, the optimal LV lead positions were the same between RVA pacing and sinus rhythm (kappa = 0.861). In 6 of the remaining 7 patients, the optimal LV lead positions were along the same radial direction, but RVA pacing shifted the optimal LV lead positions toward the base. The optimal LV lead positions measured by SPECT phase analysis were consistent, no matter whether the SPECT images were acquired under sinus rhythm or RVA pacing. In some patients, RVA pacing shifted the optimal LV lead positions toward the base. This study supports the use of baseline SPECT myocardial perfusion imaging to optimize LV lead positions to increase CRT efficacy. (orig.)

  13. Indeterminate lesions on planar bone scintigraphy in lung cancer patients: SPECT, CT or SPECT-CT?

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Punit; Kumar, Rakesh; Singh, Harmandeep; Bal, Chandrasekhar; Malhotra, Arun [All India Institute of Medical Sciences, Department of Nuclear Medicine, New Delhi (India); Julka, Pramod Kumar [All India Institute of Medical Sciences, Department of Radiation Oncology, New Delhi (India); Thulkar, Sanjay [All India Institute of Medical Sciences, Department of Radiodiagnosis, New Delhi (India)

    2012-07-15

    The objective of the present study was to compare the role of single photon emission computed tomography (SPECT), computed tomography (CT) and SPECT-CT of selected volume in lung cancer patients with indeterminate lesions on planar bone scintigraphy (BS). The data of 50 lung cancer patients (53 {+-} 10.3 years; range 30-75; male/female 38/12) with 65 indeterminate lesions on planar BS (January 2010 to November 2010) were retrospectively evaluated. All of them underwent SPECT-CT of a selected volume. SPECT, CT and SPECT-CT images were independently evaluated by two experienced readers (experience in musculoskeletal imaging, including CT: 5 and 7 years) in separate sessions. A scoring scale of 1 to 5 was used, in which 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign and 5 is definitely benign. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each modality, taking a score {<=}2 as metastatic. With receiver operating characteristic (ROC) curve analysis, areas under the curve (AUC) were calculated for each modality and compared. Clinical and imaging follow-up and/or histopathology were taken as reference standard. For both readers SPECT was inferior to CT (P = 0.004, P = 0.022) and SPECT-CT (P = 0.003, P = 0.037). However, no significant difference was found between CT and SPECT-CT for reader 1 (P = 0.847) and reader 2 (P = 0.592). The findings were similar for lytic as well as sclerotic lesions. Moderate inter-observer agreement was seen for SPECT images ({kappa} = 0.426), while almost perfect agreement was seen for CT ({kappa} = 0.834) and SPECT-CT ({kappa} = 0.971). CT alone and SPECT-CT are better than SPECT for accurate characterisation of indeterminate lesions on planar BS in lung cancer patients. CT alone is not inferior to SPECT-CT for this purpose and might be preferred because of shorter acquisition time and wider availability. (orig.)

  14. Registration and display of brain SPECT and MRI using external markers.

    Science.gov (United States)

    Pohjonen, H; Nikkinen, P; Sipilä, O; Launes, J; Salli, E; Salonen, O; Karp, P; Ylä-Jääski, J; Katila, T; Liewendahl, K

    1996-02-01

    Accurate anatomical localisation of abnormalities observed in brain perfusion single-photon emission computed tomography (SPECT) is difficult, but can be improved by correlating data from SPECT and other tomographic imaging modalities. For this purpose we have developed software to register, analyse and display 99mTc-hexamethylpropyleneamine oxime SPECT and 1.0 T MRI of the brain. For registration of SPECT and MRI data external skin markers containing 99mTc (220 kBq) in 50 microliters of coconut butter were used. The software is coded in the C programming language, and the X Window system and the OSF/Motif standards are used for graphics and definition of the user interface. The registration algorithm follows a noniterative least-squares method using singular value decomposition of a 3 x 3 covariance matrix. After registration, the image slices of both data sets are shown at identical tomographic levels. The registration error in phantom studies was on average 4 mm. In the two-dimensional display mode the orthogonal cross-sections of the data sets are displayed side by side. In the three-dimensional mode MRI data are displayed as a surface-shaded 3 D reconstruction and SPECT data as cut planes. The usefulness of this method is demonstrated in patients with cerebral infarcts, brain tumour, herpes simplex encephalitis and epilepsy.

  15. Registration and display of brain SPECT and MRI using external markers

    Energy Technology Data Exchange (ETDEWEB)

    Pohjonen, H. [Medical Engineering Centre, Helsinki University Central Hospital, Stenbaeckinkatu 9, FIN-00290 Helsinki (Finland); Nikkinen, P. [Department of Clinical Chemistry, Division of Nuclear Medicine, Helsinki University Central Hospital, Helsinki (Finland); Sipilae, O. [Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo (Finland); Launes, J. [Department of Neurology, Helsinki University Central Hospital, Helsinki (Finland); Salli, E. [Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo (Finland); Salonen, O. [Department of Radiology, Helsinki University Central Hospital, Helsinki (Finland); Karp, P. [Medical Engineering Centre, Helsinki University Central Hospital, Stenbaeckinkatu 9, FIN-00290 Helsinki (Finland); Ylae-Jaeaeski, J. [Graphic Arts Laboratory, Technical Research Centre of Finland, Espoo (Finland); Katila, T. [Medical Engineering Centre, Helsinki University Central Hospital, Stenbaeckinkatu 9, FIN-00290 Helsinki (Finland)]|[Laboratory of Biomedical Engineering, Helsinki University of Technology, Espoo (Finland); Liewendahl, K. [Department of Clinical Chemistry, Division of Nuclear Medicine, Helsinki University Central Hospital, Helsinki (Finland)

    1996-02-01

    Accurate anatomical localisation of abnormalities observed in brain perfusion single-photon emission computed tomography (SPECT) is difficult, but can be improved by correlating data from SPECT and other tomographic imaging modalities. For this purpose we have developed software to register, analyse and display {sup 99m}Tc-hexamethylpropyleneamine oxime SPECT and 1.0 T MRI of the brain. For registration of SPECT and MRI data external skin markers containing {sup 99m}Tc (220 kBq) in 50 {mu}l of coconut butter were used. The software is coded in the C programming language, and the X Window system and the OSF/Motif standards are used for graphics and definition of the user interface. The registration algorithm follows a noniterative least-squares method using singular value decomposition of a 3 x 3 covariance matrix. After registration, the image slices of both data sets are shown at identical tomographic levels. The registration error in phantom studies was on average 4 mm. In the two-dimensional display mode the orthogonal cross-sections of the data sets are displayed side by side. In the three-dimensional mode MRI data are displayed as a surface-shaded 3 D reconstruction and SPECT data as cut planes. The usefulness of this method is demonstrated in patients with cerebral infarcts, brain tumour, herpes simplex encephalitis and epilepsy. (orig.). With 9 figs.

  16. Local heterogeneities in cardiac systems suppress turbulence by generating multi-armed rotors

    Science.gov (United States)

    Zhang, Zhihui; Steinbock, Oliver

    2016-05-01

    Ventricular fibrillation is an extremely dangerous cardiac arrhythmia that is linked to rotating waves of electric activity and chaotically moving vortex lines. These filaments can pin to insulating, cylindrical heterogeneities which swiftly become the new rotation backbone of the local wave field. For thin cylinders, the stabilized rotation is sufficiently fast to repel the free segments of the turbulent filament tangle and annihilate them at the system boundaries. The resulting global wave pattern is periodic and highly ordered. Our cardiac simulations show that also thicker cylinders can establish analogous forms of tachycardia. This process occurs through the spontaneous formation of pinned multi-armed vortices. The observed number of wave arms N depends on the cylinder radius and is associated to stability windows that for N = 2, 3 partially overlap. For N = 1, 2, we find a small gap in which the turbulence is removed but the pinned rotor shows complex temporal dynamics. The relevance of our findings to human cardiology are discussed in the context of vortex pinning to more complex-shaped anatomical features and remodeled myocardium.

  17. Two large preoperative doses of erythropoietin do not reduce the systemic inflammatory response to cardiac surgery

    DEFF Research Database (Denmark)

    Poulsen, Troels Dirch; Andersen, Lars Willy; Steinbrüchel, Daniel

    2009-01-01

    OBJECTIVES: Cardiac surgery and cardiopulmonary bypass (CPB) induce an inflammatory reaction that may lead to tissue injury. Experimental studies suggest that recombinant human erythropoietin (EPO) independent of its erythropoietic effect may be used clinically as an anti-inflammatory drug. This ...... of inflammatory cytokines. In contrast, EPO may augment the TNF-alpha and NT-proBNP response. Although the long-term clinical impact remains unknown, the findings do not support use of EPO as an anti-inflammatory drug in patients undergoing cardiac surgery........ This study tested the hypothesis that 2 large doses of EPO administered shortly before CPB ameliorate the systemic inflammatory response to CPB. DESIGN AND SETTING: A prospective, double-blind, placebo-controlled and randomized study at a single tertiary care hospital. PARTICIPANTS: Patients scheduled...... concentrations of tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1beta, IL-1beta receptor antagonist, IL-6, IL-10, and N-terminal probrain natriuretic peptide (NT-proBNP). Compared with placebo, EPO at day 3 after CPB augmented the TNF-alpha response (p

  18. Brain SPECT imaging in Sydenham's chorea

    Directory of Open Access Journals (Sweden)

    Barsottini O.G.P.

    2002-01-01

    Full Text Available The objective of the present study was to determine whether brain single-photon emission computed tomography (SPECT imaging is capable of detecting perfusional abnormalities. Ten Sydenham's chorea (SC patients, eight females and two males, 8 to 25 years of age (mean 13.4, with a clinical diagnosis of SC were submitted to brain SPECT imaging. We used HMPAO labeled with technetium-99m at a dose of 740 MBq. Six examinations revealed hyperperfusion of the basal ganglia, while the remaining four were normal. The six patients with abnormal results were females and their data were not correlated with severity of symptoms. Patients with abnormal brain SPECT had a more recent onset of symptoms (mean of 49 days compared to those with normal SPECT (mean of 85 days but this difference did not reach statistical significance. Brain SPECT can be a helpful method to determine abnormalities of the basal ganglia in SC patients but further studies on a larger number of patients are needed in order to detect the phase of the disease during which the examination is more sensitive.

  19. Cardiac biopotentials influence on central nervous system functioning: first steps in hypothesis verification

    Directory of Open Access Journals (Sweden)

    Kondal'skaya Yu.O.

    2012-12-01

    Full Text Available The research goal is to verify the hypothesis on influence of cardiac biopotentials on central nervous system. Materials: 20 healthy individuals aged 18-26 years old have been participated in the investigations. Two groups composed of 10 patients each have been formed. Double increase in heart biopotentials by means of artificial impulse insertion between natural cardiac contractions has been modeled. Artificial impulses have been similar to unaffected ones, produced in a normal heart work. Additional impulses have been generated using external pacemaker and have been linked up with electrodes on the chest. They have been synchronized with the heart rhythm and located in-between R waves. The duration of those impulses has been fully matched to ventricular complex. Their amplitude has been adjusted individually depending on the height of R wave. Nervous system mobility has been used as the indicator reflecting the central nervous system functioning. Degree of mobility has been defined on the basis of tapping test results. The test has been repeated at specific intervals. Groups have been exposed to two adverse testing modes. Additional impulses have been conducted to the patients of group I within an hour over a period of the first and the third 15-minute intervals and to the patients of group II over a period of the second and the fourth 15-minute intervals. In the middle and in the end of each time interval tapping test has been carried out. After preliminary analysis two other modes of stimulation have been tested. The stimulation has been performed within the 40-minute course: over a period of the first 20-minute interval and vice versa. Results: Detailed evaluation has revealed that short-time increase of nervous processes has been checked in combination with decrease in their stability. Conclusion: The data obtained have shown that there is possible influence on central nervous system functioning. The article ends with prospects of further

  20. New gamma cameras in nuclear cardiology: D-SPECT; Les nouvelles gamma cameras en cardiologie nucleaire: D-Spect

    Energy Technology Data Exchange (ETDEWEB)

    Rouzet, F.; Bechara, T.; Ben Ali, K.; Nassar, P.; Grellier, J.F.; Burg, S.; Hyafil, F.; Le Guludec, D. [Service de medecine nucleaire, groupe hospitalier Bichat-Claude-Bernard, AP-HP, 75 - Paris (France)

    2010-08-15

    Over the past few years, advances in nuclear medicine aimed at decreasing both the duration and dosimetry of exams, without decreasing image quality. In this setting, Spectrum Dynamics (D-Spect) is a new generation gamma camera dedicated to cardiac scintigraphy. Its technology includes solid-state detectors based on pixelated semiconductors, region-centric (cardiac area) scanning, high-sensitivity collimators and resolution recovery. An additional particularity is the patient position during scanning. Phantom studies showed an improvement of sensitivity compared to conventional cameras, at the price of a loss in geometric resolution, which is compensated by resolution recovery. Semiconductors detectors provide a better energy resolution than conventional detectors suited to double isotope acquisitions, and a high count rate allowing dynamic acquisitions. Only few clinical studies are available so far, they suggest performances similar to that of conventional cameras obtained with acquisitions duration reduced to few minutes. The next step is to establish a trade-off between acquisition duration and dosimetry reduction. (authors)

  1. Fast Spiral SPECT with Stationary gamma-Cameras and Focusing Pinholes

    NARCIS (Netherlands)

    Vaissier, Pieter E. B.; Goorden, Marlies C.; Vastenhouw, Brendan; van der Have, Frans; Ramakers, Ruud M.; Beekman, Freek J.

    2012-01-01

    Small-animal SPECT systems with stationary detectors and focusing multiple pinholes can achieve excellent resolution-sensitivity trade-offs. These systems are able to perform fast total-body scans by shifting the animal bed through the collimator using an automated xyz stage. However, so far, a larg

  2. Effects of aerobic exercise training on cardiac renin-angiotensin system in an obese Zucker rat strain.

    Directory of Open Access Journals (Sweden)

    Diego Lopes Mendes Barretti

    Full Text Available OBJECTIVE: Obesity and renin angiotensin system (RAS hyperactivity are profoundly involved in cardiovascular diseases, however aerobic exercise training (EXT can prevent obesity and cardiac RAS activation. The study hypothesis was to investigate whether obesity and its association with EXT alter the systemic and cardiac RAS components in an obese Zucker rat strain. METHODS: THE RATS WERE DIVIDED INTO THE FOLLOWING GROUPS: Lean Zucker rats (LZR; lean Zucker rats plus EXT (LZR+EXT; obese Zucker rats (OZR and obese Zucker rats plus EXT (OZR+EXT. EXT consisted of 10 weeks of 60-min swimming sessions, 5 days/week. At the end of the training protocol heart rate (HR, systolic blood pressure (SBP, cardiac hypertrophy (CH and function, local and systemic components of RAS were evaluated. Also, systemic glucose, triglycerides, total cholesterol and its LDL and HDL fractions were measured. RESULTS: The resting HR decreased (∼12% for both LZR+EXT and OZR+EXT. However, only the LZR+EXT reached significance (p<0.05, while a tendency was found for OZR versus OZR+EXT (p = 0.07. In addition, exercise reduced (57% triglycerides and (61% LDL in the OZR+EXT. The systemic angiotensin I-converting enzyme (ACE activity did not differ regardless of obesity and EXT, however, the OZR and OZR+EXT showed (66% and (42%, respectively, less angiotensin II (Ang II plasma concentration when compared with LZR. Furthermore, the results showed that EXT in the OZR prevented increase in CH, cardiac ACE activity, Ang II and AT2 receptor caused by obesity. In addition, exercise augmented cardiac ACE2 in both training groups. CONCLUSION: Despite the unchanged ACE and lower systemic Ang II levels in obesity, the cardiac RAS was increased in OZR and EXT in obese Zucker rats reduced some of the cardiac RAS components and prevented obesity-related CH. These results show that EXT prevented the heart RAS hyperactivity and cardiac maladaptive morphological alterations in obese Zucker rats.

  3. [Left-ventricular hypertrophy as a cardiac risk factor: role of the renin-angiotensin-aldosterone system].

    Science.gov (United States)

    Erne, P

    1996-02-20

    Left-ventricular hypertrophy is the result of cardiac adaptation to global or regional overstress and represents an important cardiovascular risk factor, increasing the risk for development of congestive heart failure and incidence of sudden death. This review describes the pathophysiological and biochemical mechanisms involved in the development of left-ventricular hypertrophy and cardiac fibrosis with particular emphasis on the role of angiotensin II and aldosterone. Central to the cascade of cardiac fibrosis is the increased production or reduced degradation of collagen proteins in fibroblasts. Collagen proteins are proteins needed for the alignment of cellular compartments and the development of forces, contraction and relaxation of the heart. If overexpressed, an important rise of wall stiffness is observed in addition to a reduced capacity to provide oxygen to the cardiac tissue. This latter explains why in areas of histologically hypertrophied heart muscle atrophied muscle cells are observed. The characterization of the second-messenger systems involved in the regulation of cardiac cells as well as the identification of angiotensin-II receptor subtype and angiotensin IV is described. Both of these receptors are present on cardiac fibroblasts and stimulate these to collagen production, which can be inhibited by antagonists or the generation of angiotensin II by ACE inhibitors. In some forms of left-ventricular hypertrophy and in patients with congestive heart failure in addition to elevated angiotensin-II levels, increased aldosterone levels are observed. Aldosterone raises upon stimulation by angiotensin II and upon reduction of angiotensin-II generation subsequent to ACE inhibition through an escape mechanism. The contribution of aldosterone to left-ventricular hypertrophy and cardiac fibrosis can be prevented and reduced by the administration of its antagonist, spironolactone. Further and larger clinical trials are needed and in progress to evaluate if the

  4. Brain FDG-PET Scan and Brain Perfusion SPECT in the Diagnosis of Neuroacanthocytosis Syndromes

    Directory of Open Access Journals (Sweden)

    Eylem Değirmenci

    2015-06-01

    Full Text Available Neuroacanthocytosis syndromes (NA include autosomal recessive chorea-acanthocytosis and X-linked McLeod syndrome consisting of a choreatic movement disorder, psychiatric manifestations and cognitive decline, and additional multi-system features including myopathy and axonal neuropathy. Fluor 18 -2-fluoro-2-deoxyglucose (18F-FDG-PET positron emission tomography (PET and technetium 99m -d, l-hexamethyl-propylene amine oxime (99mTc-HMPAO brain single photon emission computed tomography (SPECT have been increasingly used for the detection of neurologic disorders, such as dementia, epilepsy, and movement disorders. In this case report, we report two patients with neuroacanthocytosis syndromes with the imaging features of brain metabolism by PET and brain perfusion by SPECT. Brain PET and brain SPECT findings of patients with neuroacanthocytosis syndromes were also reviewed.

  5. SPECT/CT and tumour imaging

    Energy Technology Data Exchange (ETDEWEB)

    Abikhzer, Gad [Rambam Health Care Campus, Department of Nuclear Medicine, Haifa (Israel); Keidar, Zohar [Rambam Health Care Campus, Department of Nuclear Medicine, Haifa (Israel); Technion - Israel Institute of Technology, The Ruth and Bruce Rappaport Faculty of Medicine, Haifa (Israel)

    2014-05-15

    Scintigraphic techniques are sensitive imaging modalities in the diagnosis and follow-up of cancer patients providing the functional and metabolic activity characteristics of the tumour. Hybrid SPECT/CT improves the diagnostic accuracy of these well-established imaging techniques by precise anatomical localization and characterization of morphological findings, differentiation between foci of physiological and pathological tracer uptake, resulting in a significant impact on patient management and more definitive interpretations. The use of SPECT/CT has been studied in a variety of applications in tumour imaging which are reviewed in this article. By combining functional and anatomical information in a single imaging session, SPECT/CT has become a one-stop cancer imaging modality. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-17

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

  7. Systemic Inflammatory Response and Potential Prognostic Implications After Out-of-Hospital Cardiac Arrest: A Substudy of the Target Temperature Management Trial

    DEFF Research Database (Denmark)

    Bro-Jeppesen, John; Kjaergaard, Jesper; Wanscher, Michael;

    2015-01-01

    OBJECTIVES: Whole-body ischemia during out-of-hospital cardiac arrest triggers immediate activation of inflammatory systems leading to a sepsis-like syndrome. The aim was to investigate the association between level of systemic inflammation and mortality in survivors after out-of-hospital cardiac...

  8. SPECT/CT 90Y-Bremsstrahlung images for dosimetry during therapy

    OpenAIRE

    Fabbri, C.; Sarti, G.; Agostini, M; Di Dia, A; Paganelli, G

    2008-01-01

    Background: the characteristics of 90Y, suitable for therapy, are denoted by the lack of γ-emission. Alternative methods, using analogues labelled with 111In or 86Y, are generally applied to image 90Y-conjugates, with some inevitable drawbacks. New generation SPECT/CT image systems offer improved Bremsstrahlung images. The intent of this brief communication is to show that high quality 90Y-Bremsstrahlung SPECT-CT images can be obtained, allowing the biodistribution of pure β-emitter therapeut...

  9. Gallium-SPECT in the detection of prosthetic valve endocarditis and aortic ring abscess

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, K.; Barnes, D.; Martin, R.H.; Rae, J.R. (Department of Diagnostic Radiology, Victoria General Hospital Halifax, Nova Scotia (Canada))

    1991-09-01

    A 52-yr-old man who had a bioprosthetic aortic valve developed Staphylococcus aureus bacteremia. Despite antibiotic therapy he had persistent pyrexia and developed new conduction system disturbances. Echocardiography did not demonstrate vegetations on the valve or an abscess, but gallium scintigraphy using SPECT clearly identified a focus of intense activity in the region of the aortic valve. The presence of valvular vegetations and a septal abscess was confirmed at autopsy. Gallium scintigraphy, using SPECT, provided a useful noninvasive method for the demonstration of endocarditis and the associated valve ring abscess.

  10. [Design and application of user managing system of cardiac remote monitoring network].

    Science.gov (United States)

    Chen, Shouqiang; Zhang, Jianmin; Yuan, Feng; Gao, Haiqing

    2007-12-01

    According to inpatient records, data managing demand of cardiac remote monitoring network and computer, this software was designed with relative database ACCESS. Its interface, operational button and menu were designed in VBA language assistantly. Its design included collective design, amity, practicability and compatibility. Its function consisted of registering, inquiring, statisticing and printing, et al. It could be used to manage users effectively and could be helpful to exerting important action of cardiac remote monitoring network in preventing cardiac-vascular emergency ulteriorly.

  11. Comparison of SPECT/CT and MRI in diagnosing symptomatic lesions in ankle and foot pain patients: diagnostic performance and relation to lesion type.

    Directory of Open Access Journals (Sweden)

    Seunggyun Ha

    Full Text Available The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types.Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV and negative predictive value (NPV of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests.In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016. Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P < 0.001, and its area under curve on ROC analysis was 0.787. In the analysis of each lesion type, the specificity of SPECT/CT was poor in joint lesions compared with other lesion types and MRI (P < 0.001, respectively. MRI exhibited lower specificity than SPECT/CT in bone lesions (P = 0.004 and ligament/tendon lesions (P < 0.001.SPECT/CT has MRI-comparable diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity.

  12. Non-sedating antihistamine drugs and cardiac arrhythmias -- biased risk estimates from spontaneous reporting systems?

    DEFF Research Database (Denmark)

    De Bruin, M L; van Puijenbroek, E P; Egberts, A C G

    2002-01-01

    AIMS: This study used spontaneous reports of adverse events to estimate the risk for developing cardiac arrhythmias due to the systemic use of non-sedating antihistamine drugs and compared the risk estimate before and after the regulatory action to recall the over-the-counter status of some...... was not significantly higher than 1 (OR 1.37 [95% CI: 0.85, 2.23]), whereas the risk estimate calculated after the governmental decision did significantly differ from 1 (OR 4.19 [95% CI: 2.49, 7.05]). CONCLUSIONS: Our data suggest that non-sedating antihistamines might have an increased risk for inducing arrhythmias....... Our findings, however, strongly suggest that the increased risk identified can at least partly be explained by reporting bias as a result of publications about and mass media attention for antihistamine induced arrhythmias....

  13. Discrimination between Healthy and Sick Cardiac Autonomic Nervous System by Detrended Heart Rate Variability Analysis

    CERN Document Server

    Ashkenazy, Yu; Levitan, J; Havlin, S; Saermark, K; Moelgaard, H; Bloch-Thomsen, P E

    1998-01-01

    Multiresolution Wavelet Transform and Detrended Fluctuation Analysis have been recently proven as excellent methods in the analysis of Heart Rate Variability, and in distinguishing between healthy subjects and patients with various dysfunctions of the cardiac nervous system. We argue that it is possible to obtain a distinction between healthy subjects/patients of at least similar quality by, first, detrending the time-series of RR-intervals by subtracting a running average based on a local window with a length of around 32 data points, and then, calculating the standard deviation of the detrended time-series. The results presented here indicate that the analysis can be based on very short time-series of RR-data (7-8 minutes), which is a considerable improvement relative to 24-hours Holter recordings.

  14. A system for monitoring cardiac vibration, respiration, and body movement in bed.

    Science.gov (United States)

    Mukai, Kouji; Yonezawa, Yoshiharu; Maki, Hiromichi; Ogawa, Hidekuni; Ninomiya, Ishio; Sada, Kouji; Hamada, Shingo; Hahn, Allen W

    2008-01-01

    We have developed a non-invasive system for monitoring cardiac vibrations, respiration and body movement of in-bed hospitalized patients and elderly people who need constant care. These physiological parameters are recorded by 40 kHz ultrasonic transmitter and receiver, which are installed into the bed mattress. The ultrasonic transmitter diffuses an ultrasonic wave into the mattress. The diffusion of the ultrasonic energy is changed by mattress shape variations, which modulate the amplitude of the received ultrasonic signal. The amplitude is also modulated by physiological parameters such as heart pulse, respiration and body movement. The received ultrasonic signal is demodulated by an envelope detection circuit, and the physiological parameters are detected by low, high and band pass filters.

  15. A system for monitoring cardiac vibration, respiration, and body movement in bed using an infrared.

    Science.gov (United States)

    Maki, Hiromichi; Ogawa, Hidekuni; Tsukamoto, Sosuke; Yonezawa, Yoshiharu; Caldwell, W Morton

    2010-01-01

    We have developed a non-invasive system for monitoring cardiac vibrations, respiration and body movement of in-bed hospitalized patients and elderly people who need constant care. These physiological parameters are recorded by an infrared emitting diode and a photo transistor, which are attached between spring coils in bed mattress. The infrared emitting diode diffuses infrared light into the mattress. The diffusion of this energy is changed by mattress shape variations and spring coil vibrations, which modulate the intensity of the received infrared signal. The intensity is also modulated by physiological parameters such as heart pulse, respiration and body movement. The physiological parameters are detected from the received infrared intensity signal by low, high and band pass filters.

  16. Cardiac Care Assistance using Self Configured Sensor Network—a Remote Patient Monitoring System

    Science.gov (United States)

    Sarma Dhulipala, V. R.; Kanagachidambaresan, G. R.

    2014-04-01

    Pervasive health care systems are used to monitor patients remotely without disturbing the normal day-to-day activities in real-time. Wearable physiological sensors required to monitor various significant ecological parameters of the patients are connected to Body Central Unit (BCU). Body Sensor Network (BSN) updates data in real-time and are designed to transmit alerts against abnormalities which enables quick response by medical units in case of an emergency. BSN helps monitoring patient without any need for attention to the subject. BSN helps in reducing the stress and strain caused by hospital environment. In this paper, mathematical models for heartbeat signal, electro cardio graph (ECG) signal and pulse rate are introduced. These signals are compared and their RMS difference-fast Fourier transforms (PRD-FFT) are processed. In the context of cardiac arrest, alert messages of these parameters and first aid for post-surgical operations has been suggested.

  17. Characteristics and clinical relevance of late gadolinium enhancement in cardiac magnetic resonance in patients with systemic sclerosis.

    Science.gov (United States)

    Sano, Makoto; Satoh, Hiroshi; Suwa, Kenichiro; Nobuhara, Mamoru; Saitoh, Takeji; Saotome, Masao; Urushida, Tsuyoshi; Katoh, Hideki; Shimoyama, Kumiko; Suzuki, Daisuke; Ogawa, Noriyoshi; Takehara, Yasuo; Sakahara, Harumi; Hayashi, Hideharu

    2015-11-01

    Cardiac involvement in systemic sclerosis (SSc) is considerably frequent in autopsy, but the early identification is clinically difficult. Recent advantages in cardiac magnetic resonance (CMR) enabled to detect myocardial fibrotic scar as late gadolinium enhancement (LGE). We aimed to examine the prevalence and distribution of LGE in patients with SSc, and associate them with clinical features, electrocardiographic abnormalities and cardiac function. Forty patients with SSc (58 ± 14 years-old, 35 females, limited/diffuse 25/15, disease duration 106 ± 113 months) underwent serological tests, 12-lead electrocardiogram (ECG) and CMR. Seven patients (17.5 %) showed LGE in 26 segments of left ventricle (LV). LGE distributed mainly in the basal to mid inter-ventricular septum and the right ventricular (RV) insertion points, but involved all the myocardial regions. More patients with LGE showed NYHA functional class II and more (71 vs. 21 %, p 125 pg/ml). When cardiac involvement of SSc was defined as low LVEF, ECG abnormalities or high NT-proBNP, the sensitivity, specificity positive and negative predictive values of LGE were 36, 92, 71 and 72 %, respectively. We could clarify the prevalence and distribution of LGE in Japanese patients with SSc. The presence of LGE was associated with cardiac symptom, conduction disturbance and impaired LV/RV contraction.

  18. Mechanical and optical characteristics of a new fiber optical system used for cardiac contraction measurement.

    Science.gov (United States)

    Kloppe, A; Hoeland, K; Müller, S; Hexamer, M; Nowack, G; Mügge, A; Werner, J

    2004-10-01

    In order to obtain a better physiological performance and a closer restoration of the regular rhythm of failing hearts, a new fiber optical sensor system for the measurement of cardiac contraction has been developed. It consists of an opto-electrical unit and a sensing fiber which has to be positioned in the heart. The objective of this new fiber optic sensor system is to use the inotropic information to adjust a stimulation algorithm in single or multichamber pacing or to detect arrhythmia in insufficient heart function. In this study, the mechanical and optical characteristics of different fibers are investigated. The relationship between the attenuation (with an achieved numerical maximum of 0.3 dB), the bending diameter and the angle of bending is determined in a range of 20-160 mm. The most suitable fiber for the application in cardiological problems is determined (WT8 fiber), for which the sensitivity is analyzed. Additionally, power spectra are calculated from WT8 fiber signals obtained from pig hearts, working under physiological conditions. The maximal frequency response was 23 Hz. It is concluded that the fiber optical measurement of cardiac contraction is not only feasible and reproducible, but the WT8 fiber also shows optimal behavior in the range of parameters occurring in the heart chambers. Nevertheless, in order to restrict the measured signal reliably to bending processes within the chambers only, it is concluded that a special combined fiber has to be constructed with a high sensitivity only at its terminal section within the heart.

  19. SPECT/CT versus MRI in patients with nonspecific pain of the hand and wrist - a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Huellner, Martin W.; Buerkert, Alexander; Schleich, Florian S.; Strobel, Klaus; Veit-Haibach, Patrick [Lucerne Cantonal Hospital, Department of Radiology and Nuclear Medicine, Lucerne (Switzerland); Schuerch, Maja; Hug, Urs; Wartburg, Urs von [Lucerne Cantonal Hospital, Department of Hand and Plastic Surgery, Lucerne (Switzerland)

    2012-05-15

    Hand and wrist pain is a diagnostic challenge for hand surgeons and radiologists due to the complex anatomy of the involved small structures. The American College of Radiology recommends MRI as the study of choice in patients with chronic wrist pain if radiographs are negative. Lately, state-of-the-art SPECT/CT systems have been introduced and may help in the diagnosis of this selected indication. This retrospective study included 21 patients with nonspecific pain of the hand/wrist. The diagnosis of nonspecific wrist pain was made by the referring hand surgeon based on patient history, clinical examination, plain radiography and clinical guidelines. All patients received planar early-phase imaging and late-phase SPECT/CT imaging as well as MRI. Lesions were divided into major (causative) and minor (not causative) pathologies according to clinical follow-up. Furthermore, oedema-like bone marrow changes seen on MRI were compared with focally increased tracer uptake seen on SPECT/CT images. MRI yielded a quite high sensitivity (0.86), but a low specificity (0.20). In contrast, SPECT/CT yielded a high specificity (1.00) and a low sensitivity (0.71). Oedema-like bone marrow changes were detected in 15 lesions in 11 patients. In ten lesions with bone marrow oedema on MRI, foci of elevated tracer uptake were detected on SPECT/CT. Overall, MRI was more sensitive, but SPECT/CT was more specific in the evaluation of causative pathologies. In this initial comparison, SPECT/CT showed higher specificity than MRI in the evaluation of causative pathologies in patients with nonspecific wrist pain. However, MRI was more sensitive. Thus, SPECT/CT was shown to be a useful problem-solving tool in the diagnostic work-up of these patients. (orig.)

  20. Effect of heat stress on cardiac output and systemic vascular conductance during simulated hemorrhage to presyncope in young men

    DEFF Research Database (Denmark)

    Ganio, Matthew S; Overgaard, Morten; Seifert, Thomas;

    2012-01-01

    During moderate actual or simulated hemorrhage, as cardiac output decreases, reductions in systemic vascular conductance (SVC) maintain mean arterial pressure (MAP). Heat stress, however, compromises the control of MAP during simulated hemorrhage, and it remains unknown whether this response is due...... to a persistently high SVC and/or a low cardiac output. This study tested the hypothesis that an inadequate decrease in SVC is the primary contributing mechanism by which heat stress compromises blood pressure control during simulated hemorrhage. Simulated hemorrhage was imposed via lower body negative pressure...... (LBNP) to presyncope in 11 passively heat-stressed subjects (increase core temperature: 1.2 ± 0.2°C; means ± SD). Cardiac output was measured via thermodilution, and SVC was calculated while subjects were normothermic, heat stressed, and throughout subsequent LBNP. MAP was not changed by heat stress...

  1. [Clinical and physiological methods of examination for cardiac and respiratory systems in aluminium production workers of Kolsky North].

    Science.gov (United States)

    Chashchin, M V; Skripal', B A; Torgovanov, B A; Zotov, A M; Seden'kov, D A

    2004-01-01

    The authors presented clinical and physiologic studies of cardiac and respiratory systems and peripheral circulation among workers having various professions at aluminium production in Kolsky North. Multiple functional study methods were used including tachooscillography, electrocardiography, rheovasography, rheoencephalography, thermovision. The results enabled to specify duration and character of health disorders caused by occupational environment.

  2. Application of SPECT to psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi [National Center Hospital for Mental, Nervous, and Muscular Disorders, Kodaira, Tokyo (Japan)

    1999-07-01

    Brain perfusion SPECT using {sup 99m}Tc-ethyl-cysteinate dimer ({sup 99m}Tc-ECD) was applied to psychiatric diseases with aid of statistical parametric mapping (SPM) for analysis of data. To evaluate influence of aging on brain perfusion, noninvasive measurements of cerebral blood flow using {sup 99m}Tc-ECD were performed in 53 normal volunteers, age 18 to 87 years old. Mean cerebral blood flow (mCBF) was 43.9{+-}5.0 ml/100 g/min and showed weak negative correlation with aging (r=0.451). Perisylvian cerebral cortices and medial frontal areas including anterior cingulate gyri showed greater negative correlation than other areas. These findings suggest the necessity of age-matched control regional CBF (rCBF) data to investigate rCBF abnormality in patients. Four drug-naive schizophrenic patients showed flow decrease in bilateral frontal and superior temporal areas and a left infero-posterior temporal area. Haloperidol administration induced flow decrease in bilateral frontal and left parietal areas, while flow increase in bilateral striatal and right hippocampal areas. Ten aged depressive patients showed flow decrease in bilateral frontal and left temporo-parietal areas. Even after remission patients showed flow decrease in the left frontal area as compared with normal subjects. Remission induced flow increase in the right frontal, right parietal, and right orbitofrontal areas compared with depression. These results suggest that CBF measurements using {sup 99m}Tc-ECD were useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

  3. Impact of subcortical white matter lesions on dopamine transporter SPECT.

    Science.gov (United States)

    Funke, Elisabeth; Kupsch, Andreas; Buchert, Ralph; Brenner, Winfried; Plotkin, Michail

    2013-07-01

    Subcortical arteriosclerotic encephalopathy (SAE) can affect the nigrostriatal system and presumably cause vascular parkinsonism (VP). However, in patients with SAE, the differentiation of VP from idiopathic Parkinson's disease (IPS) is challenging. The aim of the present study was to examine the striatal dopamine transporter (DAT) density in patients with parkinsonism and SAE. Fifteen consecutive patients with parkinsonian symptoms displayed SAE, as detected by magnetic resonance imaging (MRI). Fifteen retrospectively chosen, matched patients with diagnosis of IPS without any abnormalities in MRI served as a reference group. DAT SPECT was performed using the tracer ¹²³I-FP-CIT. Scans were acquired on a triple-head SPECT system (Multispect 3, Siemens) and analysed using the investigator-independent BRASS™ software (HERMES). In the SAE group, a DAT deficit was observed in 9/15 patients. In contrast, all patients from the IPS group showed a reduced DAT binding (p = 0.008). The specific binding ratios (BR) of putamen contralateral to the side of the more affected limb versus occipital lobe were in trend higher in patients with SAE versus patients in the IPS-group (p = 0.053). Indices for putaminal asymmetry (p = 0.036) and asymmetry caudate-to-putamen (p = 0.026) as well as the ratio caudate-to-putamen (p = 0.048) were significantly higher in IPS patients having no SAE. DAT deficit was less pronounced in patients with SAE and parkinsonism than in patients with IPS without any abnormalities in the MRI. A potential role of DAT SPECT in the differential diagnosis of VP and IPS requires more assessments within prospective studies.

  4. In-line Filtration Decreases Systemic Inflammatory Response Syndrome, Renal and Hematologic Dysfunction in Pediatric Cardiac Intensive Care Patients.

    Science.gov (United States)

    Sasse, Michael; Dziuba, Friederike; Jack, Thomas; Köditz, Harald; Kaussen, Torsten; Bertram, Harald; Beerbaum, Philipp; Boehne, Martin

    2015-08-01

    Cardiac surgery with cardiopulmonary bypass (CPB) frequently leads to systemic inflammatory response syndrome (SIRS) with concomitant organ malfunction. Infused particles may exacerbate inflammatory syndromes since they activate the coagulation cascade and alter inflammatory response or microvascular perfusion. In a randomized, controlled, prospective trial, we have previously shown that particle-retentive in-line filtration prevented major complications in critically ill children. Now, we investigated the effect of in-line filtration on major complications in the subgroup of cardiac patients. Children admitted to tertiary pediatric intensive care unit were randomized to either control or filter group obtaining in-line filtration throughout complete infusion therapy. Risk differences and 95 % confidence intervals (CI) of several complications such as SIRS, sepsis, mortality, various organ failure and dysfunction were compared between both groups using the Wald method. 305 children (n = 150 control, n = 155 filter group) with cardiac diseases were finally analyzed. The majority was admitted after cardiac surgery with CPB. Risk of SIRS (-11.3 %; 95 % CI -21.8 to -0.5 %), renal (-10.0 %; 95 % CI -17.0 to -3.0 %) and hematologic (-8.1 %; 95 % CI -14.2 to -0.2 %) dysfunction were significantly decreased within the filter group. No risk differences were demonstrated for occurrence of sepsis, any other organ failure or dysfunctions between both groups. Infused particles might aggravate a systemic hypercoagulability and inflammation with subsequent organ malfunction in pediatric cardiac intensive care patients. Particle-retentive in-line filtration might be effective in preventing SIRS and maintaining renal and hematologic function. In-line filtration offers a novel therapeutic option to decrease morbidity in cardiac intensive care.

  5. Development and feasibility of a smartphone, ECG and GPS based system for remotely monitoring exercise in cardiac rehabilitation.

    Directory of Open Access Journals (Sweden)

    Charles Worringham

    Full Text Available BACKGROUND: Despite its efficacy and cost-effectiveness, exercise-based cardiac rehabilitation is undertaken by less than one-third of clinically eligible cardiac patients in every country for which data is available. Reasons for non-participation include the unavailability of hospital-based rehabilitation programs, or excessive travel time and distance. For this reason, there have been calls for the development of more flexible alternatives. METHODOLOGY AND PRINCIPAL FINDINGS: We developed a system to enable walking-based cardiac rehabilitation in which the patient's single-lead ECG, heart rate, GPS-based speed and location are transmitted by a programmed smartphone to a secure server for real-time monitoring by a qualified exercise scientist. The feasibility of this approach was evaluated in 134 remotely-monitored exercise assessment and exercise sessions in cardiac patients unable to undertake hospital-based rehabilitation. Completion rates, rates of technical problems, detection of ECG changes, pre- and post-intervention six minute walk test (6 MWT, cardiac depression and Quality of Life (QOL were key measures. The system was rated as easy and quick to use. It allowed participants to complete six weeks of exercise-based rehabilitation near their homes, worksites, or when travelling. The majority of sessions were completed without any technical problems, although periodic signal loss in areas of poor coverage was an occasional limitation. Several exercise and post-exercise ECG changes were detected. Participants showed improvements comparable to those reported for hospital-based programs, walking significantly further on the post-intervention 6 MWT, 637 m (95% CI: 565-726, than on the pre-test, 524 m (95% CI: 420-655, and reporting significantly reduced levels of cardiac depression and significantly improved physical health-related QOL. CONCLUSIONS AND SIGNIFICANCE: The system provided a feasible and very flexible alternative form of

  6. 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

  7. Single-photon-emission-computed-tomography (SPECT) in basal ganglia disorders; Single-Photon-Emissions-Computer-Tomographie (SPECT) bei Erkrankungen der Basalganglien

    Energy Technology Data Exchange (ETDEWEB)

    Tatsch, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum Grosshadern, Muenchen Univ. (Germany)

    1997-03-01

    In the past, SPECT investigations of regional cerebral blood flow have played a minor role in the diagnostic work-up of patients with basal ganglia disorders. More recently, however, interest in nuclear medicine procedures has dramatically increased since with the development of selective receptor ligands diagnostic tools have been provided which address the pathology in basal ganglia disorders more specifically than other diagnostic modalities. Evaluations of the pre- and postsynaptic aspects of the dopaminergic system, for example, deliver not only interesting data from the scientific point of view but also for the daily routine work. This paper summarizes some of the experience reported in the literature on SPECT investigations in basal ganglia disorders, such as Parkinson`s disease, parkinsonian syndromes of other etiology, Wilson`s and Huntington`s disease, focal dystonias, and schizophrenia under treatment with neuroleptics. (orig.) [Deutsch] SPECT-Studien mit Perfusionstracern haben aufgrund ihrer limitierten Aussagekraft in der Vergangenheit eine untergeordnete Rolle fuer die Diagnostik von Basalganglienerkrankungen gespielt. Mit der Entwicklung selektiver Radioliganden fuer die in vivo Abbildung von Rezeptorsystemen hat sich die klinische Bedeutung von SPECT-Untersuchungen grundlegend gewandelt. Da Basalganglien eine hohe Dichte an dopaminergen Synapsen aufweisen, kommt insbesondere diesem System diagnostische Bedeutung zu. Analysen der prae- und postsynaptischen Situation an der dopaminergen Synapse sind nicht nur von wissenschaftlichem Interesse, sondern haben mittlerweile auch klinische Relevanz erlangt. Bei verschiedenen Basalganglienerkrankungen, wie Morbus Parkinson, Parkinson Syndromen anderer Aetiologie, Morbus Wilson, Chorea Huntington, Dystonien und Schizophrenie-Patienten unter Neuroleptikatherapie, wird im Schrifttum ueber charakteristische SPECT-Befunde berichtet und deren diagnostische Bedeutung abgeschaetzt. (orig.)

  8. Uncovering the dynamics of cardiac systems using stochastic pacing and frequency domain analyses.

    Science.gov (United States)

    Lemay, Mathieu; de Lange, Enno; Kucera, Jan P

    2012-01-01

    Alternans of cardiac action potential duration (APD) is a well-known arrhythmogenic mechanism which results from dynamical instabilities. The propensity to alternans is classically investigated by examining APD restitution and by deriving APD restitution slopes as predictive markers. However, experiments have shown that such markers are not always accurate for the prediction of alternans. Using a mathematical ventricular cell model known to exhibit unstable dynamics of both membrane potential and Ca²⁺ cycling, we demonstrate that an accurate marker can be obtained by pacing at cycle lengths (CLs) varying randomly around a basic CL (BCL) and by evaluating the transfer function between the time series of CLs and APDs using an autoregressive-moving-average (ARMA) model. The first pole of this transfer function corresponds to the eigenvalue (λ(alt)) of the dominant eigenmode of the cardiac system, which predicts that alternans occurs when λ(alt) ≤ -1. For different BCLs, control values of λ(alt) were obtained using eigenmode analysis and compared to the first pole of the transfer function estimated using ARMA model fitting in simulations of random pacing protocols. In all versions of the cell model, this pole provided an accurate estimation of λ(alt). Furthermore, during slow ramp decreases of BCL or simulated drug application, this approach predicted the onset of alternans by extrapolating the time course of the estimated λ(alt). In conclusion, stochastic pacing and ARMA model identification represents a novel approach to predict alternans without making any assumptions about its ionic mechanisms. It should therefore be applicable experimentally for any type of myocardial cell.

  9. Uncovering the dynamics of cardiac systems using stochastic pacing and frequency domain analyses.

    Directory of Open Access Journals (Sweden)

    Mathieu Lemay

    Full Text Available Alternans of cardiac action potential duration (APD is a well-known arrhythmogenic mechanism which results from dynamical instabilities. The propensity to alternans is classically investigated by examining APD restitution and by deriving APD restitution slopes as predictive markers. However, experiments have shown that such markers are not always accurate for the prediction of alternans. Using a mathematical ventricular cell model known to exhibit unstable dynamics of both membrane potential and Ca²⁺ cycling, we demonstrate that an accurate marker can be obtained by pacing at cycle lengths (CLs varying randomly around a basic CL (BCL and by evaluating the transfer function between the time series of CLs and APDs using an autoregressive-moving-average (ARMA model. The first pole of this transfer function corresponds to the eigenvalue (λ(alt of the dominant eigenmode of the cardiac system, which predicts that alternans occurs when λ(alt ≤ -1. For different BCLs, control values of λ(alt were obtained using eigenmode analysis and compared to the first pole of the transfer function estimated using ARMA model fitting in simulations of random pacing protocols. In all versions of the cell model, this pole provided an accurate estimation of λ(alt. Furthermore, during slow ramp decreases of BCL or simulated drug application, this approach predicted the onset of alternans by extrapolating the time course of the estimated λ(alt. In conclusion, stochastic pacing and ARMA model identification represents a novel approach to predict alternans without making any assumptions about its ionic mechanisms. It should therefore be applicable experimentally for any type of myocardial cell.

  10. Role of inflammation in the development of cardiac autonomic disfunction in patients with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2008-01-01

    Full Text Available Objective. To evaluate role of inflammation in pathogenesis of cardiac autonomic dysfunction assessed by heart rate variability (HRV analyses, in patients (pts with systemic lupus erythematosus (SLE. Material and methods. 75 female pts with SLE aged before 55 years were included. Control group consisted of 32 healthy women of comparable age. Clinical symptoms, activity degree and main cardiovascular risk factors were assessed. Common carotid duplex scanning with measurement of intima-media thickness, echocardiography, 24 h ECG ambulatory recording with determination of time domain parameters, evaluation of serum inflammation markers level (CRP, IL-6, TNFa were performed. Results. HRV time domain parameters adjusted by McanNN - SDNNn%, SDNNin%, rMSSDn%, pNN50% in women with SLE were lower than in healthy control. HRV parameters inversely correlated with inflammation markers in SLE (p<0,05. SLE pts were divided into 4 groups: 1 (n=12 - pts with low HRV parameters and high level of IL-6; 2 (n=13 - low HRV and normal IL-6; 3 (n=6 - normal HRV and high IL-6; 4 (n=44 - normal HRV and IL-6. SLEDA1 2K, left atrium size, levels of markers of inflammation in group 1 were higher, then in group 4 (p<0,05. Hypertension, dyslipidemia, smoking and subclinical atherosclerosis of carotid arteries were more frequent in group 2 compared to group 4 (p<0,05. Conclusion. These results suggest important role of autoimmune inflammation in pathogenesis of cardiac autonomic dysfunction in SLE pts with high disease activity and traditional cardiovascular risk factor, atherosclerotic changes - in low SLE activity. HRV, traditional cardiovascular risk factors and inflammatory markers combined measurement can help to identify subjects at risk of cardiovascular mortality among SLE pts.

  11. Cardiac reflections and natural vibrations: Force-frequency relation recording system in the stress echo lab

    Directory of Open Access Journals (Sweden)

    Pianelli Mascia

    2007-11-01

    Full Text Available Abstract Background The inherent ability of ventricular myocardium to increase its force of contraction in response to an increase in contraction frequency is known as the cardiac force-frequency relation (FFR. This relation can be easily obtained in the stress echo lab, where the force is computed as the systolic pressure/end-systolic volume index ratio, and measured for increasing heart rates during stress. Ideally, the noninvasive, imaging independent, objective assessment of FFR would greatly enhance its practical appeal. Objectives 1 – To evaluate the feasibility of the cardiac force measurement by a precordial cutaneous sensor. 2 – To build the curve of force variation as a function of the heart rate. 3 – To compare the standard stress echo results vs. this sensor operator-independent built FFR. Methods The transcutaneous force sensor was positioned in the precordial region in 88 consecutive patients referred for exercise, dipyridamole, or pacing stress. The force was measured as the myocardial vibrations amplitude in the isovolumic contraction period. FFR was computed as the curve of force variation as a function of heart rate. Standard echocardiographic FFR measurements were performed. Results A consistent FFR was obtained in all patients. Both the sensor built and the echo built FFR identifiy pts with normal or abnormal contractile reserve. The best cut-off value of the sensor built FFR was 15.5 g * 10-3 (Sensitivity = 0.85, Specificity = 0.77. Sensor built FFR slope and shape mirror pressure/volume relation during stress. This approach is extendable to daily physiological exercise and could be potentially attractive in home monitoring systems.

  12. Early assessment of sub-clinical cardiac involvement in systemic sclerosis (SSc) using delayed enhancement cardiac magnetic resonance (CE-MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Di Cesare, Ernesto, E-mail: ernesto.dicesare@cc.univaq.it [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Battisti, Sara; Di Sibio, Alessandra [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Cipriani, Paola; Giacomelli, Roberto; Liakouli, Vasiliky; Ruscitti, Piero [Rheumatology Clinic, Department of Internal Medicine and Public Health, University of L’Aquila, L’Aquila (Italy); Masciocchi, Carlo [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy)

    2013-06-15

    Objectives: Systemic sclerosis heart involvement (SHI) is one of systemic sclerosis (SSc) most frequent complications, both in diffuse (dcSSc) and limited (lcSSc) cutaneous forms of disease. Nowadays, SHI is a major factor decreasing SSc survival rate because, when clinically evident, is associated with 70% of mortality at 5 years. SHI shows different forms, primary and/or secondary. Primary myocardial SHI is characterized by fibrosis. Aim of our study is to assess the presence and pattern of fibrosis as detected by cardiac magnetic resonance (CMR) in systemic sclerosis. Methods: In this study, we used CE-MRI (contrast enhanced-MRI) in 58 female SSc patients. Images were evaluated to obtain functional parameters and to see presence, location and pattern (nodular, linear or diffuse) of myocardial LE, sign of fibrosis. CE-MRI findings were correlated with patients clinical setting. Results: Myocardial fibrosis was detected in 25 of 58 patients (43%). The main finding observed in 16 of these 25 patients was a late enhancement showing a linear pattern, without coronary distribution and sparing the sub-endocardial myocardial layers. A patchy nodular enhancement pattern was observed in 9 patients (36%). Patients with linear pattern presented dcSSc, on the contrary patients with nodular LE displayed the lcSSc form. Conclusions: This study shows that CE-MRI is a reliable technique to detect SHI earlier than other methods. SHI increase passive myocardial stiffness, proportional to collagen deposition degree, leading to cardiac remodelling with possible development of heart failure, even with normal ejection fraction. An early treatment of SHI might improve SSc patients outcome.

  13. Development and optimization of SPECT gated blood pool cluster analysis for the prediction of CRT outcome

    Energy Technology Data Exchange (ETDEWEB)

    Lalonde, Michel, E-mail: mlalonde15@rogers.com; Wassenaar, Richard [Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Wells, R. Glenn; Birnie, David; Ruddy, Terrence D. [Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7 (Canada)

    2014-07-15

    Purpose: Phase analysis of single photon emission computed tomography (SPECT) radionuclide angiography (RNA) has been investigated for its potential to predict the outcome of cardiac resynchronization therapy (CRT). However, phase analysis may be limited in its potential at predicting CRT outcome as valuable information may be lost by assuming that time-activity curves (TAC) follow a simple sinusoidal shape. A new method, cluster analysis, is proposed which directly evaluates the TACs and may lead to a better understanding of dyssynchrony patterns and CRT outcome. Cluster analysis algorithms were developed and optimized to maximize their ability to predict CRT response. Methods: About 49 patients (N = 27 ischemic etiology) received a SPECT RNA scan as well as positron emission tomography (PET) perfusion and viability scans prior to undergoing CRT. A semiautomated algorithm sampled the left ventricle wall to produce 568 TACs from SPECT RNA data. The TACs were then subjected to two different cluster analysis techniques, K-means, and normal average, where several input metrics were also varied to determine the optimal settings for the prediction of CRT outcome. Each TAC was assigned to a cluster group based on the comparison criteria and global and segmental cluster size and scores were used as measures of dyssynchrony and used to predict response to CRT. A repeated random twofold cross-validation technique was used to train and validate the cluster algorithm. Receiver operating characteristic (ROC) analysis was used to calculate the area under the curve (AUC) and compare results to those obtained for SPECT RNA phase analysis and PET scar size analysis methods. Results: Using the normal average cluster analysis approach, the septal wall produced statistically significant results for predicting CRT results in the ischemic population (ROC AUC = 0.73;p < 0.05 vs. equal chance ROC AUC = 0.50) with an optimal operating point of 71% sensitivity and 60% specificity. Cluster

  14. 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.

  15. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  16. Comparison of I-123 MIBG planar imaging and SPECT for the detection of decreased heart uptake in Parkinson disease.

    Science.gov (United States)

    Oh, Jin-Kyoung; Choi, Eun-Kyoung; Song, In-Uk; Kim, Joong-Seok; Chung, Yong-An

    2015-10-01

    Decreased myocardial uptake of I-123 metaiodobenzylguanidine (MIBG) is an important finding for diagnosis of Parkinson's disease (PD). This study compared I-123 MIBG SPECT and planar imaging with regard to their diagnostic yield for PD. 52 clinically diagnosed PD patients who also had decreased striatal uptake on FP-CIT PET/CT were enrolled. 16 normal controls were also included. All underwent cardiac MIBG planar scintigraphy and SPECT separately. Myocardial I-123 MIBG uptake was interpreted on planar and SPECT/CT images separately by visual and quantitative analysis. The final diagnosis was made by consensus between two readers. Kappa analyses were performed to determine inter-observer agreement for both methods. Sensitivity, specificity, and accuracy were compared with McNemar's test. The sensitivity, specificity, and accuracy were 84.6, 100, and 88.2% for planar images and 96.2, 100 and 97.1% for SPECT, respectively, with a significant difference between the two imaging methods (p diagnostic performance for PD than planar images. Increased lung uptake may cause false-negative results on planar imaging.

  17. 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...

  18. 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.

  19. 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, dopa

  20. Simple suspension culture system of human iPS cells maintaining their pluripotency for cardiac cell sheet engineering.

    Science.gov (United States)

    Haraguchi, Yuji; Matsuura, Katsuhisa; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo

    2015-12-01

    In this study, a simple three-dimensional (3D) suspension culture method for the expansion and cardiac differentiation of human induced pluripotent stem cells (hiPSCs) is reported. The culture methods were easily adapted from two-dimensional (2D) to 3D culture without any additional manipulations. When hiPSCs were directly applied to 3D culture from 2D in a single-cell suspension, only a few aggregated cells were observed. However, after 3 days, culture of the small hiPSC aggregates in a spinner flask at the optimal agitation rate created aggregates which were capable of cell passages from the single-cell suspension. Cell numbers increased to approximately 10-fold after 12 days of culture. The undifferentiated state of expanded hiPSCs was confirmed by flow cytometry, immunocytochemistry and quantitative RT-PCR, and the hiPSCs differentiated into three germ layers. When the hiPSCs were subsequently cultured in a flask using cardiac differentiation medium, expression of cardiac cell-specific genes and beating cardiomyocytes were observed. Furthermore, the culture of hiPSCs on Matrigel-coated dishes with serum-free medium containing activin A, BMP4 and FGF-2 enabled it to generate robust spontaneous beating cardiomyocytes and these cells expressed several cardiac cell-related genes, including HCN4, MLC-2a and MLC-2v. This suggests that the expanded hiPSCs might maintain the potential to differentiate into several types of cardiomyocytes, including pacemakers. Moreover, when cardiac cell sheets were fabricated using differentiated cardiomyocytes, they beat spontaneously and synchronously, indicating electrically communicative tissue. This simple culture system might enable the generation of sufficient amounts of beating cardiomyocytes for use in cardiac regenerative medicine and tissue engineering.

  1. SELECTIVE AND TIME-RELATED ACTIVATION OF THE CARDIAC RENIN-ANGIOTENSIN SYSTEM AFTER EXPERIMENTAL HEART-FAILURE - RELATION TO VENTRICULAR-FUNCTION AND MORPHOLOGY

    NARCIS (Netherlands)

    PINTO, YM; DESMET, BGJL; VANGILST, WH; MONNINK, S; DEGRAEFF, PA; WESSELING, H

    1993-01-01

    Objective: The cardiac renin-angiotensin system is activated in experimental heart failure, but it is unknown at what stage of heart failure it becomes activated, and whether activation is related to ventricular dysfunction and dilatation. Changes in activity of cardiac, renal, and plasma angiotensi

  2. SemiSPECT: a small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays.

    Science.gov (United States)

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

    2006-02-01

    The first full single-photon emission computed tomography (SPECT) imager to exploit eight compact high-intrinsic-resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT, has been completed. Each detector consists of a CZT crystal and a customized application-specific integrated circuit (ASIC). The CZT crystal is a 2.7 cm x 2.7 cm x -0.2 cm slab with a continuous top electrode and a bottom electrode patterned into a 64 x 64 pixel array by photolithography. The ASIC is attached to the bottom of the CZT crystal by indium-bump bonding. A bias voltage of -180 V is applied to the continuous electrode. The eight detectors are arranged in an octagonal lead-shielded ring. Each pinhole in the eight-pinhole aperture placed at the center of the ring is matched to each individual detector array. An object is imaged onto each detector through a pinhole, and each detector is operated independently with list-mode acquisition. The imaging subject can be rotated about a vertical axis to obtain additional angular projections. The performance of SemiSPECT was characterized using 99mTc. When a 0.5 mm diameter pinhole is used, the spatial resolution on each axis is about 1.4 mm as estimated by the Fourier crosstalk matrix, which provides an algorithm-independent average resolution over the field of view. The energy resolution achieved by summing neighboring pixel signals in a 3 x 3 window is about 10% full-width-at-half-maximum of the photopeak. The overall system sensitivity is about 0.5 x 10(-4) with the energy window of +/-10% from the photopeak. Line-phantom images are presented to visualize the spatial resolution provided by SemiSPECT, and images of bone, myocardium, and human tumor xenografts in mice demonstrate the feasibility of preclinical small-animal studies with SemiSPECT.

  3. Cerebral perfusion SPECT in transient ischemic attack

    Energy Technology Data Exchange (ETDEWEB)

    You, D.-L. E-mail: dlyou@mail.kfcc.org.tw; Shieh, F.-Y.; Tzen, K.-Y.; Tsai, M.-F.; Kao, P.-F

    2000-04-01

    Purpose: The purpose of our study is to evaluate the efficacy of cerebral perfusion single photon emission computerized tomography (SPECT) in patients with transient ischemic attack (TIA). Methods: Thirty-seven patients with TIA were collected for study. All patients had transient focal neurological symptoms or signs with complete recovery within 24 h after onset. The patients underwent cerebral perfusion SPECT between 6 h and 11 days after onset, with 10 cases performed within 24 h (group A), nine cases performed between 1 and 3 days (group B), 11 cases performed between 3 and 5 days (group C), and seven cases performed after more than 5 days (group D). A semi-quantitative method was used for analyzing the SPECT data, and the difference ratios between lesion side and contralateral normal side were calculated on each pair of regions of interest. Results: In total, 78.4% (29/37) of patients had reduced perfusion in the cerebral cortical regions or deep nuclei, and the regions with reduced perfusion corresponded with clinical presentations of the patients. The abnormal rate with reduced perfusion was 90.0% in group A, 77.8% in group B, 72.7% in group C and 71.4% in group D. Cross cerebellar diaschisis (CCD) was present in seven patients, and all of the primary cerebral perfusion defects of these patients were located at the territory of left or right middle cerebral artery. Conclusion: Cerebral perfusion SPECT is a potential tool to detect cerebral perfusion defects and CCD in patients with TIA. Although the perfusion defect may persist more than 5 days after onset, we suggest cerebral perfusion SPECT should be performed as soon as possible.

  4. 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.)

  5. Regression of cardiac hypertrophy in the SHR by combined renin-angiotensin system blockade and dietary sodium restriction

    Directory of Open Access Journals (Sweden)

    Emad Abro

    2001-03-01

    Full Text Available Altered operation of the renin-angiotensin-aldosterone system (RAAS and dietary sodium intake have been identified as independent risk factors for cardiac hypertrophy. The way in which sodium intake and the operation of the renin-angiotensin-aldosterone system interact in the pathogenesis of cardiac hypertrophy is poorly understood. The aims of this study were to investigate the cardiac effects of the renin-angiotensin system (RAS blockade in the spontaneously hypertensive rat (SHR, using co-treatment with an angiotensin II receptor blocker (ARB and an angiotensin-converting enzyme (ACE inhibitor with different sodium intakes. Our experiments with SHR show that, at high levels of sodium intake (4.0%, aggressive RAS blockade treatment with candesartan (3 mg/kg and perindopril (6 mg/kg does not result in regression of cardiac hypertrophy. In contrast, RAS blockade coupled with reduced sodium diet (0.2% significantly regresses cardiac hypertrophy, impairs animal growth and is associated with elevated plasma renin and dramatically suppressed plasma angiotensinogen levels. Histological analyses indicate that the differential effect of reduced sodium on heart growth during RAS blockade is not associated with any change in myocardial interstitial collagen, but reflects modification of cellular geometry. Dimensional measurements of enzymatically-isolated ventricular myocytes show that, in the RAS blocked, reduced sodium group, myocyte length and width were decreased by about 16—19% compared with myocytes from the high sodium treatment group. Our findings highlight the importance of `titrating' sodium intake with combined RAS blockade in the clinical setting to optimise therapeutic benefit.

  6. Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient.

    Science.gov (United States)

    Jang, Yongwon; Noh, Hyung Wook; Lee, I B; Jung, Ji-Wook; Song, Yoonseon; Lee, Sooyeul; Kim, Seunghwan

    2012-01-01

    A patch type embedded cardiac function monitoring system was developed to detect arrhythmias such as PVC (Premature Ventricular Contraction), pause, ventricular fibrillation, and tachy/bradycardia. The overall system is composed of a main module including a dual processor and a Bluetooth telecommunication module. The dual microprocessor strategy minimizes power consumption and size, and guarantees the resources of embedded software programs. The developed software was verified with standard DB, and showed good performance.

  7. Induced Effects of Transcranial Magnetic Stimulation on the Autonomic Nervous System and the Cardiac Rhythm

    Directory of Open Access Journals (Sweden)

    Mercedes Cabrerizo

    2014-01-01

    Full Text Available Several standard protocols based on repetitive transcranial magnetic stimulation (rTMS have been employed for treatment of a variety of neurological disorders. Despite their advantages in patients that are retractable to medication, there is a lack of knowledge about the effects of rTMS on the autonomic nervous system that controls the cardiovascular system. Current understanding suggests that the shape of the so-called QRS complex together with the size of the different segments and intervals between the PQRST deflections of the heart could predict the nature of the different arrhythmias and ailments affecting the heart. This preliminary study involving 10 normal subjects from 20 to 30 years of age demonstrated that rTMS can induce changes in the heart rhythm. The autonomic activity that controls the cardiac rhythm was indeed altered by an rTMS session targeting the motor cortex using intensity below the subject’s motor threshold and lasting no more than 5 minutes. The rTMS activation resulted in a reduction of the RR intervals (cardioacceleration in most cases. Most of these cases also showed significant changes in the Poincare plot descriptor SD2 (long-term variability, the area under the low frequency (LF power spectrum density curve, and the low frequency to high frequency (LF/HF ratio. The RR intervals changed significantly in specific instants of time during rTMS activation showing either heart rate acceleration or heart rate deceleration.

  8. Radius Intermedius Stenosis Induced Myocardial Perfusion Defect : Provened by the Fusion Images of Myocardial Perfusion SPECT and 64 Channel CTA

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Eun Jung; Cho, Ihn Ho; Chun, Kyung Ah; Won, Kyu Chang; Lee, Hyung Woo; Park, Jong Seon [College of Medicine, Yeungnam University, Daegu (Korea, Republic of)

    2008-02-15

    A 71-year-old woman was assigned to our department for Tc-99m myocardial perfusion SPECT(MPS) and coronary CT angiography. She admitted for substernal pain, via the ER, 2 days ago. The heart was scanned after intravenous injection of 925 MBq of {sup 99m}Tc-sestamibi adenosine-induced stress SPECT using dual head gamma camera (Hawkeye, GE healthcare. USA). The MPS shows decreased tracer uptake in the apical and mid area of anterior and lateral wall and mid and basal inferior wall. Coronary CT angiography was obtained using Discovery VCT (GE healthcare). 3D angiography portrayed significant stenosis of ramus intermedius(RI) and posterolateral branch of right coronary artery(PLB) with fibrocalcified plaque. Two images were fused using Cardiac IQ fusion software package (Advantage workstation 4.4, GE healthcare) The fusion images explain the perfusion defect of anterior, lateral and inferior wall is due to stenosis of the RI and PLB. And 3 days later, coronary angiography was done and revealed the marked stenosis of RI and PLB. Then balloon angioplasty and stent was instituted in RI. Cardiac SPECT/CT fusion imaging provides additional information about hemodynamic relevance and facilitates lesion interpretation by allowing exact allocation of perfusion defects to its subtending coronary artery.

  9. Prognosis of patients with positive exercise test and normal myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Seo, J. H.; Jeong, S. Y.; Bae, J. H.; Ahn, B. C.; Lee, J.; Lee, K. B [College of Medicine, Kyungpook National University, Daegu (Korea, Republic of)

    2004-07-01

    Exercise SPECT myocardial perfusion imaging(Ex-MPI) is regarded as a predictive technique particularly in patients with coronary artery disease(CAD) capable of performing exercise testing. In clinical practice, we encounter equivocal situations of discordant findings between exercise ECG and MPI. We evaluated the prognosis of subjects with positive ECG and normal MPI findings, and predictive factors for cardiac events. 2571 Ex-MPI studies were reviewed over a period of 3 years. Subjects were followed for more than 2 years(24-56 months, mean 35{+-}10months) for cardiac events after study. The cardiac events were defined as hard events(cardiac death and nonfatal myocardial infarction(MI)) and soft events(aggravation of CAD necessitating revascularization, congestive heart failure necessitating hospital admission). We evaluated age, sex, typical angina pain, rest ECG, hypertension, diabetes mellitus(DM), serum levels of cholesterol and LDL, smoking history, history of cerebrovascular disease(CVD) and peripheral artery disease(PAD), and rest left ventricular ejection fraction(LVEF) as clinical variables. Of 83 subjects with positive ECG and normal MPS findings, 6 were considered as false negative results confirmed with coronary angiography. There were 77 patients (mean age 52{+-}10 years, 39 males) with positive ECG and normal MPI results. During the follow-up period, of 77 there were 3 cardiac events (annual rate 1.9%), no cardiac death, 2 nonfatal MIs (annual rate 1.3%) and 1 soft event (annual rate 0.6%). 2/39 males(5.1%), and 1/38 females(2.6%) had cardiac events. All cardiac events were observed within 2 years. 1-year cardiac event rate was 0.6% and 2-year cardiac event rate was 1.9%. Among clinical factors, male sex, typical chest pain and smoking history at the time of MPI were predictive of cardiac events. Patients with positive ECG and negative EX-MPI results have low risk for cardiac events. Nevertheless, the cardiac events cannot be excluded totally in some

  10. The magnetic shielding for the neutron decay spectrometer aSPECT

    CERN Document Server

    Konrad, Gertrud; Baeßler, Stefan; Borg, Michael; Glück, Ferenc; Heil, Werner; Hiebel, Stefan; Horta, Raquel Munoz; Sobolev, Yury

    2014-01-01

    Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magnet system. While the return yoke must reduce the stray magnetic field, the internal magnetic field and its homogeneity should not be affected. As in many cases, the magnetic shielding for aSPECT must manage with limited space. In addition, we must ensure that the additional magnetic forces on the magnet coils are not destructive. In order to determine the most suitable geometry for the magnetic shielding for aSPECT, we simulated a variety of possible geometries and combinations of shielding materials of non-linear permeabi...

  11. The magnetic shielding for the neutron decay spectrometer aSPECT

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Gertrud, E-mail: gkonrad@ati.ac.at [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany); Technische Universität Wien, Atominstitut, Stadionallee 2, A-1020 Wien (Austria); Ayala Guardia, Fidel [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany); Baeßler, Stefan [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany); University of Virginia, Department of Physics, Charlottesville, VA 22904 (United States); Borg, Michael [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany); Glück, Ferenc [Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology, P.O.B. 3640, D-76021 Karlsruhe (Germany); Wigner Research Institute for Physics, P.O.B. 49, H-1525 Budapest (Hungary); Heil, Werner [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany); Hiebel, Stefan [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany); Sekels GmbH, Dieselstraße 6, D-61239 Ober-Mörlen (Germany); Muñoz Horta, Raquel; Sobolev, Yury [Universität Mainz, Institut für Physik, Staudingerweg 7, D-55128 Mainz (Germany)

    2014-12-11

    Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2 T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magnet system. While the return yoke must reduce the stray magnetic field, the internal magnetic field and its homogeneity should not be affected. As in many cases, the magnetic shielding for aSPECT must manage with limited space. In addition, we must ensure that the additional magnetic forces on the magnet coils are not destructive. In order to determine the most suitable geometry for the magnetic shielding for aSPECT, we simulated a variety of possible geometries and combinations of shielding materials of non-linear permeability. The results of our simulations were checked through magnetic field measurements both with Hall and nuclear magnetic resonance probes. The experimental data are in good agreement with the simulated values: the mean deviation from the simulated exterior magnetic field is (−1.7±4.8)%. However, in the two critical regions, the internal magnetic field deviates by 0.2% (decay volume) and <1×10{sup −4} (analyzing plane) from the simulated values.

  12. 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.

  13. Cardiac arrest

    Science.gov (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

  14. Prenatal stress and balance of the child's cardiac autonomic nervous system at age 5-6 years.

    Directory of Open Access Journals (Sweden)

    Aimée E van Dijk

    Full Text Available OBJECTIVE: Autonomic nervous system (ANS misbalance is a potential causal factor in the development of cardiovascular disease. The ANS may be programmed during pregnancy due to various maternal factors. Our aim is to study maternal prenatal psychosocial stress as a potential disruptor of cardiac ANS balance in the child. METHODS: Mothers from a prospective birth cohort (ABCD study filled out a questionnaire at gestational week 16 [IQR 12-20], that included validated instruments for state anxiety, depressive symptoms, pregnancy-related anxiety, parenting daily hassles and job strain. A cumulative stress score was also calculated (based on 80(th percentiles. Indicators of cardiac ANS in the offspring at age 5-6 years are: pre-ejection period (PEP, heart rate (HR, respiratory sinus arrhythmia (RSA and cardiac autonomic balance (CAB, measured with electrocardiography and impedance cardiography in resting supine and sitting positions. RESULTS: 2,624 mother-child pairs, only single births, were available for analysis. The stress scales were not significantly associated with HR, PEP, RSA and CAB (p≥0.17. Accumulation of maternal stress was also not associated with HR, PEP, RSA and CAB (p≥0.07. CONCLUSION: Results did not support the hypothesis that prenatal maternal psychosocial stress deregulates cardiac ANS balance in the offspring, at least in rest, and at the age of five-six years.

  15. Ligands for SPECT and PET imaging of muscarinic-cholinergic receptors of the heart and brain

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; McPherson, D.W.; Luo, H. [and others

    1995-06-01

    Interest in the potential use of cerebral SPECT and PET imaging for determination of the density and activity of muscarinic-cholinergic receptors (mAChR) has been stimulated by the changes in these receptors which occur in many neurological diseases. In addition, the important involvement of mAChR in modulating negative inotropic cardiac activity suggests that such receptor ligands may have important applications in evaluation of changes which may occur in cardiac disease. In this paper, the properties of several key muscarinic receptor ligands being developed or which have been used for clinical SPECT and PET are discussed. In addition, the ORNL development of the new iodinated IQNP ligand based on QNB and the results of in vivo biodistribution studies in rats, in vitro competitive binding studies and ex vivo autoradiographic experiments are described. The use of radioiodinated IQNP may offer several advantages in comparison to IQNB because of its easy and high yield preparation and high brain uptake and the potential usefulness of the {open_quotes}partial{close_quotes} subtype selective IONP isomers. We also describe the development of new IQNP-type analogues which offer the opportunity for radiolabeling with positron-emitting radioisotopes (carbon-11, fluorine-18 and bromine-76) for potential use with PET.

  16. Comparative value of brain perfusion SPECT and [{sup 123}I]MIBG myocardial scintigraphy in distinguishing between dementia with Lewy bodies and Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Hanyu, Haruo; Shimizu, Soichiro; Hirao, Kentaro; Kanetaka, Hidekazu; Iwamoto, Toshihiko [Tokyo Medical University, Department of Geriatric Medicine, Tokyo (Japan); Chikamori, Taishiro; Usui, Yasuhiro; Yamashina, Akira [Tokyo Medical University, 2. Department of Internal Medicine, Tokyo (Japan); Koizumi, Kiyoshi; Abe, Kimihiko [Tokyo Medical University, Department of Radiology, Tokyo (Japan)

    2006-03-15

    Both decreased occipital perfusion on brain single-photon emission computed tomography (SPECT) and reduction in cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) uptake are characteristic features of dementia with Lewy bodies (DLB), and potentially support the clinical diagnosis of DLB. The aim of this study was to compare the diagnostic value of these two methods for differentiation of DLB from Alzheimer's disease (AD). The study population comprised 19 patients with probable DLB and 39 patients with probable AD who underwent both SPECT with N-isopropyl-p-[{sup 123}I]iodoamphetamine and MIBG myocardial scintigraphy. Objective and quantitative measurement of perfusion in the medial occipital lobe, including the cuneus and lingual gyrus, was performed by the use of three-dimensional stereotactic surface projections. Medial occipital perfusion was significantly decreased in the DLB group compared with the AD group. The mean heart/mediastinum ratios of MIBG uptake were significantly lower in the DLB group than in the AD group. Although SPECT failed to demonstrate significant hypoperfusion in the medial occipital lobe in five patients with DLB, marked reduction of MIBG uptake was found in all patients with DLB. Receiver operating characteristic analysis revealed that MIBG myocardial scintigraphy enabled more accurate discrimination between DLB and AD than was possible with perfusion SPECT. MIBG myocardial scintigraphy may improve the sensitivity in the detection of DLB. In particular, this method may provide a powerful differential diagnostic tool when it is difficult to distinguish cases of DLB from AD using brain perfusion SPECT. (orig.)

  17. 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

  18. Measuring Cardiac Autonomic Nervous System (ANS) Activity in Toddlers - Resting and Developmental Challenges.

    Science.gov (United States)

    Bush, Nicole R; Caron, Zoe K; Blackburn, Katherine S; Alkon, Abbey

    2016-02-25

    The autonomic nervous system (ANS) consists of two branches, the parasympathetic and sympathetic nervous systems, and controls the function of internal organs (e.g., heart rate, respiration, digestion) and responds to everyday and adverse experiences (1). ANS measures in children have been found to be related to behavior problems, emotion regulation, and health (2-7). Therefore, understanding the factors that affect ANS development during early childhood is important. Both branches of the ANS affect young children's cardiovascular responses to stimuli and have been measured noninvasively, via external monitoring equipment, using valid and reliable measures of physiological change (8-11). However, there are few studies of very young children with simultaneous measures of the parasympathetic and sympathetic nervous systems, which limits understanding of the integrated functioning of the two systems. In addition, the majority of existing studies of young children report on infants' resting ANS measures or their reactivity to commonly used mother-child interaction paradigms, and less is known about ANS reactivity to other challenging conditions. We present a study design and standardized protocol for a non-invasive and rapid assessment of cardiac autonomic control in 18 month old children. We describe methods for continuous monitoring of the parasympathetic and sympathetic branches of the ANS under resting and challenge conditions during a home or laboratory visit and provide descriptive findings from our sample of 140 ethnically diverse toddlers using validated equipment and scoring software. Results revealed that this protocol can produce a range of physiological responses to both resting and developmentally challenging conditions, as indicated by changes in heart rate and indices of parasympathetic and sympathetic activity. Individuals demonstrated variability in resting levels, responses to challenges, and challenge reactivity, which provides additional evidence

  19. Quantitative Tc-99m myocardial perfusion SPECT with 180[degree] acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Ye, J.

    1992-01-01

    Myocardial perfusion single photon emission computed tomography (SPECT) images using 180[degrees] acquisition are degraded by the effects of scatter, nonuniform attenuation and system geometric resolution variation with source depth. Using a 180[degrees] scan orbit which is closer to the heart may provide higher image resolution, signal-to-noise ratio and defect-to-normal contrast than using a 360[degrees] orbit, however, significant object shape distortion has been observed in the 180[degrees] reconstructed images. A method has been developed that combines filtered back-projection (FBP) with iterative attenuation and three-dimensional (3-D) resolution compensation for Tc-99m myocardial perfusion imaging, data. The non-uniform attenuation coefficient distribution is obtained by a quick transmission scan using a flood source and segmentation of the reconstructed transmission image to define areas of significantly different attenuation. A priori attenuation coefficients are assigned to the areas to form the attenuation distribution map. The 3-D correction is accomplished by including both the non-uniform attenuation and depth-dependent resolution variation in the reprojection procedure of an iterative correction algorithm. The method was evaluated with both simulated and experimental data using clinical protocols with a cardiac phantom. A significant improvement in image resolution was observed with line source images was reduced from approximately 10 mm to 7.l5 mm after 7 iterations of the 3-D correction. The contrast of two perfusion defects to the surrounding normally perfused regions was significantly improved with the correction. Significant improvement in uniformity at different positions in the 100% perfused areas in the myocardium was also observed. The normalized root squared error (NRSE) of one transaxial image from the original source distribution in the simulation study was reduced from 0.8 to 0.2 after 5 iterations of the 3-D correction.

  20. Evaluation of the quality of picture in studies of sect brain acquired with various collimators; Evaluacion de la calidad de imagen en estudios de spect cerebral adquiridos con distintos colimadores

    Energy Technology Data Exchange (ETDEWEB)

    Moran Velasco, V.; Prieto Azcarete, E.; Barbes Fernandez, B.; Sancho rodriguez, L.; Ribelles Segura, M. J.; Richter echevarria, J. A.; Arbizu Lostao, J.; Marti-Climent, J. M.

    2015-07-01

    On the practice clinic , the performance of the systems SPECT depends on in large measurement of the quality of image. The goal of East study was evaluate how affect the parameters of reconstruction of studies SPECT of perfusion brain acquired with a collimator of holes parallel (LEHR) and other of holes in fan (Fan-Beam). (Author)

  1. Activity optimization method in SPECT: A comparison with ROC analysis

    Institute of Scientific and Technical Information of China (English)

    D(I)AZ Marlén Pérez; RIZO Oscar Díaz; D(I)AZ Adlin López; APARICIO Eric Estévez; D(I)AZ Reinaldo Roque

    2006-01-01

    A discriminant method for optimizing activity in nuclear medicine studies is validated by comparison with ROC performed with a cardiac phantom. Three different lesions (L1, L2 and L3) were placed in the myocardium-wall by pairs for each SPECT. Three activities (84, 37 or 18.5 MBq) of 99mTc were used as background. Linear discriminant analysis was used to select the parameters that characterize image quality among the measured variables in the images [(Background-to-Lesion (B/Li) and Signal-to-Noise (Si/N) ratio s)]. Two clusters with different image quality (P=0.021) were obtained. The ratios B/L1, B/L2 and B/L3are the parameters used to construct the function with 100% of cases correctly classified into the clusters. The value of 37 MBq was the lowest tested activity for which good results for the B/Li ratios were obtained. The result coincides with the applied ROC-analysis (r=0.89).

  2. Clinical significance of {sup 123}I-BMIPP myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Junichi [Toho Univ., Tokyo (Japan). School of Medicine

    1998-07-01

    {sup 123}I-BMIPP is a radioiodinated branched chain fatty acid analog, showing high accumulation as well as prolonged retention in the myocardium. Therefore, it is used as a metabolic imaging agent suitable for myocardial SPECT. After {sup 123}I-BMIPP is taken in the myocardium, it remains there mainly as a storage type fatty acid of triglyceride, and it shows different behavior by the stage of cardiac disease. Usually, we evaluate metabolic findings by early imaging (20 minutes) after intravenous injection of {sup 123}I-BMIPP, however, sometimes washout or fill in are seen in the case of myocardial infarction or hypertrophic cardiomyopathy by delayed imaging (after 4 hours). The mismatch of {sup 201}TlCl and {sup 123}I-BMIPP are useful for the diagnosis of stunned myocardium or evaluation of prognosis. However, behavior of {sup 123}I-BMIPP in myocardium is known still not completely. Therefore clinical significance of this examination is thought to be clarified by the stock of cases of various heart diseases. (author)

  3. Isolation of cardiac conduction system of rat heart by laser capture microdissection

    Institute of Scientific and Technical Information of China (English)

    OU Yan; NIU Xiao-lin; REN Fu-xian; HUANG Chen; LEI Cong; LI Zhe; CHEN Wei

    2005-01-01

    Objective:To isolate cells of cardiac conduction system (CCS) with laser capture microdissection (LCM) and extract and evaluate quality of small amount of RNA from cells of CCS. Methods: Cryostat sections were followed by H-E staining. 20 pieces of H-E stained cryostat sections were scraped and its RNA was assessed to insure that RNA didn't degrade in dyeing and dehydration process. Cells of CCS were captured with LCM and quality of small amount of RNA was verified with RT-PCR. Results: Cells of CCS isolated with LCM had clear morphology after staining. High quality RNA was extracted from LCM samples and scraped tissues; 18S rRNA and 28S rRNA were seen distinctly on gel electrophoresis. Low level of small amount of RNA extracted from LCM sample was below the limit of detection on gel electrophoresis or ultraviolet spectrophotometer. The housekeeping genes β-actin and GAPDH were successfully amplified with small amount of RNA. Conclusion :This study resolves the problem of acquiring material of CCS precisely that hinders gene research of CCS. It is found out that the method is easy and reliable to extract and assess the quality of small amount of RNA from microdissected cells of CCS.

  4. [Non-invasive evaluation of the cardiac autonomic nervous system by PET]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    C-11 hydroxy ephedrine, introduced as the first clinically usable norepinephrine analogue, studies employing normal volunteers and patients with various cardiac disorders was found to valuable as a nonadreneric tracer. Simultaneously, animal studies been used to assess its use following ischemic injury in order to define neuronal damage. Current research focuses on the comparison of C-11 hydroxyephedrine with other neurotransmitters such as C-11 epinephrine and C-11 threohydroxyephedrine. Epinephrine is primarily stored in vesicles of the nerve terminal, while threo-hydroxyephedrine is only substrate to uptake I mechanism. Such a combination of radiotracers may allow the dissection of uptake I mechanism as well as vesicular storage. In parallel to the refinement of presynaptic tracers for the sympathetic nervous system, we are developing radiopharmaceuticals to delineate the adrenergic receptors in the heart. The combined evaluation of pre- and postsynaptic nerve function will improve our ability to identify abnormalides. We are currently developing a new radiosynthesis of the hydrophilic adrenergic receptor antagonist C-11 CGP-12177 which has been used by others for the visualization of adrenergic receptors in the heart. We are developing radiopharmaceuticals, for the delineation of presynaptic cholinergic nerve terminals. Derivatives of benzovesamicol have been labeled in our institution and are currently under investigation. The most promising agent is F-18 benzovesamicol (FEBOBV) which allows the visualization of parasympathetic nerve terminals in the canine heart as demonstrated by, preliminary PET data.

  5. [Non-invasive evaluation of the cardiac autonomic nervous system by PET

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    C-11 hydroxy ephedrine, introduced as the first clinically usable norepinephrine analogue, studies employing normal volunteers and patients with various cardiac disorders was found to valuable as a nonadreneric tracer. Simultaneously, animal studies been used to assess its use following ischemic injury in order to define neuronal damage. Current research focuses on the comparison of C-11 hydroxyephedrine with other neurotransmitters such as C-11 epinephrine and C-11 threohydroxyephedrine. Epinephrine is primarily stored in vesicles of the nerve terminal, while threo-hydroxyephedrine is only substrate to uptake I mechanism. Such a combination of radiotracers may allow the dissection of uptake I mechanism as well as vesicular storage. In parallel to the refinement of presynaptic tracers for the sympathetic nervous system, we are developing radiopharmaceuticals to delineate the adrenergic receptors in the heart. The combined evaluation of pre- and postsynaptic nerve function will improve our ability to identify abnormalides. We are currently developing a new radiosynthesis of the hydrophilic adrenergic receptor antagonist C-11 CGP-12177 which has been used by others for the visualization of adrenergic receptors in the heart. We are developing radiopharmaceuticals, for the delineation of presynaptic cholinergic nerve terminals. Derivatives of benzovesamicol have been labeled in our institution and are currently under investigation. The most promising agent is F-18 benzovesamicol (FEBOBV) which allows the visualization of parasympathetic nerve terminals in the canine heart as demonstrated by, preliminary PET data.

  6. Reliability of myocardial perfusion quantification in angiography using a digital flat panel cardiac system

    Science.gov (United States)

    Perrin, Muriel; Vaillant, Regis; Gavit-Houdant, Laurence; Lienard, Jean; Benali, Karim

    2002-04-01

    Discordance between lesion severity from angiocardiography and physiological effects has been reported elsewhere. Quantification of myocardial perfusion during the angiography procedure may supply additional information about short- and long-term outcomes and may be helpful for clinical decision making. In previous works, myocardial perfusion has been assessed using time density curves (TDC), which represent the contrast medium dilution over time in the myocardium. The mean transit time (MTT), derived from the TDC, has been reported as a good indicator of the regional myocardial perfusion. Our objective is to estimate the accuracy and reproducibility of MTT estimation on digital flat panel (DFP) images. We have simulated typical myocardium TDC obtained with a DFP cardiac system (Innova 2000, GE), taking into account scatter and noise. Logarithmic or linear subtractions have been applied to derive a contrast medium concentration proportional quantity from image intensity. A non-linear minimisation realises the model curve fitting. MTT estimates are more stable with linear subtraction in presence of scatter. However logarithmic subtraction presents smaller bias when scatter level is small. Both approaches are equally sensible to image noise. Linear subtraction should be preferred. Image noise has a high influence on MTT accuracy and we may reduce.

  7. Exercise training improves cardiac autonomic nervous system activity in type 1 diabetic children.

    Science.gov (United States)

    Shin, Ki Ok; Moritani, Toshio; Woo, Jinhee; Jang, Ki Soeng; Bae, Ju Yong; Yoo, Jaeho; Kang, Sunghwun

    2014-01-01

    [Purpose] We investigated the effect exercise training has on cardiac autonomic nervous system (ANS) and cardiovascular risk profiles in children with type 1 diabetes mellitus (DM). [Subjects] Fifteen type 1 DM children (all boys; 13.0±1.0 years of age) were enrolled in the study. [Methods] The subjects received exercise training three times a week in a 12-week program. Each child was asked to walk on a treadmill to achieve an exercise intensity of VO2max 60%. ANS activity was measured by power spectral analysis of the electrocardiogram (ECG). Blood samples were obtained for serum lipid profiles. To evaluate Doppler-shifted Fourier pulsatility index (PI) analysis, a 5-MHz continuous wave Doppler (VASCULAB D10) set was used to measure forward blood flow velocity (FLOW) in the radial artery. [Results] Total and low-frequency (LF) power of heart rate variability increased significantly after exercise intervention. Total cholesterol (TC) levels were significant lower after exercise intervention. Total and high-frequency (HF) power were significantly correlated with higher TC levels, but diastolic blood pressure and HF was significantly correlated with lower TC levels. [Conclusion] Regular exercise intervention should be prescribed for children with type 1 DM.

  8. Are Cardiac Autonomic Nervous System Activity and Perceived Stress Related to Functional Somatic Symptoms in Adolescents? The TRAILS Study.

    Directory of Open Access Journals (Sweden)

    Karin A M Janssens

    Full Text Available Stressors have been related to medically insufficiently explained or functional somatic symptoms (FSS. However, the underlying mechanism of this association is largely unclear. In the current study, we examined whether FSS are associated with different perceived stress and cardiac autonomic nervous system (ANS levels during a standardized stressful situation, and whether these associations are symptom-specific.We examined 715 adolescents (16.1 years, 51.3% girls from the Dutch cohort study Tracking Adolescents' Individual Lives Sample during the Groningen Social Stress Test (GSST. FSS were assessed by the Youth Self-Report, and clustered into a cluster of overtiredness, dizziness and musculoskeletal pain and a cluster of headache and gastrointestinal symptoms. Perceived stress levels (i.e. unpleasantness and arousal were assessed by the Self-Assessment Manikin, and cardiac ANS activity by assessing heart rate variability (HRV-HF and pre-ejection period (PEP. Perceived stress and cardiac ANS levels before, during, and after the GSST were studied as well as cardiac ANS reactivity. Linear regression analyses were used to examine the associations.Perceived arousal levels during (beta = 0.09, p = 0.04 and after (beta = 0.07, p = 0.047 the GSST, and perceived unpleasantness levels before (beta = 0.07, p = 0.048 and during (beta = 0.12, p = 0.001 the GSST were related to FSS during the past couple of months. The association between perceived stress and FSS was stronger for the FSS cluster of overtiredness, dizziness and musculoskeletal pain than for the cluster of headache and gastrointestinal symptoms. Neither ANS activity levels before, during, and after the GSST, nor maximal HF-HRV and PEP reactivity were related to FSS.This study suggests that perceived stress levels during social stress are related to FSS, whereas cardiac ANS activity and reactivity are not related to FSS.

  9. Catecholamines, cardiac natriuretic peptides and chromogranin A: evolution and physiopathology of a 'whip-brake' system of the endocrine heart.

    Science.gov (United States)

    Tota, Bruno; Cerra, Maria Carmela; Gattuso, Alfonsina

    2010-09-15

    In the past 50 years, extensive evidence has shown the ability of vertebrate cardiac non-neuronal cells to synthesize and release catecholamines (CA). This formed the mindset behind the search for the intrinsic endocrine heart properties, culminating in 1981 with the discovery of the natriuretic peptides (NP). CA and NP, co-existing in the endocrine secretion granules and acting as major cardiovascular regulators in health and disease, have become of great biomedical relevance for their potent diagnostic and therapeutic use. The concept of the endocrine heart was later enriched by the identification of a growing number of cardiac hormonal substances involved in organ modulation under normal and stress-induced conditions. Recently, chromogranin A (CgA), a major constituent of the secretory granules, and its derived cardio-suppressive and antiadrenergic peptides, vasostatin-1 and catestatin, were shown as new players in this framework, functioning as cardiac counter-regulators in 'zero steady-state error' homeostasis, particularly under intense excitatory stimuli, e.g. CA-induced myocardial stress. Here, we present evidence for the hypothesis that is gaining support, particularly among human cardiologists. The actions of CA, NP and CgA, we argue, may be viewed as a hallmark of the cardiac capacity to organize 'whip-brake' connection-integration processes in spatio-temporal networks. The involvement of the nitric oxide synthase (NOS)/nitric oxide (NO) system in this configuration is discussed. The use of fish and amphibian paradigms will illustrate the ways that incipient endocrine-humoral agents have evolved as components of cardiac molecular loops and important intermediates during evolutionary transitions, or in a distinct phylogenetic lineage, or under stress challenges. This may help to grasp the old evolutionary roots of these intracardiac endocrine/paracrine networks and how they have evolved from relatively less complicated designs. The latter can also be used

  10. Selective quantification of the cardiac sympathetic and parasympathetic nervous systems by multisignal analysis of cardiorespiratory variability.

    Science.gov (United States)

    Chen, Xiaoxiao; Mukkamala, Ramakrishna

    2008-01-01

    Heart rate (HR) power spectral indexes are limited as measures of the cardiac autonomic nervous systems (CANS) in that they neither offer an effective marker of the beta-sympathetic nervous system (SNS) due to its overlap with the parasympathetic nervous system (PNS) in the low-frequency (LF) band nor afford specific measures of the CANS due to input contributions to HR [e.g., arterial blood pressure (ABP) and instantaneous lung volume (ILV)]. We derived new PNS and SNS indexes by multisignal analysis of cardiorespiratory variability. The basic idea was to identify the autonomically mediated transfer functions relating fluctuations in ILV to HR (ILV-->HR) and fluctuations in ABP to HR (ABP-->HR) so as to eliminate the input contributions to HR and then separate each estimated transfer function in the time domain into PNS and SNS indexes using physiological knowledge. We evaluated these indexes with respect to selective pharmacological autonomic nervous blockade in 14 humans. Our results showed that the PNS index derived from the ABP-->HR transfer function was correctly decreased after vagal and double (vagal + beta-sympathetic) blockade (P < 0.01) and did not change after beta-sympathetic blockade, whereas the SNS index derived from the same transfer function was correctly reduced after beta-sympathetic blockade in the standing posture and double blockade (P < 0.05) and remained the same after vagal blockade. However, this SNS index did not significantly decrease after beta-sympathetic blockade in the supine posture. Overall, these predictions were better than those provided by the traditional high-frequency (HF) power, LF-to-HF ratio, and normalized LF power of HR variability.

  11. Microfluidic systems to examine intercellular coupling of pairs of cardiac myocytes.

    Science.gov (United States)

    Klauke, Norbert; Smith, Godfrey; Cooper, Jonathan M

    2007-06-01

    In this paper we describe a microfluidic environment that enables us to explore cell-to-cell signalling between longitudinally linked primary heart cells. We have chosen to use pairs (or doublets) of cardiac myocyte as a model system, not only because of the importance of cell-cell signalling in the study of heart disease but also because the single cardiomyocytes are both mechanically and electrically active and their synchronous activation due to the intercellular coupling within the doublet can be readily monitored on optical and electrical recordings. Such doublets have specialised intercellular contact structures in the form of the intercalated discs, comprising the adhesive junction (fascia adherens and macula adherens or desmosome) and the connecting junction (known as gap junction). The latter structure enables adjacent heart cells to share ions, second messengers and small metabolites (<1 kDa) between them and thus provides the structural basis for the synchronous (syncytical) behaviour of connected cardiomyocytes. Using the unique environment provided by the microfluidic system, described in this paper, we explore the local ionic conditions that enable the propagation of Ca(2+) waves between two heart cells. We observe that the ability of intracellular Ca(2+) waves to traverse the intercalated discs is dependent on the relative concentrations of diastolic Ca(2+) in the two adjacent cells. These experiments rely upon our ability to independently control both the electrical stimulation of each of the cells (using integrated microelectrodes) and to rapidly change (or switch) the local concentrations of ions and drugs in the extracellular buffer within the microfluidic channel (using a nanopipetting system). Using this platform, it is also possible to make simultaneous optical recordings (including fluorescence and cell contraction) to explore the effect of drugs on one or both cells, within the doublet.

  12. TwoSpect: tuning up to search for gravitational waves from Scorpius X-1

    CERN Document Server

    Meadors, Grant David; Riles, Keith

    2015-01-01

    We describe the tuning of the TwoSpect data analysis method to search for continuous gravitational waves from sources such as the Low Mass X-ray Binary, Scorpius X-1. TwoSpect sensitivity is enhanced when the source sky location and period are known. Simulations of the orbital and gravitational-wave parameters of Scorpius X-1 have already been made in the context of a comparison of search algorithms. These simulations are here used to quantify the sensitivity enhancement and parameter estimation abilities of this tuned, directed TwoSpect method. The gravitational wave strain, gravitational wave frequency, and projected semi-major axis of the binary system are recovered and uncertainty estimated, for simulated signals that are detected. Upper limits on gravitational wave strain are set for undetected signals. Applications to future searches in gravitational-wave interferometer data are discussed. Directed TwoSpect searches analyze gravitational-wave data for signals from LMXBs; robust against spin-wandering an...

  13. Brain MRI and SPECT in the diagnosis of early neurological involvement in Wilson's disease

    Energy Technology Data Exchange (ETDEWEB)

    Piga, Mario; Satta, Loredana; Serra, Alessandra; Loi, Gianluigi [Policlinico Universitario, University of Cagliari, Nuclear Medicine, Department of Medical Science, Monserrato, Cagliari (Italy); Murru, Alessandra; Demelia, Luigi [Policlinico Universitario, University of Cagliari, Gastroenterology, Department of Medical Science, Monserrato, Cagliari (Italy); Sias, Alessandro [Policlinico Universitario, University of Cagliari, Radiology, Department of Medical Science, Monserrato, Cagliari (Italy); Marrosu, Francesco [Policlinico Universitario, University of Cagliari, Neurology, Department of Medical Science, Monserrato, Cagliari (Italy)

    2008-04-15

    To evaluate the impact of brain MRI and single-photon emission computed tomography (SPECT) in early detection of central nervous system abnormalities in patients affected by Wilson's disease (WD) with or without neurological involvement. Out of 25 consecutive WD patients, 13 showed hepatic involvement, ten hepatic and neurological manifestations, and twp hepatic, neurological, and psychiatric symptoms, including mainly movement disorders, major depression, and psychosis. Twenty-four healthy, age-gender matched subjects served as controls. All patients underwent brain MRI and {sup 99m}Tc-ethyl-cysteinate dimer (ECD) SPECT before starting specific therapy. Voxel-by-voxel analyses were performed using statistical parametric mapping to compare differences in {sup 99m}Tc-ECD brain uptake between the two groups. Brain MRI showed T2-weighted hyperintensities in seven patients (28%), six of whom were affected by hepatic and neurological forms. Brain perfusion SPECT showed pathological data in 19 patients (76%), revealing diffuse or focal hypoperfusion in superior frontal (Brodmann area (BA) 6), prefrontal (BA 9), parietal (BA 40), and occipital (BA 18, BA 39) cortices in temporal gyri (BA 37, BA 21) and in caudatus and putamen. Moreover, hepatic involvement was detected in nine subjects; eight presented both hepatic and neurological signs, while two exhibited WD-correlated hepatic, neurological, and psychiatric alterations. All but one patient with abnormal MRI matched with abnormal ECD SPECT. Pathologic MRI findings were obtained in six out of ten patients with hepatic and neurological involvement while abnormal ECD SPECT was revealed in eight patients. Both patients with hepatic, neurological, and psychiatric involvement displayed abnormal ECD SPECT and one displayed an altered MRI. These findings suggest that ECD SPECT might be useful in detecting early brain damage in WD, not only in the perspective of assessing and treating motor impairment but also in evaluating

  14. Quantitation of myocardial blood flow and myocardial flow reserve with {sup 99m}Tc-sestamibi dynamic SPECT/CT to enhance detection of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Bailing [University of Missouri-Columbia, Nuclear Science and Engineering Institute, Columbia, MO (United States); Chen, Fu-Chung; Chen, Chien-Cheng [Show Chwan Memorial Hospital, Section of Cardiology, Department of Internal Medicine, Changhua (China); Wu, Tao-Cheng [Taipei Veterans General Hospital, Section of Cardiology, Department of Internal Medicine, Taipei (China); Huang, Wen-Sheng [Changhua Christian Hospital, Department of Medical Research and Department of Nuclear Medicine, Changhua (China); Hou, Po-Nien [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Lukong Town, Changhua Shien (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Lukong Town, Changhua Shien (China); Central Taiwan University of Science and Technology, Department of Medical Imaging and Radiological Science, Taichung (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China)

    2014-12-15

    Conventional dual-head single photon emission computed tomography (SPECT)/CT systems capable of fast dynamic SPECT (DySPECT) imaging have a potential for flow quantitation. This study introduced a new method to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR) with DySPECT scan and evaluated the diagnostic performance of detecting coronary artery disease (CAD) compared with perfusion using invasive coronary angiography (CAG) as the reference standard. This study included 21 patients with suspected or known CAD who had received DySPECT, ECG-gated SPECT (GSPECT), and CAG (13 with ≥50 % stenosis in any vessel; non-CAD group: 8 with patent arteries or <50 % stenosis). DySPECT and GSPECT scans were performed on a widely used dual-head SPECT/CT scanner. The DySPECT imaging protocol utilized 12-min multiple back-and-forth gantry rotations during injections of {sup 99m}Tc-sestamibi (MIBI) tracer at rest or dipyridamole-stress stages. DySPECT images were reconstructed with full physical corrections and converted to the physical unit of becquerels per milliliter. Stress MBF (SMBF), rest MBF (RMBF), and MFR were quantified by a one-tissue compartment flow model using time-activity curves derived from DySPECT images. Perfusion images were processed for GSPECT scan and interpreted to obtain summed stress score (SSS) and summed difference score (SDS). Receiver-operating characteristic (ROC) analyses were conducted to evaluate the diagnostic performance of flow and perfusion. Using the criteria of ≥50 % stenosis as positive CAD, areas under the ROC curve (AUCs) of flow assessment were overall significantly greater than those of perfusion. For patient-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.91 ± 0.07, 0.86 ± 0.09, 0.64 ± 0.12, and 0.59 ± 0.13. For vessel-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.81 ± 0.05, 0.76 ± 0.06, 0.62 ± 0.07, and 0.56 ± 0.08, respectively. The preliminary data suggest that MBF quantitation with a

  15. 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.)

  16. 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.

  17. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo;

    2010-01-01

    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......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......, 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...

  18. {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.)

  19. Cardiac tamponade as the initial presentation of systemic lupus erythematosus: a case report and review of the literature.

    Science.gov (United States)

    Maharaj, Satish S; Chang, Simone M

    2015-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease that can involve any organ system, exhibiting great diversity in presentation. Cardiac tamponade as the initial presentation of childhood onset SLE (cSLE) is rare. We report the case of a 10 year old Afro-Caribbean female who presented with complaints of chest pain, shortness of breath and fever over 4 days. Clinical examination strongly suggested cardiac tamponade which was confirmed by investigations and treated with pericardiocentesis. After a thorough investigation, the underlying diagnosis of SLE was confirmed using the Systemic Lupus International Collaborating Clinics (SLICC) criteria and high dose corticosteroid therapy initiated. A review of recent studies shows that common initial presentations of cSLE include constitutional symptoms, renal disease, musculoskeletal and cutaneous involvement. In presenting this case and reviewing the literature we emphasize the importance of cSLE as a differential diagnosis when presented with pericarditis in the presence or absence of cardiac tamponade. In these patients early diagnosis and treatment is desired and in this regard we also discuss the sensitivity of the SLICC criteria in cSLE.

  20. Dopamine transporter density of the basal ganglia assessed with I-123 IPT SPECT in methamphetamine abusers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo Ryung; Ahn, Byeong Cheol [Kyungpook National University Medical School, Daegu (Korea, Republic of); Kewm, Do Hun [National Bugok Mental Hospital, Changryung (Korea, Republic of)] (and others)

    2005-10-15

    Functional imaging of dopamine transporter (DAT) defines integrity of the dopaminergic system, and DAT is the target site of drugs of abuse such as cocaine and methamphetamine. Functional imaging the DAT may be a sensitive and selective indicator of neurotoxic change by the drug. The aim of the present study is to evaluate the clinical implications of qualitative/quantitative analyses of dopamine transporter imaging in methamphetamine abusers. Six detoxified methamphetamine abusers (abuser group) and 4 volunteers (control group) were enrolled in this study. Brain MRI was performed in all of abuser group. Abuser group underwent psychiatric and depression assessment using brief psychiatric rating scale (BPRS) and Hamilton depression rating scale (HAMD), respectively. All of the subjects underwent I-123 IPT SPECT (IPT SPECT). IPT SPECT image was analysed with visual qualitative method and quantitative method using basal ganglia dopamine transporter (DAT) specific/non-specific binding ratio (SBR). Comparison of DAT SBR between abuser and control groups was performed. We also performed correlation tests between psychiatric and depression assessment results and DAT SBR in abuser group. All of abuser group showed normal MRI finding, but had residual psychiatric and depressive symptoms, and psychiatric and depressive symptom scores were exactly correlated (r=1.0, {rho} =0.005) each other. Five of them showed abnormal finding on qualitative visual I-123 IPT SPECT. Abuser group had lower basal ganglia DAT SBR than that of control (2.38 {+-} 0.20 vs 3.04 {+-} 0.27, {rho} =0.000). Psychiatric and depressive symptoms were negatively well correlated with basal ganglia DAT SBR (r=-0.908, {rho} =0.012, r=-0.924, {rho} =0.009) This results suggest that dopamine transporter imaging using I-123 IPT SPECT may be used to evaluate dopaminergic system of the basal ganglia and the clinical status in methamphetamine abusers.

  1. 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.

  2. Assessment of the sources of error affecting the quantitative accuracy of SPECT imaging in small animals

    Energy Technology Data Exchange (ETDEWEB)

    Joint Graduate Group in Bioengineering, University of California, San Francisco and University of California, Berkeley; Department of Radiology, University of California; Gullberg, Grant T; Hwang, Andrew B.; Franc, Benjamin L.; Gullberg, Grant T.; Hasegawa, Bruce H.

    2008-02-15

    Small animal SPECT imaging systems have multiple potential applications in biomedical research. Whereas SPECT data are commonly interpreted qualitatively in a clinical setting, the ability to accurately quantify measurements will increase the utility of the SPECT data for laboratory measurements involving small animals. In this work, we assess the effect of photon attenuation, scatter and partial volume errors on the quantitative accuracy of small animal SPECT measurements, first with Monte Carlo simulation and then confirmed with experimental measurements. The simulations modeled the imaging geometry of a commercially available small animal SPECT system. We simulated the imaging of a radioactive source within a cylinder of water, and reconstructed the projection data using iterative reconstruction algorithms. The size of the source and the size of the surrounding cylinder were varied to evaluate the effects of photon attenuation and scatter on quantitative accuracy. We found that photon attenuation can reduce the measured concentration of radioactivity in a volume of interest in the center of a rat-sized cylinder of water by up to 50percent when imaging with iodine-125, and up to 25percent when imaging with technetium-99m. When imaging with iodine-125, the scatter-to-primary ratio can reach up to approximately 30percent, and can cause overestimation of the radioactivity concentration when reconstructing data with attenuation correction. We varied the size of the source to evaluate partial volume errors, which we found to be a strong function of the size of the volume of interest and the spatial resolution. These errors can result in large (>50percent) changes in the measured amount of radioactivity. The simulation results were compared with and found to agree with experimental measurements. The inclusion of attenuation correction in the reconstruction algorithm improved quantitative accuracy. We also found that an improvement of the spatial resolution through the

  3. Assessment of the sources of error affecting the quantitative accuracy of SPECT imaging in small animals

    Science.gov (United States)

    Hwang, Andrew B.; Franc, Benjamin L.; Gullberg, Grant T.; Hasegawa, Bruce H.

    2008-05-01

    Small animal SPECT imaging systems have multiple potential applications in biomedical research. Whereas SPECT data are commonly interpreted qualitatively in a clinical setting, the ability to accurately quantify measurements will increase the utility of the SPECT data for laboratory measurements involving small animals. In this work, we assess the effect of photon attenuation, scatter and partial volume errors on the quantitative accuracy of small animal SPECT measurements, first with Monte Carlo simulation and then confirmed with experimental measurements. The simulations modeled the imaging geometry of a commercially available small animal SPECT system. We simulated the imaging of a radioactive source within a cylinder of water, and reconstructed the projection data using iterative reconstruction algorithms. The size of the source and the size of the surrounding cylinder were varied to evaluate the effects of photon attenuation and scatter on quantitative accuracy. We found that photon attenuation can reduce the measured concentration of radioactivity in a volume of interest in the center of a rat-sized cylinder of water by up to 50% when imaging with iodine-125, and up to 25% when imaging with technetium-99m. When imaging with iodine-125, the scatter-to-primary ratio can reach up to approximately 30%, and can cause overestimation of the radioactivity concentration when reconstructing data with attenuation correction. We varied the size of the source to evaluate partial volume errors, which we found to be a strong function of the size of the volume of interest and the spatial resolution. These errors can result in large (>50%) changes in the measured amount of radioactivity. The simulation results were compared with and found to agree with experimental measurements. The inclusion of attenuation correction in the reconstruction algorithm improved quantitative accuracy. We also found that an improvement of the spatial resolution through the use of resolution

  4. 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

  5. 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.

  6. Imaging of cardiac allograft rejection in dogs using indium-111 monoclonal antimyosin Fab

    Energy Technology Data Exchange (ETDEWEB)

    Addonizio, L.J.; Michler, R.E.; Marboe, C.; Esser, P.E.; Johnson, L.L.; Seldin, D.W.; Gersony, W.M.; Alderson, P.O.; Rose, E.A.; Cannon, P.J.

    1987-03-01

    The acute rejection of cardiac allografts is currently diagnosed by the presence of myocyte necrosis on endomyocardial biopsy. We evaluated the efficacy of noninvasive scintigraphic imaging with indium-111-labeled anticardiac myosin Fab fragments (indium-111 antimyosin) to detect and quantify cardiac allograft rejection. Six dogs that had intrathoracic heterotopic cardiac allograft transplantation were injected with indium-111 antimyosin and planar and single photon emission computed tomographic (SPECT) images were obtained in various stages of acute and subacute rejection. Four dogs had an allograft older than 8 months and had been on long-term immunosuppressive therapy; two dogs had an allograft less than 2 weeks old and were not on immunosuppressive therapy. Count ratios comparing heterotopic with native hearts were calculated from both SPECT images and in vitro scans of excised and sectioned hearts and were compared with the degree of rejection scored by an independent histopathologic review. Indium-111 antimyosin uptake was not visible in planar or SPECT images of native hearts. Faint diffuse uptake was apparent in cardiac allografts during long-term immunosuppression and intense radioactivity was present in hearts with electrocardiographic evidence of rejection. The heterotopic to native heart count ratios in SPECT images correlated significantly with the count ratios in the excised hearts (r = 0.93) and with the histopathologic rejection score (r = 0.97). The distribution of indium-111 antimyosin activity in right and left ventricles corresponded to areas of histopathologic abnormalities.

  7. 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 coreg