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Sample records for cardiac spect systems

  1. Design and assessment of cardiac SPECT systems

    Science.gov (United States)

    Lee, Chih-Jie

    Single-photon emission computed tomography (SPECT) is a modality widely used to detect myocardial ischemia and myocardial infarction. Objectively assessing and comparing different SPECT systems is important so that the best detectability of cardiac defects can be achieved. Whitaker, Clarkson, and Barrett's study on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than reconstruction data. Thus, this observer model assesses overall hardware performance independent by any reconstruction algorithm. In addition, we will show that the run time of image-quality studies is significantly reduced. Several systems derived from the GE CZT-based dedicated cardiac SPECT camera Discovery 530c design, which is officially named the Alcyone Technology: Discovery NM 530c, were assessed using the performance of the SLO for the task of detecting cardiac defects and estimating the properties of the defects. Clinically, hearts can be virtually segmented into three coronary artery territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can correctly predict in which territory the defect exists. A good estimation of the defect extent from the images is also very helpful for determining the seriousness of the myocardial ischemia. In this dissertation, both locations and extent of defects were estimated by the SLO, and system performance was assessed using localization receiver operating characteristic (LROC) / estimation receiver operating characteristic (EROC) curves. Area under LROC curve (AULC) / area under EROC curve (AUEC) and true positive fraction (TPF) at specific false positive fraction (FPF) can be treated as the gures of merit (FOMs). As the results will show, a

  2. Recent advances in cardiac SPECT instrumentation and system design.

    Science.gov (United States)

    Smith, Mark F

    2013-08-01

    Recent advances in clinical cardiac SPECT instrumentation are reviewed from a systems perspective. New hardware technologies include pixelated scintillator and semiconductor detector elements; photodetectors such as position-sensitive photomultiplier tubes (PSPMT), avalanche photodiodes (APD) and silicon photomultipliers (SiPM); and novel cardiac collimation methods. There are new approaches for positioning detectors and controlling their motion during cardiac imaging. Software technology advances include iterative image reconstruction with modeling of Poisson statistics and depth-dependent collimator response. These new technologies enable faster acquisitions, the lowering of administered activity and radiation dose, and improved image resolution. Higher sensitivity collimators are a significant factor enabling faster acquisitions. Several clinical systems incorporating new technologies are discussed and different system designs can achieve similar performance. With detector elements such as APDs, SiPMs and semiconductors that are insensitive to magnetic fields, the potential for cardiac SPECT imagers that are MRI compatible opens up new frontiers in clinical cardiac research and patient care. PMID:23832650

  3. 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 < 0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with 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 < 0.05) compared to EXG-SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased noise on

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

    International Nuclear Information System (INIS)

    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 < 0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with 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 < 0.05) compared to EXG-SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased

  5. Quantitative cardiac SPECT

    International Nuclear Information System (INIS)

    This thesis studied automated statistical mapping in myocardial perfusion SPECT to detect coronary artery disease (CAD). Registering myocardial studies to a 3D template allows an analysis on a voxel by voxel basis. Normal mean and standard deviation templates were created for each sex by registering 25 male and 25 female studies to a standard shape and position. A test group of 104 patients undergoing dipyridamole technetium-99m tetrofosmin SPECT and angiography were used to assess the automated method. Patients were divided into those with angiographic evidence of CAD (n=56) and those without (n=48). The test studies were registered to the templates and count normalized by minimizing the sum of absolute differences. A Z-score map of the statistical differences between registered study and template were calculated for all voxels within the myocardium. The contrast (Z-score) and extent (number of voxels in a cluster exceeding the contrast threshold) thresholds for detection of CAD were optimized using receiver operating characteristic (ROC) analysis. The optimal thresholds resulted in a sensitivity of 73% and a specificity of 92% for automatic detection of CAD. The area under the fitted ROC curve (±1 SE) was 0.86±0.08 for a Z-score contrast threshold of 5. The performance of this method and that of three experienced observers was compared by continuous ROC analysis. There was no statistically significant difference between the performances of the three observers and that of automatic detection in terms of the area under the ROC curves (p≥0.25). The use of this automated statistical mapping approach shows a performance comparable with experienced observers, but avoids observer variability

  6. 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.

  7. Reconstruction of dynamic gated cardiac SPECT

    International Nuclear Information System (INIS)

    In this paper we propose an image reconstruction procedure which aims to unify gated single photon emission computed tomography (SPECT) and dynamic SPECT into a single method. We divide the cardiac cycle into a number of gate intervals as in gated SPECT, but treat the tracer distribution for each gate as a time-varying signal. By using both dynamic and motion-compensated temporal regularization, our reconstruction procedure will produce an image sequence that shows both cardiac motion and time-varying tracer distribution simultaneously. To demonstrate the proposed reconstruction method, we simulated gated cardiac perfusion imaging using the gated mathematical cardiac-torso (gMCAT) phantom with Tc99m-Teboroxime as the imaging agent. Our results show that the proposed method can produce more accurate reconstruction of gated dynamic images than independent reconstruction of individual gate frames with spatial smoothness alone. In particular, our results show that the former could improve the contrast to noise ratio of a simulated perfusion defect by as much as 100% when compared to the latter

  8. Dynamic molecular imaging of cardiac innervation using a dual head pinhole SPECT system

    International Nuclear Information System (INIS)

    Typically 123I-MIBG is used for the study of innervation and function of the sympathetic nervous system in heart failure. The protocol involves two studies: first a planar or SPECT scan is performed to measure initial uptake of the tracer, followed some 3-4 hours later by another study measuring the wash-out of the tracer from the heart. A fast wash-out is indicative of a compromised heart. In this work, a dual head pinhole SPECT system was used for imaging the distribution and kinetics of 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats. The system geometry was calibrated based on a nonlinear point projection fitting method using a three-point source phantom. The angle variation effect of the parameters was modeled with a sinusoidal function. A dynamic acquisition was performed by injecting 123I-MIBG into rats immediately after starting the data acquisition. The detectors rotated continuously performing a 360o data acquisition every 90 seconds. We applied the factor analysis (FA)method and region of interest (ROI) sampling method to obtain time activity curves (TACs)in the blood pool and myocardium and then applied two-compartment modeling to estimate the kinetic parameters. Since the initial injection bolus is too fast for obtaining a consistent tomographic data set in the first few minutes of the study, we applied the FA method directly to projections during the first rotation. Then the time active curves for blood and myocardial tissue were obtained from ROI sampling. The method was applied to determine if there were differences in the kinetics between SHR and WKY rats and requires less time by replacing the delayed scan at 3-4 hours after injection with a dynamic acquisition over 90 to 120 minutes. The results of a faster washout and a smaller distribution volume of 123I-MIBG near the end of life in the SHR model of hypertrophic cardiomyopthy may be indicative of a failing heart in late stages of heart

  9. Breath-hold CT attenuation correction for quantitative cardiac SPECT

    OpenAIRE

    Koshino, Kazuhiro; Fukushima, Kazuhito; Fukumoto, Masaji; Sasaki, Kazunari; Moriguchi, Tetsuaki; Hori, Yuki; Zeniya, Tsutomu; Nishimura, Yoshihiro; Kiso, Keisuke; Iida, Hidehiro

    2012-01-01

    Background Attenuation correction of a single photon emission computed tomography (SPECT) image is possible using computed tomography (CT)-based attenuation maps with hybrid SPECT/CT. CT attenuation maps acquired during breath holding can be misaligned with SPECT, generating artifacts in the reconstructed images. The purpose of this study was to investigate the effects of respiratory phase during breath-hold CT acquisition on attenuation correction of cardiac SPECT imaging. Methods A series o...

  10. OSEM in accurate evaluation of CAD using cardiac SPECT

    International Nuclear Information System (INIS)

    Filtered Backprojection (FBP) has been used as standard processing method for almost all of the SPECT studies. Recently, iterative algorithms such as MLEM and the newest one, Ordered Subset Expectation Maximization (OSEM) introduced as an alternative method to reconstruction and applied for many SPECT studies like brain, bone, and...Application of this method in car dia SPECT was restricted merely in some of research centers. However, does iterative reconstruction as compared to FBP increase the accuracy of myocardial perfusion SPECT in evaluation of coronary artery disease? We aimed to investigate the diagnostic performance of OSEM over FBP. 15 coronary artery diseased patients underwent stress/rest cardiac perfusion study. The images were obtained by SMV SPECT system and two-day protocol was performed. Each raw data was processed by both methods. FBP was done with a METZ 4 filter and iterative reconstruction was done with the OSEM software (5 iterative, 16-10 iterative, 32-5 iterative, 16 and...) without any truncation. Comparison of OSEM versus FBP was performed both visually and quantitatively used a square ROI over each of 8 segments of LV and a mean activity ratio (defect to normal ratio) and signal to noise (Bk g. activity) were obtained. All quantitatively parameters were analyzed with SPSS software statistically and correlation coefficient was calculated upon Pear son's correlation formula. Kean correlation coefficient value between OSEM and FBP was high (r2=0/96) when an negative number of 5 was used. Difference value for mean of D/N activity was <2.5% and for in count ratio was low (4%). Visually, the image quality was rather high in preference of OSEM to FBP. the above results revealed similarity between these two methods with reduction of noise in OSEM reconstructed images, and indicated that OSEM can provide improvement in accuracy if co per number of iteration and subset level were selected. The obtained results concluded that OSEM could be used as

  11. Design optimization of multi-pinhole micro-SPECT configurations by signal detection tasks and system performance evaluations for mouse cardiac imaging

    International Nuclear Information System (INIS)

    An optimized configuration of multi-pinhole aperture can improve the spatial resolution and the sensitivity of pinhole SPECT simultaneously. In this study, an optimization strategy of the multi-pinhole configuration with a small detector is proposed for mouse cardiac imaging. A 14 mm-diameter spherical field-of-view (FOV) is used to accommodate the mouse heart. To accelerate the optimization process, the analytic models are applied to rapidly obtain the projection areas of the FOV, the sensitivities and the spatial resolutions of numerous system designs. The candidates of optimal multi-pinhole configuration are then decided by the preliminary evaluations with the analytic models. Subsequently, the pinhole SPECT systems equipped with the designed multi-pinhole apertures are modeled in GATE to generate the imaging system matrices (H matrices) for the system performance assessments. The area under the ROC curves (AUC) of the designed systems is evaluated by signal-known-exactly/background-known-statistically detection tasks with their corresponding H matrices. In addition, the spatial resolutions are estimated by the Fourier crosstalk approach, and the sensitivities are calculated with the H matrices of designed systems, respectively. Furthermore, a series of OSEM reconstruction images of synthetic phantoms, including the hot-rod phantom, mouse heart phantom and Defrise phantom, are reconstructed with the H matrices of designed systems. To quantify the sensitivity and resolution competition in the optimization process, the AUC from the detection tasks and the resolution estimated by the Fourier crosstalk are used as the figure of merits. A trade-off function of AUC and resolution is introduced to find the optimal multi-pinhole configuration. According to the examining results, a 22.5° rotated detector plus a 4-pinhole aperture with 22.5° rotation, 20% multiplexing and 1.52X magnification is the optimized multi-pinhole configuration for the micro pinhole-SPECT

  12. Design optimization of multi-pinhole micro-SPECT configurations by signal detection tasks and system performance evaluations for mouse cardiac imaging

    Science.gov (United States)

    Lee, M.-W.; Lin, W.-T.; Chen, Y.-C.

    2015-01-01

    An optimized configuration of multi-pinhole aperture can improve the spatial resolution and the sensitivity of pinhole SPECT simultaneously. In this study, an optimization strategy of the multi-pinhole configuration with a small detector is proposed for mouse cardiac imaging. A 14 mm-diameter spherical field-of-view (FOV) is used to accommodate the mouse heart. To accelerate the optimization process, the analytic models are applied to rapidly obtain the projection areas of the FOV, the sensitivities and the spatial resolutions of numerous system designs. The candidates of optimal multi-pinhole configuration are then decided by the preliminary evaluations with the analytic models. Subsequently, the pinhole SPECT systems equipped with the designed multi-pinhole apertures are modeled in GATE to generate the imaging system matrices (H matrices) for the system performance assessments. The area under the ROC curves (AUC) of the designed systems is evaluated by signal-known-exactly/background-known-statistically detection tasks with their corresponding H matrices. In addition, the spatial resolutions are estimated by the Fourier crosstalk approach, and the sensitivities are calculated with the H matrices of designed systems, respectively. Furthermore, a series of OSEM reconstruction images of synthetic phantoms, including the hot-rod phantom, mouse heart phantom and Defrise phantom, are reconstructed with the H matrices of designed systems. To quantify the sensitivity and resolution competition in the optimization process, the AUC from the detection tasks and the resolution estimated by the Fourier crosstalk are used as the figure of merits. A trade-off function of AUC and resolution is introduced to find the optimal multi-pinhole configuration. According to the examining results, a 22.5° rotated detector plus a 4-pinhole aperture with 22.5° rotation, 20% multiplexing and 1.52X magnification is the optimized multi-pinhole configuration for the micro pinhole-SPECT

  13. 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.

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

    International Nuclear Information System (INIS)

    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.

  15. Evaluation of left ventricular volumes and ejection fraction by gated myocardial perfusion SPECT versus cardiac MRI

    International Nuclear Information System (INIS)

    It is stated that cardiac MRI imaging can provide accurate estimation of left ventricular (LV) volumes and ejection fraction (EF). The purpose of this study was to evaluate the accuracy of gated myocardial perfusion single photon emission computed tomography (SPECT) for assessment of LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF, using cardiac MRI as the reference methods/(methodology). Gated myocardial perfusion SPECT images were analyzed with two different quantification software, quantitative gated SPECT (QGS) and 4D-MSPECT. Thirty-four consecutive patients were studied. Myocardial perfusion SPECT and cardiac MRI had excellent intra/interobserver reproducibility. Correlation between the results of gated myocardial perfusion SPECT and cardiac MRI were high for EDV and EF. However, ESV and EDV were significantly underestimated by gated myocardial perfusion SPECT compared to cardiac MRI. Moreover, gated myocardial perfusion SPECT overestimated EF for small heart. One reason for the difference in volumes and EF is the delineation of the endocardial border. Cardiac MRI has higher spatial resolution. We should understand the differences of volumes and EF as determined by gated myocardial perfusion SPECT and cardiac MRI. (author)

  16. Automated Functional Morphology Measurement Using Cardiac SPECT Images

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seok Yoon; Ko, Seong Jin; Kang, Se Sik; Kim, Chang Soo; Kim, Jung Hoon [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Pusan (Korea, Republic of)

    2012-06-15

    For the examination of nuclear medicine, myocardial scan is a good method to evaluate a hemodynamic importance of coronary heart disease. but, the automatized qualitative measurement is additionally necessary to improve the decoding efficiency. we suggests the creation of cardiac three-dimensional model and model of three-dimensional cardiac thickness as a new measurement. For the experiment, cardiac reduced cross section was obtained from SPECT. Next, the pre-process was performed and image segmentation was fulfilled by level set. for the modeling of left cardiac thickness, it was realized by applying difference equation of two-dimensional laplace equation. As the result of experiment, it was successful to measure internal wall and external wall and three-dimensional modeling was realized by coordinate. and, with laplace formula, it was successful to develop the thickness of cardiac wall. through the three-dimensional model, defects were observed easily and position of lesion was grasped rapidly by the revolution of model. The model which was developed as the support index of decoding will provide decoding information to doctor additionally and reduce the rate of false diagnosis as well as play a great role for diagnosing IHD early.

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

    International Nuclear Information System (INIS)

    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

  18. Gated three-dimensional dynamic cardiac SPECT phantom with oscillating sealed cylinder driven by cams

    International Nuclear Information System (INIS)

    A gated dynamic cardiac phantom for SPECT has been a topic of interest for many years. A simpler and less expensive three-dimensional dynamic cardiac phantom is needed to calibrate the growing number of SPECT systems. The success of previous attempts with balloons was limited because balloons would eventually burst and create a hazardous situation. A new phantom has been designed. It moves a cylindrical tube, filled with activities, in and our of the camera field of view (FOV). The activity volume is partially covered by a lead shield. The linearly oscillating motion of the cylinder exposes time-varying volume of activity into the FOV, simulating the heart motion, and the oscillation triggers a gating signal. Ejection fraction is adjusted by either adjusting the amplitude of the oscillation or by driving the activity volume with a cam that mimics the heart motion. Initial results indicate that this relatively simple and compact device performs with a high degree of reproducibility and reliability. It can produce ejection fraction and blood volume measurement accurately and precisely. A moving volume of activities can be used as a dynamic cardiac phantom for SPECT

  19. 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.

  20. Quality assurance for SPECT systems

    International Nuclear Information System (INIS)

    Quality control is crucial to all aspects of nuclear medicine practice, including the measurement of radioactivity, the preparation of radiopharmaceuticals, the use of instrumentation to obtain images, computations to calculate functional parameters, and the interpretation of the results by the physician. It plays an integral part in fulfilling the regulatory requirement for establishing a comprehensive quality assurance programme as described in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. In 1984, the IAEA published IAEA-TECDOC-317, Quality Control of Nuclear Medicine Instruments, which addressed the quality control of radionuclide activity calibrators (also known as dose calibrators), gamma counters, and single and multiprobe counting systems, rectilinear scanners and scintillation cameras. An updated version of IAEA-TECDOC-317 was issued in 1991 as IAEA-TECDOC-602, and this included new chapters on scanner-computer systems and single photon emission computed tomography (SPECT) systems. The rapidly increasing use of SPECT systems during the 1990s prompted the need for a further update of these publications with special emphasis on SPECT systems, planar scintillation cameras, camera-computer systems and whole body scanning systems. Since rectilinear scanners have already been, or will soon be, phased out in Member States, the current publication excludes them completely. Quality assurance and quality control aspects of instrumentation for radioactivity measurements in nuclear medicine are addressed in Technical Reports Series No. 454, Quality Assurance for Radioactivity Measurement in Nuclear Medicine. The current publication is intended to be a resource for medical physicists, technologists and other healthcare professionals who are responsible for ensuring optimal performance of imaging instruments, particularly SPECT systems, in their respective institutions. It is intended for

  1. Benefits of quantitative gated SPECT in evaluation of perioperative cardiac risk in noncardiac surgery

    International Nuclear Information System (INIS)

    Gated single-photon emission computed tomography (G-SPECT) was used to evaluate cardiac risk associated with noncardiac surgery and determine the benefits and indications of this technique for this type of surgery. Patients scheduled to undergo noncardiac surgery under the supervision of anesthesiologists and subjected to preoperative cardiac evaluation using G-SPECT during the 26-month period between June 2000 and August 2002 were followed for the presence/absence of cardiac events (id est (i.e.), cardiac death, myocardial infarction, unstable angina, congestive heart failure, or fatal arrhythmia) during surgery and the postoperative period until discharged. Relationships between the occurrence of cardiac events and preoperative G-SPECT findings were evaluated. A total of 39 patients underwent G-SPECT; 6 of the 39 exhibited abnormal ejection fraction (left ventricular ejection fraction, left ventricular ejection fraction (LVEF)≤50%) and end-systolic volume (end-systolic volume (ESV)≥50 ml). Surgery was suspended for three of these six patients and cardiac events developed in the remaining three patients. Both abnormal perfusion images (PI) and abnormal wall thickening (WT) were observed in all six patients. All six patients exhibited abnormal LVEF and/or ESV. Three patients had either abnormal PI or WT, and a cardiac event occurred in one of them. Of the five patients who experienced cardiac events during or after surgery, two exhibited a short run of ventricular tachycardia requiring a continuous administering of antiarrhythmic drugs, whereas the remaining three patients exhibited cardiac failure requiring inotropic support following surgery. The results of this study indicate that the occurrence of perioperative cardiac events can be predicted by considering the severity of expected surgical stress and preoperative G-SPECT findings for LVEF, PI, and WT. We conclude that G-SPECT is quite useful for cardiac risk assessment in patients undergoing noncardiac

  2. First clinical experiences with parametric SPECT of the gated cardiac blood pool

    International Nuclear Information System (INIS)

    SPECT of the gated cardiac blood pool as well as conventional 300LAO equilibrium radionuclide ventriculography was performed in a total of 12 patients (4 healthy subjects and 8 patients with CAD or cardiomyopathy). Seven out of 8 patients with myocardial pathology showed abnormalities of the anterior wall motion. In all of the respective cases SPECT and laevocardiography yielded concordant results while conventional radionuclide ventriculography was limited to the detection of septal and posterior wall motion abnormalities. Thus, SPECT of the cardiac blood pool is an anternative to ''first pass'' techniques which are limited to only few heart beats. (orig.)

  3. Filters in 2D and 3D Cardiac SPECT Image Processing

    Directory of Open Access Journals (Sweden)

    Maria Lyra

    2014-01-01

    Full Text Available Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast.

  4. Variable linesource response in attenuation corrected cardiac SPECT

    International Nuclear Information System (INIS)

    Full text: Varying line source response can result in errors due to the reference scan being inappropriate. The incidence of this problem and its effect on cardiac perfusion SPECT was investigated. Acquisitions of transmission data without the bed or a patient were used to determine the variation in global sensitivity and uniformity of the transmission with respect to camera position over a period of 4 months. The average variations for various parameters were: Influence of variations in regional sensitivity on the reconstructed attenuation map and ultimately the patient study was investigated. Counts in selected sections of patient transmission images were reduced by 5 to 30 percent and then reconstructed in the patient study with iterative reconstruction for 30 iterations (Butterworth 0.66 nyquist frequency order 10). The reconstructed scans were compared to the original study which had minimal linesource misalignment and the percentage differences were calculated to determine the effect of regional sensitivity differences with angle. At the level of variation of regional sensitivity (5-10%) it was found data varied by up to 20% in portions of the patient myocardium compared to the original data. Additional line source quality control is essential and variation in transmission counts with rotation minimised. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  5. Dynamic cardiac SPECT computer simulations for teboroxime kinetics

    International Nuclear Information System (INIS)

    A series of computer simulations was performed to examine the effect that each of seven factors have on the accuracy of the kinetic parameters (k21 and k12) of teboroxime (a 99mTc-labeled heart perfusion agent). The parameters k21 and k12 can be estimated using dynamic SPECT imaging and tracer kinetic modeling. The factors investigated were: (1) projection/reconstruction process of a time-varying tracer, (2) cardiac motion, (3) temporal resolution of the images, (4) attenuation effects, (5) emission statistics, (6) correlation of estimated parameters, and (7) decreased extraction fraction of teboroxime over time. The results showed that factors (3) and (6) affected only the %RMS error of the estimated parameters k21 and k12 and that the smallest error can be obtained by: using 5 second temporal resolution and selecting tissue ROIs which contain the least amount of intraventricular blood. Factors (2), (4), (5), and (7) significantly affected the accuracy of either k21 or k12 and efforts should be made in the future to either model or correct for these factors

  6. Cardiac conduction system

    Science.gov (United States)

    The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals ... to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle ...

  7. Patient position alters attenuation effects in multipinhole cardiac SPECT

    International Nuclear Information System (INIS)

    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

  8. 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

  9. Transmission scans using Gd-153 line sources in cardiac SPECT studies: What is the additional patient radiation dose burden?

    International Nuclear Information System (INIS)

    Aim: To determine the contribution of transmission scan acquisition obtained for attenuation/scatter correction to total patient effective dose from cardiac SPECT studies. Materials and Methods: A dual-headed L-shaped gamma camera equipped with a transmission scan acquisition system based on two 153Gd line sources was used. Transmission scan acquisition was performed on a humanoid phantom. Thermoluminescence dosimeters were used to directly monitor the dose to 550 measuring points in the phantom. Patient effective dose and associated risk from transmission scans acquisition were estimated and compared to those associated to the radiopharmaceutical injected. Results: The maximum effective dose from a typical transmission measurements acquisition was 1.3 μSv and 1.9 μSv for male and female patients, respectively. The contribution of the typical transmission scans acquisition to total patient radiation risk from a cardiac SPECT study was less than 10-3. Conclusion: Radiation exposure may not be considered as a limiting factor for the clinical application of attenuation correction methods based on transmission measurements in cardiac SPECT

  10. The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera.

    Science.gov (United States)

    Roberts, J; Maddula, R; Clackdoyle, R; DiBella, E; Fu, Z

    2007-08-01

    The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period. PMID:17634648

  11. The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, J [Department of Radiology, University of Utah, Salt Lake City, UT 84108 (United States); Maddula, R [Department of Radiology, University of Utah, Salt Lake City, UT 84108 (United States); Clackdoyle, R [Department of Radiology, University of Utah, Salt Lake City, UT 84108 (United States); DiBella, E [Department of Radiology, University of Utah, Salt Lake City, UT 84108 (United States); Fu, Z [Department of Physics, University of Utah, Salt Lake City, UT 84112 (United States)

    2007-08-07

    The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period.

  12. The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera

    International Nuclear Information System (INIS)

    The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period

  13. Integration of AdaptiSPECT, a small-animal adaptive SPECT imaging system

    OpenAIRE

    Chaix, Cécile; Kovalsky, Stephen; Kosmider, Matthew; Barrett, Harrison H.; Furenlid, Lars R.

    2013-01-01

    AdaptiSPECT is a pre-clinical adaptive SPECT imaging system under final development at the Center for Gamma-ray Imaging. The system incorporates multiple adaptive features: an adaptive aperture, 16 detectors mounted on translational stages, and the ability to switch between a non-multiplexed and a multiplexed imaging configuration. In this paper, we review the design of AdaptiSPECT and its adaptive features. We then describe the on-going integration of the imaging system.

  14. Comparison of radionuclide ventriculography using SPECT and planar techniques in different cardiac conditions

    International Nuclear Information System (INIS)

    Accurate assessment of ventricular function is required to optimize therapeutic management of cardiac diseases. The aim of this study was to correlate planar equilibrium multigated acquisition (MUGA) with tomographic ventriculography (SPECT) in patients with diverse volumes and wall motion abnormalities. Eighty-three studies in 80 patients (56±14 years; 56% women) were classified according to ventricular dilation, wall motion abnormalities and systolic dysfunction. Left and right ventricular ejection fraction (LVEF and RVEF) and end-diastolic and end-systolic left ventricular volumes (EDV and ESV) were obtained using a commercial QBS program for SPECT. On planar acquisition, LVEF and RVEF were obtained using standard techniques and volumes were determined using the count-based method, without blood sampling. A. Total group: With the planar method, LVEF was 44±17%, RVEF 42±13%, left EDV 147±97 ml (range 31-487 ml) and left ESV 93±85 ml (range 15-423 ml); with SPECT the corresponding values were 40±20%, 49±16%,131±95 ml and 91±89 ml, respectively (p=NS for all but RVEF). Linear correlation was 0.845 for LVEF, 0.688 for RVEF, 0.927 for left EDV and 0.94 for left ESV, with good intra-class correlation. B. Subgroups: Global and intra-class correlations between planar imaging and SPECT were high for volumes, RVEF and LVEF in all subgroups, except in patients with normal wall motion and function, who showed smaller volumes with SPECT. The group with diffuse wall motion abnormalities had a lower EDV on SPECT. In the abnormal left ventricle, RVEF was higher with SPECT. Good correlation and agreement exist between SPECT and planar MUGA with respect to LVEF and left ventricular volumes. SPECT is useful in patients with functional abnormalities, but less reliable in those with normal small cavities. A combined technique is still necessary, and RVEF should be interpreted cautiously. (orig.)

  15. PET and SPECT of neurobiological systems

    International Nuclear Information System (INIS)

    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. 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''.

  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. The effect of heart motion on parameter bias in dynamic cardiac SPECT

    International Nuclear Information System (INIS)

    Dynamic cardiac SPECT can be used to estimate kinetic rate parameters which describe the wash-in and wash-out of tracer activity between the blood and the myocardial tissue. These kinetic parameters can in turn be correlated to myocardial perfusion. There are, however, many physical aspects associated with dynamic SPECT which can introduce errors into the estimates. This paper describes a study which investigates the effect of heart motion on kinetic parameter estimates. Dynamic SPECT simulations are performed using a beating version of the MCAT phantom. The results demonstrate that cardiac motion has a significant effect on the blood, tissue, and background content of regions of interest. This in turn affects estimates of wash-in, while it has very little effect on estimates of wash-out. The effect of cardiac motion on parameter estimates appears not to be as great as effects introduced by photon noise and geometric collimator response. It is also shown that cardiac motion results in little extravascular contamination of the left ventricle blood region of interest

  19. 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)

  20. The influence of different SPECT reconstruction algorithms on cardiac ischemia with the use artificial neural networks

    International Nuclear Information System (INIS)

    The aim of the study was the attempt to evaluate the influence of two different methods of cardiac perfusion SPECT reconstruction (FBP and ITW) on clinical efficacy in diagnosing the coronary artery disease as well as the cardiac ischemia detection in three areas of heart vascularized by main coronary arteries: LAD, LCX and RCA with the use of artificial neural networks (ANN). The study was performed retrospectively with the use of the diagnostic image records as well as clinical dataset of 43 patients. Myocardial perfusion stress/rest SPECT study and X-ray coronarography data were evaluated for each patient. The results of coronary angiography were considered the reference method. The cardiac SPECT data were reconstructed using the two different methods: filtered backprojection (FBP) and iterative Wallis method (ITW). The local perfusion deficits denominated in stress and rest study in three main vessel cardiac segments were the main input values for the ANN. The sensitivity of detection of coronary artery disease with the of ANN was 95% for both FBP and ITW reconstruction technique (p≥0.05). The sensitivity analysis of regional ischemia detection by ANN in areas LAD, LCX and RCA provided 97%, 65% and 64%, correspondingly for FDP method. With the use of ITW algorithm the sensitivity in the respective regions was: 65%, 55% and 60%. The difference in sensitivity of ANN ischemia detection for the LAD region was statistically significant for FDP versus ITW reconstruction algorithm (p=0.0007). No statistical discrepancy in sensitivity was stated in the other regions due to reconstruction technique (p≥0.005). The compared method of reconstruction of myocardial perfusion SPECT studies the do not influence the clinical efficacy in diagnosing the coronary disease with the use of ANN. In case of ANN application for local ischemia recognition results of the study indicate the FBP algorithm effective. (author)

  1. Factor analysis with a priori knowledge - application in dynamic cardiac SPECT

    International Nuclear Information System (INIS)

    Two factor analysis of dynamic structures (FADS) methods for the extraction of time-activity curves (TACs) from cardiac dynamic SPECT data sequences were investigated. One method was based on a least squares (LS) approach which was subject to positivity constraints. The other method was the well known apex-seeking (AS) method. A post-processing step utilizing a priori information was employed to correct for the non-uniqueness of the FADS solution. These methods were used to extract 99mTc-teboroxime TACs from computer simulations and from experimental canine and patient studies. In computer simulations, the LS and AS methods, which are completely different algorithms, yielded very similar and accurate results after application of the correction for non-uniqueness. FADS-obtained blood curves correlated well with curves derived from region of interest (ROI) measurements in the experimental studies. The results indicate that the factor analysis techniques can be used for semi-automatic estimation of activity curves derived from cardiac dynamic SPECT images, and that they can be used for separation of physiologically different regions in dynamic cardiac SPECT studies. (author)

  2. Semi-automatic detection and correction of body organ motion, particularly cardiac motion in SPECT studies

    International Nuclear Information System (INIS)

    Aim: Detect patient motion during SPECT imaging. Material and Method: SPECT study is carried out on a patient's body organ, such as the heart, and frame of image data are thereby acquired. The image data in these frames are subjected to a series of mappings and computations, from which frame containing a significant quantity of organ motion can be identified. Quantification of motion occurs by shifting some of the mapped data within a predetermined range, and selecting that data shift which minimizes the magnitude of a motion sensitive mathematical function. The sensitive mathematical function is constructed from all set of image frames using the pixel data within a region covering the body organ. Using cine display of planar image data, the operator defines the working region by marking two points, which define two horizontal lines covering the area of the body organ. This is the only operator intervention. The mathematical function integrates pixel data from all set of image frames and therefore does not use derivatives which may cause distortion in noisy data. Moreover, as a global function, this method is superior than that using frame-to-frame cross-correlation function to identify motion between adjacent frames. Using standard image processing software, the method was implemented computationally. Ten SPECT studies with movement (Sestamibi cardiac studies and 99m-ECD brain SPECT studies) were selected plus two others with no movement. The acquisition SPECT protocol for the cardiac study was as follow: Step and shoot mode, non-circular orbit, 64 stops 20s each, 64x64x16 matrix and LEHR colimator. For the brain SPECT, 128 stops over 3600 were used. Artificial vertical displacements (±1-2 pixels) over several frames were introduced in those studies with no movement to simulate patient motion. Results: The method was successfully tested in all cases and was capable to recognize SPECT studies with no body motion as well as those with body motion (both from the

  3. GATED SPECT IN PATIENTS WITH BIOPSY-NEGATIVE CARDIAC TRANSPLANT REJECTION

    Directory of Open Access Journals (Sweden)

    E. N. Ostroumov

    2009-05-01

    Full Text Available Humoral rejection of the cardiac allograft is still a challenging problem associated with high incidence of graft loss and patient mortality. These episodes of rejection are often more severe, and more difficult to treat, than classical acute cellular rejection. Hemodynamic compromise, in the absence of acute cellular rejection, called biopsy-negative rejection occurs in 10 to 20% of cardiac allograft recipients. The assessment of hemodynamic compromise can provide functional data in transplant patients that is complementary to myocardial biopsies if the biopsy can miss significant rejection. We present three cases of the biopsy-negative rejection. All patients have studied with gated SPECT phase analysis. 

  4. Development of a New Cardiac and Torso Phantom for Verifying the Accuracy of Myocardial Perfusion SPECT

    International Nuclear Information System (INIS)

    Corrections of attenuation, scatter and resolution are important in order to improve the accuracy of single photon emission computed tomography (SPECT) image reconstruction. Especially, the heart movement by respiration and beating cause the errors in the corrections. Myocardial phantom is used to verify the correction methods, but there are many different parts in the current phantoms in actual human body. Therefore the results using a phantom are often considered apart from the clinical data. We developed a new phantom that implements the human body structure around the thorax more faithfully. The new phantom has the small mediastinum which can simulate the structure in which the lung adjoins anterior, lateral and apex of myocardium. The container was made of acrylic and water-equivalent material was used for mediastinum. In addition, solidified polyurethane foam in epoxy resin was used for lung. Five different sizes of myocardium were developed for the quantitative gated SPECT (QGS). The septa of all different cardiac phantoms were designed so that they can be located at the same position. The proposed phantom was attached with liver and gallbladder, the adjustment was respectively possible for the height of them. The volumes of five cardiac ventricles were 150.0, 137.3, 83.1, 42.7 and 38.6 ml respectively. The SPECT were performed for the new phantom, and the differences between the images were examined after the correction methods were applied. The three-dimensional tomography of myocardium was well reconstructed, and the subjective evaluations were done to show the difference among the various corrections. We developed the new cardiac and torso phantom, and the difference of various corrections was shown on SPECT images and QGS results.

  5. Evaluation of left ventricular volumes and ejection fraction by gated SPECT and cardiac MRI in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    The goal of this study was to evaluate the accuracy of gated single photon emission computed tomography (SPECT) in the assessment of left ventricular (LV) end-diastolic/end-systolic volumes (EDV, ESV) and ejection fraction (LVEF) in patients with dilated cardiomyopathy, using cardiac magnetic resonance imaging (MRI) as the reference method. Furthermore, software-specific characteristics of Quantitative Gated SPECT (QGS), Emory Cardiac Toolbox (ECTB) and 4D-MSPECT were analysed. Thirty-six patients with dilated cardiomyopathy who underwent gated 99mTc-methoxyisobutylisonitrile SPECT and cardiac MRI were included. LV EDV, ESV and LVEF values of gated SPECT were calculated using QGS, ECTB and 4D-MSPECT. The correlation between the results of gated SPECT and cardiac MRI was excellent for EDV [R = 0.872 (QGS), R = 0.879 (ECTB), R = 0.869 (4D-MSPECT)], ESV [R = 0.908 (QGS), R = 0.897 (ECTB), R = 0.880 (4D-MSPECT)] and LVEF [R = 0.794 (QGS), R = 0.763 (ECTB), R = 0.710 (4D-MSPECT)]. EDV and ESV assessed by QGS did not differ significantly from those assessed by cardiac MRI (all p = NS), whereas EDV and ESV were overestimated by ECTB and 4D-MSPECT compared with cardiac MRI (all p < 0.05). LVEF was overestimated by QGS, ECTB and 4D-MSPECT compared with cardiac MRI (all p < 0.05). The correlation between gated SPECT and cardiac MRI is excellent for LV volume and LVEF values calculated by QGS, ECTB and 4D-MSPECT in patients with dilated cardiomyopathy. However, algorithm-varying over- or underestimation of LV volumes and LVEF should be accounted for in the clinical context. (orig.)

  6. Non linear warping in cardiac SPECT 2D imaging

    International Nuclear Information System (INIS)

    We present a preliminary work to a new tool of visualization and analysis of the whole tridimensional (3D) myocardium using the elastic warping. 48 myocardium horizontal and vertical long axis middle slices, taken from 24 patients 3D myocardium obtained by Single Photon Emission Computed Tomography (SPECT), were subjected to deformations using the Thin Plate Splines (TPS) method. Firstly, source landmarks have been taken on the normals, chosen at regular intervals, to an ellipse arc fitting a myocardium slice skeleton. Afterwards, target landmarks have been picked up on a set of perpendicular lines to an horizontal one having the same length as the ellipse arc. The two sets of landmarks obtained have then been used to drive a myocardium slice warping through the TPS, where every source landmark is put in correspondence to its target homologous, transforming thus a slice, previously 'horseshoe-shaped', to an horizontal bar. This work, wholly automatized, showed that the myocardium slices where slightly affected in quantity: the slice surfaces were equal to 96.3 ± 2.1 % compared to the target one. Their histograms showed that the observed light variations were confined at the borders, preserving thus the myocardium rendering and its internal characteristics after warping. (author)

  7. Myocordial perfusion SPECT with dipyridamole stress test in cardiac syndrome X

    Energy Technology Data Exchange (ETDEWEB)

    Czepczynski, R.; Smolarek, I.; Sowinski, J. [Nuclear Medicine Unit, Dept. of Endocrinology and Metabolism, Poznan Univ. of Medical Sciences, Poznan (Poland); Rogacka, D.; Kazmierczak, M.; Wysocki, H. [Dept. of Intensive Care and Cardiology, Poznan Univ. of Medical Sciences, Poznan (Poland)

    2006-07-01

    Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. Aim of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. Patients, methods: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using {sup 99m}Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of {sup 99m}Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point - normal uptake, 4 points - no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). Results: mean SRS was 7.9 {+-} 4.8 and mean SSS was 7.2 {+-} 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: (1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, (2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, (3) in 20 patients (29.4%), no significant change of the myocordial perfusion between rest and stress images occurred. Conclusions: in cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology. (orig.)

  8. Evaluation of myocardiotoxicity with SPECT cardiac blood pool imaging for patients treated with adriamycin

    International Nuclear Information System (INIS)

    Evaluation of myocardiotoxicity on adriamycin (ADM) with SPECT cardiac blood pool imaging was presented. SPECT was done to monitor left ventricular function in 49 patients with Non-Hodgkin's Lymphoma and small cell carcinoma, they were treated with ADM of which the accumulation dose were over 300 mg/m2. The results showed that parameters of EF, PER and PFR before and after treatment with ADM were 57 +- 6%, 3.08 +- 0.63 EDV·s-1, 2.99 +- 0.23 EDV·s-1 and 50 +- 11%, 2.25 +- 0.66 EDV·s-1, 2.53 +- 0.35 EDV·s-1 respectively. The difference of these data are significant (P<0.05). The larger the accumulative dose of ADM, the more the parameters decrease, among them PFR is the most sensitive one. It was concluded that SPECT measurement of left ventricular function is a sensitive and useful method in monitoring ADM myocardiotoxicity

  9. 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.

  10. Usefulness of I-123 MIBG myocardial SPECT in patients with dilated cardiomyopathy for predicting cardiac events

    International Nuclear Information System (INIS)

    We evaluated cardiac sympathetic nerve activity in patients with dilated cardiomyopathy (DCMP) using I-123 metaiodobenzylguanidine (MIBG) myocardial SPECT, and tried to find variables to predict disease progression (DP). MIBG SPECT was performed in 17 patients (M:F = 11:6, age 63.9±11.1 years) with DCMP (idiopathic = 14, ischemic = 2 and other = 1). At 15 min and 4 hs after IV injection of I-123 MIBG (5 mCi), planar and SPECT images were acquired. Using planar images, heart to mediastinum (H/M) ratios, and washout rate (WR) 100 x [ (H-M)15min (H-M)4hr]/(H-M) 15min were calculated with ROIs drawn for heart contour and mediastinum (7x7 pixels). Using SPECT images, total uptake score (TUS) was defined as sum of 17 myocardial segments using 3-point scale. Using M-mode echocardiography, LV ejection fraction (LVEF) was calculated as follows: (LVDd2-LVDs2)/LVDd2. The decline of EF more than 5%, or hospitalization due to dyspnea aggravation was defined as DP. All the patients were observed for 339±106 days. During follow up periods, no mortality cases were observed but 2 cases suffered from EF decline, 2 hospitalization and 1 both EF decline and hospitalization. However Cox proportion hazard regression analysis did not identify significant parameter for DP among H/M ratio, WR, TUS, and deltaTUS. Patients could be divided into 2 groups based on WR, the known prognostic marker. The high WR patients (more than 50%, n=9) had significantly lower H/M ratio (1.55±0.27 versus 2.01±0.32 p<0.01) and significantly lower TUS4hr (12.1±13.9 versus 32.7±11.4, p<0.01) than low WR patients (less than 50%, n=8). WR and TUS4hr showed negative correlation (rho=-0.705, p<0.01). MIBG SPECT was applied to DCMP patients for evaluation of DP. Longer follow up period of more than 1 year seems to be essential for prognosis evaluation. In addition to WR, TUS obtained at 4 hour MIBG SPECT may be used as a useful marker of DCMP

  11. Hybrid cardiac SPECT/64-slice CTA-derived LV function parameters: Correlation and reproducibility assessment

    International Nuclear Information System (INIS)

    The purpose of this study is to define the relationship between SPECT and CTA measured parameters of left ventricular (LV) function and volumes obtained in a single session using SPECT/64-slice CT hybrid imaging device, and in addition, to assess the reproducibility of LV parameters measured using 64-slice CTA. Materials and methods: Seventy-six patients with suspected or known coronary artery disease underwent cardiac CTA and GSPECT in one session using a hybrid SPECT/CT device. LV end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF) were measured on each component of the hybrid device. For the CTA component, these parameters were re-measured by the same investigator and by a second investigator with an interval of 3-54 weeks. Corresponding GSPECT and CTA measured parameters were compared. For CTA, intra-observer and inter-observer variability of LV function and volume measurements were calculated. Results: A very good correlation was found between the GSPECT and CTA measured LVEF (r = 0.81), ESV (r = 0.90) and EDV (r = 0.82). There was a small positive difference by CTA measured LVEF (3.9 ± 14.2%), and more prominent positive differences by CTA measured ESV and EDV (9.8 ± 14.8 and 44.9 ± 23.1 cm3, respectively). There was excellent reproducibility in the measurements of all parameters with very low intra- and inter-observer variability (r = 0.93 for EF and 0.98 for EDV and ESV). Conclusions: Although a good correlation was found between the EF measurements obtained from CTA and SPECT, interchangeable use of EF measurements between the two modalities should be done cautiously and interchangeable use of LV EDV and ESV should be avoided.

  12. 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. PMID:19928105

  13. Taking the perfect nuclear image: quality control, acquisition, and processing techniques for cardiac SPECT, PET, and hybrid imaging.

    Science.gov (United States)

    Case, James A; Bateman, Timothy M

    2013-10-01

    Nuclear Cardiology for the past 40 years has distinguished itself in its ability to non-invasively assess regional myocardial blood flow and identify obstructive coronary disease. This has led to advances in managing the diagnosis, risk stratification, and prognostic assessment of cardiac patients. These advances have all been predicated on the collection of high quality nuclear image data. National and international professional societies have established guidelines for nuclear laboratories to maintain high quality nuclear cardiology services. In addition, laboratory accreditation has further advanced the goal of the establishing high quality standards for the provision of nuclear cardiology services. This article summarizes the principles of nuclear cardiology single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging and techniques for maintaining quality: from the calibration of imaging equipment to post processing techniques. It also will explore the quality considerations of newer technologies such as cadmium zinc telleride (CZT)-based SPECT systems and absolute blood flow measurement techniques using PET. PMID:23868070

  14. Tc99m/T1201 cross-talk corrections on a dedicated cardiac CZT SPECT camera

    Science.gov (United States)

    Chiasson, Stephanie

    Single Photon Emission Computed Tomography (SPECT) is a standard method for evaluating heart disease. A new dedicated cardiac camera with CZT detectors offers improved energy resolution and sensitivity compared to standard SPECT systems. Simultaneous Tc99m/T1201 protocols are fast, but correction for cross-talk between isotopes is necessary to achieve good image quality. The Triple-Energy-Window (TEW) correction method is easy to implement and provides accurate scatter estimation in single-isotope studies. We retrospectively assessed the cross-talk correction using clinically acquired single-isotope studies: 52 T1201 studies and 52 Tc99m-tetrofosmin studies, matched by gender and BMI. Projection data from Tl-stress and Tc-rest studies were combined to create contaminated data before reconstruction. TEW corrections were evaluated in both primary energy windows. Modifications to the corrections were required. The modified approach results in residual cross-talk as low as 2% but high noise levels were present in the corrected images. Further modifications are needed to reduce noise.

  15. SPECT data acquisition and image reconstruction in a stationary small animal SPECT/MRI system

    Science.gov (United States)

    Xu, Jingyan; Chen, Si; Yu, Jianhua; Meier, Dirk; Wagenaar, Douglas J.; Patt, Bradley E.; Tsui, Benjamin M. W.

    2010-04-01

    The goal of the study was to investigate data acquisition strategies and image reconstruction methods for a stationary SPECT insert that can operate inside an MRI scanner with a 12 cm bore diameter for simultaneous SPECT/MRI imaging of small animals. The SPECT insert consists of 3 octagonal rings of 8 MR-compatible CZT detectors per ring surrounding a multi-pinhole (MPH) collimator sleeve. Each pinhole is constructed to project the field-of-view (FOV) to one CZT detector. All 24 pinholes are focused to a cylindrical FOV of 25 mm in diameter and 34 mm in length. The data acquisition strategies we evaluated were optional collimator rotations to improve tomographic sampling; and the image reconstruction methods were iterative ML-EM with and without compensation for the geometric response function (GRF) of the MPH collimator. For this purpose, we developed an analytic simulator that calculates the system matrix with the GRF models of the MPH collimator. The simulator was used to generate projection data of a digital rod phantom with pinhole aperture sizes of 1 mm and 2 mm and with different collimator rotation patterns. Iterative ML-EM reconstruction with and without GRF compensation were used to reconstruct the projection data from the central ring of 8 detectors only, and from all 24 detectors. Our results indicated that without GRF compensation and at the default design of 24 projection views, the reconstructed images had significant artifacts. Accurate GRF compensation substantially improved the reconstructed image resolution and reduced image artifacts. With accurate GRF compensation, useful reconstructed images can be obtained using 24 projection views only. This last finding potentially enables dynamic SPECT (and/or MRI) studies in small animals, one of many possible application areas of the SPECT/MRI system. Further research efforts are warranted including experimentally measuring the system matrix for improved geometrical accuracy, incorporating the co

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

    International Nuclear Information System (INIS)

    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. - Highlights: • Industrial SPECT system provides the flow behavior of industrial multiphase processes. • A 12-fold-array industrial SPECT system was constructed using diverging collimators. • The constructed system turned out to be very suitable to examine the fluid behavior

  17. 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

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

    International Nuclear Information System (INIS)

    We developed a realistic simulation dataset for simultaneous respiratory and cardiac (R and 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 and 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 and 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 and 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 and C motions and the reduction of image artifact due to R and C motions by gating and attenuation corrections. We concluded that the realistic 4D NCAT phantom and Monte Carlo simulated SPECT projection datasets with R and C motions are powerful tools in the study of the effects of R and C motions, as well as in the development of R and C

  19. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    International Nuclear Information System (INIS)

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99mTc-sestamibi/123I-BMIPP imaging protocol in place of the commonly used sequential rest/stress 99mTc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

  20. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    Science.gov (United States)

    Trott, CM; Ouyang, J; El Fakhri, G

    2011-01-01

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99mTc-sestamibi/123I-BMIPP imaging protocol in place of the commonly-used sequential rest/stress 99mTc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity, and (2) sub-endocardial from transmural defects. We consider cardiac infarcts, for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size. PMID:21048290

  1. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    Energy Technology Data Exchange (ETDEWEB)

    Trott, C M; Ouyang, J; El Fakhri, G, E-mail: ctrott@pet.mgh.harvard.ed [Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114 (United States)

    2010-11-21

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest {sup 99m}Tc-sestamibi/{sup 123}I-BMIPP imaging protocol in place of the commonly used sequential rest/stress {sup 99m}Tc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

  2. Quantitative simultaneous 99mTc∕123I cardiac SPECT using MC-JOSEM

    Science.gov (United States)

    Ouyang, Jinsong; Zhu, Xuping; Trott, Cathryn M.; El Fakhri, Georges

    2009-01-01

    Simultaneous rest 99mTc-Sestamibi∕123I-BMIPP cardiac SPECT imaging has the potential to replace current clinical 99mTc-Sestamibi rest∕stress imaging and therefore has great potential in the case of patients with chest pain presenting to the emergency department. Separation of images of these two radionuclides is difficult, however, because their emission energies are close. The authors previously developed a fast Monte Carlo (MC)-based joint ordered-subset expectation maximization (JOSEM) iterative reconstruction algorithm (MC-JOSEM), which simultaneously compensates for scatter and cross talk as well as detector response within the reconstruction algorithm. In this work, the authors evaluated the performance of MC-JOSEM in a realistic population of 99mTc∕123I studies using cardiac phantom data on a Siemens e.cam system using a standard cardiac protocol. The authors also compared the performance of MC-JOSEM for estimation tasks to that of two other methods: standard OSEM using photopeak energy windows without scatter correction (NSC-OSEM) and standard OSEM using a Compton-scatter energy window for scatter correction (SC-OSEM). For each radionuclide the authors separately acquired high-count projections of radioactivity in the myocardium wall, liver, and soft tissue background compartments of a water-filled torso phantom, and they generated synthetic projections of various dual-radionuclide activity distributions. Images of different combinations of myocardium wall∕background activity concentration ratios for each radionuclide were reconstructed by NSC-OSEM, SC-OSEM, and MC-JOSEM. For activity estimation in the myocardium wall, MC-JOSEM always produced the best relative bias and relative standard deviation compared with NSC-OSEM and SC-OSEM for all the activity combinations. On average, the relative biases after 100 iterations were 8.1% for 99mTc and 3.7% for 123I with MC-JOSEM, 39.4% for 99mTc and 23.7% for 123I with NSC-OSEM, and 20.9% for 99mTc with SC

  3. 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.

  4. Detection of viable myocardium by FDG coincidence SPECT predicts major adverse cardiac events in patients with coronary artery disease and LV dysfunction

    International Nuclear Information System (INIS)

    Introduction and Methods: PET imaging with 18F-fluorodeoxyglucose (FDG) is the gold standard for detection of myocardial viability. However, the use of PET is limited and, coincidence SPECT imaging with FDG has been proposed as a viable alternative. SPECT imaging using Thallium, on the other hand, though more widely available, has lower specificity compared to PET imaging. We compared coincidence SPECT imaging using FDG and Thallium (T1-201Chloride) to coronary angiograms in 51 patients (age 60±SD 14 years; 41 male, 10 females) with known CAD (32 pts with >3 vessel, 19 patients with 5% of total myocardium) on the FDG SPECT images. Four patients had cardiac death, all showing multiple coronary territory nonviable tissue on both FDG and Thallium imaging and all had LVEF 5% of total myocardium) on the FDG coincidence SPECT predicts major adverse cardiac events better compared to conventional imaging with Thallium. (authors)

  5. Design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals

    Science.gov (United States)

    Tsui, Benjamin M. W.; Hugg, James W.; Xu, Jingyan; Chen, Si; Meier, Dirk; Edelstein, William; El-Sharkawy, Abdel; Wagenaar, Douglas J.; Patt, Bradley E.

    2011-03-01

    We describe a continuing design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals. A first generation prototype SPECT system was designed and constructed to fit inside a MRI system with a gradient bore inner diameter of 12 cm. It consists of 3 angularly offset rings of 8 detectors (1"x1", 16x16 pixels MR-compatible solid-state CZT). A matching 24-pinhole collimator sleeve, made of a tungsten-compound, provides projections from a common FOV of ~25 mm. A birdcage RF coil for MRI data acquisition surrounds the collimator. The SPECT system was tested inside a clinical 3T MRI system. Minimal interference was observed on the simultaneously acquired SPECT and MR images. We developed a sparse-view image reconstruction method based on accurate modeling of the point response function (PRF) of each of the 24 pinholes to provide artifact-free SPECT images. The stationary SPECT system provides relatively low resolution of 3-5 mm but high geometric efficiency of 0.5- 1.2% for fast dynamic acquisition, demonstrated in a SPECT renal kinetics study using Tc-99m DTPA. Based on these results, a second generation prototype MR-compatible SPECT system with an outer diameter of 20 cm that fits inside a mid-sized preclinical MRI system is being developed. It consists of 5 rings of 19 CZT detectors. The larger ring diameter allows the use of optimized multi-pinhole collimator designs, such as high system resolution up to ~1 mm, high geometric efficiency, or lower system resolution without collimator rotation. The anticipated performance of the new system is supported by simulation data.

  6. Normal value of functional parameters in gated myocardial perfusion SPECT in patients with low risk of coronary artery disease: emory cardiac tool box program

    Energy Technology Data Exchange (ETDEWEB)

    Kang, D. Y.; Kim, M. H.; Kim, Y. D.; Kim, D. K. [Donga University College of Medicine, Busan (Korea, Republic of)

    2002-07-01

    Absolute value of the functional data of gated myocardial perfusion SPECT is necessary to determine that individual patient is normal or not. Tc-99m MIBI gated myocardial perfusion SPECT was performed using emory cardiac tool box program. All patients (M:F=15:36, age 64{+-}10 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded; previous angina or MI, ECG change with Q wave or ST-T change, diabetes mellitus, hypercholesterolemia, typical chest pain and hypertension. In all patients, myocardial mass is 117{+-}23 g in stress gated SPECT, 106{+-}22 g in stress ungated SPECT and 102{+-}21 g in rest ungated SPECT. EDV is 90{+-}28 ml, ESV 26{+-}20 ml, SV 66{+-}21 ml, EF 73{+-}10 % and TID 1.06{+-}0.14. Myocardial mass in rest ungated SPECT is significantly different between men and women (p=0.025). Myocardial mass is significantly different between stress gated SPECT and stress ungated SPECT (p=0.000), and between stress ungated SPECT and rest ungated SPECT (p=0.003). We provide normal value of functional parameters to determine the abnormality of individual patients in patients with low risk of coronary artery disease.

  7. Normal value of functional parameters in gated myocardial perfusion SPECT in patients with low risk of coronary artery disease: emory cardiac tool box program

    International Nuclear Information System (INIS)

    Absolute value of the functional data of gated myocardial perfusion SPECT is necessary to determine that individual patient is normal or not. Tc-99m MIBI gated myocardial perfusion SPECT was performed using emory cardiac tool box program. All patients (M:F=15:36, age 64±10 yrs) showed normal myocardial perfusion. The patients with following characteristics were excluded; previous angina or MI, ECG change with Q wave or ST-T change, diabetes mellitus, hypercholesterolemia, typical chest pain and hypertension. In all patients, myocardial mass is 117±23 g in stress gated SPECT, 106±22 g in stress ungated SPECT and 102±21 g in rest ungated SPECT. EDV is 90±28 ml, ESV 26±20 ml, SV 66±21 ml, EF 73±10 % and TID 1.06±0.14. Myocardial mass in rest ungated SPECT is significantly different between men and women (p=0.025). Myocardial mass is significantly different between stress gated SPECT and stress ungated SPECT (p=0.000), and between stress ungated SPECT and rest ungated SPECT (p=0.003). We provide normal value of functional parameters to determine the abnormality of individual patients in patients with low risk of coronary artery disease

  8. Efficacy of the phase images in fourier analysis using gated cardiac POOL-SPECT for determining the indication for cardiac resynchronization therapy

    International Nuclear Information System (INIS)

    Although cardiac resynchronization therapy (CRT) improves quality of life and survival for patients with heart failure, exact methods to estimate the effect of cardiac asynchrony have not yet been defined. Initially, to examine whether the phase analysis images in the Fourier analysis using gated cardiac pool single photon emission computed tomography (POOL-SPECT) could be used to evaluate cardiac asynchrony, 19 consecutive patients with dilated cardiomyopathy were studied. Interventricular asynchrony was defined by whether the peak of the picture elements of the right ventricle in the phase histogram fitted that of the left ventricle and intraventricular asynchrony by whether the phase image was described homogenously or not. The patients with both inter- and intraventricular asynchrony had significant deterioration in both left ventricular ejection fraction (p<0.01) and New York Heart Association functional class (p<0.01). To evaluate the efficacy of these phase images for CRT setting, 7 patients were tested before and after CRT. During a 3.9±3.6 month follow-up period, all patients had an improvement in their condition, and the inter- and intraventricular asynchrony significantly improved after CRT. The degrees of the inter- and intraventricular asynchrony were related to the degree of cardiac depression pre CRT. These results have shown that the phase images from POOL-SPECT are useful for assessing the effect of CRT in patients with heart failure, which suggests that it may provide information about the indication for CRT. (author)

  9. A modified method of cardiac functional analysis for ECG gated SPECT. Study of functional G-maps

    Energy Technology Data Exchange (ETDEWEB)

    Onoguchi, Masahisa; Takayama, Teruhiko [Kanazawa Univ. (Japan). School of Medicine; Maruno, Hirotaka; Murata, Hajime; Mori, Kazuaki; Toyama, Hinako; Yoshioka, Katsunori; Irimoto, Masahiro; Katayama, Hitoshi

    1998-07-01

    To evaluate the cardiac function accurately using ECG gated SPECT images, we performed a modified method of cardiac functional analysis (Functional G-maps). One hour after the intravenous injection of 1,110 MBq of {sup 99m}Tc-tetrofosmin, gated SPECT data was acquired dividing a cardiac cycle into 12 frames. Every short-axis images were usually reconstructed using first 11 of 12 frames. The reconstruction of these images was repeated performing slice thickness correction. Because the apex-to-base length is different at any frame during a cardiac cycle, 10 slices of short-axis images were obtained with the same thickness for each frame. Subsequently each short-axis image was divided by 40 radii, and the time activity curve was generated from the total counts included in each segment plus both neighboring segment. Afterwards the curve fitting was performed using the second reverse Fourier function. From fitted curves and their differentials, we estimated a variety of parameters including Max (End-systolic count), Min (End-diastolic count), %CI (Percent count increase), Uptake, PCR (Peak contraction rate), PDR (Peak distention rate) and CT (Contraction time). In 5 normal subjects, %Max was greater in the anterior and septal regions, whereas %Min was greater in the apex and lateral regions. %CI and %PCR were similarly greater in the septal, anterior and inferior regions. On the other hand, %PDR in the lateral or inferior region was lower than the values in the other regions. In conclusion, this modified method is expected to be useful for accurate assessment of regional cardiac function and myocardial perfusion. (author)

  10. A modified method of cardiac functional analysis for ECG gated SPECT. Study of functional G-maps

    International Nuclear Information System (INIS)

    To evaluate the cardiac function accurately using ECG gated SPECT images, we performed a modified method of cardiac functional analysis (Functional G-maps). One hour after the intravenous injection of 1,110 MBq of 99mTc-tetrofosmin, gated SPECT data was acquired dividing a cardiac cycle into 12 frames. Every short-axis images were usually reconstructed using first 11 of 12 frames. The reconstruction of these images was repeated performing slice thickness correction. Because the apex-to-base length is different at any frame during a cardiac cycle, 10 slices of short-axis images were obtained with the same thickness for each frame. Subsequently each short-axis image was divided by 40 radii, and the time activity curve was generated from the total counts included in each segment plus both neighboring segment. Afterwards the curve fitting was performed using the second reverse Fourier function. From fitted curves and their differentials, we estimated a variety of parameters including Max (End-systolic count), Min (End-diastolic count), %CI (Percent count increase), Uptake, PCR (Peak contraction rate), PDR (Peak distention rate) and CT (Contraction time). In 5 normal subjects, %Max was greater in the anterior and septal regions, whereas %Min was greater in the apex and lateral regions. %CI and %PCR were similarly greater in the septal, anterior and inferior regions. On the other hand, %PDR in the lateral or inferior region was lower than the values in the other regions. In conclusion, this modified method is expected to be useful for accurate assessment of regional cardiac function and myocardial perfusion. (author)

  11. 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

    In patients with heart failure (HF) due to coronary disease, a combined evaluation of perfusion and glucose metabolism by cardiac single photon emission computed tomography (SPECT)/positron emission tomography (PET) can be used to distinguish viable from non-viable myocardium, and current...... their ground in a population with TTC. From 1 September 2009 to 1 October 2012, 24 patients suspected of TTC were enrolled in a multimodality cardiac imaging research project. Echocardiography, (99m)Tc SPECT, and (18)F FDG PET were performed during the acute admission and at follow-up 4 months later. Nineteen...

  12. Frequency and severity of myocardial perfusion abnormalities using Tc-99m MIBI SPECT in cardiac syndrome X

    International Nuclear Information System (INIS)

    Cardiac syndrome X is defined by a typical angina pectoris with normal or near normal (stenosis <40%) coronary angiogram with or without electrocardiogram (ECG) change or atypical angina pectoris with normal or near normal coronary angiogram plus a positive none-invasive test (exercise tolerance test or myocardial perfusion scan) with or without ECG change. Studies with myocardial perfusion imaging on this syndrome have indicated some abnormal perfusion scan. We evaluated the role of myocardial perfusion imaging (MPI) and also the severity and extent of perfusion abnormality using Tc-99m MIBI Single Photon Emission Computed Tomography (SPECT) in these patients. The study group consisted of 36 patients with cardiac syndrome X. The semiquantitative perfusion analysis was performed using exercise Tc-99m MIBI SPECT. The MPI results were analyzed by the number, location and severity of perfusion defects. Abnormal perfusion defects were detected in 13 (36.10%) cases, while the remaining 23 (63.90%) had normal cardiac imaging. Five of 13 (38.4%) abnormal studies showed multiple perfusion defects. The defects were localized in the apex in 3, apical segments in 4, midventricular segments in 12 and basal segments in 6 cases. Fourteen (56%) of all abnormal segments revealed mild, 7(28%) moderate and 4 (16%) severe reduction of tracer uptake. No fixed defects were identified. The vessel territories were approximately the same in all subjects. The Exercise treadmill test (ETT) was positive in 25(69%) and negative in 11(30%) patients. There was no consistent pattern as related to the extent of MPI defects or exercise test results. Our study suggests that multiple perfusion abnormalities with different levels of severity are common in cardiac syndrome X, with more than 30 % of these patients having at least one abnormal perfusion segment. Our findings suggest that in these patients microvascular angina is probably more common than is generally believed

  13. Observer detection limits for a dedicated SPECT breast imaging system

    Science.gov (United States)

    Cutler, S. J.; Perez, K. L.; Barnhart, H. X.; Tornai, M. P.

    2010-04-01

    An observer-based contrast-detail study is performed in an effort to evaluate the limits of object detectability using a dedicated CZT-based breast SPECT imaging system under various imaging conditions. A custom geometric contrast-resolution phantom was developed that can be used for both positive ('hot') and negative contrasts ('cold'). The 3 cm long fillable tubes are arranged in six sectors having equal inner diameters ranging from 1 mm to 6 mm with plastic wall thicknesses of SPECT camera having 2.5 mm intrinsic pixels, the mean detectable rod was ~3.4 mm at a 10:1 ratio, degrading to ~5.2 mm with the 2.5:1 concentration ratio. The smallest object detail was observed using a 45° tilted trajectory acquisition. The complex 3D projected sine wave acquisition, however, had the most consistent combined intra- and inter-observer results, making it potentially the best imaging approach for consistent results.

  14. 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.

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

    International Nuclear Information System (INIS)

    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 99mTc-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.)

  16. An evaluation of data-driven motion estimation in comparison to the usage of external-surrogates in cardiac SPECT imaging

    International Nuclear Information System (INIS)

    Motion estimation methods in single photon emission computed tomography (SPECT) can be classified into methods which depend on just the emission data (data-driven), or those that use some other source of information such as an external surrogate. The surrogate-based methods estimate the motion exhibited externally which may not correlate exactly with the movement of organs inside the body. The accuracy of data-driven strategies on the other hand is affected by the type and timing of motion occurrence during acquisition, the source distribution, and various degrading factors such as attenuation, scatter, and system spatial resolution. The goal of this paper is to investigate the performance of two data-driven motion estimation schemes based on the rigid-body registration of projections of motion-transformed source distributions to the acquired projection data for cardiac SPECT studies. Comparison is also made of six intensity based registration metrics to an external surrogate-based method. In the data-driven schemes, a partially reconstructed heart is used as the initial source distribution. The partially-reconstructed heart has inaccuracies due to limited angle artifacts resulting from using only a part of the SPECT projections acquired while the patient maintained the same pose. The performance of different cost functions in quantifying consistency with the SPECT projection data in the data-driven schemes was compared for clinically realistic patient motion occurring as discrete pose changes, one or two times during acquisition. The six intensity-based metrics studied were mean-squared difference, mutual information, normalized mutual information (NMI), pattern intensity (PI), normalized cross-correlation and entropy of the difference. Quantitative and qualitative analysis of the performance is reported using Monte-Carlo simulations of a realistic heart phantom including degradation factors such as attenuation, scatter and system spatial resolution. Further the

  17. Performance of a semiconductor SPECT system: comparison with a conventional Anger-type SPECT instrument

    OpenAIRE

    Takahashi, Yasuyuki; MIYAGAWA, MASAO; Nishiyama, Yoshiko; Ishimura, Hayato; Mochizuki, Teruhito

    2012-01-01

    Objective The performance of a new single photon emission computed tomography (SPECT) scanner with a cadmium-zinc-telluride (CZT) solid-state semiconductor detector (Discovery NM 530c; D530c) was evaluated and compared to a conventional Anger-type SPECT with a dual-detector camera (Infinia). Methods Three different phantom studies were performed. Full width at half maximum (FWHM) was measured using line sources placed at different locations in a cylindrical phantom. Uniformity was measured us...

  18. Brain SPECT

    International Nuclear Information System (INIS)

    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)

  19. Clinical value of rapid clearance in resting sestamibi cardiac SPECT in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    Resting 99mTc sestamibi (MIBI) SPECT and exercise-reinjection thallium-201 (Tl) SPECT were performed in fourteen patients with acute myocardial infarction (AMI). MIBI SPECT were obtained 90 min (MIBI-90) and 300 min (MIBI-300) after injection of 370 MBq of MIBI at rest. MIBI-90 and MIBI-300 were compared with exercise Tl imaging (Tl-EX) and Tl reinjection imaging (REINJ). Each SPECT image was divided into 22 segments and myocardial uptake was scored visually. Abnormal perfusion defects were observed in 94 myocardial regions. Worsening of the score was observed in 79 segments (84%) on MIBI-300 compared with MIBI-90. Total MIBI-300 uptake score per person was significantly greater than that at MIBI-90 (14.8±8.6 vs. 7.7±7.9, p=0.001). The concordance rate of defect score between MIBI-90 and REINJ was significantly higher than that between MIBI-300 and REINJ (55% vs. 17%, p=0.001). In nine patients without recanalization of an infarct-related artery, perfusion defects were seen in 74 segments. The concordance rate of defect scores between MIBI-300 and T1-EX was significantly higher than that between MIBI-90 and Tl-EX (45% vs. 16%, p=0.001). In conclusion, rapid clearance of MIBI was observed frequently in patients with AMI. MIBI-90 and MIBI-300 may reflect myocardial viability and areas at risk for AMI, respectively. (author)

  20. Design of a CZT based BreastSPECT system

    International Nuclear Information System (INIS)

    A high-resolution SPECT instrument dedicated to breast imaging has been designed incorporating arrays of collimated Cadmium-Zinc-Telluride (CZT) detectors tiled on either a cylindrical surface or a hemispherical surface surrounding the breast. The performance characteristics of a three-segment rotating parallel-hole collimator as well as a stationary multiple pin-hole collimator were considered for the cylindrical system. A stationary multiple pin-hole collimated system was also considered for the hemispherical design. Monte Carlo studies suggest that at almost equal spatial resolution of 0.5 cm, the cylindrical design with parallel-hole collimator would have an approximately a factor of two higher geometrical efficiency than the hemispherical pin-hole collimated system including effects of attenuation in the breast. However, whereas the parallel-hole collimator must be rotated to acquire data from multiple angles of view, the pin-hole version has the advantage of recording data from 112 views in a stationary mode. Monte Carlo studies of filtered backprojections as well as a Bayesian reconstruction approach including attenuation and scatter within the breast, where the breast was modeled as a 15 cm hemisphere of uniform activity distribution containing three spherical lesions of diameters 1.0 cm, 0.7 cm and 0.5 cm respectively suggest that the 0.5 cm could be detected with either design in a one-hour SPECT study assuming a 10:1 tumor to background ratio. The authors conclude that a high resolution Breast SPECT instrument where the resolution is limited to about 0.5 cm is viable with CZT detectors

  1. Design of a CZT based BreastSPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Singh, M.; Mumcuoglu, E. [Univ. of Southern California, Los Angeles, CA (United States)

    1998-06-01

    A high-resolution SPECT instrument dedicated to breast imaging has been designed incorporating arrays of collimated Cadmium-Zinc-Telluride (CZT) detectors tiled on either a cylindrical surface or a hemispherical surface surrounding the breast. The performance characteristics of a three-segment rotating parallel-hole collimator as well as a stationary multiple pin-hole collimator were considered for the cylindrical system. A stationary multiple pin-hole collimated system was also considered for the hemispherical design. Monte Carlo studies suggest that at almost equal spatial resolution of 0.5 cm, the cylindrical design with parallel-hole collimator would have an approximately a factor of two higher geometrical efficiency than the hemispherical pin-hole collimated system including effects of attenuation in the breast. However, whereas the parallel-hole collimator must be rotated to acquire data from multiple angles of view, the pin-hole version has the advantage of recording data from 112 views in a stationary mode. Monte Carlo studies of filtered backprojections as well as a Bayesian reconstruction approach including attenuation and scatter within the breast, where the breast was modeled as a 15 cm hemisphere of uniform activity distribution containing three spherical lesions of diameters 1.0 cm, 0.7 cm and 0.5 cm respectively suggest that the 0.5 cm could be detected with either design in a one-hour SPECT study assuming a 10:1 tumor to background ratio. The authors conclude that a high resolution Breast SPECT instrument where the resolution is limited to about 0.5 cm is viable with CZT detectors.

  2. Observer detection limits for a dedicated SPECT breast imaging system

    OpenAIRE

    Cutler, S J; Perez, K L; Barnhart, H. X.; Tornai, M P

    2010-01-01

    An observer-based contrast-detail study is performed in an effort to evaluate the limits of object detectability using a dedicated CZT-based breast SPECT imaging system under various imaging conditions. A custom geometric contrast-resolution phantom was developed that can be used for both positive (‘hot’) and negative contrasts (‘cold’). The 3 cm long fillable tubes are arranged in six sectors having equal inner diameters ranging from 1 mm to 6 mm with plastic wall thicknesses of

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

    International Nuclear Information System (INIS)

    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)

  4. A new modular detector for a cylindrical brain SPECT system

    International Nuclear Information System (INIS)

    A new detector module has been developed for a prototype system, McSPECT 2, which is being constructed for high-resolution clinical brain imaging. The detector module is the building block of the cylindrical detector system of the McSPECT 2. Each detector module contains 5 NaI(Tl) bars and is backed by a glass window in an aluminum housing. Each detector module is associated with 6 PMTs to form a functional unit for position estimation. Bench-top tests performed on a sample unit demonstrated an average of 10.5% local energy resolution (ER) at 140 keV. Centroid calculations were applied in both orthogonal directions of the module for position estimation. In the longitudinal direction, a two-step centroid method yields a 13 cm UFOV (useful field-of-view) along the bar and an 11 cm CFOV (center FOV), with intrinsic spatial resolution of < 5.5 and 3.8 ± 0.3 mm FWHM, respectively. In the transverse direction, the task of identifying the bar detector involved in an event is simplified, with an accuracy better than 99% when photons are incident normally

  5. Monte Carlo simulation on SPECT imaging and the development of a low cost and high performance SPECT system in China

    International Nuclear Information System (INIS)

    SPECT was investigated in the 1970's, developed in the 1980's and popularized in the 1990's in developed countries. Now there are more than 160 systems working in those countries. The Institute of Heavy Ion Physics, Beijing University, has built a laboratory. The goal of the laboratory is to develop a low cost and high performance SPECT system with 37 PMT and PC computer system because the number of PMT is not so important for space resolution while it costs too much. The speed of PC development is the fastest among all computers. The high speed, large size of memory and wide developed environment of software is suitable for such purpose. During the development, the Monte Carlo simulation is very important to make the design of the production better

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

    International Nuclear Information System (INIS)

    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 201Tl (84 patients) or 99mTc-sestamibi (87 patients) with an Anger or a CZT camera. A predictive model was validated in a group of patients routinely referred for 201Tl (78 patients) or 99mTc-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 201Tl than for 99mTc-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 99mTc-sestamibi and 30.5 and 13.1ppm for 201Tl, 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 99mTc-sestamibi and 39 and 91 MBq for 201Tl, 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 99mTc-sestamibi and in non-obese subjects. (orig.)

  8. Sci—Thur PM: Imaging — 01: Position-sensitive noise characteristics in multi-pinhole cardiac SPECT imaging

    International Nuclear Information System (INIS)

    Myocardial perfusion imaging (MPI) with Single Photon Emission Computed Tomography (SPECT) is invaluable in the diagnosis and management of heart disease. It provides essential information on myocardial blood flow and ischemia. Multi-pinhole dedicated cardiac-SPECT cameras offer improved count sensitivity, and spatial and energy resolutions over parallel-hole camera designs however variable sensitivity across the field-of-view (FOV) can lead to position-dependent noise variations. Since MPI evaluates differences in the signal-to-noise ratio, noise variations in the camera could significantly impact the sensitivity of the test for ischemia. We evaluated the noise characteristics of GE Healthcare's Discovery NM530c camera with a goal of optimizing the accuracy of our patient assessment and thereby improving outcomes. Theoretical sensitivity maps of the camera FOV, including attenuation effects, were estimated analytically based on the distance and angle between the spatial position of a given voxel and each pinhole. The standard deviation in counts, σ was inferred for each voxel position from the square root of the sensitivity mapped at that position. Noise was measured experimentally from repeated (N=16) acquisitions of a uniform spherical Tc-99m-water phantom. The mean (μ) and standard deviation (σ) were calculated for each voxel position in the reconstructed FOV. Noise increased ∼2.1× across a 12 cm sphere. A correlation of 0.53 is seen when experimental noise is compared with theory suggesting that ∼53% of the noise is attributed to the combined effects of attenuation and the multi-pinhole geometry. Further investigations are warranted to determine the clinical impact of the position-dependent noise variation

  9. GATED SPECT IN PATIENTS WITH BIOPSY-NEGATIVE CARDIAC TRANSPLANT REJECTION

    OpenAIRE

    E. N. Ostroumov; V. M. Zakharevich; E. D. Kotina; N. N. Mojeiko; A. G. Kupriyanova; E. I. Ryaboshtanova; B. N. Morozov; N.Z. Meboniya; Mironov, S. V.; A. Y. Kormer; I. M. Ilynsky; L. V. Beletskaya; E. N. Kazakov

    2009-01-01

    Humoral rejection of the cardiac allograft is still a challenging problem associated with high incidence of graft loss and patient mortality. These episodes of rejection are often more severe, and more difficult to treat, than classical acute cellular rejection. Hemodynamic compromise, in the absence of acute cellular rejection, called biopsy-negative rejection occurs in 10 to 20% of cardiac allograft recipients. The assessment of hemodynamic compromise can provide functional data in transpla...

  10. MRC-SPECT: A sub-500 µm resolution MR-compatible SPECT system for simultaneous dual-modality study of small animals

    International Nuclear Information System (INIS)

    In this paper, we will report the development of an ultrahigh resolution MR-compatible SPECT system that can be operated inside a pre-existing clinical MR scanner for simultaneous dual-modality imaging of small animals. This system is constructed with 40 small-pixel CdTe detector modules assembled in a fully stationary ring SPECT geometry. We have experimentally demonstrated that this system is capable of providing an imaging resolution of <500 μm when operating inside MR scanners. We will report the design, construction of the MRI-compatible SPECT system, including the detector technology, collimator, system development and so on. The first imaging results obtained with this newly constructed SPECT system will also be reported

  11. Clinical applications of SPECT/CT: New hybrid nuclear medicine imaging system

    International Nuclear Information System (INIS)

    Interest in multimodality imaging shows no sign of subsiding. New tracers are spreading out the spectrum of clinical applications and innovative technological solutions are preparing the way for yet more modality marriages: hybrid imaging. Single photon emission computed tomography (SPECT) has enabled the evaluation of disease processes based on functional and metabolic information of organs and cells. Integration of X ray computed tomography (CT) into SPECT has recently emerged as a brilliant diagnostic tool in medical imaging, where anatomical details may delineate functional and metabolic information. SPECT/CT has proven to be valuable in oncology. For example, in the case of a patient with metastatic thyroid cancer, neither SPECT nor CT alone could identify the site of malignancy. SPECT/CT, a hybrid image, precisely identified where the surgeon should operate. However SPECT/CT is not just advantageous in oncology. It may also be used as a one-stop-shop for various diseases. Clinical applications with SPECT/CT have started and expanded in developed countries. It has been reported that moving from SPECT alone to SPECT/CT could change diagnoses in 30% of cases. Large numbers of people could therefore benefit from this shift all over the world. This report presents an overview of clinical applications of SPECT/CT and a relevant source of information for nuclear medicine physicians, radiologists and clinical practitioners. This information may also be useful for decision making when allocating resources dedicated to the health care system, a critical issue that is especially important for the development of nuclear medicine in developing countries. In this regard, the IAEA may be heavily involved in the promotion of programmes aimed at the IAEA's coordinated research projects and Technical Cooperation projects

  12. Observer detection limits for a dedicated SPECT breast imaging system

    International Nuclear Information System (INIS)

    An observer-based contrast-detail study is performed in an effort to evaluate the limits of object detectability using a dedicated CZT-based breast SPECT imaging system under various imaging conditions. A custom geometric contrast-resolution phantom was developed that can be used for both positive ('hot') and negative contrasts ('cold'). The 3 cm long fillable tubes are arranged in six sectors having equal inner diameters ranging from 1 mm to 6 mm with plastic wall thicknesses of <0.25 mm, on a pitch of twice their inner diameters. Scans of the activity filled tubes using simple circular trajectories are obtained in a 215 mL uniform water filled cylinder, varying the rod:background concentration ratios from 10:1 to 1:10 simulating a large range of biological uptake ratios. The rod phantom is then placed inside a non-uniformly shaped 500 mL breast phantom and scans are again acquired using both simple and complex 3D trajectories for similarly varying contrasts. Summed slice and contiguous multi-slice images are evaluated by five independent readers, identifying the smallest distinguishable rod for each concentration and experimental setup. Linear and quadratic regression is used to compare the resulting contrast-detail curves. Results indicate that in a moderately low-noise 500 mL background, using the SPECT camera having 2.5 mm intrinsic pixels, the mean detectable rod was ∼3.4 mm at a 10:1 ratio, degrading to ∼5.2 mm with the 2.5:1 concentration ratio. The smallest object detail was observed using a 45 deg. tilted trajectory acquisition. The complex 3D projected sine wave acquisition, however, had the most consistent combined intra- and inter-observer results, making it potentially the best imaging approach for consistent results.

  13. Observer detection limits for a dedicated SPECT breast imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, S J; Tornai, M P [Department of Biomedical Engineering, Duke University, Durham, NC 27708 (United States); Perez, K L [Department of Radiology, Duke University Medical Center, Durham, NC 27710 (United States); Barnhart, H X [Department of Biostatistics and Bioinformatics, Duke University, Durham, NC 27715 (United States)], E-mail: spencer.cutler@duke.edu

    2010-04-07

    An observer-based contrast-detail study is performed in an effort to evaluate the limits of object detectability using a dedicated CZT-based breast SPECT imaging system under various imaging conditions. A custom geometric contrast-resolution phantom was developed that can be used for both positive ('hot') and negative contrasts ('cold'). The 3 cm long fillable tubes are arranged in six sectors having equal inner diameters ranging from 1 mm to 6 mm with plastic wall thicknesses of <0.25 mm, on a pitch of twice their inner diameters. Scans of the activity filled tubes using simple circular trajectories are obtained in a 215 mL uniform water filled cylinder, varying the rod:background concentration ratios from 10:1 to 1:10 simulating a large range of biological uptake ratios. The rod phantom is then placed inside a non-uniformly shaped 500 mL breast phantom and scans are again acquired using both simple and complex 3D trajectories for similarly varying contrasts. Summed slice and contiguous multi-slice images are evaluated by five independent readers, identifying the smallest distinguishable rod for each concentration and experimental setup. Linear and quadratic regression is used to compare the resulting contrast-detail curves. Results indicate that in a moderately low-noise 500 mL background, using the SPECT camera having 2.5 mm intrinsic pixels, the mean detectable rod was {approx}3.4 mm at a 10:1 ratio, degrading to {approx}5.2 mm with the 2.5:1 concentration ratio. The smallest object detail was observed using a 45 deg. tilted trajectory acquisition. The complex 3D projected sine wave acquisition, however, had the most consistent combined intra- and inter-observer results, making it potentially the best imaging approach for consistent results.

  14. Quality control and measurement of physical parameters of SPECT system

    International Nuclear Information System (INIS)

    The quality control of nuclear medicine systems are one of the most important parameters that is affecting the studies performed on patients. Any defect in performance of the system may lead to appearance of artifacts that affect the quantitative and qualitative information obtained from images. In this paper the results of quality control performed on both ADAC and SOPHA single head SPECT systems in Shahid Rajaei Heart Hospital are presented. Energy resolution, spatial resolution, temporal resolution sensitivity, uniformity, linearity, center of rotation and multi window energy registration were performed according to NEMA standards. In addition to the above mentioned tests MTF was obtained for various collimators of both systems. Apart from the linearity and uniformity of ADAC system which were unacceptable and later were corrected by the company engineers, all the above factors were within acceptable range for both systems. Comparison of MLF curves at various frequencies for SOPHA HEGP collimator and ADAC HEAP collimator shows superior performance of SOPHA system using this collimator

  15. Research For Developing CT/SPECT Technique Utilizing The Lab-Scaled Of Industrial One Source - One Detector CT System

    International Nuclear Information System (INIS)

    The Research for developing CT/SPECT technique utilizing the lab-scaled of industrial one source - one detector CT system is the continued project following the project Design and fabrication of a lab-scaled of industrial one source - one detector CT system. The main aim of this project is to approach the SPECT technique for the development of the imaging technique research in the Centre for Applications of nuclear technique in industry (CANTI); fabricate and set up a hardware configuration; develop the image reconstruction software for CT/SPECT. Since the project budget is limited, the main product of this project is an associated hardware configuration of SPECT and CT (2 detector for SPECT and one source - one detector for CT) which can be taken SPECT/CT image in static condition. The SPECT/CT images can be reconstructed either by Filtered back projection (FBP) or Algebraic reconstruction technique (ART) or Expectation Maximization (EM) algorithms. (author)

  16. Performance of a semiconductor SPECT system. Comparison with a conventional anger-type SPECT instrument

    International Nuclear Information System (INIS)

    The performance of a new single photon emission computed tomography (SPECT) scanner with a cadmium-zinc-telluride (CZT) solid-state semiconductor detector (Discovery NM 530c; D530c) was evaluated and compared to a conventional Anger-type SPECT with a dual-detector camera (Infinia). Three different phantom studies were performed. Full width at half maximum (FWHM) was measured using line sources placed at different locations in a cylindrical phantom. Uniformity was measured using cylindrical phantoms with 3 different diameters (80, 120, and 160 mm). Spatial resolution was evaluated using hot-rod phantoms of various diameters (5, 9, 13, 16, and 20 mm). Three different myocardial phantom studies were also performed, acquiring projection data with and without defects, and evaluating the interference of liver and gallbladder radioactivity. In a clinical study, the D530c employed list-mode raw data acquisition with electrocardiogram (ECG)-gated acquisition over a 10-min period. From the 10-min projection data, 1-, 3-, 5-, 7- and 10-min SPECT images were reconstructed. The FWHM of the D503c was 1.73-3.48 mm (without water) and 3.88-6.64 mm (with water), whereas the FWHM of the Infinia was 8.17-12.63 mm (without water) and 15.48-16.28 mm (with water). Non-uniformity was larger for the D530c than for the Infinia. Truncation artifacts were also observed with the D530c in a Φ160 mm phantom. The contrast ratio, as defined by myocardial defect/non-defect ratio, was better for the D530c than for the Infinia, and the influence from liver and gallbladder radioactivities was less. Quantitative gated SPECT (QGS) software demonstrated significant differences between data captured over a 10-min period, relative to those acquired over periods of <5 min; there was no difference between ejection fractions calculated using data capture for periods ≥5 min (p<0.05). The D530c is superior to the Infinia, with regard to both spatial resolution and sensitivity. In this study, these

  17. Creation of an ensemble of simulated cardiac cases and a human observer study: tools for the development of numerical observers for SPECT myocardial perfusion imaging

    Science.gov (United States)

    O'Connor, J. Michael; Pretorius, P. Hendrik; Gifford, Howard C.; Licho, Robert; Joffe, Samuel; McGuiness, Matthew; Mehurg, Shannon; Zacharias, Michael; Brankov, Jovan G.

    2012-02-01

    Our previous Single Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (MPI) research explored the utility of numerical observers. We recently created two hundred and eighty simulated SPECT cardiac cases using Dynamic MCAT (DMCAT) and SIMIND Monte Carlo tools. All simulated cases were then processed with two reconstruction methods: iterative ordered subset expectation maximization (OSEM) and filtered back-projection (FBP). Observer study sets were assembled for both OSEM and FBP methods. Five physicians performed an observer study on one hundred and seventy-nine images from the simulated cases. The observer task was to indicate detection of any myocardial perfusion defect using the American Society of Nuclear Cardiology (ASNC) 17-segment cardiac model and the ASNC five-scale rating guidelines. Human observer Receiver Operating Characteristic (ROC) studies established the guidelines for the subsequent evaluation of numerical model observer (NO) performance. Several NOs were formulated and their performance was compared with the human observer performance. One type of NO was based on evaluation of a cardiac polar map that had been pre-processed using a gradient-magnitude watershed segmentation algorithm. The second type of NO was also based on analysis of a cardiac polar map but with use of a priori calculated average image derived from an ensemble of normal cases.

  18. 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.

  19. 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

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

    International Nuclear Information System (INIS)

    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; p53FL/+ and Tie2Cre; p53FL/− 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; p53FL/− mice. In Tie2Cre; p53FL/− mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53FL/+ mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R2 = 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; p53FL/− 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 complementary to microSPECT for

  1. Comparison of myocardial perfusion SPECT with 64-slice multi-slice computed tomography angiography in cardiac screening of asymptomatic diabetic patients

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Il Han; Lee, Won Woo; Chang, Hyuck Jae; Choi, Sang II; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    Asymptomatic diabetic patients may suffer silent ischemia. However, the question that what is the optimal screening tool for detection of cardiac disease in asymptomatic diabetic patients has not been addressed. We prospectively recruited diabetic patients who had not complained chest pain, and obtained myocardial perfusion SPECT (MPS) and cardiac CT angiography (CTA). We compared perfusion status on MPS with findings on CTA. A total of 110 diabetic patients (Age range 41-84, mean age 61.6{+-}7.74; gender, M: F 66:44) without cardiac symptom underwent both MPS and CTA. The MPS protocol was one-day single isotope study, adenosine stress Tc-99m MIBI/rest Tc-99m MIBI. CTA was conducted using 64-slice multi-slice CT (Brillance64, Philips Medical Systems). Perfusion status on MPS was assessed by summed-stress score (SSS) using 20-segment model, and SSS of {>=}4 was considered abnormal. Coronary stenosis of more than 50% luminal narrowing in CTA was considered significant, and coronary artery calcium scoring (CACS) was graded as: < or =10, 11-100, 101-400, or >400. MPS found abnormal perfusion in 11.8% (13/110) and CTA significant coronary stenosis in 20.9% (23/110). Five patients showed both abnormal perfusion and significant coronary stenosis. CACS (n=103 patients) were measured as; < or =10 in 45.6%, 11-100 in 28.1%, 101-400 in 19.4%, and >400 in 6.8%. The patient proportion of abnormal MPS in each CACS group were; 10.6% with < or = 10, 17.2% with 11-100, 5% with 101-400, and 0% with >400. The patient proportion of significant coronary stenosis on CTA in each CACS group were; 2.13% with < or =10, 27.6% with 11-100, 35% with 101-400, and 57.1% with >400. In asymptomatic diabetic patients, coronary stenosis by CTA showed correlation with coronary artery calcium scoring, but myocardial perfusion status by MPS did not. Long-term evaluation is essential for determination of prognostic significance of MPS and cardiac CTA.

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

    Science.gov (United States)

    Hamamura, Mark J.; Ha, Seunghoon; Roeck, Werner W.; Tugan Muftuler, L.; Wagenaar, Douglas J.; Meier, Dirk; Patt, Bradley E.; Nalcioglu, Orhan

    2010-03-01

    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 B0 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.

  3. 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.

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

    International Nuclear Information System (INIS)

    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 B0 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.

  5. SPECT Analysis of Cardiac Perfusion Changes After Whole-Breast/Chest Wall Radiation Therapy With or Without Active Breathing Coordinator: Results of a Randomized Phase 3 Trial

    Energy Technology Data Exchange (ETDEWEB)

    Zellars, Richard, E-mail: zellari@jhmi.edu [Johns Hopkins Medical Institution, Baltimore, Maryland (United States); Bravo, Paco E. [University of Washington Medical Center, Seattle, Washington (United States); Tryggestad, Erik [Mayo Clinic, Rochester, Minnesota (United States); Hopfer, Kari [Hahnemann University, Philadelphia, Pennsylvania (United States); Myers, Lee; Tahari, Abdel; Asrari, Fariba; Ziessman, Harvey [Johns Hopkins Medical Institution, Baltimore, Maryland (United States); Garrett-Mayer, Elizabeth [Medical University of South Carolina, Charleston, South Carolina (United States)

    2014-03-15

    Purpose: Cardiac muscle perfusion, as determined by single-photon emission computed tomography (SPECT), decreases after breast and/or chest wall (BCW) irradiation. The active breathing coordinator (ABC) enables radiation delivery when the BCW is farther from the heart, thereby decreasing cardiac exposure. We hypothesized that ABC would prevent radiation-induced cardiac toxicity and conducted a randomized controlled trial evaluating myocardial perfusion changes after radiation for left-sided breast cancer with or without ABC. Methods and Materials: Stages I to III left breast cancer patients requiring adjuvant radiation therapy (XRT) were randomized to ABC or No-ABC. Myocardial perfusion was evaluated by SPECT scans (before and 6 months after BCW radiation) using 2 methods: (1) fully automated quantitative polar mapping; and (2) semiquantitative visual assessment. The left ventricle was divided into 20 segments for the polar map and 17 segments for the visual method. Segments were grouped by anatomical rings (apical, mid, basal) or by coronary artery distribution. For the visual method, 2 nuclear medicine physicians, blinded to treatment groups, scored each segment's perfusion. Scores were analyzed with nonparametric tests and linear regression. Results: Between 2006 and 2010, 57 patients were enrolled and 43 were available for analysis. The cohorts were well matched. The apical and left anterior descending coronary artery segments had significant decreases in perfusion on SPECT scans in both ABC and No-ABC cohorts. In unadjusted and adjusted analyses, controlling for pretreatment perfusion score, age, and chemotherapy, ABC was not significantly associated with prevention of perfusion deficits. Conclusions: In this randomized controlled trial, ABC does not appear to prevent radiation-induced cardiac perfusion deficits.

  6. SPECT Analysis of Cardiac Perfusion Changes After Whole-Breast/Chest Wall Radiation Therapy With or Without Active Breathing Coordinator: Results of a Randomized Phase 3 Trial

    International Nuclear Information System (INIS)

    Purpose: Cardiac muscle perfusion, as determined by single-photon emission computed tomography (SPECT), decreases after breast and/or chest wall (BCW) irradiation. The active breathing coordinator (ABC) enables radiation delivery when the BCW is farther from the heart, thereby decreasing cardiac exposure. We hypothesized that ABC would prevent radiation-induced cardiac toxicity and conducted a randomized controlled trial evaluating myocardial perfusion changes after radiation for left-sided breast cancer with or without ABC. Methods and Materials: Stages I to III left breast cancer patients requiring adjuvant radiation therapy (XRT) were randomized to ABC or No-ABC. Myocardial perfusion was evaluated by SPECT scans (before and 6 months after BCW radiation) using 2 methods: (1) fully automated quantitative polar mapping; and (2) semiquantitative visual assessment. The left ventricle was divided into 20 segments for the polar map and 17 segments for the visual method. Segments were grouped by anatomical rings (apical, mid, basal) or by coronary artery distribution. For the visual method, 2 nuclear medicine physicians, blinded to treatment groups, scored each segment's perfusion. Scores were analyzed with nonparametric tests and linear regression. Results: Between 2006 and 2010, 57 patients were enrolled and 43 were available for analysis. The cohorts were well matched. The apical and left anterior descending coronary artery segments had significant decreases in perfusion on SPECT scans in both ABC and No-ABC cohorts. In unadjusted and adjusted analyses, controlling for pretreatment perfusion score, age, and chemotherapy, ABC was not significantly associated with prevention of perfusion deficits. Conclusions: In this randomized controlled trial, ABC does not appear to prevent radiation-induced cardiac perfusion deficits

  7. Automatic registration and alignment on a template of cardiac stress and rest reoriented SPECT images.

    Science.gov (United States)

    Declerck, J; Feldmar, J; Goris, M L; Betting, F

    1997-12-01

    Single photon emission computed tomography (SPECT) imaging with 201Tl or 99mTc agent is used to assess the location or the extent of myocardial infarction or ischemia. A method is proposed to decrease the effect of operator variability in the visual or quantitative interpretation of scintigraphic myocardial perfusion studies. To effect this, the patient's myocardial images (target cases) are registered automatically over a template image, utilizing a nonrigid transformation. The intermediate steps are: 1) Extraction of feature points in both stress and rest three-dimensional (3-D) images. The images are resampled in a polar geometry to detect edge points, which in turn are filtered by the use of a priori constraints. The remaining feature points are assumed to be points on the edges of the left ventricular myocardium. 2) Registration of stress and rest images with a global affine transformation. The matching method is an adaptation of the iterative closest point algorithm. 3) Registration and morphological matching of both stress and rest images on a template using a nonrigid local spline transformation following a global affine transformation. 4) Resampling of both stress and rest images in the geometry of the template. Optimization of the method was performed on a database of 40 pairs of stress and rest images selected to obtain a wide variation of images and abnormalities. Further testing was performed on 250 cases selected from the same database on the basis of the availability of angiographic results and patient stratification. PMID:9533574

  8. Assessment of myocardial perfusion and cardiac sympathetic nerve dysfunction in patients with sick sinus syndrome. Evaluation of coronary hemodynamics and 201TlCl/123I-MIBG myocardial SPECT

    International Nuclear Information System (INIS)

    To clarify the coronary hemodynamics, myocardial perfusion and cardiac sympathetic nerve function in patients with sick sinus syndrome (SSS), we performed left coronary digital subtraction angiography (DSA) in 41 patients, exercise 201TlCl-myocardial scintigraphy (planar and SPECT) in 69 patients, and 201TlCl/123I-MIBG myocardial dual SPECT in 13 patients without significant organic coronary stenosis. Coronary artery spasm was documented on coronary angiography in 25/43 (58%) patients with SSS by ergonovine provocation test. Compared with normals, patients with SSS demonstrated prolongation of left coronary circulation time (CCT) on own heart beats and right atrial pacing. We suspected that prolonged CCT may be induced by increased peripheral coronary vascular resistance and impaired coronary micro-circulation in patients with SSS. Forty-two patients (60.9%) developed exercise-induced 201Tl-myocardial perfusion defect on SPECT images. On myocardial dual SPECT images, 11/13 (85%) patients showed localized myocardial low uptake in 123I-MIBG-SPECT images. In eight patients with normal findings on 201Tl-SPECT, six patients showed abnormality on 123I-MIBG-SPECT. We suspected that coronary vasospasm, impaired coronary micro-circulation and cardiac sympathetic nerve dysfunction are taken a part of pathophysiology in SSS (decreased β-adrenergic receptor of peripheral coronary arteries?). (author)

  9. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    OpenAIRE

    Trott, CM; Ouyang, J.; El Fakhri, G

    2010-01-01

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99mTc-sestamibi/123I-BMIPP imaging protocol in place of the commonly-used sequential rest/stress 99mTc-sestamibi protocol. The...

  10. Normal limits of ejection fraction and volumes determined by gated SPECT in clinically normal patients without cardiac events: a study based on the J-ACCESS database

    International Nuclear Information System (INIS)

    Quantitative gated single-photon emission computed tomography (SPECT) is known to have high accuracy and precision for measurement of the principal cardiac functional parameters. We hypothesised that normal values for EF and LV volumes may differ among nationalities, and that optimal threshold values specific to the study population are required. Among 4,670 consecutively registered patients for a J-ACCESS (Japanese investigation regarding prognosis based on gated SPECT) study from 117 hospitals, a total of 268 (149 women, 119 men) were selected who had no baseline cardiac diseases and had experienced no cardiac events during the preceding 3-year period. A gated SPECT study was performed with 99mTc-tetrofosmin and analysed with Cedars Sinai Medical Center's quantitative gated SPECT (QGS) software. The results in respect of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV), and EDV, ESV and SV normalised by body surface area (EDVI, ESVI and SVI), were calculated and summarised to obtain normal limits. EF for women and men was 74 ± 9% and 63 ± 7%, respectively (p < 0.0001). EDV, ESV and SV were significantly smaller in women than in men. Based on multiple regressions for linear models, the primary and secondary predictors of EF, EDVI, ESVI were gender and age. By stepwise multiple regression analysis, a statistically significant third predictor for EDV, ESV, SV and SVI was body weight. No colinearity was found between age and body weight. Important factors for the studied Japanese population included a high incidence of small hearts in women and the relatively advanced age of the population (the mean age ±SD was 64.1 ± 10.0 years for women and 60.9 ± 11.7 years for men). EF and volumes determined by gated SPECT with QGS were significantly affected by gender and age, with body weight as a third predictor for volumes. Moreover, the normal limits were so specific for the population studied that standards

  11. 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.

  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. Nuclear medicine. What can we know about cardiac functions using SPECT images

    International Nuclear Information System (INIS)

    Recent development of medical treatments of contagious diseases and rapid westernization of our lives, have made cardiovascular and cerebrovascular diseases the second and third leading causes of death in Japan. These are called the diseases associated with adult lifestyle, or diseases of adult people. The cardiovascular diseases are apprehended to be prevailing in 2030' not only in our country but also in the now developing countries. Thus it is urgently expected to develop a method to diagnose the disease. We developed a method (Quantification of segmental function by solving Poisson equation, QSFP) to calculate shortening in distances between two points on the cardiac wall. This method enables us to compute synchronicity of contraction and regional works. A brief explanation of the method was presented and theoretical and technical problems of QSFP were discussed. (author)

  14. Clinical validation of the gated blood pool SPECT QBS processing software for evaluating cardiac function in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Full text: The study was carried out to evaluate the commercially available automated GBPS processing software for LVEF and RVEF measurement in patients with cardiomyopathy. Patients (total=41; 24 males; mean age-44 ± 14 years) referred to our department for assessment of cardiac function in patients having dilated cardiomyopathy were prospectively included in the study. In patients with DCM, First pass radionuclide ventriculography (FP-RNV) and planar multi-gated radionuclide angiography (MUGA) were performed at rest after in-vivo labeling of RBCs. LVEF was also calculated by Echo in these patients. LVEF and RVEF were calculated by MUGA and FP-RNV respectively. Immediately after obtaining the planar views, GBPS was performed with GE Infinia Hawkeye4 camera, detectors in L-mode configuration, with step and shoot mode acquisition - 60 steps over 180 deg, 20 s per step, 16 frames per cardiac cycle, 64 x 64 matrix. GBPS was processed using the fully automated QBS algorithm and LVEF, RVEF were calculated. Spearman's coefficient (r) of correlation was calculated for the different sets of values. The level of statistical significance was set at < 5%. Bland-Altman plots were inspected to visually assess the association between measurements from different methods. Results: Head on comparison of the mean values for patients: PLANAR QBPS ECHO LVEF (%) 31 ± 11 VS 34 ± 12; RVEF (%) 46 ± 14 VS 43 ± 17. In patients with DCM, LVEF values calculated from GBPS showed very good correlation with MUGA (r=0.91) and echocardiography (r=0.83; all p<0.0001). Bland-Altman plot showed overestimation for GBPS-LVEF values compared to MUGA. RVEF values calculated by FPRNV and QBS-SPECT also showed good correlation (r=0.87; p<0.0001). Bland-Altman plot for RVEF values showed a tendency for an overestimation of higher RVEF values with GBPS. Patients with DCM also tend to suffer from right ventricular cardiomyopathy. Isolated right sided cardiomyopathy is also a known entity. Since RVEF is

  15. 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

  16. 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.

  17. Gated myocardial perfusion SPECT underestimates left ventricular volumes and shows high variability compared to cardiac magnetic resonance imaging -- a comparison of four different commercial automated software packages

    Directory of Open Access Journals (Sweden)

    Arheden Håkan

    2010-05-01

    Full Text Available Abstract Background We sought to compare quantification of left ventricular volumes and ejection fraction by different gated myocardial perfusion SPECT (MPS programs with each other and to magnetic resonance (MR imaging. Methods N = 100 patients with known or suspected coronary artery disease were examined at rest with 99 mTc-tetrofosmin gated MPS and cardiac MR imaging. Left ventricular end-diastolic volume (EDV, end-systolic volume (ESV, stroke volume (SV and ejection fraction (EF were obtained by analysing gated MPS data with four different programs: Quantitative Gated SPECT (QGS, GE MyoMetrix, Emory Cardiac Toolbox (ECTb and Exini heart. Results All programs showed a mean bias compared to MR imaging of approximately -30% for EDV (-22 to -34%, p Conclusions Gated MPS, systematically underestimates left ventricular volumes by approximately 30% and shows a high variability, especially for ESV. For EF, accuracy was better, with a mean bias between -15 and 6% of EF. It may be of value to take this into consideration when determining absolute values of LV volumes and EF in a clinical setting.

  18. A practical head tracking system for motion correction in neurological SPECT and PET

    International Nuclear Information System (INIS)

    Full text: Patient motion during data acquisition can degrade the quality of SPECT and PET images. Techniques for motion correction in neurological studies in both modalities based on continuous monitoring of head position have been proposed. However difficulties in developing suitable head tracking systems have so far impeded clinical implementations. We have developed a head tracking system based on the mechanical ADL-1 tracker (Shooting Star Technology, Rosedale, Canada) on a Trionix triple-head SPECT camera A software driver running on a SUN Sparc host computer communicates with the tracker over a serial line providing up to 300 updates per second with angular and positional resolutions of 0.05 degrees and 0.2 mm respectively. The SUN Sparc workstation which acquires the SPECT study also communicates with the tracker, eliminating synchronisation problems. For motion correction, the motion parameters provided by the tracker within its own coordinate system must be converted to the camera's coordinate system. The conversion requires knowledge of the rotational relationships between the two coordinate systems and the displacement of their origins, both of which are determined from a calibration procedure. The tracker has been tested under clinical SPECT imaging conditions with a 3D Hoffman brain phantom. Multiple SPECT acquisitions were performed. After each acquisition the phantom was moved to a new position and orientation. Motion parameters reported by the tracker for each applied movement were compared with those obtained by applying an automated image registration program to the sequential reconstructed studies. Maximum differences were < 0.5 degrees and < 2mm, within the expected errors of the registration procedure. We conclude that this tracking system will be suitable for clinical evaluation of motion correction in SPECT and PET

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

    International Nuclear Information System (INIS)

    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 PhantomTM), 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 pinhole

  20. 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

  1. 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...

  2. SU-E-I-80: Quantification of Respiratory and Cardiac Motion Effect in SPECT Acquisitions Using Anthropomorphic Models: A Monte Carlo Simulation Study

    Energy Technology Data Exchange (ETDEWEB)

    Papadimitroulas, P; Kostou, T; Kagadis, G [University of Patras, Rion, Ahaia (Greece); Loudos, G [Technological Educational Institute of Athens, Egaleo, Attika (Greece)

    2015-06-15

    Purpose: The purpose of the present study was to quantify, evaluate the impact of cardiac and respiratory motion on clinical nuclear imaging protocols. Common SPECT and scintigraphic scans are studied using Monte Carlo (MC) simulations, comparing the resulted images with and without motion. Methods: Realistic simulations were executed using the GATE toolkit and the XCAT anthropomorphic phantom as a reference model for human anatomy. Three different radiopharmaceuticals based on 99mTc were studied, namely 99mTc-MDP, 99mTc—N—DBODC and 99mTc—DTPA-aerosol for bone, myocardium and lung scanning respectively. The resolution of the phantom was set to 3.5 mm{sup 3}. The impact of the motion on spatial resolution was quantified using a sphere with 3.5 mm diameter and 10 separate time frames, in the ECAM modeled SPECT scanner. Finally, respiratory motion impact on resolution and imaging of lung lesions was investigated. The MLEM algorithm was used for data reconstruction, while the literature derived biodistributions of the pharmaceuticals were used as activity maps in the simulations. Results: FWHM was extracted for a static and a moving sphere which was ∼23 cm away from the entrance of the SPECT head. The difference in the FWHM was 20% between the two simulations. Profiles in thorax were compared in the case of bone scintigraphy, showing displacement and blurring of the bones when respiratory motion was inserted in the simulation. Large discrepancies were noticed in the case of myocardium imaging when cardiac motion was incorporated during the SPECT acquisition. Finally the borders of the lungs are blurred when respiratory motion is included resulting to a dislocation of ∼2.5 cm. Conclusion: As we move to individualized imaging and therapy procedures, quantitative and qualitative imaging is of high importance in nuclear diagnosis. MC simulations combined with anthropomorphic digital phantoms can provide an accurate tool for applications like motion correction

  3. SU-E-I-80: Quantification of Respiratory and Cardiac Motion Effect in SPECT Acquisitions Using Anthropomorphic Models: A Monte Carlo Simulation Study

    International Nuclear Information System (INIS)

    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 mm3. 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

  4. Feasibility and Initial Performance of Simultaneous SPECT-CT Imaging Using a Commercial Multi-Modality Preclinical Imaging System

    Directory of Open Access Journals (Sweden)

    Dustin R. Osborne

    2015-01-01

    Full Text Available Multi-modality imaging provides coregistered PET-CT and SPECT-CT images; however such multi-modality workflows usually consist of sequential scans from the individual imaging components for each modality. This typical workflow may result in long scan times limiting throughput of the imaging system. Conversely, acquiring multi-modality data simultaneously may improve correlation and registration of images, improve temporal alignment of the acquired data, increase imaging throughput, and benefit the scanned subject by minimizing time under anesthetic. In this work, we demonstrate the feasibility and procedure for modifying a commercially available preclinical SPECT-CT platform to enable simultaneous SPECT-CT acquisition. We also evaluate the performance of simultaneous SPECT-CT tomographic imaging with this modified system. Performance was accessed using a 57Co source and image quality was evaluated with Tc99m phantoms in a series of simultaneous SPECT-CT scans.

  5. Feasibility and Initial Performance of Simultaneous SPECT-CT Imaging Using a Commercial Multi-Modality Preclinical Imaging System

    Science.gov (United States)

    Osborne, Dustin R.; Austin, Derek W.

    2015-01-01

    Multi-modality imaging provides coregistered PET-CT and SPECT-CT images; however such multi-modality workflows usually consist of sequential scans from the individual imaging components for each modality. This typical workflow may result in long scan times limiting throughput of the imaging system. Conversely, acquiring multi-modality data simultaneously may improve correlation and registration of images, improve temporal alignment of the acquired data, increase imaging throughput, and benefit the scanned subject by minimizing time under anesthetic. In this work, we demonstrate the feasibility and procedure for modifying a commercially available preclinical SPECT-CT platform to enable simultaneous SPECT-CT acquisition. We also evaluate the performance of simultaneous SPECT-CT tomographic imaging with this modified system. Performance was accessed using a 57Co source and image quality was evaluated with 99mTc phantoms in a series of simultaneous SPECT-CT scans. PMID:26146568

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-06-01

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

  7. Validation of a rotating camera based SPECT system for dosimetry applications

    International Nuclear Information System (INIS)

    The authors have evaluated the quantitative properties of a rotating camera based SPECT system using three isotopes commonly used clinically (Tc-99m, In-111, and I-123 contaminated with I-124). The isotopes were chosen due to their different imaging characteristics. The Alderson body phantom was used with 'hot' spheres, with and without background activity, to determine system sensitivity and linearity. An analytic post processing attenuation correction routine was implemented which increased system linearity with respect to position in the phantom and was used throughout the study. Up to four organ phantoms were placed in the body phantom and imaged in two ways. First, a two view planar technique, and second, a circular rotation SPECT acquisition. The two view planar technique uses a combination arithmetic and geometric mean with correction for attenuation. The planar technique showed good correlation to actual activity in absence of background (slope .98; R .99), and slightly degraded accuracy with background (slope .91; R .97). However, it was only able to quantitate activity when no overlying or underlying organs were present. The SPECT system, though, was clearly able to distinguish regions of activity in transverse section for which accurate quantitation was possible. Very good correlation between SPECT activity and measured activity was observed both with (slope .98; R .98), and without (slope 1.02; R .99) background activity present. Accurate quantitation of total organ activity is very useful not only for dosimetry applications, but also for radiotherapy planning and monitoring of treatment

  8. Preliminary evaluation of the tomographic performance of the mediSPECT small animal imaging system

    Science.gov (United States)

    Accorsi, Roberto; Curion, Assunta Simona; Frallicciardi, Paola; Lanza, Richard C.; Lauria, Adele; Mettivier, Giovanni; Montesi, Maria Cristina; Russo, Paolo

    2007-02-01

    We report on the tests of a prototype (MediSPECT) system developed at University & INFN Napoli, for Single Photon Emission Computed Tomography (SPECT) imaging on small animals with a small Field of View (FoV) and high spatial resolution. MediSPECT is a SPECT imaging system based on a 1-mm-thick CdTe pixel detector, bump-bonded to the Medipix2 CMOS readout circuit operating in single-photon counting. The CdTe detector has 256×256 square array of pixels arranged with a 55 μm pitch, for a sensitive area of 14×14 mm 2. In its present version, this system implements a single detector head, mounted on a rotating gantry. For preliminary testing and calibration of the acquisition equipment and image reconstruction algorithms, 90 projections of a γ-ray point source ( 109Cd) through a single pinhole (diameter 0.4 mm; radius of rotation about 2.5 cm; focal length about 4.5 cm) were acquired for 20 min each in a step-and-shoot mode. Capillaries, 800 μm in diameter, were arranged in a Y-shape to form a more complex phantom ( 125I, 1 mm pinhole diameter, 45 projections, each acquired for 25 min). Images were reconstructed with a custom algorithm implementing standard OS-EM with center of rotation correction and spatial resolution of 0.2 mm over a FoV of 2 mm was obtained.

  9. Preliminary evaluation of the tomographic performance of the mediSPECT small animal imaging system

    International Nuclear Information System (INIS)

    We report on the tests of a prototype (MediSPECT) system developed at University and INFN Napoli, for Single Photon Emission Computed Tomography (SPECT) imaging on small animals with a small Field of View (FoV) and high spatial resolution. MediSPECT is a SPECT imaging system based on a 1-mm-thick CdTe pixel detector, bump-bonded to the Medipix2 CMOS readout circuit operating in single-photon counting. The CdTe detector has 256x256 square array of pixels arranged with a 55 μm pitch, for a sensitive area of 14x14 mm2. In its present version, this system implements a single detector head, mounted on a rotating gantry. For preliminary testing and calibration of the acquisition equipment and image reconstruction algorithms, 90 projections of a γ-ray point source (109Cd) through a single pinhole (diameter 0.4 mm; radius of rotation about 2.5 cm; focal length about 4.5 cm) were acquired for 20 min each in a step-and-shoot mode. Capillaries, 800 μm in diameter, were arranged in a Y-shape to form a more complex phantom (125I, 1 mm pinhole diameter, 45 projections, each acquired for 25 min). Images were reconstructed with a custom algorithm implementing standard OS-EM with center of rotation correction and spatial resolution of 0.2 mm over a FoV of 2 mm was obtained

  10. SPECT detector system design based on embedded system

    International Nuclear Information System (INIS)

    A single-photon emission computed tomography detector system based on embedded Linux designed. This system is composed of detector module, data acquisition module, ARM MPU module, network interface communication module and human machine interface module. Its software uses multithreading technology based on embedded Linux. It can achieve high speed data acquisition, real-time data correction and network data communication. It can accelerate the data acquisition and decrease the dead time. The accuracy and the stability of the system can be improved. (authors)

  11. Targeted multi-pinhole SPECT

    International Nuclear Information System (INIS)

    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.)

  12. A SPECT Camera for Combined MRI and SPECT for Small Animals

    OpenAIRE

    Meier, D.; Wagenaar, D J; Chen, S; Xu, J.; Yu, J.; Tsui, B. M. W.

    2011-01-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technolo...

  13. Proceedings of clinical SPECT [single photon emission computed tomography] symposium

    International Nuclear Information System (INIS)

    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

  14. 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...

  15. The Cardiac Conduction System: Generation and Conduction of the Cardiac Impulse.

    Science.gov (United States)

    Kennedy, Alan; Finlay, Dewar D; Guldenring, Daniel; Bond, Raymond; Moran, Kieran; McLaughlin, James

    2016-09-01

    In this article, the authors outline the key components behind the automated generation of the cardiac impulses and the effect these impulses have on cardiac myocytes. Also, a description of the key components of the normal cardiac conduction system is provided, including the sinoatrial node, the atrioventricular node, the His bundle, the bundle branches, and the Purkinje network. Finally, an outline of how each stage of the cardiac conduction system is represented on the electrocardiogram is described, allowing the reader of the electrocardiogram to translate background information about the normal cardiac conduction system to everyday clinical practice. PMID:27484656

  16. Specification of the Cardiac Conduction System by Transcription Factors

    OpenAIRE

    Hatcher, Cathy J.; Basson, Craig T.

    2009-01-01

    Diseases of the cardiovascular system that cause sudden cardiac deaths are often caused by lethal arrhythmias that originate from defects in the cardiac conduction system. Development of the cardiac conduction system is a complex biological process that can be wrought with problems. Although several genes involved in mature conduction system function have been identified, their association with development of specific subcomponents of the cardiac conduction system remains challenging. Several...

  17. Diagnosis of pancreatic cancer using 201Tl-chloride and a three-head rotating gamma camera SPECT system

    International Nuclear Information System (INIS)

    201Tl SPECT was performed on 17 patients with pancreatic cancer or chronic pancreatitis using a three-head rotating gamma camera SPECT system. In 7 of 10 patients with pancreatic cancer, the lesions were clearly delineated by 201Tl SPECT. Whereas the lesion of 30 mm in diameter was visualized, a large tumor of 80 mm in diameter could not be visualized. Namely, it was thought that 201Tl uptake by pancreatic cancer might be well correlated with tumor blood flow and/or its histological subtype rather than with tumor size. In 5 of 7 patients with chronic pancreatitis, no uptake by the pancreas was shown. The sensitivity, specificity, and accuracy in diagnosing pancreatic cancer by 201Tl SPECT were 70%, 71%, and 71%, respectively. The present results obtained by 201Tl SPECT were thought satisfactory enough to evaluate pancreatic cancer under the present conditions where there was no useful imaging agent for visualizing pancreatic cancer by SPECT. 201Tl SPECT is expected to be a new diagnostic tool for investigation of pancreatic tumorous lesion. (author)

  18. Design and performance evaluation of high-resolution small animal SPECT system

    International Nuclear Information System (INIS)

    A high-resolution and low-cost small animal single photon emission computed tomography (SPECT) system was designed based on a clinical scanner and a pinhole collimator. Optimal design schemes of a single-pinhole collimator and a seven-pinhole one were proposed, in terms of achieving the best trade-off of field of view size, spatial resolution and sensitivity. System performances of the two design schemes were compared by evaluating the average spatial resolution and sensitivity over the full field of view, and the seven-pinhole collimator design demonstrated improved resolution and better sensitivity. Monte Carlo simulation studies validate that ultra-high 0.5 mm spatial resolution can be achieved with the proposed seven-pinhole design, which is cost-effective comparing to the existing animal SPECT systems equipped with dedicated detector. (authors)

  19. Validation of variance reduction techniques in Mediso (SPIRIT DH-V) SPECT system by Monte Carlo

    International Nuclear Information System (INIS)

    Monte Carlo simulation of nuclear medical imaging systems is a widely used method for reproducing their operation in a real clinical environment, There are several Single Photon Emission Tomography (SPECT) systems in Cuba. For this reason it is clearly necessary to introduce a reliable and fast simulation platform in order to obtain consistent image data. This data will reproduce the original measurements conditions. In order to fulfill these requirements Monte Carlo platform GAMOS (Geant4 Medicine Oriented Architecture for Applications) have been used. Due to the very size and complex configuration of parallel hole collimators in real clinical SPECT systems, Monte Carlo simulation usually consumes excessively high time and computing resources. main goal of the present work is to optimize the efficiency of calculation by means of new GAMOS functionality. There were developed and validated two GAMOS variance reduction techniques to speed up calculations. These procedures focus and limit transport of gamma quanta inside the collimator. The obtained results were asses experimentally in Mediso (SPIRIT DH-V) SPECT system. Main quality control parameters, such as sensitivity and spatial resolution were determined. Differences of 4.6% sensitivity and 8.7% spatial resolution were reported against manufacturer values. Simulation time was decreased up to 650 times. Using these techniques it was possible to perform several studies in almost 8 hours each. (Author)

  20. A SPECT system simulator built on the SolidWorksTM 3D-Design package

    OpenAIRE

    LI, XIN; Furenlid, Lars R.

    2014-01-01

    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 SolidWorksTM-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 scint...

  1. Feasibility study of SPECT system for online dosimetry imaging in boron neutron capture therapy.

    Science.gov (United States)

    Hales, B; Katabuchi, T; Hayashizaki, N; Terada, K; Igashira, M; Kobayashi, T

    2014-06-01

    A single collimator version of a proposed PG-SPECT system was manufactured and experimentally tested. Combining this experimental data with Monte Carlo simulation, the viability of Ge and CdTe semiconductors detectors was calculated. It was determined that the best detector of the ones compared would be a CdTe detector of 2-3mm, aided by the benefit of adding a Compton-suppression anti-coincidence timing detector. PMID:24378365

  2. IBZM tool: a fully automated expert system for the evaluation of IBZM SPECT studies

    International Nuclear Information System (INIS)

    Visual reading of [123I]IBZM SPECT scans depends on the experience of the interpreter. Therefore, semi-quantification of striatal IBZM uptake is commonly considered mandatory. However, semi-quantification is time consuming and prone to error, particularly if the volumes of interest (VOIs) are positioned manually. Therefore, the present paper proposes a new software tool (''IBZM tool'') for fully automated and standardised processing, evaluation and documentation of [123I]IBZM SPECT scans. The IBZM tool is an easy-to-use SPM toolbox. It includes automated procedures for realignment and summation of multiple frames (motion correction), stereotactic normalisation, scaling, VOI analysis of striatum-to-reference ratio R, classification of R and standardised display. In order to evaluate the tool, which was developed at the University of Hamburg, the tool was transferred to the University of Hannover. There it was applied to 27 well-documented subjects: eight patients with multi-system atrophy (MSA), 12 patients with Parkinson's disease (PD) and seven controls. The IBZM tool was compared with manual VOI analysis. The sensitivity and specificity of the IBZM tool for the differentiation of the MSA subjects from the controls were 100% and 86%, respectively. The IBZM tool provided improved statistical power compared with manual VOI analysis. The IBZM tool is an expert system for the detection of reduced striatal D2 availability on [123I]IBZM SPECT scans. The standardised documentation supports visual and semi-quantitative evaluation, and it is useful for presenting the findings to the referring physician. The IBZM tool has the potential for widespread use, since it appears to be fairly independent of the performance characteristics of the particular SPECT system used. The tool is available free of charge. (orig.)

  3. IBZM tool: a fully automated expert system for the evaluation of IBZM SPECT studies

    Energy Technology Data Exchange (ETDEWEB)

    Buchert, Ralph; Wilke, Florian; Martin, Brigitte; Borczyskowski, Daniel von; Mester, Janos; Brenner, Winfried; Clausen, Malte [University Medical Center Hamburg-Eppendorf, Department of Nuclear Medicine, Hamburg (Germany); Berding, Georg [University School of Medicine Hannover, Department of Nuclear Medicine, Hannover (Germany)

    2006-09-15

    Visual reading of [{sup 123}I]IBZM SPECT scans depends on the experience of the interpreter. Therefore, semi-quantification of striatal IBZM uptake is commonly considered mandatory. However, semi-quantification is time consuming and prone to error, particularly if the volumes of interest (VOIs) are positioned manually. Therefore, the present paper proposes a new software tool (''IBZM tool'') for fully automated and standardised processing, evaluation and documentation of [{sup 123}I]IBZM SPECT scans. The IBZM tool is an easy-to-use SPM toolbox. It includes automated procedures for realignment and summation of multiple frames (motion correction), stereotactic normalisation, scaling, VOI analysis of striatum-to-reference ratio R, classification of R and standardised display. In order to evaluate the tool, which was developed at the University of Hamburg, the tool was transferred to the University of Hannover. There it was applied to 27 well-documented subjects: eight patients with multi-system atrophy (MSA), 12 patients with Parkinson's disease (PD) and seven controls. The IBZM tool was compared with manual VOI analysis. The sensitivity and specificity of the IBZM tool for the differentiation of the MSA subjects from the controls were 100% and 86%, respectively. The IBZM tool provided improved statistical power compared with manual VOI analysis. The IBZM tool is an expert system for the detection of reduced striatal D{sub 2} availability on [{sup 123}I]IBZM SPECT scans. The standardised documentation supports visual and semi-quantitative evaluation, and it is useful for presenting the findings to the referring physician. The IBZM tool has the potential for widespread use, since it appears to be fairly independent of the performance characteristics of the particular SPECT system used. The tool is available free of charge. (orig.)

  4. 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).

  5. Quantification of left ventricular volumes and ejection fraction from gated {sup 99m}Tc-MIBI SPECT: validation of an elastic surface model approach in comparison to cardiac magnetic resonance imaging, 4D-MSPECT and QGS

    Energy Technology Data Exchange (ETDEWEB)

    Stegger, Lars; Kies, Peter; Schober, Otmar; Schaefers, Michael [University Hospital, Westfaelische Wilhelms-University Muenster, Department of Nuclear Medicine, Muenster (Germany); Lipke, Claudia S.A.; Nowak, Bernd; Buell, Udalrich; Schaefer, Wolfgang M. [University Hospital,Aachen University of Technology, Department of Nuclear Medicine, Aachen (Germany)

    2007-06-15

    The segmentation algorithm ESM based on an elastic surface model was validated for the assessment of left ventricular volumes and ejection fraction from ECG-gated myocardial perfusion SPECT. Additionally, it was compared with the commercially available quantification packages 4D-MSPECT and QGS. Cardiac MRI was used as the reference method. SPECT and MRI were performed on 70 consecutive patients with suspected or proven coronary artery disease. End-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were derived from SPECT studies by using the segmentation algorithms ESM, 4D-MSPECT and QGS and from cardiac MRI. ESM-derived values for EDV and ESV correlated well with those from cardiac MRI (correlation coefficients R = 0.90 and R = 0.95, respectively), as did the measurements for LVEF (R = 0.86). Both EDV and ESV were slightly overestimated for larger ventricles but not for smaller ventricles; LVEF was slightly overestimated irrespective of ventricle size. The above correlation coefficients are comparable to those for the 4D-MSPECT and QGS segmentation algorithms. However, results obtained with the three segmentation algorithms are not interchangeable. The ESM algorithm can be used to assess EDV, ESV and LVEF from gated perfusion SPECT images. Overall, the performance was similar to that of 4D-MSPECT and QGS when compared with cardiac MRI. Results obtained with the three tested segmentation methods are not interchangeable, so that the same algorithm should be used for follow-up studies and control subjects. (orig.)

  6. Quantification of left ventricular volumes and ejection fraction from gated 99mTc-MIBI SPECT: validation of an elastic surface model approach in comparison to cardiac magnetic resonance imaging, 4D-MSPECT and QGS

    International Nuclear Information System (INIS)

    The segmentation algorithm ESM based on an elastic surface model was validated for the assessment of left ventricular volumes and ejection fraction from ECG-gated myocardial perfusion SPECT. Additionally, it was compared with the commercially available quantification packages 4D-MSPECT and QGS. Cardiac MRI was used as the reference method. SPECT and MRI were performed on 70 consecutive patients with suspected or proven coronary artery disease. End-diastolic (EDV) and end-systolic (ESV) volumes and left ventricular ejection fraction (LVEF) were derived from SPECT studies by using the segmentation algorithms ESM, 4D-MSPECT and QGS and from cardiac MRI. ESM-derived values for EDV and ESV correlated well with those from cardiac MRI (correlation coefficients R = 0.90 and R = 0.95, respectively), as did the measurements for LVEF (R = 0.86). Both EDV and ESV were slightly overestimated for larger ventricles but not for smaller ventricles; LVEF was slightly overestimated irrespective of ventricle size. The above correlation coefficients are comparable to those for the 4D-MSPECT and QGS segmentation algorithms. However, results obtained with the three segmentation algorithms are not interchangeable. The ESM algorithm can be used to assess EDV, ESV and LVEF from gated perfusion SPECT images. Overall, the performance was similar to that of 4D-MSPECT and QGS when compared with cardiac MRI. Results obtained with the three tested segmentation methods are not interchangeable, so that the same algorithm should be used for follow-up studies and control subjects. (orig.)

  7. Design and imaging studies of a position sensitive photomultiplier based dynamic SPECT system

    International Nuclear Information System (INIS)

    The design and image reconstruction aspects of a new generation of dynamic SPECT instrumentation utilizing multiple rings of position sensitive photomultiplier tubes (PSPMTs) are reported. A diverging cone-beam collimator is attached to each PSPMT to achieve a 22 cm diameter spherical field of view in a system designed for head imaging. The resolution with the diverging collimator is estimated to be approximately 20% worse than a parallel hole collimator. Iterative and direct cone-beam reconstruction algorithms have been investigated under different conditions of angular sampling and counting statistics. The ramifications of temporal resolution and signal to noise ratio are discussed in relation to dynamic SPECT imaging of labeled cisplatin for chemotherapy

  8. 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.

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

    International Nuclear Information System (INIS)

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

    Science.gov (United States)

    Wei, Qingyang; Wang, Shi; Ma, Tianyu; Wu, Jing; Liu, Hui; Xu, Tianpeng; Xia, Yan; Fan, Peng; Lyu, Zhenlei; Liu, Yaqiang

    2015-06-01

    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.

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

    International Nuclear Information System (INIS)

    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. Evaluation of both perfusion and atrophy in multiple system atrophy of the cerebellar type using brain SPECT alone

    International Nuclear Information System (INIS)

    Partial volume effects in atrophied areas should be taken into account when interpreting brain perfusion single photon emission computed tomography (SPECT) images of neurodegenerative diseases. To evaluate both perfusion and atrophy using brain SPECT alone, we developed a new technique applying tensor-based morphometry (TBM) to SPECT. After linear spatial normalization of brain perfusion SPECT using 99mTc-ethyl cysteinate dimer (99mTc-ECD) to a Talairach space, high-dimension-warping was done using an original 99mTc-ECD template. Contraction map images calculated from Jacobian determinants and spatially normalized SPECT images using this high-dimension-warping were compared using statistical parametric mapping (SPM2) between two groups of 16 multiple system atrophy of the cerebellar type (MSA-C) patients and 73 age-matched normal controls. This comparison was also performed in conventionally warped SPECT images. SPM2 demonstrated statistically significant contraction indicating local atrophy and decreased perfusion in the whole cerebellum and pons of MSA-C patients as compared to normal controls. Higher significance for decreased perfusion in these areas was obtained in high-dimension-warping than in conventional warping, possibly due to sufficient spatial normalization to a 99mTc-ECD template in high-dimensional warping of severely atrophied cerebellum and pons. In the present high-dimension-warping, modification of tracer activity remained within 3% of the original tracer distribution. The present new technique applying TBM to brain SPECT provides information on both perfusion and atrophy at the same time thereby enhancing the role of brain perfusion SPECT

  14. 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

    International Nuclear Information System (INIS)

    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 m2] undergoing stress 99mTc-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.)

  15. 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.)

  16. Reliability systems for implantable cardiac defibrillator batteries

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, E.S. [Wilson Greatbatch Ltd., Clarence, NY (United States)

    1995-03-01

    The reliability of the power sources used in implantable cardiac defibrillators is critical due to the life-saving nature of the device. Achieving a high reliability power source depends on several systems functioning together. Appropriate cell design is the first step in assuring a reliable product. Qualification of critical components and of the cells using those components is done prior to their designation as implantable grade. Product consistency is assured by control of manufacturing practices and verified by sampling plans using both accelerated and real-time testing. Results to date show that lithium/silver vanadium oxide cells used for implantable cardiac defibrillators have a calculated maximum random failure rate of 0.005% per test month. (orig.)

  17. Reliability systems for implantable cardiac defibrillator batteries

    Science.gov (United States)

    Takeuchi, Esther S.

    The reliability of the power sources used in implantable cardiac defibrillators is critical due to the life-saving nature of the device. Achieving a high reliability power source depends on several systems functioning together. Appropriate cell design is the first step in assuring a reliable product. Qualification of critical components and of the cells using those components is done prior to their designation as implantable grade. Product consistency is assured by control of manufacturing practices and verified by sampling plans using both accelerated and real-time testing. Results to date show that lithium/silver vanadium oxide cells used for implantable cardiac defibrillators have a calculated maximum random failure rate of 0.005% per test month.

  18. 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

    International Nuclear Information System (INIS)

    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. (paper)

  19. 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.

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

    International Nuclear Information System (INIS)

    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.

  1. Noninvasive ambulatory measurement system of cardiac activity.

    Science.gov (United States)

    Pino, Esteban J; Chavez, Javier A P; Aqueveque, Pablo

    2015-08-01

    This work implements a noninvasive system that measures the movements caused by cardiac activity. It uses unobtrusive Electro-Mechanical Films (EMFi) on the seat and on the backrest of a regular chair. The system detects ballistocardiogram (BCG) and respiration movements. Real data was obtained from 54 volunteers. 19 of them were measured in the laboratory and 35 in a hospital waiting room. Using a BIOPAC acquisition system, the ECG was measured simultaneously to the BCG for comparison. Wavelet Transform (WT) is a better option than Empirical Mode Decomposition (EMD) for signal extraction and produces higher effective measurement time. In the laboratory, the best results are obtained on the seat. The correlation index was 0.9800 and the Bland-Altman limits of agreement were 0.7136 ± 4.3673 [BPM]. In the hospital waiting room, the best results are also from the seat sensor. The correlation index was 0.9840, and the limits of agreement were 0.4386 ± 3.5884 [BPM]. The system is able to measure BCG in an unobtrusive way and determine the cardiac frequency with high precision. It is simple to use, which means the system can easily be used in non-standard settings: resting in a chair or couch, at the gym, schools or in a hospital waiting room, as shown. PMID:26738057

  2. Quantitative uptake measurements of I-131 (364 keV) within the tomographic plane of a specially collimated SPECT system

    International Nuclear Information System (INIS)

    The use of SPECT for uptake measurements requires a linear relationship between the measured counts within a tomographic plane and its activity distribution. Many factors influence this relationship, and these include filter type and attenuation correction methods. However, for higher photon energy (I-131, 364 keV), photon penetration through the collimator or detector shielding may degrade, for example, the tomographic plane and slice thickness resolution and the ability to differentiate activity within a slice and between slices. A SPECT system (Picker International Dyna Camera), equipped with a specialized (low sensitivity) thick septa collimator for I-131 (364 keV) and 511 keV detector shielding is proposed for quantitative measurements. The influence of photon penetration was significantly reduced, with transverse plane and slice thickness resolution of 18 mm FWHM and 37 mm FWIM for a radius of rotation of 14 cm. Iodine collimators typically have FWTM 5-10 times the FWHM. A Jaszczak phantom was imaged with I-131, with two bar quadrants observed with diameters of 16 and 12.7 mm. The SPECT resolution data was equal to a low energy general purpose collimator. A multi-concentric ring (contrast) phantom was designed to quantitatively evaluate the SPECT system. A linear relationship was observed between the measured counts for a transverse plane and I-131 activity within the rings. Data suggest that with appropriate collimation and detector shielding SPECT systems may be used for quantitative measurements at higher photon energy

  3. Gene Regulatory Networks in Cardiac Conduction System Development

    OpenAIRE

    Munshi, Nikhil V.

    2012-01-01

    The cardiac conduction system is a specialized tract of myocardial cells responsible for maintaining normal cardiac rhythm. Given its critical role in coordinating cardiac performance, a detailed analysis of the molecular mechanisms underlying conduction system formation should inform our understanding of arrhythmia pathophysiology and affect the development of novel therapeutic strategies. Historically, the ability to distinguish cells of the conduction system from neighboring working myocyt...

  4. 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.

  5. Block-iterative techniques for fast 4D reconstruction using a priori motion models in gated cardiac SPECT

    International Nuclear Information System (INIS)

    We introduce a fast block-iterative maximum a posteriori (MAP) reconstruction algorithm and apply it to four-dimensional reconstruction of gated SPECT perfusion studies. The new algorithm, called RBI-MAP, is based on the rescaled block iterative EM (RBI-EM) algorithm. We develop RBI-MAP based on similarities between the RBI-EM, ML-EM and MAP-EM algorithms. RBI-MAP requires far fewer iterations than MAP-EM, and so should result in acceleration similar to that obtained from using RBI-EM or OS-EM as opposed to ML-EM. When complex four-dimensional clique structures are used in the prior, however, evaluation of the smoothing prior dominates the processing time. We show that a simple scheme for updating the prior term in the heart region only for RBI-MAP results in savings in processing time of a factor of six over MAP-EM. The RBI-MAP algorithm incorporating 3D collimator-detector response compensation is demonstrated on a simulated 99mTc gated perfusion study. Results of RBI-MAP are compared with RBI-EM followed by a 4D linear filter. For the simulated study, we find that RBI-MAP provides consistently higher defect contrast for a given degree of noise smoothing than does filtered RBI-EM. This is an indication that RBI-MAP smoothing does less to degrade resolution gained from 3D detector response compensation than does a linear filter. We conclude that RBI-MAP can provide smooth four-dimensional reconstructions with good visualization of heart structures in clinically realistic processing times. (author)

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

    International Nuclear Information System (INIS)

    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 99mTc-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 correlation between both 8-frame

  7. 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

  8. 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.

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

    International Nuclear Information System (INIS)

    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.

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

    Science.gov (United States)

    Ryu, Hyun-Ju; Lee, Young-Jin; Lee, Seung-Wan; Cho, Hyo-Min; Choi, Yu-Na; Kim, Hee-Joung

    2012-07-01

    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 radiopharmaceuticals 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.

  11. A SPECT camera for combined MRI and SPECT for small animals

    Science.gov (United States)

    Meier, D.; Wagenaar, D. J.; Chen, S.; Xu, J.; Yu, J.; Tsui, B. M. W.

    2011-10-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a Ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI.

  12. A SPECT camera for combined MRI and SPECT for small animals

    Energy Technology Data Exchange (ETDEWEB)

    Meier, D., E-mail: dirk.meier@gm-ideas.com [Gamma Medica - Ideas (Norway) AS, Martin Linges Vei 25, Snaroya, POB 1, N-1330 Fornebu (Norway); Wagenaar, D.J. [Gamma Medica - Ideas, Inc.,19355 Business Center Dr., Ste 8, 91324 Northridge (United States); Chen, S.; Xu, J.; Yu, J.; Tsui, B.M.W. [Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD (United States)

    2011-10-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a O25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI.

  13. A SPECT camera for combined MRI and SPECT for small animals

    International Nuclear Information System (INIS)

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a O25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI.

  14. Development Of Software For Automation And Data Acquisition System For Gamma Spider And SPECT

    International Nuclear Information System (INIS)

    The portable system of gamma-ray computed tomography known as Gamma Spider and Single-Photon Emission Computed Tomography (SPECT) are designed for the detection and measurement of the physical condition of small object that can fit within the diameter of 50 cm. The project consists of two major components; the scanner hardware and the system software. This paper describes the system software components which are linear and rotate motor control, data acquisition for rate meter and data recording. The scanning resolution for linear movement can be set to 0.25 cm, 0.5 cm or 1.0 cm whereas the rotation movement can be set to 5 or 10 degree depending on user requirement. The selections for scanning offset are set to three diameters which are 30 cm, 40 cm and 50 cm. The algorithm for this automation system and issues on development are also discussed in this paper. (author)

  15. Adaptation of the modified Bouc–Wen model to compensate for hysteresis in respiratory motion for the list-mode binning of cardiac SPECT and PET acquisitions: Testing using MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dasari, Paul K. R.; Shazeeb, Mohammed Salman [Department of Radiology, Division of Nuclear Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01655 and Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609 (United States); Könik, Arda; Lindsay, Clifford; Mukherjee, Joyeeta M.; Johnson, Karen L.; King, Michael A., E-mail: Michael.King@umassmed.edu [Department of Radiology, Division of Nuclear Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States)

    2014-11-01

    Purpose: Binning list-mode acquisitions as a function of a surrogate signal related to respiration has been employed to reduce the impact of respiratory motion on image quality in cardiac emission tomography (SPECT and PET). Inherent in amplitude binning is the assumption that there is a monotonic relationship between the amplitude of the surrogate signal and respiratory motion of the heart. This assumption is not valid in the presence of hysteresis when heart motion exhibits a different relationship with the surrogate during inspiration and expiration. The purpose of this study was to investigate the novel approach of using the Bouc–Wen (BW) model to provide a signal accounting for hysteresis when binning list-mode data with the goal of thereby improving motion correction. The study is based on the authors’ previous observations that hysteresis between chest and abdomen markers was indicative of hysteresis between abdomen markers and the internal motion of the heart. Methods: In 19 healthy volunteers, they determined the internal motion of the heart and diaphragm in the superior–inferior direction during free breathing using MRI navigators. A visual tracking system (VTS) synchronized with MRI acquisition tracked the anterior–posterior motions of external markers placed on the chest and abdomen. These data were employed to develop and test the Bouc–Wen model by inputting the VTS derived chest and abdomen motions into it and using the resulting output signals as surrogates for cardiac motion. The data of the volunteers were divided into training and testing sets. The training set was used to obtain initial values for the model parameters for all of the volunteers in the set, and for set members based on whether they were or were not classified as exhibiting hysteresis using a metric derived from the markers. These initial parameters were then employed with the testing set to estimate output signals. Pearson’s linear correlation coefficient between the

  16. Adaptation of the modified Bouc–Wen model to compensate for hysteresis in respiratory motion for the list-mode binning of cardiac SPECT and PET acquisitions: Testing using MRI

    International Nuclear Information System (INIS)

    Purpose: Binning list-mode acquisitions as a function of a surrogate signal related to respiration has been employed to reduce the impact of respiratory motion on image quality in cardiac emission tomography (SPECT and PET). Inherent in amplitude binning is the assumption that there is a monotonic relationship between the amplitude of the surrogate signal and respiratory motion of the heart. This assumption is not valid in the presence of hysteresis when heart motion exhibits a different relationship with the surrogate during inspiration and expiration. The purpose of this study was to investigate the novel approach of using the Bouc–Wen (BW) model to provide a signal accounting for hysteresis when binning list-mode data with the goal of thereby improving motion correction. The study is based on the authors’ previous observations that hysteresis between chest and abdomen markers was indicative of hysteresis between abdomen markers and the internal motion of the heart. Methods: In 19 healthy volunteers, they determined the internal motion of the heart and diaphragm in the superior–inferior direction during free breathing using MRI navigators. A visual tracking system (VTS) synchronized with MRI acquisition tracked the anterior–posterior motions of external markers placed on the chest and abdomen. These data were employed to develop and test the Bouc–Wen model by inputting the VTS derived chest and abdomen motions into it and using the resulting output signals as surrogates for cardiac motion. The data of the volunteers were divided into training and testing sets. The training set was used to obtain initial values for the model parameters for all of the volunteers in the set, and for set members based on whether they were or were not classified as exhibiting hysteresis using a metric derived from the markers. These initial parameters were then employed with the testing set to estimate output signals. Pearson’s linear correlation coefficient between the

  17. A survey of head movement during clinical brain SPECT using an optical tracking system

    International Nuclear Information System (INIS)

    Full text: The aim of this study was to survey patient motion during clinical brain SPECT using a commercial motion detection system called Polaris. Polaris is an optical tracker that remotely tracks head position and orientation via a small target attached to the patient. Its accuracy for position measurement is 1mm or 1 degree (deg), 33% moved > 2mm or 2deg and 10% moved > 4mm or 4deg. 65% of subjects moved 3 or more times. Motion in the D and P groups was equally likely to be small (<3mm or <3deg) or large and equally likely to occur early or late during acquisition. Motion in the N, F and C groups was less likely to be large and for N and F more likely to occur late in the acquisition suggesting fatigue was the main cause. The most common large movements were anterior-posterior translations and axial (Z) rotations. Significant head movement is common in brain SPECT, particularly in dementia and psychiatric subjects, and accurate motion correction is desirable to maintain image quality. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  18. IBZM- and CIT-SPECT of the dopaminergic system in Parkinsonism

    International Nuclear Information System (INIS)

    Parkinsonism is most of the time caused by idiopathic Parkinson's disease (IPD). Considering the differences in therapeutic response and prognosis. in viva discrimination between IPD and 'Parkinsonism-plus' syndromes is important. Recently, ligands have become available for imaging the pre- and postsynaptic dopaminergic system by Single Photon Emission Computed Tomography (SPECT). Visualization of postsynaptic D2 dopamine receptors using 123I-iodobenzamide (123I-IBZM) may contribute to the differential diagnosis between IPD and 'Parkinsonism-plus' syndromes as IPD is a pure presynaptic disease. Imaging of the presynaptic dopamine transporters using [123I]β-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) may be used as a diagnostic technique. Early disease detection in subjects suspected to be at risk for developing IPD has become possible using [123I]β-CIT or other ligands for the dopamine transporter. Furthermore, with SPECT one is probably able to monitor in an objective way the efficacy of new pharmacological therapies. (author)

  19. 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

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

    International Nuclear Information System (INIS)

    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-[123I]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 dementia

  1. Design of a SPECT tomographic image system for online dosimetry in BNCT

    International Nuclear Information System (INIS)

    We present here a numerical analysis of a projected tomographic image system for online dose measurements in Boron Neutron Capture Therapy. In 94% of neutron capture reactions in boron, the 7Li ion is emitted in an excited state which decays through a characteristic 478 keV prompt gamma ray. In BNCT a large fraction of this radiation escapes from the patient body. Its detection is thus attractive for a noninvasive boron dose measurement and an online absorbed dose evaluation. For this purpose we have proposed a dedicated SPECT (Single Photon Emission Computed Tomography) imaging system. The proposed system can obtain images of 21x21cm2 divided in 1x1cm2 pixels by measuring 20 projections with 41 bins each, with 8% uncertainties in reconstructed dose. (author)

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

    International Nuclear Information System (INIS)

    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 β-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

  3. 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)

  4. Optimization technique for a prompt gamma-ray SPECT collimator system

    International Nuclear Information System (INIS)

    Because background radiation in an irradiation room creates a problem with the PG-SPECT (Prompt Gamma-ray Single Photon Emission Computed Tomography) system, which evaluates the absorbed dose for the Boron Neutron Capture Therapy treatment, optimization of a collimator system was performed while taking the shielding of background gamma-rays into consideration. Assuming that a parallel-beam collimator is used, three parameters - the diameter of a hole, the length of the collimator, and the number of detectors (the number of holes of the collimator) - were selected for optimization. Because the combinations of these parameters are limitless, it is difficult to determine them simultaneously. Therefore, a statistically derived Optimization Criterion has been proposed to optimize these parameters. When the spatial resolution was 1 cm-FWHM (full width at half maximum), the optimal diameter of the collimator was 5.4 mm, the optimal length was 321 mm, and the optimal number of detectors was 31 x 31. (author)

  5. Evaluating the normal individual cardiac function in different imaging phases post exercise and rest by gated SPECT myocardial perfusion

    International Nuclear Information System (INIS)

    Full text: Objectives: To evaluate the normal individual cardiac function in the different imaging phases post-exercise and rest by GSPECT. Methods: 46 normal individuals underwent exercise/rest GSPECT using 99mTc-MIBI by 2- day program. Sequential imaging was started 15, 35 and 120 minutes after exercise and rest imaging was performed the following day. The left ventricular EF and EDV, ESV values were calculated with the Cedars-Sinai program. Results: The EF values of post- exercise at 15, 35, and 120m was 64.48±7.43%, 65.02±7.66%, and 60.98±7.28% respectively, and the rest EF value was 61.46±7.23%. The post exercise EF at 15m and 35m was higher than EF at post- exercise 120m and rest, but there is a significant difference only between post exercise 35m and rest (P< 0.05), and all post exercise EF did not increase at least 5% from EF at-rest. The EDV and ESV values did not have statistically significant differences at 15, 35,120m post-exercise and rest. The heart rate at 15,35m post- exercise was higher significantly than at rest. Conclusions: The different imaging phases after exercise with 99mTc-MIBI GSPECT affects LVEF in normal individuals, the 35m post- exercise EF is highest. (author)

  6. Clinical investigation of elderly patients with central nervous system diseases using SPECT and 99Tcm-HMPAO

    International Nuclear Information System (INIS)

    99Tcm-HMPAO (hexamethylpropylene amine oxime) single photon emission computed tomography (SPECT) images were acquired for 177 elderly patients with central nervous system diseases. Among them were 132 cases of cerebrovascular disease, 33 cases of Parkinson's disease and 12 cases of dementia. A comparative study with computed tomography (CT)/magnetic resonance imaging (MRI) was performed. The detectable rate of cerebral infarction was 96.1% and the hypoperfusion area in SPECT coincided with the respective abnormal area in MRI or CT, but with a greater size. This was probably due to the inclusion of both infarction and 'ischaemic penumbra' (IP). Six cases of infarction of the basal ganglia accompanies by cerebral cortical hypoperfusion may be neurological functional communication disturbances (similar to diathesis). In 61.9% of transient ischaemic attacks, the hypoperfusion area can be detected. In 66.7% of the cases of Parkinson's disease, there was cortical hypoperfusion and 18.2% showed asymmetrical low perfusion in the basal ganglia. This finding was not related to the Hoehn-Yahr stage and the laterality of motor symptoms. In the dementia group, six cases of Alzheimer's disease showed unilateral or diffusing cortical hypoperfusion, but in six cases of multiple infarction dementia, SPECT showed multiple, irregular cortical hypoperfusion, mostly involved with basal ganglia or cerebellum hypoperfusion, which can be differentiated from Alzheimer's disease. In conclusion, SPECT provided an objective diagnostic tool for elderly patients with central nervous system disease. (author). 6 refs

  7. Risk stratification systems in cardiac surgery

    Directory of Open Access Journals (Sweden)

    G. Tinică

    2012-08-01

    Full Text Available n medicine, as in any other field, quality is a prerequisite of competitiveness. In this paper we do a brief description and definition of commonly used preoperative risk scores for heart surgery with regard to their predictive values and clinical applicability for current population. Although most of the selected score systems were primarily designed to predict mortality, postoperative morbidity has been acknowledged as the major determinant of hospital cost and quality of life after surgery. Any method of evaluation and optimization of quality is based on a risk stratification system. Risk system development and their application in current medical practice have become increasingly popular in the recent years because of the many therapeutic options available for some cardiovascular diseases, which until now were considered difficult to address, due to technical advances that are enabling risk taking. Risk stratification is a powerful decision-making tool and should represent an incumbent part of the cardiac surgical practice, just like the knowledge of anatomy and the practice of surgical techniques. These models also play an increasingly important role in risk management and performance measurement processes like quality analysis, meaningful comparison of outcomes, and identifying the optimal relationship between cost, quality of medical care and efficiency.

  8. 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. PMID:21828904

  9. SPECT detectors: the Anger Camera and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Todd E [Institute of Imaging Science, Department of Radiology and Radiological Sciences, Department of Physics, and Program in Chemical and Physical Biology, Vanderbilt University, Nashville, TN (United States); Furenlid, Lars R, E-mail: todd.e.peterson@vanderbilt.edu [Center for Gamma-Ray Imaging, Department of Radiology, and College of Optical Sciences, University of Arizona, Tucson, AZ (United States)

    2011-09-07

    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. (topical review)

  10. Comparison of gated SPECT, echocardiography and cardiac magnetic resonance imaging for the assessment of left ventricular ejection fraction and volumes

    International Nuclear Information System (INIS)

    Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) can be determined non-invasively by two-dimensional echocardiography (ECHO), gated single photon emission computed tomography (GSPECT) and cardiac magnetic resonance imaging (CMRI). This study was designed to analyze the concordance between LVEF, EDV and ESV values derived from ECHO, GSPECT and CMRI. ECHO, GSPECT and CMRI were performed in a group of 21 patients with suspected coronary artery disease. LVEF, EDV and ESV values were calculated. The mean LVEF measured with GSPECT, ECHO and CMRI were 5.9+-17.8%, 55.7+-16.4% and 56.4+-15.7% respectively. The mean EDV measured with GSPECT, ECHO and CMRI were 109.2+-42.4 mL, 127.5+-42.2 mL and 91.1+-38.0 mL, respectively. The mean ESV measured with GSPECT, ECHO and CMRI were 54.2+-41.2 mL, 59.9+-37.6 mL, respectively. The results of liner regression analysis showed very good correlation between LVEF and ESV values derived from GSPECT, ECHO and CMRI (r=0.91, r=0.92, r=0.97 for LVEF and r=0.86, r=0.91, r=0.91 for ESV, P<0.091). Good correlation were found between EDV values obtained from GSPECT, ECHO and CMRI (r=0.71, r=0.68, r=0.73, P<0.01). Agreement between these techniques in LVEF values was also good, but not in LV volumes, according to Bland-Altman plots. This study showed good overall correlations between LVEF, EDV and ESV values derived from GSPECT, ECHO and LVEF obtained from any of these three imaging modalities could be used interchangeably. However, care should be taken in comparing LV volumes. (author)

  11. The value of right lateral decubitus position to decrease artificial defect of cardiac anterior wall in 99Tcm-MIBI SPECT myocardial perfusion imaging for women

    International Nuclear Information System (INIS)

    Objective: To explore the value of right lateral decubitus position MPI for differentiating myocardial perfusion defect from cardiac anterior wall attenuation artificial defect, caused by breast of woman. Methods: Forty-nine patients(average age (61.5±8.4) years) who had low likelihood of coronary artery disease and had perfusion defect in the anterior wall after exercise stress 99Tcm-MIBI MPI were included. All underwent supine and right lateral decubitus position during resting SPECT images. The myocardial perfusion SPECT images at left ventricle were reconstructed and were measured by Bull's-eye, based on the counts. Results from both supine position imaging and right lateral decubitus position imaging were compared. Paired t test was used to statistically analyse the data by SPSS 13.0. Results: Compared with supine position, the counts of the anterior, inferior, apex and lateral wall in right lateral decubitus position were significantly higher: (71.30±3.53)% vs (66.50±3.85)%, (70.06±4.45)% vs (65.44±4.16)%, (77.90±3.00)% vs (75.81±4.08)%,(79.30±2.26)% vs (72.60±3.87)% (t=6.731, 5.286, 3.555, 10.885, all P<0.01). The counts of septal wall were significantly lower ((66.60±3.98)% vs (70.06±4.51)%, t=-4.625, P<0.01) in right lateral decubitus position than that in supine position. Among the different regions of anterior wall, the counts of the anterior-middle ((76.40 ± 3.80)% vs (68.60 ± 4.76)%) and anterior-apex region ((77.10±3.24)% vs (69.00±3.54)%) were significantly higher (t=9.916, 8.870, both P<0.01) in right lateral decubitus position than those in supine position, but there was insignificance ((56.94±6.06)% vs (58.50±4.98)%, t=-1.493, P>0.05) at anterior-basal region. The artificial defect of different degrees in anterior wall was observed in all patients in supine position, 23 cases (46.9%, 23/49) showed artificial defect in the anterior-middle region and 16 cases (32.7%, 16/49) in the anterior-apex region. All artificial defect

  12. Study of clinical application of 18F-FDG spect with coincidence in the recurrent or metastatic tumor of digestive system

    International Nuclear Information System (INIS)

    Purpose: To investigate the clinical value of 18F-FDG SPECT with coincidence in the diagnosis of recurrent or metastatic tumor of digestive system. Methods: 35 cases of postoperative patients with tumor of digestive system were enrolled in this study with 18F-FDG SPECT with coincidence. The results were analyzed by calculating its accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and 95% confidence interval and compared with UB, CT and MRI. Results: In 35 cases of postoperative patients with tumor of digestive system, the accuracy, sensitivity, specificity, PPV and NPV were 91.4%, 88.9%, 100%, 100%, 72.7%, respectively, and their 95% confidence interval were 77% - 98%, 71% - 98%, 63% - 100%, 86% - 100%, 39% - 94%, respectively. The diagnostic accuracy and sensitivity of 18F-FDG SPECT with coincidence were significantly higher than that of UB, while there were no significant difference between the result of other 18F-FDG SPECT with coincidence and CT and MRI. The analysis of 95% confidence interval showed a higher tendency in 18F-FDG SPECT with coincidence than in UB, CT and MRI. There is complementation among 18F-FDG SPECT with coincidence combined with UB, CT and MRI in some cases. Conclusions: 18F-FDG SPECT/PET has high clinical value in the diagnosis of recurrent or metastatic tumor of digestive system. (authors)

  13. Inter-comparative study to evaluate the current state of gamma cameras and SPECT systems in Cuba

    International Nuclear Information System (INIS)

    The aim of this study was to perform an inter-comparative study to evaluate the current state of the gamma cameras and SPECT systems in Cuba. In situ measurements were carried out in all the nuclear medicine departments participating in the study. This work was performed as part of a global project to establish a national programme for quality control of nuclear medicine instruments. The Cuban regulatory authorities (CCEEM) participated and supported this job. Firstly, a survey was carried out in order to collect data about the features of the instruments and availability of accessories for the quality control procedures. The selected tests and procedures were based on international standards for quality control of nuclear medicine instruments. Evaluations of uniformity, spatial resolution, sensitivity, energy resolution, linearity, tomographic uniformity, center of rotation, tomographic resolution and total performance for SPECT systems were carried out in the five gamma cameras and five SPECT system available in the country. Nuclear medicine services and equipments were codified in order to maintain anonymity. Table 1 summarizes the parameters measured in all the equipment. In general, the outcome of the quality control measurements showed that most of the evaluated equipment was working in an appropriate and acceptable technical state. As a rule, the instruments with longer period of use showed higher irregularities in the evaluated parameters. Some detected problems were solved by means of corrective procedures during the measurement period; otherwise, suggestions were provided to the engineering services in order to fix them. Outcomes were recorded in a technical report and a formal information was provided to hospital authorities and the national regulatory authorities. In spite of the results showing that majority of the equipment had acceptable non-uniformity values (integral and differential) below 5% for UFOV and CFOV, two gamma cameras (PH-3) and (SH-2

  14. SPECT and PET in paediatrics

    International Nuclear Information System (INIS)

    SPECT and PET are useful tools in paediatrics as well as in adults, improving the sensitivity and the diagnostic accuracy. Both techniques have a special interest for the the correlative image, improving the clinical usefulness of both metabolic (SPECT and PET) and anatomic images (MRI, CT, US). SPECT tomographic images are useful in most of the paediatric fields, but specially in oncology, neurology, orthopaedia and cardiology. In paediatric oncology, SPECT images obtained after the injection of metabolic tracers as MIBG, sodium iodine or octreotide allows us to detect residual tumour (neuroblastoma, thyroid tumour or carcinoid). SPECT increases the sensitivity to detect small lesions, lesions closed to bigger tumours, deep lesions or lung metastasis of osteosarcoma. Radioguided surgery is an emerging field in Nuclear Medicine. In Paediatrics, SPECT and SPECT-CT (or SPECT-MR) are useful to assist the surgeon to localize residual tumoral mass (neuroblastoma, thyroid cancer lymph nodes) as well as radioguides biopsy (lymphoma). The usefulness of brain SPECT in paediatric neurology is well known. Brain SPECT images are routinely used to localize epileptic foci, but also for a better understanding of most of the neuropsychologic paediatric diseases (brain death, trauma, vascular diseases, encephalitis, brain maturation, language disorders, obsessive-compulsive disorder, attention deficit disorderhyperactivity, etc.). In benign bone diseases, like Perthes disease, osteoid osteoma, bone infection or bone fractures, SPECT images improve the sensitivity and accuracy of bone scan and white blood cell scintigraphy. The tomographic frames, alone or fused with CT or MRI, provide important clinical information referred to the lesion extension or localization (v.g. radioguided surgery for an optimal removal of the nidus in osteoid osteoma). In nephrourology, the benefit of SPECT images compared to DMSA cortical renal scintigraphy is not well accepted by most of the authors

  15. Single photon emission computed tomography (SPECT): Fundamentals, technique, clinical applications

    International Nuclear Information System (INIS)

    The fundamentals of SPECT (Single Photon Emission Computed Tomography) are presented, and the requirements on rotating SPECT systems are listed. SPECT with a rotating gamma camera has found general acceptance as an imaging method in nuclear medicine. Compared with conventional, two-dimensional imaging techniques, SPECT offers higher contrast and three-dimensional transversal, sagittal, coronal or oblique sectional images. (orig./MG)

  16. Recovery of the cardiac frequency to the minute post effort as early indicator of myocardial ischemia

    International Nuclear Information System (INIS)

    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)

  17. Brain SPECT in childhood

    International Nuclear Information System (INIS)

    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)

  18. Development and performance evaluation of an animal SPECT system using Philips ARGUS gamma camera and pinhole collimators

    International Nuclear Information System (INIS)

    We developed an animal SPECT system using clinical Philips ARGUS scintillation camera, pinhole collimator with specially manufactured small apertures and laser alignment system to minimize center of rotation error. In this study, we evaluated the physical characteristics of this system and biological feasibility for animal experiments. Rotating station for small animals using a step motor and laser alignment system were developed. Pinhole inserts with small apertures (0.5, 1.0, and 2.0 mm) were manufactured and physical parameters including planar and reconstructed spatial resolution and sensitivity were measured for some apertures. Using manufactured multiple line sources; the size of usable field of view was measured. Using a Tc-99m line source with 0.5 mm diameter placed in the exact center of field of view, planar spatial resolution according to the distance was measured. Calibration factor to obtain FWHM values in mm unit was calculated from the planar image of two separated line sources. Tc-99m point source with 1 mm diameter was used for the measurement of system sensitivity. In addition, SPECT data of micro phantom with cold inserts and rat brain after intravenous injection of [I-123]FP-CIT were acquired using laser alignment system and reconstructed using filtered back projection and ordered subsets expectation maximization reconstruction algorithm. Size of usable field of view was proportional to the distance and that could be fitted into a linear equation.(y=1.4x+0.5 x:distance) System sensitivity and planar spatial resolution at 3 cm measured using 1.0 mm aperture was 71 cps/MBq and 1.24 mm, respectively. In the SPECT image of rat brain the distribution of dopamine transporter in the striatum was well identified in each hemisphere. We verified that this new animal SPECT system with the Philips ARGUS scanner and small apertures had sufficient performance for small animal imaging

  19. 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

  20. Feasibility and Initial Performance of Simultaneous SPECT-CT Imaging Using a Commercial Multi-Modality Preclinical Imaging System

    OpenAIRE

    Osborne, Dustin R.; Derek W. Austin

    2015-01-01

    Multi-modality imaging provides coregistered PET-CT and SPECT-CT images; however such multi-modality workflows usually consist of sequential scans from the individual imaging components for each modality. This typical workflow may result in long scan times limiting throughput of the imaging system. Conversely, acquiring multi-modality data simultaneously may improve correlation and registration of images, improve temporal alignment of the acquired data, increase imaging throughput, and benefi...

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

    OpenAIRE

    Kim, Joong Hyun; Ito, Mikiko; 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 r...

  2. 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.

  3. A modular data acquisition and position analysis system for a multi-bar cylindrical SPECT scanner

    International Nuclear Information System (INIS)

    This paper reports on a modular data acquisition and position analysis system (DAPAS) designed and tested for a multi-bar cylindrical SPECT scanner. The detector assembly is a position-sensitive cylindrical gamma camera comprised of multiple detector modules, each of which contains multiple NaI(Tl) bars. An array of PMTs is coupled on the outside of the detector cylinder for position analysis. The major components of the module data acquisition system are: a regional pulse height summation network for each detector module; an analog multiplexer/encoder network to select the output of the relevant PMTs; an ADC system to digitize the selected PMT outputs and store in FIFOs. The position analysis, performed in real-time by a digital signal processor (DSP), involves identifying the bar in the detector module and calculating axial position along the bar for each accepted scintillation event. Throughput rate for the position analysis of the DSP is estimated to be 35 kHz

  4. 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.

  5. 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.

  6. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous 99mTc/201Tl SPECT imaging: A Monte Carlo simulation study

    International Nuclear Information System (INIS)

    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 99mTc/201Tl 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 201Tl (77±10% keV) and 99mTc (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

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

    Science.gov (United States)

    Heidary, Saeed; Setayeshi, Saeed

    2015-01-01

    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 99mTc/201Tl 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 201Tl (77±10% keV) and 99mTc (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. 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.

  9. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    The invention relates to cardiac imaging systems and methods employing computerised tomographic scanning. Apparatus is described which allows an image of the radiation attenuation of the heart at a desired phase of the cardiac cycle. The patients ECG signal can be used in a transverse-and-rotate type CT scanner as a time base, so that the beam reaches the heart at a desired phase of the cardiac cycle, or, in a purely rotational-type CT scanner continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves by shuttering or switching the power supply can be controlled by the ECG signal. A pacemaker is used to stabilize the cardiac period. Also used is a system for recognising unacceptable variations in the cardiac period and discarding corresponding scan data. In a transverse-and-rotate type fan-beam CT scanner, the effective beam width is narrowed to reduce the duration of the traverse of the heart. (U.K.)

  10. Variability in the Cardiac Venous System of Wistar Rats

    Science.gov (United States)

    Krešáková, Lenka; Purzyc, Halina; Schusterová, Ingrid; Fulton, Benjamin; Maloveská, Marcela; Vdoviaková, Katarina; Kravcová, Zuzanna; Boldižár, Martin

    2015-01-01

    Rats are often used as animal models in experimental cardiology for studying myocardial infarctions and various cardiologic procedures. Currently the cardiac venous system is a target for the delivery of drugs, gene vectors, angiogenetic growth factors, stem cells, and cardioprotective reagents. The purpose of this study was to describe the anatomic configuration and variability of the cardiac venous system in Wistar rats, by using the corrosion cast method and perfusion of colored latex. The distribution of veins in the rat heart disagrees with prior descriptions for other mammals, except mice, which have a similar pattern. Coronary venous drainage in the 36 rats examined consistently involved the left cardiac, left conal, major caudal, right cardiac, and right conal veins. Other veins involved inconsistently included the cranial cardiac vein (58.3% of cases), minor caudal veins (16.7%), conoanastomotic vein (66.7%), and left atrial vein (75%). In 4 cases (11.1%), the collateral veins were located between the left conal and left cardiac veins. In this study, high morphologic variability between cases was manifested by differences in the arrangement, size, mode of opening, and formation of the common root and affected all regions of the heart but primarily the right ventricle. PMID:25651085

  11. Brain (18)F-FDG, (18)F-Florbetaben PET/CT, (123)I-FP-CIT SPECT and Cardiac (123)I-MIBG Imaging for Diagnosis of a "Cerebral Type" of Lewy Body Disease.

    Science.gov (United States)

    Van Der Gucht, Axel; Cleret de Langavant, Laurent; Bélissant, Ophélie; Rabu, Corentin; Cottereau, Anne-Ségolène; Evangelista, Eva; Chalaye, Julia; Bonnot-Lours, Sophie; Fénelon, Gilles; Itti, Emmanuel

    2016-09-01

    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. (18)F-FDG PET/CT showed hypometabolism in the posterior associative cortex including the occipital cortex, suggesting Lewy body dementia, but (123)I-FP-CIT SPECT was normal and cardiac (123)I-MIBG imaging showed no signs of sympathetic denervation. Alzheimer's disease was excluded by a normal (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. PMID:27540431

  12. 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.

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

    International Nuclear Information System (INIS)

    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)

  14. 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)

  15. Total variation penalized maximum-likelihood image reconstruction for a stationary small animal SPECT system

    International Nuclear Information System (INIS)

    We have developed a 3D total variation (TV) penalized maximum likelihood (ML) image reconstruction method and tested it in simulated dynamic SPECT scans using a stationary ring-type SPECT insert for simultaneous small animal SPECTMR imaging. The SPECT insert consists of 5 (axial) x 19 (transaxial) MR-compatible CZT detectors that form a seamless 19-side detector ring, inside which a cylindrical collimator sleeve with 36 focused pinholes is inserted for dynamic SPECT acquisition. The short duration of the individual time frames and the stationary data acquisition nature may cause severe noise and sparse-view artifacts in the reconstructed images, and as a result affect the time-activity curve (TAC) derived from the 4D image sequence. The TV potential function favors piece-wise constant image reconstruction therefore is capable of reducing these image artifacts. Our implementation of the ML-TV method used the Douglas-Rachford splitting to deal with the non-smooth TV function. We applied the ML-TV method to a computer-simulated dynamic mouse renal SPECT scan, and evaluated the method in terms of pixel-wise TAC estimation compared to the conventional ML-EM. The pixel-wise TAC obtained by the MLEM method exhibited large fluctuation around the truth; this large fluctuation was significantly suppressed by using ML-TV. Our next step is to incorporate time-domain correlation and develop fully 4D (3D spatial + 1D time) image reconstruction methods for dynamic stationary small animal SPECT studies. (orig.)

  16. Total variation penalized maximum-likelihood image reconstruction for a stationary small animal SPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jingyan; Tsui, Benjamin M.W. [Johns Hopkins Univ., Baltimore, MD (United States). Div. of Medical Imaging Physics; Chen, Si [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Electrical and Computer Engineering

    2011-07-01

    We have developed a 3D total variation (TV) penalized maximum likelihood (ML) image reconstruction method and tested it in simulated dynamic SPECT scans using a stationary ring-type SPECT insert for simultaneous small animal SPECTMR imaging. The SPECT insert consists of 5 (axial) x 19 (transaxial) MR-compatible CZT detectors that form a seamless 19-side detector ring, inside which a cylindrical collimator sleeve with 36 focused pinholes is inserted for dynamic SPECT acquisition. The short duration of the individual time frames and the stationary data acquisition nature may cause severe noise and sparse-view artifacts in the reconstructed images, and as a result affect the time-activity curve (TAC) derived from the 4D image sequence. The TV potential function favors piece-wise constant image reconstruction therefore is capable of reducing these image artifacts. Our implementation of the ML-TV method used the Douglas-Rachford splitting to deal with the non-smooth TV function. We applied the ML-TV method to a computer-simulated dynamic mouse renal SPECT scan, and evaluated the method in terms of pixel-wise TAC estimation compared to the conventional ML-EM. The pixel-wise TAC obtained by the MLEM method exhibited large fluctuation around the truth; this large fluctuation was significantly suppressed by using ML-TV. Our next step is to incorporate time-domain correlation and develop fully 4D (3D spatial + 1D time) image reconstruction methods for dynamic stationary small animal SPECT studies. (orig.)

  17. 201Tl brain SPECT in differentiating central nervous system lymphoma from toxoplasmosis in AIDS patients

    International Nuclear Information System (INIS)

    In AIDS patients, toxoplasmosis and lymphoma are the leading causes of CNS mass lesions. It is important to make the correct diagnosis expeditiously, since the two diseases require markedly different treatments and have different prognoses. In general, CT and MR imaging have failed to provide specific distinguishing characteristics to differentiate CNS lymphoma from toxoplasmosis, and it is difficult to differentiate these entities clinically. We performed 201Tl brain SPECT in order to differentiate two diseases. Counts ratio of a lesion to the normal brain (L/N ratio) was elevated in patients of lymphoma compared in patients of toxoplasmosis. 201Tl brain SPECT is useful to differentiate CNS lymphoma from toxoplasmosis. (author)

  18. Evaluation of the D-SPECT System: geometry considerations and respiratory motion

    OpenAIRE

    Salvado, Débora Sofia Almeida Silva

    2012-01-01

    O D-SPECT é um sistema de aquisição SPECT (do inglês Single Photon Emission Computed Tomography), desenvolvido especificamente para imagiologia cardíaca e está apenas disponível em alguns países no mundo. Este sistema tem uma configuração curva para se adaptar ao lado esquerdo do torso do paciente, que é onde se localiza o coração. É constituído por 9 detectores CZT (cádmio-zinco-telúrio), montados verticalmente e que têm a possibilidade de rodar individualmente sobre o seu eixo. Esta capacid...

  19. 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 resonance imaging in 20 patients undergoing coronary artery bypass grafting. METHODS: Correlation was measured using Spearman's correlation coefficient (ρ. 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 (ρ = 0.85; p =0.0001, moderate correlation for end-diastolic volume (ρ = 0.51; p = 0.02, and non-significant correlation for end-diastolic volume (ρ = 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.

  20. Is the cardiac function improvement after PTCA predictable by the quantitative indices from exercise stress 201Tl myocardial SPECT, in patients with old myocardial infarction?

    International Nuclear Information System (INIS)

    We examined whether the improvement of left ventricular function after percutaneous transluminal coronary angioplasty (PTCA) in patients with one diseased vessel can be predicted by the quantitative indices from exercise stress 201Tl single photon emission computed tomography (SPECT) and radionuclide angiography (RNA) before PTCA. Exercise stress 201Tl myocardial SPECT and RNA were performed before and after PTCA in 28 patients with old myocardial infarction (OMI). The patients were divided into two groups according to the results of coronary angiogram performed at 3 to 6 months after PTCA; patency was confirmed in 22 patients (Group P) and restenosis was observed in the remaining 6 patients (Group S). In Group P, the count ratios defined as 201Tl uptake in the PTCA region divided by the uptake in the normal region were significantly improved at 1 week and 3 to 6 months after PTCA in the initial image. 201Tl washout rates in the normal regions were significantly increased at 1 week after PTCA in Group S, and these rates in the PTCA regions were significantly increased at 1 week after PTCA in Group P. Left ventricular ejection fractions (LVEF) obtained from RNA were significantly improved 1 week and 3 to 6 months after PTCA in Group P. The changes of LVEF between pre-PTCA and 3 to 6 months after PTCA (ΔLVEF) were significantly correlated with the count ratios of both initial and delayed SPECT images in Group P (r=0.652; p<0.01, r=0.645; p<0.01 respectively). From the multiple regression analysis using stepwise methods, the count ratio in delayed image and the LVEF before PTCA were selected as independent predictive variables for ΔLVEF (multiple correlation coefficient=0.776). Thus, the improvement of LVEF after PTCA may be predictable by the count ratio in the delayed SPECT image and LVEF before PTCA when the treated vessel is persistently patent. (author)

  1. 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

  2. Correction of nonuniform attenuation and image fusion in SPECT imaging by means of separate X-ray CT

    International Nuclear Information System (INIS)

    Improvements in image quality and quantitation measurement, and the addition of detailed anatomical structures are important topics for single-photon emission tomography (SPECT). The goal of this study was to develop a practical system enabling both nonuniform attenuation correction and image fusion of SPECT images by means of high-performance X-ray computed tomography (CT). A SPECT system and a helical X-ray CT system were placed next to each other and linked with Ethernet. To avoid positional differences between the SPECT and X-ray CT studies, identical flat patient tables were used for both scans; body distortion was minimized with laser beams from the upper and lateral directions to detect the position of the skin surface. For the raw projection data of SPECT, a scatter correction was performed with the triple energy window method. Image fusion of the X-ray CT and SPECT images was performed automatically by auto-registration of fiducial markers attached to the skin surface. After registration of the X-ray CT and SPECT images, an X-ray CT-derived attenuation map was created with the calibration curve for 99mTc. The SPECT images were then reconstructed with scatter and attenuation correction by means of a maximum likelihood expectation maximization algorithm. This system was evaluated in torso and cylindlical phantoms and in 4 patients referred for myocardial SPECT imaging with Tc-99m tetrofosmin. In the torso phantom study, the SPECT and X-ray CT images overlapped exactly on the computer display. After scatter and attenuation correction, the artifactual activity reduction in the inferior wall of the myocardium improved. Conversely, the increased activity around the torso surface and the lungs was reduced. In the abdomen, the liver activity, which was originally uniform, had recovered after scatter and attenuation correction processing. The clinical study also showed good overlapping of cardiac and skin surface outlines on the fused SPECT and X-ray CT images. The

  3. 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

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

    International Nuclear Information System (INIS)

    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

  5. The multi-module multi-resolution SPECT system: A tool for variable-pinhole small-animal imaging

    Science.gov (United States)

    Hesterman, Jacob Yost

    The multi-module, multi-resolution SPECT system (M 3R) was developed and evaluated at the University of Arizona's Center for Gamma-Ray Imaging (CGRI). The system consists of four modular gamma cameras stationed around a Cerrobend shielding assembly. Slots machined into the shielding allow for the easy interchange of pinhole apertures, providing M3R with excellent hardware flexibility. Motivation for the system included serving as a prototype for a tabletop, small-animal SPECT system, acting as a testbed for image quality by enabling the experimental validation of imaging theory, and aiding in the development of techniques for the emerging field of adaptive SPECT imaging. Development of the system included design and construction of the shielding assembly and pinhole apertures. The issue of pinhole design and evaluation represents a recurring theme of the presented work. Existing calibration methods were adapted for use with M3R. A new algorithm, the contracting grid-search algorithm, that is capable of being executed in hardware was developed for use in position estimation. The algorithm was successfully applied in software and progress was made in hardware implementation. Special equipment and interpolation techniques were also developed to deal with M3R's unique system design and calibration requirements. A code library was created to simplify the many image processing steps required to realize successful analysis of measured image and calibration data and to achieve reconstruction. Observer studies were performed using both projection data and reconstructed images. These observer studies sought to explore signal-detection and activity estimation for various pinhole apertures. Special attention was paid to object variability, including the development and statistical analysis of a phantom capable of generating multiple realizations of a random, textured background. The results of these studies indicate potential for multiple-pinhole, multiplexed apertures but

  6. Performance characterization of a new CZT-based preclinical SPECT system: a comparative study of different collimators

    Science.gov (United States)

    Yu, A. R.; Park, S.-J.; Choi, Y. Y.; Kim, K. M.; Kim, H.-J.

    2015-09-01

    Triumph X-SPECT is a newly released CZT-based preclinical small-animal SPECT system with interchangeable collimators. The purpose of this work was to evaluate and systematically compare the imaging performances of three different collimators in the CZT-based preclinical small-animal system: a single-pinhole collimator (SPH), a multi-pinhole collimator (MPH) and a parallel-hole collimator. We measured the spatial resolutions and sensitivities of the three collimators with 99mTc sources, considering three distinct energy window widths (5, 10, and 20%), and used the NEMA NU4-2008 Image Quality phantom to test the imaging performance of the three collimators in terms of uniformity and spill-over ratio (SOR) for each energy window. With a 10% energy window width at a radius of rotation (ROR) of 30 mm, the system resolution of the SPH, MPH and parallel-hole collimators was 0.715, 0.855 and 3.270 mm FWHM, respectively. For the same energy window, the sensitivity of the system with SPH, MPH and parallel-hole collimators was 32.860, 152.514 and 49.205 counts/sec/MBq at a 100 mm source-to-detector distance and 6.790, 33.376 and 49.038 counts/sec/MBq at a 130 mm source-to-detector distance, respectively. The image noise and SORair for the three collimators were 20.137, 12.278 and 11.232 (%STDunif) and 0.106, 0.140 and 0.161, respectively. Overall, the results show that the SPH had better spatial resolution than the other collimators. The MPH had the highest sensitivity at 100 mm source-to-collimator distance, and the parallel-hole collimator had the highest sensitivity at 130 mm-source-to-detector distance. Therefore, the proper collimator for Triumph X-SPECT system must be determined by the task. These results provide valuable reference data and insight into the imaging performance of various collimators in CZT-based preclinical small-animal SPECT.

  7. Development and performance evaluation of an animal SPECT system using Philips ARGUS gamma camera and pinhole collimator

    International Nuclear Information System (INIS)

    We developed an animal SPECT system using clinical Philips ARGUS scintillation camera and pinhole collimator with specially manufactured small apertures. In this study, we evaluated the physical characteristics of this system and biological feasibility for animal experiments. Rotating station for small animals using a step motor and operating software were developed. Pinhole inserts with small apertures (diameter of 0.5, 1.0, and 2.0 mm) were manufactured and physical parameters including planar spatial resolution and sensitivity and reconstructed resolution were measured for some apertures. In order to measure the size of the usable field of view according to the distance from the focal point, manufactured multiple line sources separated with the same distance were scanned and numbers of lines within the field of view were counted. Using a Tc-99m line source with 0.5 mm diameter and 12 mm length placed in the exact center of field of view, planar spatial resolution according to the distance was measured. Calibration factor to obtain FWHM values in 'mm' unit was calculated from the planar image of two separated line sources. Tc-99m point source with 1 mm diameter was used for the measurement of system sensitivity. In addition, SPECT data of micro phantom with cold and hot line inserts and rat brain after intravenous injection of [I-123]FP-CIT were acquired and reconstructed using filtered back projection reconstruction algorithm for pinhole collimator. Size of usable field of view was proportional to the distance from the focal point and their relationship could be fitted into a linear equation (y=1,4x + 0.5, x: distance). System sensitivity and planar spatial resolution at 3 cm measured using 1.0 mm aperture was 71 cps/MBq and 1.24 mm, respectively. In the SPECT image of rat brain with [I-123]FP-CIT acquired using 1.0 mm aperture, the distribution of dopamine transporter in the striatum was well identified in each hemisphere. We verified that this new animal SPECT

  8. Performance characterization of a new CZT-based preclinical SPECT system: a comparative study of different collimators

    International Nuclear Information System (INIS)

    Triumph X-SPECT is a newly released CZT-based preclinical small-animal SPECT system with interchangeable collimators. The purpose of this work was to evaluate and systematically compare the imaging performances of three different collimators in the CZT-based preclinical small-animal system: a single-pinhole collimator (SPH), a multi-pinhole collimator (MPH) and a parallel-hole collimator. We measured the spatial resolutions and sensitivities of the three collimators with 99mTc sources, considering three distinct energy window widths (5, 10, and 20%), and used the NEMA NU4-2008 Image Quality phantom to test the imaging performance of the three collimators in terms of uniformity and spill-over ratio (SOR) for each energy window. With a 10% energy window width at a radius of rotation (ROR) of 30 mm, the system resolution of the SPH, MPH and parallel-hole collimators was 0.715, 0.855 and 3.270 mm FWHM, respectively. For the same energy window, the sensitivity of the system with SPH, MPH and parallel-hole collimators was 32.860, 152.514 and 49.205 counts/sec/MBq at a 100 mm source-to-detector distance and 6.790, 33.376 and 49.038 counts/sec/MBq at a 130 mm source-to-detector distance, respectively. The image noise and SORair for the three collimators were 20.137, 12.278 and 11.232 (%STDunif) and 0.106, 0.140 and 0.161, respectively. Overall, the results show that the SPH had better spatial resolution than the other collimators. The MPH had the highest sensitivity at 100 mm source-to-collimator distance, and the parallel-hole collimator had the highest sensitivity at 130 mm-source-to-detector distance. Therefore, the proper collimator for Triumph X-SPECT system must be determined by the task. These results provide valuable reference data and insight into the imaging performance of various collimators in CZT-based preclinical small-animal SPECT

  9. Cardiac and systemic haemodynamic complications of liver cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Møller, Søren

    2009-01-01

    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......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...... 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, and...

  10. 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. PMID:27098778

  11. Modelling the cardiac transverse-axial tubular system

    Czech Academy of Sciences Publication Activity Database

    Pásek, Michal; Šimurda, J.; Christé, G.; Orchard, C.

    2008-01-01

    Roč. 96, - (2008), s. 226-246. ISSN 0079-6107 Institutional research plan: CEZ:AV0Z20760514 Keywords : cardiac cell * transverse-axial tubular system * quantitative modelling Subject RIV: BO - Biophysics Impact factor: 6.388, year: 2008

  12. 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

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

    International Nuclear Information System (INIS)

    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-[18F]fluorodopamine, (-)-6-[18F]fluoronorepinephrine and (-)-[11C]epinephrine, and radiolabelled catecholamine analogues, such as [123I]meta-iodobenzylguanidine, [11C]meta-hydroxyephedrine, [18F]fluorometaraminol, [11C]phenylephrine and meta-[76Br]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 (-)-[18F]fluoroethoxybenzovesamicol display a high degree of non-specific binding in myocardium which restricts their utility for cardiac neuronal imaging. (orig.)

  14. An accurate and efficient system model of iterative image reconstruction in high-resolution pinhole SPECT for small animal research

    International Nuclear Information System (INIS)

    Accurate modeling of the photon acquisition process in pinhole SPECT is essential for optimizing resolution. In this work, the authors develop an accurate system model in which pinhole finite aperture and depth-dependent geometric sensitivity are explicitly included. To achieve high-resolution pinhole SPECT, the voxel size is usually set in the range of sub-millimeter so that the total number of image voxels increase accordingly. It is inevitably that a system matrix that models a variety of favorable physical factors will become extremely sophisticated. An efficient implementation for such an accurate system model is proposed in this research. We first use the geometric symmetries to reduce redundant entries in the matrix. Due to the sparseness of the matrix, only non-zero terms are stored. A novel center-to-radius recording rule is also developed to effectively describe the relation between a voxel and its related detectors at every projection angle. The proposed system matrix is also suitable for multi-threaded computing. Finally, the accuracy and effectiveness of the proposed system model is evaluated in a workstation equipped with two Quad-Core Intel X eon processors.

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

    OpenAIRE

    Cai, Liang; Meng, Ling-Jian

    2012-01-01

    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 depositio...

  16. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    OpenAIRE

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seungjoon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2013-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

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

  19. 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.

  20. The application and development of animal SPECT

    International Nuclear Information System (INIS)

    Animal SPECT is an important research approach for translating preclinical to clinical study. It has been widely applied in drug development and the researches of physiology and diseases in small animal models. With the rapid progresses of hardware technology and algorithm of image reconstruction, the systemic sensitivity,spatial resolution and quantitative accuracy of animal SPECT have been greatly improved. Animal SPECT has great advantages over animal PET with the feasibility of study, the convenience acquisition of radiopharmaceuticals and relative low cost. In a certain period, animal SPECT will still be a main approach for preclinical researches of molecular imaging. (author)

  1. Locally derived system for cardiac operative risk evaluation

    Directory of Open Access Journals (Sweden)

    Mihajlović Bogoljub

    2014-01-01

    Full Text Available Introduction. During the last two decades, many authors have found that European Systems for Cardiac Operative Risk Evaluation (additive and logistic models overestimate the risk in cardiac surgery. The new European model has recently been introduced as an update to previous versions. The aim of the study was to investigate the significance of locally derived system for cardiac operative risk evaluation and to compare its predictive power with the existing European systems. Material and Methods. For developing a local risk prediction model, data from 2681 patients submitted to cardiac surgery at the Institute of Cardiovascular Diseases Vojvodina have thoroughly been collected. Logistic regression analysis was used to construct a local model for prediction of outcome. The evaluation of the local model and three European systems was performed by comparing the observed and expected hospital mortality. Results. The difference between the predicted and observed mortality regardless of the type of surgery was statistically insignificant for the additive European system (p=0.073 and the local model (p=0.134. The logistic European system overestimated the operative risk, while the new European model underestimated mortality. In coronary surgery, all models, except the logistic European system, performed well. In valvular surgery, the new European model and the local model underestimated mortality significantly, while the additive and logistic European models performed well. In combined surgery, the new European system significantly underestimated mortality (p=0.029, while the local model performed well (p=0.252. Conclusion. The locally derived model shows satisfactory results, with good calibration and discriminative power. The local model specifically outperforms all other European systems in terms of discriminatory power in combined surgery subset.

  2. Low-dose dobutamine stress test for the evaluation of cardiac function using ECG-gated SPECT scintigraphy with 99mTc-MIBI

    International Nuclear Information System (INIS)

    Although 201TlCl myocardial scintigraphy has so far been widely used for the evaluation of the viability of the myocardial infarcted area, functional evaluation using low dose dobutamine (DOB) loaded echography also became recently available. We performed 99mTc-MIBI gated SPECT on eight cases of myocardial infarction at rest and low dose (4-6μg/kg/min) DOB-loading and related data were collected. Next, we calculated myocardial count increase rate (%WT=ES-ED/ED x 100) with left ventricular contraction from end-diastolic (ED) and end-systolic (ES) pictures in short-axial image, and made a comparative examination of regional contractilities at rest and DOB-loading. DOB-loaded echography performed on the same cases at the same dose revealed 15 segments as infarcted area (WM(+)) presenting improvement in wall movement at loading and 5 segments as infarcted area (WM(-)) presenting no such improvement, and %WT at rest and loading were 29.1±6.2 and 33.2±2.4 for (WM(-)) and 26.8±9.8 and 40.0±12.3 for (WM(+)), indicating a significant increase (p<0.05) at loading. Contractility analysis using MIBI gated SPECT in combined use of DOB-loading was considered as a useful method of examination in view of its reflectionality in the evaluation of the wall movement in DOB-loaded echography and of its high quantitativity. (author)

  3. Evaluation of cerebral perfusion in patients with neuropsychiatric systemic lupus erythematosus using 123I-IMP SPECT

    International Nuclear Information System (INIS)

    In the course of systemic lupus erythematosus (SLE), central nervous system (CNS) complications occur at a high frequency. An accurate diagnosis of CNS lupus, differentiated from secondary CNS involvement, is difficult. CNS lupus is indicative of advancing primary disease and is treated by steroid pulse therapy or increased dosage of steroids. In contrast, if symptoms are caused by secondary CNS complications, it is possible to observe or treat these complications using symptomatic therapy. We examined whether quantitative cerebral blood flow (CBF) measured using cerebral perfusion single photon emission computed tomography (SPECT) can be used to differentiate CNS lupus from secondary CNS involvement. We divided 18 SLE patients with CNS symptoms into a CNS lupus group and a non-CNS lupus group, and then compared the mean cerebral blood flow (mCBF) of each group of patients. SPECT was performed with N-isopropyl-p-[123I] iodoamphetamine (IMP), with quantitation carried out by table look-up and autoradiographic methods. The mCBF of both groups was decreased; however, the mCBF of patients with CNS lupus was significantly lower than that of non-CNS lupus patients. Quantitative CBF may provide a useful tool to distinguish CNS lupus from non-CNS lupus. (author)

  4. Digital stethoscope system: the feasibility of cardiac auscultation

    Science.gov (United States)

    Pariaszewska, Katarzyna; Młyńczak, Marcel; Niewiadomski, Wiktor; Cybulski, Gerard

    2013-10-01

    The application of the digital stethoscope system is a new tendency in methods of cardiac auscultation. Heart sounds, generated by the fluctuations of blood velocity and vibrations of muscle structure, are an important signal in the primary diagnosis of heart diseases. Since the XIXs century for physical examination an analog stethoscope was used, but the development of microelectronics enable the construction of digital stethoscopes which started modern phonocardiography. The typical hardware of the system could be divided into analog and digital parts, respectively. The first one consists of microphone and pre-amplifier. The second one contains a microcontroller with peripherals for data saving and transmission. Usually the specialized software is applied for the signal acquisition and digital signal processing (filtering, spectral analysis and others). This paper presents an overview of methods used in cardiac auscultation and expected developing path in the future. It also contains the description of our digital stethoscope system, which is planned to be used in poliphysiographical studies.

  5. SPECT/CT with a hybrid imaging system in the study of lower gastrointestinal bleeding with technetium-99m red blood cells

    International Nuclear Information System (INIS)

    Aim. Lower gastrointestinal (G I) hemorrhage is a complex clinical problem that requires disciplined evaluation for successful management. This study was conducted to evaluate the applicability of single photon emission computed tomography/computed tomography (SPECT/CT) in patients with acute lower gastrointestinal bleeding undergoing scintigraphy with 99m Tc-labelled red blood cells (RBC), and to assess the additional clinical value of fused images when compared to the standard radionuclide scan. Methods. Twenty-seven patients presenting with acute lower G I tract hemorrhage were studied with conventional dynamic and planar 99m Tc-RBC imaging. In 19 patients with positive findings on scans taken within 6 hours, a SPECT/CT study was immediately performed using a hybrid system composed of a dual-head, variable angle gamma camera and an X-ray tube. The number of patients in whom SPECT/CT changed the scintigraphic interpretation with regard to the presence or site of G I blood loss as confirmed by other diagnostic or therapeutical procedures was recorded. Results. Image fusion was easy and successful in all patients showing perfect correspondence between SPECT and CT data and allowing precise anatomical localization of the sites of 99m Tc-RBC extravasation. SPECT/CT had significant impact on the scintigraphic results in 7/19 patients (36.8%): in 6 patients it precisely localized the bleeding foci whose location could not be identified in standard scans and in one it excluded the presence of an active G I hemorrhage. Conclusion. SPECT/CT with a hybrid system is feasible and useful for facilitating imaging interpretation and improving the accuracy of 99m Tc-RBC scintigraphy in patients with acute lower G I bleeding.

  6. 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

    International Nuclear Information System (INIS)

    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 β-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.)

  7. 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.)

  8. PET and SPECT imaging of the opioid system: receptors, radioligands and avenues for drug discovery and development.

    Science.gov (United States)

    Lever, John R

    2007-01-01

    As we celebrate the bicentennial of the isolation of morphine by Sertürner, opioids continue to dominate major sectors of the analgesic market worldwide. The pharmaceutical industry stands to benefit greatly from molecular imaging in preclinical and early clinical trials of new or improved opioid drugs. At this juncture, it seems fitting to summarize the past twenty or so years of research on molecular imaging of the opioid system from the viewpoint of drug discovery and development. Opioid receptors were first imaged in human volunteers by positron emission tomography (PET) in 1984. Now, quantitative PET imaging of the major opioid receptor types (micro, delta , kappa) is possible in the brain and peripheral organs of healthy persons and patient populations. Radioligands are under development for single photon emission computed tomography (SPECT) of opioid receptors as well. These functional, nuclear imaging techniques can trace the fate of radiolabeled molecules directly, but non-invasively, and allow precise pharmacokinetic and pharmacodynamic measurements. Molecular imaging provides unique data that can aid in selecting the best drug candidates, determining optimal dosing regimens, clearing regulatory hurdles and lowering risks of failure. Using a historical perspective, this review touches on opioid receptors as drug targets, and focuses on the status and use of radiotracers for opioid receptor PET and SPECT. Selected studies are discussed to illustrate the power of molecular imaging for facilitating opioid drug discovery and development. PMID:17266587

  9. Radioimmunoassay of myosin heavy beta chains in human serum for the evaluation of the size of myocardial infarction: correlation with myocardial Tl-201 SPECT and cardiac angioscintigraphy

    International Nuclear Information System (INIS)

    To determine the relationship between serum levels of myosin heavy beta chains assessed by an IRMA technique and other radionuclide and enzymatic parameters in the evaluation of the size of myocardial infarction, we studied 22 patients with acute myocardial infarction. Blood samples taken daily between 1st to 13th day of evolution allow the determination of peak and integral of myosine release that showed a good correlation (p<0.01) with myocardial underperfusion score in T1-201 SPECT, left ventricular ejection fractions at 1st day and at the pre-discharge study, just as CPK peak. This new assay is an interesting mean to evaluate the size of myocardial infarction

  10. 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

  11. 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

  12. 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. PMID:17284482

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

    International Nuclear Information System (INIS)

    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

  14. Three-dimensional quantitation of regional cerebral blood flow in mice using a high-resolution pinhole SPECT system and 123I-iodoamphetamine

    International Nuclear Information System (INIS)

    Introduction: This study is intended to evaluate the feasibility of using a high-resolution pinhole SPECT system and iodine-123-N-isopropyl-4-iodoamphetamine (123I-IMP) for three-dimensional (3D) absolute quantitation of regional cerebral blood flow (rCBF) in mice. Methods: The pinhole SPECT system consists of a rotating stage and a pinhole collimator attached to a clinical gamma camera. The collimator's focal length is 251 mm. Phantom studies were performed to evaluate sensitivity and full-width half-maximum (FWHM) spatial resolution. The aperture-to-object distance was 15 mm. Six mice were studied. Cerebral infarctions were induced by ligating and disconnecting the distal portion of the left middle cerebral artery. Ex vivo SPECT studies were performed using harvested brains and skulls. The CBF volumetric image was computed using the standardized input function. Results: Excellent spatial resolution of 0.9-mm FWHM and uniform sensitivity throughout the 3D volume were demonstrated in the phantom experiments. The CBF images showed a defect in the infarcted areas and a reduction of CBF values in the infarcted region as compared with the control region. Conclusions: This study demonstrated the feasibility of the 3D quantitation of rCBF in mice using a high-resolution pinhole SPECT system and 123I-IMP.

  15. Theory and realization of a 2D high resolution and high sensitivity SPECT system with an angle-encoding attenuator pattern

    Science.gov (United States)

    Feng, Tao; Wang, Jizhe; Tsui, Benjamin M. W.

    2016-04-01

    The camera of the conventional SPECT system requires a collimator to allow incoming photons from a specific range of incident angle to reach the detector. It is the major factor that determines the spatial resolution of the camera. Moreover, it also greatly reduces the number of detected photons and hence increases statistical fluctuations in the acquired image data. The goal of this paper is to propose a theory and design for a novel high resolution and high sensitivity SPECT system without conventional collimators. The key is to resolve the incident photons from all directional angles and detected by every detector bin. Special ‘attenuators’ were designed to ‘encode’ the incoming photons from different directions similar to coded aperture to form projection data for image reconstruction. Each encoded angular pattern of detected photons was recorded as one measurement. Different angular patterns were achieved by changing the configurations of the attenuators so that angular pattern of different measurements or measurement matrix (MM) is invertible, which guarantee a unique reconstructed image. In simulation, the attenuators were fitted on a virtual full-ring gamma camera, as an alternative to the collimators in conventional SPECT systems. To evaluate the performance of the new SPECT system, analytical simulated projection data in 2D scenario were generated from the XCAT phantom. Noisy simulation using 100 noise realizations suggests that the new attenuator design provides much improved image quality in terms of contrast-noise trade-offs (~30% improvement). The results suggest that the new design of using attenuators to replace collimator is feasible and could potentially improve sensitivity without sacrificing resolution in today’s SPECT systems.

  16. 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....

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

    OpenAIRE

    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 called U-SPECT. With the U-SPECT it is possible to study the function of organs and tissue in vivo at sub-half millimeter scale using radioactively labeled tracers. The first prototype (U-SPECT-I) ...

  18. 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)

  19. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Accorsi, R. [Department of Radiology, The Children' s Hospital of Philadelphia, Philadelphia, PA (United States); Autiero, M. [Dipartimento di Scienze Fisiche, Universita di Napoli Federico II, Naples (Italy); Celentano, L. [Dipartimento di Scienze Biomorfologiche e Funzionali, Universita di Napoli Federico II, Naples (Italy)] (and others)

    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 256x256 matrix of 55 {mu}m square pixels) operating in single photon counting for detection of gamma-rays with low and medium energy (e.g. {sup 125}I, 27-35 keV, {sup 99m}Tc, 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 {mu}m 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.

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

    International Nuclear Information System (INIS)

    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 256x256 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

  2. 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

    Science.gov (United States)

    Tossios, Paschalis; Müller-Ehmsen, Jochen; Schmidt, Matthias; Scheid, Christof; Ünal, Nermin; Moka, Detlef; Schwinger, Robert HG; Mehlhorn, Uwe

    2006-01-01

    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 < 6 days before and 3 months after the intervention. 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

  3. 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

    International Nuclear Information System (INIS)

    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. 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 < 6 days before and 3 months after the intervention. 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. 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

  4. Right-sided cardiac function in healthy volunteers measured by first-pass radionuclide ventriculography and gated blood-pool SPECT: comparison with cine MRI

    DEFF Research Database (Denmark)

    Kjaer, Andreas; Lebech, Anne-Mette; Hesse, Birger;

    2005-01-01

    evaluation of right-sided cardiac function. The aim of our study was to compare the agreement between these methods when measuring right-sided cardiac function. METHODS: Twenty-four healthy volunteers were included. Mean age was 44 years (range: 25-60) and 29% were females. All participants had FP, GBPS and...... 6 ml m(-2) (95% CI: 0-11). CONCLUSIONS: (i) Normal values of RVEF differ between MRI, FP and GBPS with wide limits of agreement, accordingly it is difficult to evaluate changes over time if measured by different methods, (ii) RV volumes are in the same range when measured by MRI or GBPS but with...... wide limits of agreement, and (iii) if MRI is considered gold standard then FP is more accurate than GBPS for RVEF measurements....

  5. Cardiac manifestation's history in the systemic lupus erythematosus

    International Nuclear Information System (INIS)

    In this paper it is broadly and in depth reviewed the cardiac manifestation's history of systemic lupus erythematosus (SLE), since an historical analysis of clinical manifestations both in pre and post corticosteroids period. The way how the heart and the cardiovascular system's functions have been studied by clinical and semiological views are showed, through clinical manifestations such as myocarditis pericarditis, endocarditis, rhythm alterations, etc, and the evolution of laboratory methods used to its study as well as immunologic prognostic markers and risk factors for coronary disease in SLE

  6. 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

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

    International Nuclear Information System (INIS)

    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

  8. 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.

  9. 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.)

  10. SPECT/CT and pulmonary embolism.

    Science.gov (United States)

    Mortensen, Jann; Gutte, Henrik

    2014-05-01

    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 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. PMID:24213621

  11. Optimization of an ultra-high-resolution parallel-hole collimator for CdTe semiconductor SPECT system

    International Nuclear Information System (INIS)

    Recently, there has been an increase in the demand for semiconductor detectors in the field of nuclear medicine imaging. The development of semiconductor detectors using materials such as CdTe that allowed for improved spatial resolution greatly advanced the field. However, the pinhole collimator that allows for high spatial resolution compromises the sensitivity due to the small size of the hole. An improvement in both sensitivity and spatial resolution may be achieved by using a pixelated parallel-hole collimator where the hole and pixel sizes are the same. The purpose of this study was to optimize the design of a detector and collimator system to achieve excellent resolution and high sensitivity for a SPECT detector based on a CdTe detector. We performed a simulation study of the PID 350 (Ajat Oy Ltd., Finland) CdTe detector by using a Geant4 Application for Tomographic Emission (GATE). In addition to the above-mentioned pixelated parallel-hole collimator, we also designed a hexagonal parallel-hole collimator with similar hole size, and we evaluated the sensitivity and spatial resolution of each to determine which set-up was optimal for the PID 350 CdTe detector. Our results indicated that the average sensitivity and spatial resolution were 33.48% and 10.97% higher for the pixelated parallel-hole collimator than for the hexagonal parallel-hole collimator, respectively. We resolved a diameter of 0.5 mm in hot-rod phantom images with the pixelated parallel-hole collimator at a distance of 2 cm. Based on our results, we recommend the pixelated parallel-hole collimator for improving the sensitivity and spatial resolution of SPECT systems with CdTe semiconductor detectors.

  12. Examination concerning dissociation of left ventricular volume calculation value based on difference of analytical algorithm and perfusion tracer in gated myocardial SPECT

    International Nuclear Information System (INIS)

    According to improvement of SPECT system, ECG-gated SPECT with 201TlCl have been applied to the left ventricular volumetry. In this study 24 patients without ischemia demonstrated by stress (99mTc-TF) and rest (201TlCl) dual-isotope ECG-gated myocardial SPECT were enrolled. To evaluate left ventricular volumetry using 201Tl ECG-gated SPECT data, the left ventricular end diastolic volumes (EDV) were compared between Quantitative Gated SPECT (QGS) and Emory Cardiac Toolbox (ECT) as well as between dual-isotopes based on the same ECG-gated data. The EDV values with 99mTc data (EDVTc) using QGS were well correlated with those using ECT (r=0.96, pTc (r=0.98, p201Tl (EDVTl) (r=0.93, pTl compared with EDVTc. In contrast, EDVTl were significantly higher than EDVTc in ECT performance. The QGS errors subtracting EDVTl from EDVTc were more evident according to the left ventricular volume increase. On the other hand, ECT error showed no tendency associated with the left ventricular volume. From these results, a careful strategy for selection of tracers and softwares should be necessary to assessment of quantitative values derived from ECG-gated SPECT data because of interaction with softwares, tracers, and subjects. (author)

  13. 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...

  14. 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.

  15. PET and SPECT in neurology

    International Nuclear Information System (INIS)

    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.

  16. Data acquisition in a wireless diabetic and cardiac monitoring system.

    Science.gov (United States)

    Harvey, Paul; Woodward, Bryan; Datta, Sekharjit; Mulvaney, David

    2011-01-01

    A telemedicine system is described for monitoring the vital signs and general health indicators of patients with cardiac and diabetic conditions. Telemetry from wireless sensors and readings from other instruments are combined into a comprehensive patient health dataset. The data can be stored, accessed and displayed using mobile Internet communications with a server. The paper concentrates on the data acquisition process, using an alternative sensor network protocol to Bluetooth and manual data entry into a smartphone application and HTML5 web browser. PMID:22255009

  17. Performance evaluation of a newly developed high-resolution, dual-head animal SPECT system based on the NEMA NU1-2007 standard.

    Science.gov (United States)

    Moji, Vahideh; Zeratkar, Navid; Farahani, Mohammad Hossein; Aghamiri, Mahmoud Reza; Sajedi, Salar; Teimourian, Behnoosh; Ghafarian, Pardis; Sarkar, Saeed; Ay, Mohammad Reza

    2014-01-01

    Small-animal single-photon emission computed tomography (SPECT) system plays an important role in the field of drug development and investigation of potential drugs in the preclinical phase. The small-animal High-Resolution SPECT (HiReSPECT) scanner has been recently designed and developed based on compact and high-resolution detectors. The detectors are based on a high-resolution parallel hole collimator, a cesium iodide (sodium-activated) pixelated crystal array and two H8500 position-sensitive photomultiplier tubes. In this system, a full set of data cor- rections such as energy, linearity, and uniformity, together with resolution recovery option in reconstruction algorithms, are available. In this study, we assessed the performance of the system based on NEMA-NU1-2007 standards for pixelated detector cameras. Characterization of the HiReSPECT was performed by measure- ment of the physical parameters including planar and tomographic performance. The planar performance of the system was characterized with flood-field phantom for energy resolution and uniformity. Spatial resolution and sensitivity were evaluated as functions of distance with capillary tube and cylindrical source, respectively. Tomographic spatial resolution was characterized as a function of radius of rotation (ROR). A dedicated hot rod phantom and image quality phantom was used for the evaluation of overall tomographic quality of the HiReSPECT. The results showed that the planar spatial resolution was ~ 1.6 mm and ~ 2.3 mm in terms of full-width at half-maximum (FWHM) along short- and long-axis dimensions, respectively, when the source was placed on the detector surface. The integral uniformity of the system after uniformity correction was 1.7% and 1.2% in useful field of view (UFOV) and central field of view (CFOV), respectively. System sensitivity on the collimator surface was 1.31 cps/μCi and didn't vary significantly with distance. Mean tomographic spatial resolution was measured ~ 1.7 mm

  18. Performance evaluation of Siemens E.CAM(R) SPECT system at Korle-Bu Teaching Hospital (Ghana)

    International Nuclear Information System (INIS)

    Performance evaluation tests on Siemens e.cam(R) Signature Series Single Photon Emission Computed Tomography (SPECT)System at Korle-Bu Teaching Hospital (Ghana) were conducted for compliance with Manufacturer's specifications and user's requirements. The tests were performed according to National Electrical Manufacturer's Association protocols, and different measuring instruments and phantoms containing 99m-Tc were used. Extrinsic uniformity, system energy resolution, system spatial resolution (without scattering), detector shield leakage and system planar sensitivity were evaluated. The system energy resolution measured was 9.38 % as against manufacturer's specification of ≤ 9.9 %, Planar sensitivity value measured was 232.92 c/min/mCi while manufacturers' specification was 202 c/min/mCi, and detector shield leakage values measured were 0.001 %, 0.002 % and 0.025 % against an accepted value of < 1 %. The performance evaluation confirmed that the system met requirements for clinical nuclear medicine imaging, and the values could be used as database for future quality control measurements. (au)

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

    International Nuclear Information System (INIS)

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

  20. Progress In The Development Of A Tomographic SPECT System For Online Dosimetry In BNCT

    International Nuclear Information System (INIS)

    In boron neutron capture therapy (BNCT) the delivered dose to the patient depends both on the neutron beam characteristics and on the 10B body distribution which, in turn, is governed by the tumor specificity of the 10B drug-carrier. BNCT dosimetry is a complex matter due to the several interactions that neutrons can undergo with the different nuclei present in tissue. However the boron capture reaction 10B(n,α)7Li accounts for about 80 % of the total dose in a tumor with 40 ppm in 10B concentration. Present dosimetric methods are indirect, based on drug biodistribution statistical data and subjected to inter and intra-patient variability. In order to overcome the consequences of the concomitant high dosimetric uncertainties, we propose a SPECT (Single Photon Emission Tomography) approach based on the detection of the prompt gamma-ray (478 keV) emitted in 94 % of the cases from 7Li. For this purpose we designed, built and tested a prototype based on LaBr3(Ce) scintillators. Measurements on a head and tumor phantom were performed in the accelerator-based BNCT facility of the University of Birmingham (UK). They result in the first tomographic image of the 10B capture distribution obtained in a BNCT facility.

  1. 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.)

  2. 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...

  3. 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.

  4. Brain renin angiotensin system in cardiac hypertrophy and failure

    Directory of Open Access Journals (Sweden)

    MichaelBader

    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.

  5. 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.

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

    International Nuclear Information System (INIS)

    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

    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.

  8. Evaluation of the diagnosis for hypertrophic cardiomyopathy (HCM) with SPECT

    International Nuclear Information System (INIS)

    A heart phantom-7070 was used to measure the wall thickness of cardiac chambers. Two methods were employed: (1) profile curve measurement, (2) calculation of the thickness of cardiac walls. 9 normal cases and 13 patients with hypertrophic cardiomyopathy were studied using 99mTc-CDI SPECT. 4 patterns were obtained: (1) Local hypertrophy of ventricular septum; (2) The predominant hypertrophy localized in left ventricular lateral wall; (3) Markedly hypertrophied septum and also involving left ventricular walls, especially the apical region; (4) Markedly hypertrophied papillary muscles with perfusion defects in the left wall and septum. These results suggest that myocardial SPECT is a promising and noninvasive method for the diagnosis of HCM

  9. Comparison of photon counting and conventional scintillation detectors in a pinhole SPECT system for small animal imaging: Monte carlo simulation studies

    Science.gov (United States)

    Lee, Young-Jin; Park, Su-Jin; Lee, Seung-Wan; Kim, Dae-Hong; Kim, Ye-Seul; Kim, Hee-Joung

    2013-05-01

    The photon counting detector based on cadmium telluride (CdTe) or cadmium zinc telluride (CZT) is a promising imaging modality that provides many benefits compared to conventional scintillation detectors. By using a pinhole collimator with the photon counting detector, we were able to improve both the spatial resolution and the sensitivity. The purpose of this study was to evaluate the photon counting and conventional scintillation detectors in a pinhole single-photon emission computed tomography (SPECT) system. We designed five pinhole SPECT systems of two types: one type with a CdTe photon counting detector and the other with a conventional NaI(Tl) scintillation detector. We conducted simulation studies and evaluated imaging performance. The results demonstrated that the spatial resolution of the CdTe photon counting detector was 0.38 mm, with a sensitivity 1.40 times greater than that of a conventional NaI(Tl) scintillation detector for the same detector thickness. Also, the average scatter fractions of the CdTe photon counting and the conventional NaI(Tl) scintillation detectors were 1.93% and 2.44%, respectively. In conclusion, we successfully evaluated various pinhole SPECT systems for small animal imaging.

  10. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    A novel method for obtaining cardiac images with X-rays is described. The problem of blurring of the image due to motion of the heart and its associated blood vessels is overcome by monitoring the cardiac cycle to produce a repeating pulse signal indicative of the same selectable phase; a pacemaker may be used to stabilize the cardiac period. Conventional CT scanning may then be performed and only the information recorded in coincidence with certain phases of the cardiac cycle is compounded to produce cardiac images which are free from blurring. Alternatively, the X-ray tube may be gated on and off by the pulse derived from the cardiac cycle in order to reduce X-ray dosage. (U.K.)

  11. Small-animal SPECT and SPECT/CT: application in cardiovascular research

    International Nuclear Information System (INIS)

    Preclinical cardiovascular research using noninvasive radionuclide and hybrid imaging systems has been extensively developed in recent years. Single photon emission computed tomography (SPECT) is based on the molecular tracer principle and is an established tool in noninvasive imaging. SPECT uses gamma cameras and collimators to form projection data that are used to estimate (dynamic) 3-D tracer distributions in vivo. Recent developments in multipinhole collimation and advanced image reconstruction have led to sub-millimetre and sub-half-millimetre resolution SPECT in rats and mice, respectively. In this article we review applications of microSPECT in cardiovascular research in which information about the function and pathology of the myocardium, vessels and neurons is obtained. We give examples on how diagnostic tracers, new therapeutic interventions, pre- and postcardiovascular event prognosis, and functional and pathophysiological heart conditions can be explored by microSPECT, using small-animal models of cardiovascular disease. (orig.)

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

    OpenAIRE

    Othman, Khaled M.; Naglaa Youssef Assaf; Hanan Mohamed Farouk; Iman M. Aly Hassan

    2010-01-01

    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 an...

  13. 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.

  14. PET and SPECT in psychiatry

    International Nuclear Information System (INIS)

    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.

  15. Initial Investigation of Preclinical Integrated SPECT and MR Imaging

    OpenAIRE

    Hamamura, Mark J.; Ha, Seunghoon; Roeck, Werner W.; Wagenaar, Douglas J.; Meier, Dirk; Patt, Bradley E.; Nalcioglu, Orhan

    2010-01-01

    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 utilized a dual modality SPECT/MRI (MRSPECT) system to investigate the integration of SPECT and MRI for improved image accuracy. The MRSPECT system consisted of a cadmium-zinc-telluride (CZT) nuclear radiation detector interfaced with a ...

  16. 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.

  17. 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.)

  18. First determination of the heart-to-mediastinum ratio using cardiac dual isotope (123I-MIBG/99mTc-tetrofosmin) CZT imaging in patients with heart failure: the ADRECARD study

    International Nuclear Information System (INIS)

    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 123I-MIBG injection (236.4 ± 39.7 MBq). To localize the heart using D-SPECT, 99mTc-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 (123I and 99mTc) 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 123I MIBG HMR obtained using a CZT camera and that from conventional planar imaging. (orig.)

  19. Quantitative simultaneous 99mTc-ECD/123I-FP-CIT SPECT in Parkinson's disease and multiple system atrophy

    International Nuclear Information System (INIS)

    The purpose of this study was to investigate the feasibility and utility of dual-isotope SPECT for differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). Simultaneous 99mTc-ECD/123I-FP-CIT studies were performed in nine normal controls, five IPD patients, and five MSA patients. Projections were corrected for scatter, cross-talk, and high-energy penetration, and iteratively reconstructed while correcting for patient-specific attenuation and variable collimator response. Perfusion and dopamine transporter (DAT) function were assessed using voxel-based statistical parametric mapping (SPM2) and volume of interest quantitation. DAT binding potential (BP) and asymmetry index (AI) were estimated in the putamen and caudate nucleus. Striatal BP was lower in IPD (55%) and MSA (23%) compared to normal controls (p<0.01), and in IPD compared to MSA (p<0.05). AI was greater for IPD than for MSA and controls in both the caudate nucleus and the putamen (p<0.05). There was significantly decreased perfusion in the left and right nucleus lentiformis in MSA compared to IPD and controls (p<0.05). Dual-isotope studies are both feasible in and promising for the diagnosis of parkinsonian syndromes. (orig.)

  20. 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 ...

  1. Combined 201Tl and 67Ga brain SPECT in patients with suspected central nervous system lymphoma or germinoma. Clinical and economic value

    International Nuclear Information System (INIS)

    Surgical resection is costly and an unfavorable prognostic factor for primary central nervous system (CNS) lymphoma and germinoma patients. The purpose of this study was to assess the diagnostic and economic impact of combined 201Tl and 67Ga brain SPECT on the management of patients suspected of having CNS lymphoma or germinoma. Sequential 201Tl and 67Ga brain SPECT was performed in 40 patients with cranial tumors to assess the diagnostic and economic impact of combined 201Tl and 67Ga SPECT on the management of patients suspected of having CNS lymphoma or germinoma. All intracranial masses were pathologically confirmed. The final diagnoses of a total of 47 foci were: 11 non-Hodgkin's lymphomas in 10 patients, 3 germinomas in 2 patients, 10 glioblastomas in 9 patients, 10 cerebral metastases in 8 patients, 13 meningiomas in 11 patients. Decision-tree sensitivity analysis for pretest probability regarding expected cost saving was performed for introduction of the combined study. All but one focus of CNS lymphomas or germinomas (92.9%, 13/14) exhibited more intense uptake of 67Ga than of 201Tl (p201Tl than of 67Ga (p67Ga-positive and 201Tl-positive pattern with more intense uptake of 67Ga than 201Tl probably suggests CNS lymphoma or germinoma. This combination study appears to be cost-effective only in patients highly suspected of having CNS lymphoma or germinoma. (author)

  2. SPECT quantification of regional radionuclide distributions

    International Nuclear Information System (INIS)

    SPECT quantification of regional radionuclide activities within the human body is affected by several physical and instrumental factors including attenuation of photons within the patient, Compton scattered events, the system's finite spatial resolution and object size, finite number of detected events, partial volume effects, the radiopharmaceutical biokinetics, and patient and/or organ motion. Furthermore, other instrumentation factors such as calibration of the center-of-rotation, sampling, and detector nonuniformities will affect the SPECT measurement process. These factors are described, together with examples of compensation methods that are currently available for improving SPECT quantification. SPECT offers the potential to improve in vivo estimates of absorbed dose, provided the acquisition, reconstruction, and compensation procedures are adequately implemented and utilized. 53 references, 2 figures

  3. 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; Larroude, Charlotte Ellen; Kanters, Jørgen Kim; Boomsma, Frans; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    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 with...

  4. 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.

  5. A comparative study on PET and SPECT image formation systems for a proper scanner choice in a considered PET center

    International Nuclear Information System (INIS)

    In the last twenty years, the developed technology is being applied, making available better diagnoses and therapy to a variety of diseases. Since then the short-lived radionuclides were available only in the large physics research centers. The increasing clinical applications of radiopharmaceuticals have led to the rapid rise in the number of compact cyclotrons throughout the world. All medical cyclotrons currently available are suitable for sustaining programs for PET research and clinical application. To date, up to 122 medical cyclotrons have been established worldwide, and Brazil is about to install a new dedicated cyclotron (RDS111 from CTI), to its first PET Center, in Rio de Janeiro. Also the number of scanners in use in the world has increased, mainly those based on the positrons emission and annihilation. The better result gotten in the final contrast of the object imposes necessarily a comparative study and analysis of the image formation process, either in a system based on a Single Photon Emission Computerized Tomography (SPECT), as well as on Positron Emission Tomography (PET.) This comparative study should at least follow same increasing rates of the new devices with technological advances. That kind of study can be helpful on the decision of what type of scan should be the proper one, to a PET Center, on a specific region. Obviously, many other parameters are involved in that decision, and this discussion and analyses are the main subject of the present work. The objective is to make available a realistic comparative scenario, considering as many as possible the parameters involving. Many of the new devices have been introduced making great progresses. As an example, in the new PET scanners, the reduction of examination time, and the remarkable improvement on the diagnoses based on images. As a consequence, we have a broadening on the field of application, better performance, and making possible the precocious discovery of males. Presently multi

  6. Prognostic value of myocardial perfusion SPECT imaging in elderly patients without history of coronary artery disease and low prevalence of them

    International Nuclear Information System (INIS)

    Elderly patients without history of coronary artery disease are difficult to characterized because the clinical symptoms are often atypical, occult or absent. On the other hand, these patients frequently cannot achieve adequate level of exercise during stress testing and this limitation can compromise the diagnostic and prognostic ability of the test. Generally the prognostic value of myocardial perfusion SPECT is well established for a general population but not for elderly patients. Aim: This study assessed the prognostic value of Tc99m-sestamibi SPECT in a group of patients older than 65 years with low prevalence of coronary artery disease. Material and Methods: Population: 161 consecutive patients older than 65 years without history of coronary artery disease and low prevalence of them were studied with Tc99m-sestamibi SPECT perfusion imaging. Mean age 71 years old (65-87), male 55%, mean pretest likelihood 11%. Risk factors: diabetes 17%, high blood pressure 74%, high cholesterol 45%, smokers 88%. Stress test: bicycle exercise 39% and dipyridamole 61%. Myocardial perfusion SPECT: semiquantitative analysis to evaluate perfusion defects with a 14-segments model and 4-point scoring system for uptake reduction. Scintigraphic indices: SSS (sum of the stress scores), SRS (sum of the rest scores) and SDS (SSS-SRS). Follow up: cardiac events: hard (acute myocardial infarction and cardiac death) and soft (need for PTCA/CABG and angina). Results: Mean follow up: 508 days. Events rate: hard 0.6% (1 acute myocardial infarction), soft 5.6%. Univariate analysis identified sex (p=0.017) and SDS (p=0.009) as cardiac events predictors. Complete or reduced (independent variables which predicted events) logistic regression analysis correctly predicted the absence of events but did not predict the presence of events. Conclusion: In this elderly population with a low clinical risk where the stress test is a suboptimal method of study for coronary artery disease, semiquantitative

  7. 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.)

  8. Brain SPECT in psychiatry: Delusion or reality?

    International Nuclear Information System (INIS)

    Aim: The need for functional information is becoming increasingly evident for proper therapeutic approaches to the treatment and follow up of psychiatric diseases. While data on this subject already exists, there is a general lack of consensus about the use of brain SPECT in this domain and also a considerable negative prejudice due to a number of factors including poor quality imaging and unrealistic expectations. Based on a large group of brain SPECT-s performed over the past 3 years we attempted to sort and refine the indications for SPECT in psychiatry. Materials and Methods: High resolution brain SPECT was performed with triple head gamma camera, super-high resolution fan beam collimator and Tc-HMPAO. A comprehensive semiquantitative color, 3D surface as well as multi-thresholded volume display was routinely used and supplemented by automatic realignment in case of longitudinal follow-up. Results: 470 brain SPECT-s done on 432 patients were all referred by psychiatrists or neuro-psychiatrists for a wide spectrum of psychiatric diseases and ranged in age from 7 to 88 years. The most common primary reasons for referral were : attention deficit hyperactive disorder (ADHD); anxiety; obsessive-compulsive disease, depression (refractory, chronic, bipolar ), impulse control problems; oppositional defiance, post traumatic brain injury; seizures, learning difficulties, pervasive development disorders, memory loss and differential of dementia. Among common denominators were long duration of the disease, unresponsiveness to treatment, worsening of clinical status, and presence of multiple conditions at the same time. The multiparametric display used enabled a comprehensive evaluation of the brain volume which included the hemispheric surfaces; the basal ganglia (striatum) and the thalamus, several components of the limbic and paralimbic systems: anterior and posterior cingulate and their respective subdivisions, insula-s and their subdivisions, apical and mesial

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

    International Nuclear Information System (INIS)

    To evaluate the potential cost-effectiveness of exercise 201Tl 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 201Tl SPECT for diagnosing angina pectoris, and its prevalence were assumed to be 95%, 85%, and 33%, respectively. The mean costs were 84.9 x 104 yen/patient in the CAG group, 30.2 x 104 yen/patient in the follow-up group, and 71.0 x 104 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 104 yen/patient, as compared to the CAG group. In conclusion, the exercise 201Tl myocardial SPECT strategy for patients with chest pain has the potential to reduce health care costs in Japan. (author)

  10. SPECT assay of radiolabeled monoclonal antibodies

    International Nuclear Information System (INIS)

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

  11. 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 and...

  12. 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

  13. A system for seismocardiography-based identification of quiescent heart phases: implications for cardiac imaging.

    Science.gov (United States)

    Wick, Carson A; Su, Jin-Jyh; McClellan, James H; Brand, Oliver; Bhatti, Pamela T; Buice, Ashley L; Stillman, Arthur E; Tang, Xiangyang; Tridandapani, Srini

    2012-09-01

    Seismocardiography (SCG), a representation of mechanical heart motion, may more accurately determine periods of cardiac quiescence within a cardiac cycle than the electrically derived electrocardiogram (EKG) and, thus, may have implications for gating in cardiac computed tomography. We designed and implemented a system to synchronously acquire echocardiography, EKG, and SCG data. The device was used to study the variability between EKG and SCG and characterize the relationship between the mechanical and electrical activity of the heart. For each cardiac cycle, the feature of the SCG indicating Aortic Valve Closure was identified and its time position with respect to the EKG was observed. This position was found to vary for different heart rates and between two human subjects. A color map showing the magnitude of the SCG acceleration and computed velocity was derived, allowing for direct visualization of quiescent phases of the cardiac cycle with respect to heart rate. PMID:22581141

  14. Novel high resolution SPECT instrumentation and techniques for molecular imaging of small animals

    International Nuclear Information System (INIS)

    The main purpose of the project is the development and tuning of an advanced detector system for molecular imaging with radionuclides on small animal. The equipment has sub-millimeter spatial resolution, adequate sensitivity and field of view, It is designed for studies, on animal models, of diagnostic and/or therapeutic techniques in cardiovascular diseases, such as detection and identification of vulnerable plaques in atherosclerosis and stem cell therapy for cardiac repair. The present activities is carried on in collaboration with groups from Johns Hopkins University (Baltimore), Jefferson Lab (Newport News), Istituto Nazionale Fisica Nucleare (INFN) and ISS (Dept. Technology and Health and Dept. Therapeutic Research and Medicines Evaluation). The main results of the last two years are summarized as follows: development of the SPECT system prototype; set up of the technique for vulnerable plaques detection;demonstration of detectability of the cardiac perfusion via peritoneum injection of the radiotracer

  15. A Monte Carlo simulation study of the feasibility of a high resolution parallel-hole collimator with a CdTe pixelated semiconductor SPECT system

    International Nuclear Information System (INIS)

    It is recommended that a pixelated parallel-hole collimator in which the hole and pixel sizes are equal be used to improve the sensitivity and spatial resolution when using a small pixel size and a single-photon emission computed tomography (SPECT) system with pixelated semiconductor detector materials (e.g., CdTe and CZT). However, some significant problems arise in the manufacturing of a pixelated parallel-hole collimator. Therefore, we sought to simulate a pixelated semiconductor SPECT system with various collimator geometric designs. The purpose of this study was to compare the quality of images generated with a pixelated semiconductor SPECT system simulated with pixelated parallel-hole collimators of various geometric designs. The sensitivity and spatial resolution of the various collimator geometric designs with varying septal heights and hole sizes were measured. Moreover, to evaluate the overall performance of the imaging system, a hot-rod phantom was designed using a Monte Carlo simulation. According to the results, the average sensitivity using a 15 mm septal height was 1.80, 2.87, and 4.16 times higher than that obtained with septal heights of 20, 25, and 30 mm, respectively. Also, the average spatial resolution using the 30 mm septal height was 44.33, 22.08, and 9.26% better than that attained with 15, 20, and 25 mm septal heights, respectively. When the results acquired with 0.3 and 0.6 mm hole sizes were compared, the average sensitivity with the 0.6 mm hole size was 3.97 times higher than that obtained with the 0.3 mm hole size, and the average spatial resolution with the 0.3 mm hole size was 45.76% better than that with the 0.6 mm hole size. We have presented the pixelated parallel-hole collimators of various collimator geometric designs and evaluations. Our results showed that the effect of various collimator geometric designs can be investigated by Monte Carlo simulation so as to evaluate the feasibility of a high resolution parallel

  16. A Monte Carlo simulation study of the feasibility of a high resolution parallel-hole collimator with a CdTe pixelated semiconductor SPECT system

    Science.gov (United States)

    Lee, Y.-J.; Park, S.-J.; Lee, S.-W.; Kim, D.-H.; Kim, Y.-S.; Jo, B.-D.; Kim, H.-J.

    2013-03-01

    It is recommended that a pixelated parallel-hole collimator in which the hole and pixel sizes are equal be used to improve the sensitivity and spatial resolution when using a small pixel size and a single-photon emission computed tomography (SPECT) system with pixelated semiconductor detector materials (e.g., CdTe and CZT). However, some significant problems arise in the manufacturing of a pixelated parallel-hole collimator. Therefore, we sought to simulate a pixelated semiconductor SPECT system with various collimator geometric designs. The purpose of this study was to compare the quality of images generated with a pixelated semiconductor SPECT system simulated with pixelated parallel-hole collimators of various geometric designs. The sensitivity and spatial resolution of the various collimator geometric designs with varying septal heights and hole sizes were measured. Moreover, to evaluate the overall performance of the imaging system, a hot-rod phantom was designed using a Monte Carlo simulation. According to the results, the average sensitivity using a 15 mm septal height was 1.80, 2.87, and 4.16 times higher than that obtained with septal heights of 20, 25, and 30 mm, respectively. Also, the average spatial resolution using the 30 mm septal height was 44.33, 22.08, and 9.26% better than that attained with 15, 20, and 25 mm septal heights, respectively. When the results acquired with 0.3 and 0.6 mm hole sizes were compared, the average sensitivity with the 0.6 mm hole size was 3.97 times higher than that obtained with the 0.3 mm hole size, and the average spatial resolution with the 0.3 mm hole size was 45.76% better than that with the 0.6 mm hole size. We have presented the pixelated parallel-hole collimators of various collimator geometric designs and evaluations. Our results showed that the effect of various collimator geometric designs can be investigated by Monte Carlo simulation so as to evaluate the feasibility of a high resolution parallel

  17. Using the Wiener estimator to determine optimal imaging parameters in a synthetic-collimator SPECT system used for small animal imaging

    Science.gov (United States)

    Lin, Alexander; Johnson, Lindsay C.; Shokouhi, Sepideh; Peterson, Todd E.; Kupinski, Matthew A.

    2015-03-01

    In synthetic-collimator SPECT imaging, two detectors are placed at different distances behind a multi-pinhole aperture. This configuration allows for image detection at different magnifications and photon energies, resulting in higher overall sensitivity while maintaining high resolution. Image multiplexing the undesired overlapping between images due to photon origin uncertainty may occur in both detector planes and is often present in the second detector plane due to greater magnification. However, artifact-free image reconstruction is possible by combining data from both the front detector (little to no multiplexing) and the back detector (noticeable multiplexing). When the two detectors are used in tandem, spatial resolution is increased, allowing for a higher sensitivity-to-detector-area ratio. Due to variability in detector distances and pinhole spacings found in synthetic-collimator SPECT systems, a large parameter space must be examined to determine optimal imaging configurations. We chose to assess image quality based on the task of estimating activity in various regions of a mouse brain. Phantom objects were simulated using mouse brain data from the Magnetic Resonance Microimaging Neurological Atlas (MRM NeAt) and projected at different angles through models of a synthetic-collimator SPECT system, which was developed by collaborators at Vanderbilt University. Uptake in the different brain regions was modeled as being normally distributed about predetermined means and variances. We computed the performance of the Wiener estimator for the task of estimating activity in different regions of the mouse brain. Our results demonstrate the utility of the method for optimizing synthetic-collimator system design.

  18. Physiological role of transverse-axial tubular system in cardiac ventricular myocytes: a simulation study

    Czech Academy of Sciences Publication Activity Database

    Pásek, Michal; Šimurda, J.; Orchard, C.; Christé, G.

    Lyon : IEEE, 2005, s. 393-395. [Computers in cardiology. Lyon (FR), 25.09.2005-28.09.2005] Institutional research plan: CEZ:AV0Z20760514 Keywords : cardiac cell * tubular system * quantitative modelling Subject RIV: BO - Biophysics

  19. SPECT in psychiatry

    International Nuclear Information System (INIS)

    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-D2 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.)

  20. Natriuretic peptides in relation to the cardiac innervation and conduction system.

    Science.gov (United States)

    Hansson, Magnus

    2002-09-01

    During the past two decades, the heart has been known to undergo endocrine action, harbouring peptides with hormonal activities. These, termed "atrial natriuretic peptide (ANP)," "brain natriuretic peptide (BNP)," and "C-type natriuretic peptide (CNP)," are polypeptides mainly produced in the cardiac myocardium, where they are released into the circulation, producing profound hypotensive effects due to their diuretic, natriuretic, and vascular dilatory properties. It is, furthermore, well established that cardiac disorders such as congestive heart failure and different forms of cardiomyopathy are combined with increased expression of ANP and BNP, leading to elevated levels of these peptides in the plasma. Besides the occurrence of natriuretic peptides (NPs) in the ordinary myocardium, the presence of ANP in the cardiac conduction system has been described. There is also evidence of ANP gene expression in nervous tissue such as the nodose ganglion and the superior cervical ganglion of the rat, ganglia known to be involved in the neuronal regulation of the heart. Furthermore, in the mammalian heart, ANP appears to affect the cardiac autonomic nervous system by sympathoinhibitory and vagoexcitatory actions. This article provides an overview of the relationship between the cardiac conduction system, the cardiac innervation and NPs in the mammalian heart and provides data for the concept that ANP is also involved in neuronal cardiac regulation. PMID:12226807

  1. Design study of a cardiac-dedicated PET system

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hao, E-mail: penghao@mcmaster.ca [Department of Medical Physics, McMaster University, Canada L8S 4K1 (Canada); Department of Electrical and Computer Engineering, McMaster University, Canada L8S 4K1 (Canada)

    2015-04-11

    The work studies the feasibility of developing a cardiac-dedicated PET system using Monte Carlo simulation tools. The proposed system comprises a dual-panel geometry and both panels utilize fine crystal elements (~2–3 mm) to help improve high spatial resolution. The system performances were studied with respect to photon detection sensitivity, count-rate performances, spatial resolution, depth-of-interaction (DOI) capability, and potential contrast recovery improvement due to time-of-flight (TOF). For a 2:3 dual panel configuration (front panel: 24.0×18.0 cm{sup 2} and back panel: 36.0×27.0 cm{sup 2}), the system is able to achieve a peak photon sensitivity of ~13.0% at the location of the heart. For count-rate performances, the system is able to yield a continuous increase of noise equivalent count rate (NECR) as a function of the total activity of radiotracers between 10 mCi and 50 mCi. When crystal elements of 2×2×20 cm{sup 3} are deployed in the front panel and crystal elements of 3×3×20 cm{sup 3} are deployed in the back panel, the proposed system is not only able to revolve 2 mm diameter spheres in the image slices parallel to the panels but also demonstrates good resolution uniformity of less than 5%. On the other hand, significant resolution degradation occurs in the direction perpendicular to the panels due to the following two factors: limited angular coverage and finite DOI resolution. Such degradation was quantitatively analyzed for five different DOI resolutions (0 mm, 2.5 mm, 5 mm, 10 mm and 20 mm), as well as three different crystal configurations. Finally, the contrast study with a heart-like phantom (comprising lumen, aortic wall, myocardium and small lesions) indicates that TOF capability (time resolution: 250–500 ps) does not significantly improve image quality and lesion detectability, in terms of contrast-to-noise ratio (CNR)

  2. 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

  3. Scatter and crosstalk corrections for 99mTc/123I dual-radionuclide imaging using a CZT SPECT system with pinhole collimators

    International Nuclear Information System (INIS)

    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 99mTc/123I 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 99mTc and 123I 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 observed with both

  4. Integred record system for standard reporting operations in pediatric cardiac surgey and complexity estimation

    OpenAIRE

    Taddei, Alessandro; Dalmiani, Stefano; Baldacci, Silvia; Piccini, Giacomo; Crucean, Andrea; Bernabei, Massimo; Luisi, Stefano; Vanini, Vittorio

    2002-01-01

    The Hospital Information System, first developed at our main institute for the integration of clinical, administrative and management resources in Cardiology, has been recently extended for use at our section specialised in Cardiac Surgery. Extension of the electronic medical record (EMR) to the management of patients admitted in Pediatric Cardiac Surgery started with the development of a system for reporting operations in structured form and for estimating their complexity, according to a mo...

  5. Optimization of the SPECT systems based on a CdTe pixelated semiconductor detector using novel parallel-hole collimators

    International Nuclear Information System (INIS)

    , and based on our results, we recommend using 4:1 ratio with CdTe pixelated semiconductor detector in SPECT system

  6. A comparative study on PET and SPECT image formation systems for a proper scanner choice in a considered PET center

    International Nuclear Information System (INIS)

    Full text: In the last twenty years, the conjunction of technology and research had provided exceptional conditions for improvements on the quality of life, specially on nuclear medicine. In this area, the developed technology is being applied, making available better diagnoses and therapy to a variety of diseases. Since then the short-lived radionuclides were available only in the large physics research centers. The increasing clinical applications have led to the rapid rise in the number of compact cyclotrons throughout the world. All medical cyclotrons currently are suitable for sustaining programs for PET research and clinical application. To date, up to 122 medical cyclotrons have been established worldwide, and Brazil is about to install a new dedicated cyclotron (RDS111 from CTI), to its first PET Center, in Rio de Janeiro. Also the number of scanners worldwide has increased, mainly those based on the positrons emission and annihilation. The better result gotten in the final contrast of the object imposes a comparative study and analysis of the image formation process, either in a system based on a Single Photon Emission Computerized Tomography (SPECT), as well as on Positron Emission Tomography (PET.) This comparative study should at least follow same increasing rates of the new devices with technological advances. That kind of study can be helpful on the decision of what type of scan should be the proper one, to a PET Center, on a specific region. Obviously, many other parameters are involved in that decision, and this discussion and analyses are the main subject of the present work. The objective is to make available a realistic comparative scenario. Many of the new devices have been introduced making progresses. As an example, in the new PET scanners, the reduction of examination time, and the remarkable improvement on the diagnoses based on images. As a consequence, we have a broadening on application, better performance, and making possible the

  7. Small-animal SPECT and SPECT/CT: application in cardiovascular research

    OpenAIRE

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

    2010-01-01

    Preclinical cardiovascular research using noninvasive radionuclide and hybrid imaging systems has been extensively developed in recent years. Single photon emission computed tomography (SPECT) is based on the molecular tracer principle and is an established tool in noninvasive imaging. SPECT uses gamma cameras and collimators to form projection data that are used to estimate (dynamic) 3-D tracer distributions in vivo. Recent developments in multipinhole collimation and advanced image reconstr...

  8. Rapid construction of pinhole SPECT system matrices by distance-weighted Gaussian interpolation method combined with geometric parameter estimations

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ming-Wei; Chen, Yi-Chun, E-mail: ycchen@dop.ncu.edu.tw

    2014-02-11

    In pinhole SPECT applied to small-animal studies, it is essential to have an accurate imaging system matrix, called H matrix, for high-spatial-resolution image reconstructions. Generally, an H matrix can be obtained by various methods, such as measurements, simulations or some combinations of both methods. In this study, a distance-weighted Gaussian interpolation method combined with geometric parameter estimations (DW-GIMGPE) is proposed. It utilizes a simplified grid-scan experiment on selected voxels and parameterizes the measured point response functions (PRFs) into 2D Gaussians. The PRFs of missing voxels are interpolated by the relations between the Gaussian coefficients and the geometric parameters of the imaging system with distance-weighting factors. The weighting factors are related to the projected centroids of voxels on the detector plane. A full H matrix is constructed by combining the measured and interpolated PRFs of all voxels. The PRFs estimated by DW-GIMGPE showed similar profiles as the measured PRFs. OSEM reconstructed images of a hot-rod phantom and normal rat myocardium demonstrated the effectiveness of the proposed method. The detectability of a SKE/BKE task on a synthetic spherical test object verified that the constructed H matrix provided comparable detectability to that of the H matrix acquired by a full 3D grid-scan experiment. The reduction in the acquisition time of a full 1.0-mm grid H matrix was about 15.2 and 62.2 times with the simplified grid pattern on 2.0-mm and 4.0-mm grid, respectively. A finer-grid H matrix down to 0.5-mm spacing interpolated by the proposed method would shorten the acquisition time by 8 times, additionally. -- Highlights: • A rapid interpolation method of system matrices (H) is proposed, named DW-GIMGPE. • Reduce H acquisition time by 15.2× with simplified grid scan and 2× interpolation. • Reconstructions of a hot-rod phantom with measured and DW-GIMGPE H were similar. • The imaging study of normal

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-15

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

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

    International Nuclear Information System (INIS)

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

  11. Cardiac arrhythmias and left ventricular hypertrophy in systemic hypertension

    International Nuclear Information System (INIS)

    Background: Hypertensive left ventricular hypertrophy (LVH) is associated with increased risk of arrhythmias and mortality. Objective was to investigate the prevalence of cardiac arrhythmias and LVH in systemic hypertension. Methods: In all subjects blood pressure was measured, electrocardiography and echocardiography was done. Holter monitoring and exercise test perform in certain cases. There were 500 hypertensive patients, 156 (31.2%) men and 344 (69%) women >30 years of age in the study. Among them 177 (35.4%) were diabetic, 224 (45%) were dyslipidemia, 188 (37.6%) were smokers, and 14 (3%) had homocysteinemia. Mean systolic BP (SBP) was 180 +- 20 mm Hg and diastolic BP (DBP) was 95 +- 12 in male and female patients. Left ventricular mass index (LVMI) was 119.2 +- 30 2 2gm/m in male while 103 +- 22 gm/m in female patients. Palpitation was seen in 126 (25%) male and 299 (59.8%) female patients. Atrial fibrillation was noted in 108 (21.6%) male and 125 (25%) female patients, 30 (6%) male and 82 (16.4%) female patients had atrial flutter. Ventricular tachycardia was noted in 37 (7.4%) male and 59 (11.8%) female patients. Holter monitoring showed significant premature ventricular contractions (PVC'S) in 109 (21.8%) male and 128 (25.69%) female patients while Holter showed atrial arrhythmias (APC'S) in 89 (17.8%) males and 119 (23.8%) females. Angiography findings diagnosed coronary artery disease in 119 (23.8%) with CAD male and 225 (45%) without CAD while 47 (9.4%) females presented with CAD and 109 (21.8%) without CAD. Conclusion: A significant association has been demonstrated between hypertension and arrhythmias. Diastolic dysfunction of the left ventricle, left atrial size and function, as well as LVH have been suggested as the underlying risk factors for supraventricular, ventricular arrhythmias and sudden death in hypertensives with LVH. (author)

  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. Computer-assisted system for diagnosing degenerative dementia using cerebral blood flow SPECT and 3D-SSP. A multicenter study

    International Nuclear Information System (INIS)

    Due to increasing numbers of patients with dementia, more physicians who do not specialize in brain nuclear medicine are being asked to interpret SPECT images of cerebral blood flow. We conducted a multicenter study to determine whether a computer-assisted diagnostic system Z-score summation analysis method (ZSAM) using three-dimensional stereotactic surface projections (3D-SSP) can differentiate Alzheimer's disease (AD)/dementia with Lewy bodies (DLB) and non-AD/DLB in institutions using various types of gamma cameras. We determined the normal thresholds of Z-sum (summed Z-score) within a template region of interest for each single photon emission computed tomography (SPECT) device and then compared them with the Z-sums of patients and calculated the accuracy of the differential diagnosis by ZSAM. We compared the diagnostic accuracy between ZSAM and visual assessment. We enrolled 202 patients with AD (mean age, 76.8 years), 40 with DLB (mean age 76.3 years) and 36 with non-AD/DLB (progressive supranuclear palsy, n=10; frontotemporal dementia, n=20; slowly progressive aphasia, n=2 and one each with idiopathic normal pressure hydrocephalus, corticobasal degeneration, multiple system atrophy and Parkinson's disease) who underwent N-isopropyl-p-[123I] iodoamphetamine cerebral blood flow SPECT imaging at each participating institution. The ZSAM sensitivity to differentiate between AD/DLB and non-AD/DLB in all patients, as well as those with mini-mental state examination scores of ≥24 and 20-23 points were 88.0, 78.0 and 88.4%, respectively, with specificity of 50.0, 44.4 and 60.0%, respectively. The diagnostic accuracy rates were 83.1, 72.9 and 84.2%, respectively. The areas under receiver operating characteristics curves for visual inspection by four expert raters were 0.74-0.84, 0.66-0.85 and 0.81-0.93, respectively, in the same patient groups. The diagnostic accuracy rates were 70.9-89.2%, 50.9-84.8% and 76.2-93.1%, respectively. The diagnostic accuracy

  14. Determination of optimum filter in inferolateral view of myocardial SPECT

    International Nuclear Information System (INIS)

    Background: In myocardial perfusion SPECT imaging, images are degraded by photon attenuation, distance-dependent collimator, detector response and photon scattering. As filters greatly affect quality of nuclear medicine images, in this study determination of optimum filter for inferolateral view is our prime objective. Materials and Methods: .A phantom simulating heart left ventricle was built. About 1mCi of 99mTc, was injected into the phantom. Images were taken from this phantom. Parzen, Hamming, Hanning, Butter worth and Gaussian filters were exerted on the images obtained from the phantom.. By defining some criteria such as contrast, signal to noise ratio, and defect size delectability, the best filter was determined for our ADAC spect system at our nuclear medicine center. In this study, 27 patients who previously had undergone coronary angiography were chosen to be included. All of these patients revealed significant stenosis in the left circumflex artery. Myocardial SPECT images of these patients had inferolateral defect. The images of these patients were processed with 12 filters including the optimum filters obtained from phantom study and some other non-optimum filters. A nuclear medicine physician quantified the results by assigmng mark from 0 to 4. to every image. 0 mark for images that didn't show the defect properly and 4 for the best one. The data from patient study were analyzed with non-related, non -parametric Friedman test. Results: Nyquist frequency of 0.325 and 0.5 were obtained as the optimum cut-off frequencies for hamming and Hanning filters respectively. Order 11 and cut-off frequency of 0.45 and order 20. with cut-off frequency of 0.5 were found to be optimum for Butter worth and Gaussian filters. In patient studies it was found that, Butter worth filter with cut-off frequency of 0.45 and order of 11 produced the best quality images. Conclusion: In this study. Butter worth filter with cut-off frequency of 0.45 and order of 11 was the

  15. Myocardial perfusion SPECT imaging in patients with myocardial bridging

    International Nuclear Information System (INIS)

    Objective: Stress myocardial perfusion SPECT imaging was used to assess myocardial ischemia in patients with myocardial bridging. Methods: Ninety-six patients with myocardial bridging of the left anterior descending artery documented by coronary angiography were included in this study. All under- went exercise or pharmacological stress myocardial perfusion SPECT assessing myocardial ischemia. None had prior myocardial infarction. One year follow-up by telephone interview was performed in all patients. Results The mean stenotic severity of systolic phase on angiography was (65 ± 19)%. In the SPECT study, 20 of 96 (20.8%) patients showed abnormal perfusion. This percentage was significantly higher than that of stress electrocardiogram (ECG). The higher positive rate of SPECT perfusion images was showed in the group of patients with severe systolic narrowing (≥75%) than that with mild-to-moderate systolic narrowing (50% vs 6.3%, P<0.001). The prevalence of abnormal image was significantly higher in ELDERLY PEOPLE; patients with STT change on rest ECG than in those with normal rest ECG (54.2% vs 9.7%, P<0.001). During follow-up, one patient with abnormal SPECT perfusion image sustained angina and accepted percutaneous coronary intervention, and no cardiac event occurred in patients with normal images. Conclusions: Stress myocardial perfusion SPECT imaging can be used effectively for assessing myocardial ischemia and has potential prognostic value for patients with myocardial bridging. (authors)

  16. Usefulness of myocardial perfusion SPECT after percutaneous coronary intervention (PCI)

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-02-15

    As the indication of percutaneous coronary intervention (PCI) has expanded to the more difficult and complicated cases, frequent restenosis is still expected after PCI. According to AHA/ACC guideline of the present time, routine use of myocardial perfusion single photon emission tomography (SPECT) is not recommended after coronary intervention, but symptom itself or exercise EKG is not enough for the detection of restensis or for the prediction of event-free survival. In high risk and/or symptomatic subjects, direct coronary angiography is required. Myocardial perfusion SPECT could detect restenosis in 79% of the patients if performed 2 to 9 months after PCI. Reversible perfusion decrease in the myocardial perfusion SPECT is known to be the major prognostic indicator of major adverse cardiac event in PCI patients and also the prognosis is benign in the patients without reversible perfusion decrease. Though the cumulated specificity is 79% in the literature and optimal timing of myocardial perfusion SPECT is in controversy, SPECT is recommended even in asymptomatic patients at 3 to 9 months after PCI. Considering the evidences recently reported in the literature, myocardial perfusion SPECT is useful for risk stratification and detection of coronary artery restenosis requiring re-intervention in the asymptomatic patients after PCI.

  17. 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. PMID:26857347

  18. 18F-DG PET and RCBF SPECT in epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, C. [Dept. of Nuclear Medicine, Univ. Bonn (Germany); Gruenwald, F. [Dept. of Nuclear Medicine, Univ. Bonn (Germany); Shih, W.J. [Dept. of Diagnostic Radiology, Nuclear Medicine Div., Kentucky Univ., KY (United States); Biersack, H.J. [Dept. of Nuclear Medicine, Univ. Bonn (Germany)

    1994-12-31

    Functional imaging of cortical metabolism and perfusion is of growing importance in the presurgical evaluation of patients suffering from intractable epilepsy. PET and SPECT are of proven value in functional imaging prior to epilepsy surgery. To date the best clinical experience was gained by using 18-fluorodeoxyglucose for PET and tracers for measurement of regional cerebral blood flow (rCBF) like 99mTc-HMPO or 99mTc-ECD for SPECT respectively. Their relative contribution towards detection of a probable focus site in epilepsy is still controversial. To determine the relative value of both procedures the literature has been reviewed with special respect to ictal SPECT studies. With regard to different standards used for correlation a relative sensitivity of 62.4% was found for interictal rCBF SPECT. 71% for 18-FDG-PET and 87% for ictal rCBF SPECT studies. In conclusion, earlier reported advantages of PET over SPECT seem to closely reflect the better spatial resolution of PET. Modern SPECT systems, dedicated for brain SPECT, provide appropriate and almost equal sensitivity. Regarding the limited specificity of interictal studies, both rCBF SPECT and FDG-PET need precise indications. However, further to detection of a probable focus site, metabolism and rCBF studies seem to be of value to predicit the post-surgical patients outcome as to seizure frequency and mental functions secondarily affected by epilepsy surgery such as memory impairment. Ictal rCBF SPECT provides higher sensitivity and specificity and virtually allows the detection lateralisation in almost every case. This means that a relatively precise anatomical localisation of an epileptogenic focus is being found in a rising number of patients. (orig.) [Deutsch] Die Bedeutung der funktionellen Bildgebung unter Verwendung der PET und der SPECT zum Nachweis einer gestoerten regionalen Durchblutung oder eines Zerebralen Hyopmetabolismus von Glukose hat heute einen festen Platz in der praechirurgischen

  19. Multiple-pinhole SPECT/CBCT system and its application on animal model on tumor

    Science.gov (United States)

    Bao, Shanglian; Li, Jun

    2011-12-01

    Characterized by wisdom and creativity, human beings are huge, complex, giant systems. Each person's life is experienced the process of birth, growth, aging and death. The genetic stability keeps human beings no change, and the mutation keeps the human beings in progress. The balance between stability and mutation are controlled by the nature laws automatically. But the balance often broken because the body's biochemical processes is out of order in vivo, which is scaled by quantitative concentrations for all molecular in human body. Now day, the biomedical imaging tools can investigate these process quantitatively.

  20. Differential effects of defibrillation on systemic and cardiac sympathetic activity

    OpenAIRE

    Bode, F; U. Wiegand; Raasch, W; Richardt, G.; Potratz, J

    1998-01-01

    Objective—To assess the effect of defibrillation shocks on cardiac and circulating catecholamines.
Design—Prospective examination of myocardial catecholamine balance during dc shock by simultaneous determination of arterial and coronary sinus plasma concentrations. Internal countershocks (10-34 J) were applied in 30 patients after initiation of ventricular fibrillation for a routine implantable cardioverter defibrillator test. Another 10 patients were externally cardioverted (50-360 J) for at...

  1. [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. PMID:26596202

  2. The usefulness of treatment evaluation of severe heart failure by ECG-gated myocardial SPECT

    International Nuclear Information System (INIS)

    Our purpose of study was to investigate the usefulness of treatment evaluation of severe heart failure by Electrocardiogram (ECG)-gated myocardial single photon emission computed tomography (SPECT). We evaluated the cardiac function in the case of severe heart failure by gated SPECT and compared it with the cardiac function obtained by left ventriculography (LVG), echocardiography, cardiac MRI, and B-type natriuretic peptide (BNP) values. We investigated the correlation of ejection fraction (EF), time lag of wall motion between the septal and lateral walls of the left ventricle for cardiac resynchronization therapy (CRT) and wall thickening (WT). We classified the left ventricular (LV) into basal, middle and apical areas for comparison of WT. We investigated the effect of a perfusion defect score in these comparisons. The gated SPECT results were correlated with comparative subjects in EF. The results were correlated with MRI on the middle area of the LV in the comparison of WT. We thought it was possible that there was an effect from a perfusion defect score in a time lag comparison of wall motion. Treatment evaluation of severe heart failure by gated SPECT is useful, because it is able to obtain three-dimensional cardiac function analysis, and it offers objectivity and reproducible quantitative evaluation. At the same time, perfusion SPECT is helpful for CRT and LV-plasty. (author)

  3. Validation of a short-scan-time imaging protocol for thallium-201 myocardial SPECT with a multifocal collimator

    International Nuclear Information System (INIS)

    IQ-SPECT (Siemens AG, Munich, Germany) is a highly sensitive single-photon-emission computed tomography (SPECT) myocardial perfusion imaging (MPI) system that uses a multifocal collimator. We searched for a suitable protocol for short-time imaging by IQ-SPECT in thallium-201 (Tl-201) MPI by evaluating phantom images and also by comparing human IQ-SPECT images with conventional SPECT images as reference standards. We assessed the image quality using the normalized mean square error (NMSE) and drew up count profiles in Tl-201 SPECT images acquired with IQ-SPECT in a phantom study. We also performed Tl-201 stress myocardial SPECT/CT in 21 patients and compared delayed images acquired by using IQ-SPECT with 36 or 17 views per head with images obtained by using conventional SPECT. The NMSE of SPECT images from IQ-SPECT with 36 views was approximately one-fifth of that with 17 views. The myocardial count profile of images with 17 views was lower than those of images with 36 or 104 views in some regions. Defect scores were significantly lower, and image quality scores higher, in images from conventional SPECT than in those from IQ-SPECT with 17 views. Defect scores and image quality scores were equivalent in images from conventional SPECT and those from IQ-SPECT with 36 views. Agreement with the results of conventional SPECT in terms of coronary artery territory-based defect judgment was the best in IQ-SPECT with 36 views with computed tomography-derived attenuation correction (CTAC): the kappa values for IQ-SPECT with 36 views were 0.76 (without CTAC) and 0.83 (with CTAC), and those for IQ-SPECT with 17 views were 0.62 (without CTAC) and 0.59 (with CTAC). The difference in quantitative tracer uptake between conventional SPECT images and IQ-SPECT images was significantly greater for IQ-SPECT images with 17 views than for those with 36 views. Scanning with 36 views per head with CTAC may be appropriate for Tl-201 MPI using IQ-SPECT, because it provides images equivalent to

  4. 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

  5. Lipid-Calcium Phosphate Nanoparticles for Delivery to the Lymphatic System and SPECT/CT Imaging of Lymph Node Metastases

    OpenAIRE

    Tseng, Yu-cheng; Xu, Zhenghong; Guley, Kevin; Yuan, Hong; Huang, Leaf

    2014-01-01

    A lipid/calcium/phosphate (LCP) nanoparticle (NP) formulation (particle diameter ~25 nm) with superior siRNA delivery efficiency was developed and reported previously. Here, we describe the successful formulation of 111In into LCP for SPECT/CT imaging. Imaging and biodistribution studies showed that, polyethylene glycol grafted 111In-LCP preferentially accumulated in the lymph nodes at ~70% ID/g in both C57BL/6 and nude mice when the improved surface coating method was used. Both the liver an...

  6. SPECT in psychiatry

    International Nuclear Information System (INIS)

    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.)

  7. 18F-DG PET and RCBF SPECT in epilepsy

    International Nuclear Information System (INIS)

    Functional imaging of cortical metabolism and perfusion is of growing importance in the presurgical evaluation of patients suffering from intractable epilepsy. PET and SPECT are of proven value in functional imaging prior to epilepsy surgery. To date the best clinical experience was gained by using 18-fluorodeoxyglucose for PET and tracers for measurement of regional cerebral blood flow (rCBF) like 99mTc-HMPO or 99mTc-ECD for SPECT respectively. Their relative contribution towards detection of a probable focus site in epilepsy is still controversial. To determine the relative value of both procedures the literature has been reviewed with special respect to ictal SPECT studies. With regard to different standards used for correlation a relative sensitivity of 62.4% was found for interictal rCBF SPECT. 71% for 18-FDG-PET and 87% for ictal rCBF SPECT studies. In conclusion, earlier reported advantages of PET over SPECT seem to closely reflect the better spatial resolution of PET. Modern SPECT systems, dedicated for brain SPECT, provide appropriate and almost equal sensitivity. Regarding the limited specificity of interictal studies, both rCBF SPECT and FDG-PET need precise indications. However, further to detection of a probable focus site, metabolism and rCBF studies seem to be of value to predicit the post-surgical patients outcome as to seizure frequency and mental functions secondarily affected by epilepsy surgery such as memory impairment. Ictal rCBF SPECT provides higher sensitivity and specificity and virtually allows the detection lateralisation in almost every case. This means that a relatively precise anatomical localisation of an epileptogenic focus is being found in a rising number of patients. (orig.)

  8. Usefulness of brain SPECT

    International Nuclear Information System (INIS)

    Brain SPECT was not effectively exploited until I-123 isopropyl amphetamine (IAMP), indicator able to penetrate the blood brain barrier, became available. Although the experience of research teams working with IAMP is quite restricted due to the high cost of the indicator, some applications now appear to be worth the cost and in some cases provide data which cannot be obtained with routine techniques, especially in cerebrovascular patients, in epilepsy and some cases of tumor. Brain SPECT appears as an atraumatic test which is useful to establish a functional evaluation of the cerebral parenchyma, and which is a complement to arteriography, X-ray scan and regional cerebral blood flow measurement

  9. Performance evaluation of high-resolution square parallel-hole collimators with a CZT room temperature pixelated semiconductor SPECT system: a Monte Carlo simulation study

    International Nuclear Information System (INIS)

    The pixelated semiconductor based on cadmium zinc telluride (CZT) is a promising imaging device that provides many benefits compared with conventional scintillation detectors. By using a high-resolution square parallel-hole collimator with a pixelated semiconductor detector, we were able to improve both sensitivity and spatial resolution. Here, we present a simulation of a CZT pixleated semiconductor single-photon emission computed tomography (SPECT) system with a high-resolution square parallel-hole collimator using various geometric designs of 0.5, 1.0, 1.5, and 2.0 mm X-axis hole size. We performed a simulation study of the eValuator-2500 (eV Microelectronics Inc., Saxonburg, PA, U.S.A.) CZT pixelated semiconductor detector using a Geant4 Application for Tomographic Emission (GATE). To evaluate the performances of these systems, the sensitivity and spatial resolution was evaluated. Moreover, to evaluate the overall performance of the imaging system, a hot-rod phantom was designed. Our results showed that the average sensitivity of the 2.0 mm collimator X-axis hole size was 1.34, 1.95, and 3.92 times higher than that of the 1.5, 1.0, and 0.5 mm collimator X-axis hole size, respectively. Also, the average spatial resolution of the 0.5 mm collimator X-axis hole size was 28.69, 44.65, and 55.73% better than that of the 1.0, 1.5, and 2.0 mm collimator X-axis hole size, respectively. We discuss the high-resolution square parallel-hole collimator of various collimator geometric designs and our evaluations. In conclusion, we have successfully designed a high-resolution square parallel-hole collimator with a CZT pixelated semiconductor SPECT system

  10. Performance evaluation of high-resolution square parallel-hole collimators with a CZT room temperature pixelated semiconductor SPECT system: a Monte Carlo simulation study

    Science.gov (United States)

    Lee, Y.; Kang, W.

    2015-07-01

    The pixelated semiconductor based on cadmium zinc telluride (CZT) is a promising imaging device that provides many benefits compared with conventional scintillation detectors. By using a high-resolution square parallel-hole collimator with a pixelated semiconductor detector, we were able to improve both sensitivity and spatial resolution. Here, we present a simulation of a CZT pixleated semiconductor single-photon emission computed tomography (SPECT) system with a high-resolution square parallel-hole collimator using various geometric designs of 0.5, 1.0, 1.5, and 2.0 mm X-axis hole size. We performed a simulation study of the eValuator-2500 (eV Microelectronics Inc., Saxonburg, PA, U.S.A.) CZT pixelated semiconductor detector using a Geant4 Application for Tomographic Emission (GATE). To evaluate the performances of these systems, the sensitivity and spatial resolution was evaluated. Moreover, to evaluate the overall performance of the imaging system, a hot-rod phantom was designed. Our results showed that the average sensitivity of the 2.0 mm collimator X-axis hole size was 1.34, 1.95, and 3.92 times higher than that of the 1.5, 1.0, and 0.5 mm collimator X-axis hole size, respectively. Also, the average spatial resolution of the 0.5 mm collimator X-axis hole size was 28.69, 44.65, and 55.73% better than that of the 1.0, 1.5, and 2.0 mm collimator X-axis hole size, respectively. We discuss the high-resolution square parallel-hole collimator of various collimator geometric designs and our evaluations. In conclusion, we have successfully designed a high-resolution square parallel-hole collimator with a CZT pixelated semiconductor SPECT system.

  11. SPECT/CT in diagnostics of the hand joint; SPECT/CT in der Handgelenkdiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Huellner, M.W.; Strobel, K.; Veit-Haibach, P. [Luzerner Kantonsspital, Institut fuer Radiologie und Nuklearmedizin, Luzern (Switzerland); Hug, U.; Wartburg, U. von [Luzerner Kantonsspital, Abteilung fuer Hand- und Plastische Chirurgie, Luzern (Switzerland)

    2012-07-15

    Hand and wrist pain remains a diagnostic challenge, both for hand surgeons and for radiologists. Especially chronic wrist pain is often hard to localize clinically and further cross-sectional imaging is often indispensable. The well-established standard for non-invasive diagnostic imaging in chronic wrist pain is magnetic resonance imaging (MRI). Recently, state-of-the-art single photon emission computed tomography/computed tomography (SPECT/CT) systems have been introduced into the diagnostic array for musculoskeletal conditions. Besides morphological data SPECT/CT also provides metabolic information. SPECT/CT allows an exact detection and precise anatomical mapping of different pathologies of the wrist, which is often crucial for therapy. In patients with chronic wrist pain, SPECT/CT is more specific than MRI. It is also beneficial in patients with posttraumatic conditions and metal implants and may serve as a problem-solving tool in difficult cases. It is considered that SPECT/CT imaging is useful if MRI results are equivocal or present no clearly leading pathology. A primary examination with SPECT/CT seems to be a reasonable option for patients with certain bone pathologies, metal implants and non-specific wrist pain. (orig.) [German] Handgelenkschmerzen sind eine diagnostische Herausforderung fuer Handchirurgen und Radiologen. Insbesondere chronische Handgelenkschmerzen sind oft nur schwer einer genauen Lokalisation zuzuordnen, eine Schnittbildgebung ist deshalb oft unerlaesslich. Der etablierte Standard zur nichtinvasiven Diagnostik chronischer Handgelenkschmerzen ist die Magnetresonanztomographie. In den letzten Jahren ist mit der ''single photon emission computed tomography''/CT (SPECT/CT) eine neue Modalitaet zum diagnostischen Spektrum muskuloskelettaler Veraenderungen hinzugetreten, welche neben morphologischen Daten auch metabolische Informationen liefert. Die SPECT/CT ermoeglicht eine genaue Detektion und praezise anatomische

  12. SPECT/CT - Technical aspects and optimization possibilities

    International Nuclear Information System (INIS)

    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.)

  13. Ready for prime time? Dual tracer PET and SPECT imaging

    Science.gov (United States)

    Fakhri, Georges El

    2012-01-01

    Dual isotope single photon emission computed tomography (SPECT) and dual tracer positron emission tomography (PET) imaging have great potential in clinical and molecular applications in the pediatric as well as the adult populations in many areas of brain, cardiac, and oncologic imaging as it allows the exploration of different physiological and molecular functions (e.g., perfusion, neurotransmission, metabolism, apoptosis, angiogenesis) under the same physiological and physical conditions. This is crucial when the physiological functions studied depend on each other (e.g., perfusion and metabolism) hence requiring simultaneous assessment under identical conditions, and can reduce greatly the quantitation errors associated with physical factors that can change between acquisitions (e.g., human subject or animal motion, change in the attenuation map as a function of time) as is detailed in this editorial. The clinical potential of simultaneous dual isotope SPECT, dual tracer PET and dual SPECT/PET imaging are explored and summarized. In this issue of AJNMMI (http://www.ajnmmi.us), Chapman et al. explore the feasibility of simultaneous and sequential SPECT/PET imaging and conclude that down-scatter and crosstalk from 511 keV photons preclude obtaining useful SPECT information in the presence of PET radiotracers. They report on an alternative strategy that consists of performing sequential SPECT and PET studies in hybrid microPET/SPECT/CT scanners, now widely available for molecular imaging. They validate their approach in a phantom consisting of a 96-well plate with variable 99mTc and 18F concentrations and illustrate the utility of such approaches in two sequential SPECT-PET/CT studies that include 99mTc-MAA/18F-NaF and 99mTc-Pentetate/18F-NaF. These approaches will need to be proven reproducible, accurate and robust to variations in the experimental conditions before they can be accepted by the molecular imaging community and be implemented in routine molecular

  14. Dual SPECT of dopamine system using [99mTc]TRODAT-1 and [123I]IBZM in normal and 6-OHDA-lesioned formosan rock monkeys

    International Nuclear Information System (INIS)

    Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by a severe loss of the dopaminergic neurons in the substantia nigra pars compacta. In this study, we evaluated pre- and post-synaptic binding sites of the dopamine system in three normal and one parkinsonian monkeys using simultaneous [99mTc]TRODAT-1 and [123I]IBZM imaging. The parkinsonian monkey was induced by injecting 6-hydroxydopamine (6-OHDA) bilaterally into the medial forebrain bundle under MRI guidance. [99mTc]TRODAT-1 (targeting dopamine transporters) and [123I]IBZM (targeting D2/D3 receptors) were administered almost simultaneously and the SPECT images were acquired over 4 h using a dual-headed gamma camera equipped with ultra-high resolution fan-beam collimators. Data were obtained using energy window of 15% centered on 140 keV for 99mTc in conjunction with 10% asymmetric energy window in a lower bound at 159 keV for 123I. Single SPECT studies of [99mTc]TRODAT-1 and [123I]IBZM were also performed. We found a comparable image quality and uptake ratios between single- and dual-isotope studies. There are higher TRODAT-1 uptakes in the control monkeys than the 6-OHDA-lesioned monkey. The uptake of [123I] IBZM showed no significant difference between controls and 6-OHDA-lesioned monkey. Our results suggest that dual isotope imaging using [99mTc]TRODAT-1 and [123I]IBZM may be a useful means in evaluating the changes of both pre- and post-synaptic dopamine system in a primate model of parkinsonism

  15. Real-time system for respiratory-cardiac gating in positron tomography

    International Nuclear Information System (INIS)

    A Macintosh-based signal processing system has been developed to support simultaneous respiratory and cardiac gating on the ECAT EXACT HR PET scanner. Using the Lab-View real-time software environment, the system reads analog inputs from a pneumatic respiratory bellows and an EGG monitor to compute an appropriate histogram memory location for the PET data. Respiratory state is determined by the bellows signal amplitude; cardiac state is based on the time since the last R-wave. These two states are used in a 2D lookup table to determine a combined respiratory-cardiac state. A 4-bit address encoding the selected histogram is directed from the system to the ECAT scanner, which dynamically switches the destination of tomograph events as respiratory-cardiac state changes. to Test the switching efficiency of the combined Macintosh/ECAT system, a rotating emission phantom was built. Acquisitions with 25 msec states while the phantom was rotating at 240 rpm demonstrate the system could effectively stop motion at this rate, with approximately 5 msec switching time between states

  16. Myocardial viability assessed by Tl-201 SPECT. Redistribution versus reinjection

    International Nuclear Information System (INIS)

    The purpose of this study was to verify if a third series of images acquired by reinjection thallium-201, 24 h after conventional myocardial perfusion with the radioisotope, improves the identification of myocardial viability segments. The methods: we studied 30 patients, mean age 57.7 ±9.4 years, with old myocardial infarction using thallium (Tl)-201 SPECT, and we obtained three series of images (stress, redistribution after 4 h and reinjection after 24 h. Cardiac images were divided in 5 segments (apical, lateral, anterior, septal and inferior) and each one received a value by a score system according to the Tl-201 myocardial uptake (0=normal uptake; 1=mild hypoperfusion; 2=moderate hypoperfusion; 3=severe hypoperfusion or no myocardial uptake). We considered viable myocardium when the uptake of Tl-201 in the segment related to te myocardial infarction increases at least 1 point in two different axis of Tl-201 SPECT. The results: seven (23,3%) patients demonstrated increase of Tl-201 uptake only at reinjection images, showing a high efficacy of the method. Nine (30%) patients showed persistent hypoperfusion at all series of images suggesting only fibrosis in the are related to the infarction. Fourteen (46,7%) patients showed increase of Tl-201 concentration at redistribution images; among these patients, six showed improvement of myocardial uptake at reinjection. This condition was interpreted as regional chronic ischemic process: hibernating myocardium. The conclusion was that Tl-201 hypoperfusion at redistribution images without significant changes in relation to the stress images do not represent fibrosis at all. The reinjection technic was better than conventional redistribution in the detection of viable myocardium. This data allows a better therapeutic orientation. (author)

  17. Anatomically standardized statistical mapping of 123I-IMP SPECT in brain tumors

    International Nuclear Information System (INIS)

    123I-iodoamphetamine Single Photon Emission Computed Tomography (IMP SPECT) is used to evaluate cerebral blood flow. However, application of IMP SPECT to patients with brain tumors has been rarely reported. Primary central nervous system lymphoma (PCNSL) is a rare tumor that shows delayed IMP uptake. The relatively low spatial resolution of SPECT is a clinical problem in diagnosing brain tumors. We examined anatomically standardized statistical mapping of IMP SPECT in patients with brain lesions. This study included 49 IMP SPECT images for 49 patients with brain lesions: 20 PCNSL, 1 Burkitt's lymphoma, 14 glioma, 4 other tumor, 7 inflammatory disease and 3 without any pathological diagnosis but a clinical diagnosis of PCNSL. After intravenous injection of 222 MBq of 123I-IMP, early (15 minutes) and delayed (4 hours) images were acquired using a multi-detector SPECT machine. All SPECT data were transferred to a newly developed software program iNeurostat+ (Nihon Medi-physics). SPECT data were anatomically standardized on normal brain images. Regions of increased uptake of IMP were statistically mapped on the tomographic images of normal brain. Eighteen patients showed high uptake in the delayed IMP SPECT images (16 PCNSL, 2 unknown). Other tumor or diseases did not show high uptake of delayed IMP SPECT, so there were no false positives. Four patients with pathologically proven PCNSL showed no uptake in original IMP SPECT. These tumors were too small to detect in IMP SPECT. However, statistical mapping revealed IMP uptake in 18 of 20 pathologically verified PCNSL patients. A heterogeneous IMP uptake was seen in homogenous tumors in MRI. For patients with a hot IMP uptake, statistical mapping showed clearer uptake. IMP SPECT is a sensitive test to diagnose of PCNSL, although it produced false negative results for small posterior fossa tumor. Anatomically standardized statistical mapping is therefore considered to be a useful method for improving the diagnostic

  18. Ready for prime time? Dual tracer PET and SPECT imaging

    OpenAIRE

    Fakhri, Georges El

    2012-01-01

    Dual isotope single photon emission computed tomography (SPECT) and dual tracer positron emission tomography (PET) imaging have great potential in clinical and molecular applications in the pediatric as well as the adult populations in many areas of brain, cardiac, and oncologic imaging as it allows the exploration of different physiological and molecular functions (e.g., perfusion, neurotransmission, metabolism, apoptosis, angiogenesis) under the same physiological and physical conditions. T...

  19. Aggressive Cardiac Involvement in Systemic Lupus Erythematosus: A Case Report and a Comprehensive Literature Review

    Directory of Open Access Journals (Sweden)

    Reza Ashrafi

    2011-01-01

    Full Text Available Background. We present the case of a 35-year-old gentleman who presented with an aggressive cardiomyopathy with normal coronary arteries. He was later diagnosed with systemic lupus-related cardiomyopathy. Methods. We undertook an extensive review of the literature regarding cardiac manifestations of lupus and used over 100 journals to identify the key points in pathology, diagnosis, and treatment. Results. We have shown that cardiac lupus can be rapidly progressive and, unless treated early, can have severe consequences. The predominant pathologies are immune complex and accelerated atherosclerosis drive. Treatment comprised of high-level immunosuppression.

  20. Anatomy of the cardiac nervous system with clinical and comparative morphological implications.

    Science.gov (United States)

    Kawashima, Tomokazu

    2011-03-01

    Unlike autonomic nervous preservation in other surgeries for improving patient quality of life, autonomic cardiac nervous system (ACNS) preservation has been neglected in cardiovascular surgery because of technical difficulties and other unsolved issues. Because such ACNS preservation in cardiovascular surgery is anticipated in the future, detailed anatomical investigation of the human ACNS is required. Therefore, we have conducted morphological studies of the ACNS from macroscopic, clinical, and evolutionary anatomical viewpoints. In this study, I review detailed anatomical studies of the human ACNS together with their clinical implications. In addition, the evolutionary comparative anatomical significance of primate ACNS is also summarized to help understand and translate the findings of functional experiments to humans. These integrated findings will be the subject of a future study unifying molecular embryological and anatomical findings to clarify cardiac functions based on functional animal experiments, clinical applications such as improving surgery techniques and individual order-made surgery in cardiac surgery, and for future evaluation in regenerative medicine. PMID:21116884

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-02-01

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

  2. A large permissive regulatory domain exclusively controls Tbx3 expression in the cardiac conduction system

    NARCIS (Netherlands)

    van Weerd, Jan Hendrik; Badi, Ileana; van den Boogaard, Malou; Stefanovic, Sonia; van de Werken, Harmen J G; Gomez-Velazquez, Melisa; Badia-Careaga, Claudio; Manzanares, Miguel; de Laat, Wouter; Barnett, Phil; Christoffels, Vincent M

    2014-01-01

    RATIONALE: The evolutionary conserved Tbx3/Tbx5 gene cluster encodes T-box transcription factors that play crucial roles in the development and homeostasis of the cardiac conduction system in human and mouse. Both genes are expressed in overlapping patterns and function in strictly tissue-specific a

  3. A quantitative model of the cardiac ventricular cell incorporating the transverse-axial tubular system

    Czech Academy of Sciences Publication Activity Database

    Pásek, Michal; Christé, G.; Šimurda, J.

    2003-01-01

    Roč. 22, č. 3 (2003), s. 355-368. ISSN 0231-5882 R&D Projects: GA ČR GP204/02/D129 Institutional research plan: CEZ:AV0Z2076919 Keywords : cardiac cell * tubular system * quantitative modelling Subject RIV: BO - Biophysics Impact factor: 0.794, year: 2003

  4. Cardiac repolarization during hypoglycaemia in type 1 diabetes: impact of basal renin-angiotensin system activity

    DEFF Research Database (Denmark)

    Due-Andersen, Rikke; Høi-Hansen, Thomas; Larroude, Charlotte Ellen; Olsen, Niels Vidiendal; Kanters, Jørgen Kim; Boomsma, Frans; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger

    2008-01-01

    AIMS: Hypoglycaemia-induced cardiac arrhythmias may be involved in the pathogenesis of the 'dead-in-bed syndrome' in patients with type 1 diabetes. Evidence suggests that the renin-angiotensin system (RAS) influences the occurrence of arrhythmias. The aim of this study was to explore if basal RAS...

  5. Systemic mastocytosis presenting as cardiac tamponade with CD25(+) pericardial mast cells.

    Science.gov (United States)

    Sukrithan, Vineeth K; Salamon, Jason N; Berulava, Giorgi; Sibinga, Nicholas E; Verma, Amit

    2016-03-01

    In this first-in-literature case, we describe a patient with Systemic mastocytosis presenting with life-threatening cardiac tamponade associated with the presence of aberrant mast cells in the pericardium. Procedures involving surgical incisions through the pericardium in such cases can lead to uncontrolled mast cell degranulation leading to circulatory collapse. PMID:27014452

  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. Evaluation of a CZT gamma-ray detection module concept for SPECT

    International Nuclear Information System (INIS)

    CZT detectors are the basic building block of a variety of new SPECT systems. Their modularity allows to adapt system architecture to specific applications such as cardiac, breast, brain or small animal imaging. Thanks to their high quantum yield, these direct conversion detectors exhibit better energy and spatial resolutions than usual scintillation detectors based on NaI(Tl). However, it remains often unclear if SPECT imaging really can take profit of that performance gain. We propose here to conduct a case study based on the latest results obtained in our laboratory with current state of the art ICs and CZT crystals to investigate the system performance of a classical module dimensioning of 5 mm thick CZT with a segmented anode at a 2.5 * 2.5 mm pitch. This dimensioning, though being quite conservative, allows an easy integration in terms of crystal hybridization or PCB layout but still allows to obtain impressive results. Compared with X-ray counting were the only information retrieved is the occurrence of a photon interaction, spectrometric imaging performance is not only determined by photon statistics but also by readout noise, that ultimately limits time, energy and spatial resolutions associated with each photon event. After a first part dealing with the noise performance achieved by integrated circuits and a discussion on the key limiting factors, we present the typical readout architecture used and show how the signal processing is optimized for multiple parameter estimation. In a subsequent part, multi-pixel data acquisition scheme is discussed to show how raw channel data is used to extract photon parameters (energy, time-stamp, and 3D position) while taking into account material non-uniformities. We will show how such data can be used to build images and quantify resulting improvement. Finally, we open the discussion on SPECT collimation and architecture by demonstrating with simulations how a tomographical system dimensioning depends on detector

  8. Monte Carlo scatter correction for SPECT

    Science.gov (United States)

    Liu, Zemei

    The goal of this dissertation is to present a quantitatively accurate and computationally fast scatter correction method that is robust and easily accessible for routine applications in SPECT imaging. A Monte Carlo based scatter estimation method is investigated and developed further. The Monte Carlo simulation program SIMIND (Simulating Medical Imaging Nuclear Detectors), was specifically developed to simulate clinical SPECT systems. The SIMIND scatter estimation (SSE) method was developed further using a multithreading technique to distribute the scatter estimation task across multiple threads running concurrently on multi-core CPU's to accelerate the scatter estimation process. An analytical collimator that ensures less noise was used during SSE. The research includes the addition to SIMIND of charge transport modeling in cadmium zinc telluride (CZT) detectors. Phenomena associated with radiation-induced charge transport including charge trapping, charge diffusion, charge sharing between neighboring detector pixels, as well as uncertainties in the detection process are addressed. Experimental measurements and simulation studies were designed for scintillation crystal based SPECT and CZT based SPECT systems to verify and evaluate the expanded SSE method. Jaszczak Deluxe and Anthropomorphic Torso Phantoms (Data Spectrum Corporation, Hillsborough, NC, USA) were used for experimental measurements and digital versions of the same phantoms employed during simulations to mimic experimental acquisitions. This study design enabled easy comparison of experimental and simulated data. The results have consistently shown that the SSE method performed similarly or better than the triple energy window (TEW) and effective scatter source estimation (ESSE) methods for experiments on all the clinical SPECT systems. The SSE method is proven to be a viable method for scatter estimation for routine clinical use.

  9. Clinical validation of a new thermodilution system for the assessment of cardiac output and volumetric parameters

    OpenAIRE

    Kiefer, Nicholas; Hofer, Christoph K; Marx, Gernot; Geisen, Martin; Giraud, Raphaël; Siegenthaler, Nils; Hoeft, Andreas; Bendjelid, Karim; Rex, Steffen

    2012-01-01

    ABSTRACT: INTRODUCTION: Transpulmonary thermodilution is used to measure cardiac output (CO), global end-diastolic volume (GEDV) and extravascular lung water (EVLW). A system has been introduced (VolumeView/EV1000™ system, Edwards Lifesciences, Irvine CA, USA) that employs a novel algorithm for the mathematical analysis of the thermodilution curve. Our aim was to evaluate the agreement of this method with the established PiCCO™ method (Pulsion Medical Systems SE, Munich, Germany, clinicaltria...

  10. Development of a Customized Database Management System for the Cardiac Catheterization Laboratory

    OpenAIRE

    MILLER, MICHAEL R.

    1980-01-01

    A simple database management system has been developed for use by the Cardiac Catheterization Laboratory at University of Iowa Hospitals and Clinics. The system was developed with limited resources in a period of eight months. Major functions provided by the DBMS are data acquisition, report generation and selective retrieval by diagnosis. The modular design of the system provides for growth in the database without modification of existing programs. The project was divided into four stages: d...

  11. The second messenger system(s) mediating the secretion of atrial natriuretic peptide (ANP) from the isolated rat heart during rapid cardiac pacing.

    Science.gov (United States)

    Doubell, A F

    1989-01-01

    This study demonstrates that rapid cardiac pacing elevates Atrial Natriuretic Peptide (ANP) levels, independently from atrial stretch. The second messenger system mediating this response was examined. The phosphoinositide system, generally regarded to be important in mediating ANP release, was shown to play only a modulating role during rapid cardiac pacing. The main mediator would appear to be calcium, and a non-calmodulin dependent, calcium mediated system controlling ANP release during rapid cardiac pacing is suggested. PMID:2532285

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

    International Nuclear Information System (INIS)

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

  13. Mnemonic activation by SPECT

    International Nuclear Information System (INIS)

    Data of literature show that SPECT is able to detect cerebral activations induced by sensory-motor stimuli. The facts are not clearly established in what concerns the cognitive activations the amplitude of which is lower. We have studied an activation paradigm such as the Grober and Bruschke test which implies the long term explicit memory. It comprises a visual presentation of words followed by their indexed recall. By using a two-day protocol, 2 SPECTs were achieved in 4 healthy right-handed voluntaries as follows: one of activation (A) and one of control (B). The fifth subject benefited by a SPECT B and of an MRI. The injection for the examination A has been done during the indexed recall stage and for the examination B at the moment when the patient repeated several times the same 3 words. The SPECT data were collected 1 hour after the injection of 370 MBq of ECD making use of a 3-head camera equipped with UHR fan collimators and ending by a LMH on the reconstructed images of 8 mm. The MRI has been achieved by means of a Signa 1.5 Tesla magnet. The SPECT A and B of the subjects 1 to 4 were matched elastically to that of the subject 5 and that of the subject 5 was rigidly matched on its MRI. In this way the individual activation cards of the 4 subjects could be averaged and superimposed on the MRI of the 5. subject. One observes an internal temporal activation (maximal activation of left tonsil, +25% and right uncus, +23%) and a right cingulum activation (maximal activation, +25%), in agreement with the neuro-physiological data. The elastic matching makes possible the inter-subject averaging, what increases the signal-to-noise ratio of activation. The inter-modality rigid matching facilitates the anatomical localisation of the activation site. With these adapted tools, the cognitive activation is thus possible by SPECT and opens perspectives for early diagnosis of neurological troubles, namely of Alzheimer's disease

  14. Objective evaluation of reconstruction methods for quantitative SPECT imaging in the absence of ground truth

    OpenAIRE

    Jha, Abhinav K.; Song, Na; Caffo, Brian; Frey, Eric C.

    2015-01-01

    Quantitative single-photon emission computed tomography (SPECT) imaging is emerging as an important tool in clinical studies and biomedical research. There is thus a need for optimization and evaluation of systems and algorithms that are being developed for quantitative SPECT imaging. An appropriate objective method to evaluate these systems is by comparing their performance in the end task that is required in quantitative SPECT imaging, such as estimating the mean activity concentration in a...

  15. 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.

  16. 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

  17. 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

    OpenAIRE

    Cláudio Tinoco Mesquita; Maria Carolina Pinheiro Pessoa; Paulo Pontes Vasconcelos; Amarino Carvalho de Oliveira Júnior; Hans Fernando Rocha Dohmann; Adair Gomes dos Reis; Lea Mirian Barbosa da Fonseca

    2009-01-01

    FUNDAMENTO: A avaliação da função ventricular esquerda pode ser limitada pela movimentação anômala do septo interventricular, freqüentemente encontrada após cirurgia de revascularização miocárdica (CRM). A validação do Gated SPECT como ferramenta para avaliação da função ventricular nesse grupo de pacientes é escassa. OBJETIVO: Investigamos a concordância e a correlação entre a fração de ejeção do ventrículo esquerdo (FEVE), o volume diastólico final (VDF) e o volume sistólico final (VDF), ob...

  18. Intraoperative 3-D mapping of parathyroid adenoma using freehand SPECT

    OpenAIRE

    Rahbar, K.; Colombo-Benkmann, M. (Mario); Haane, C. (Christina); Wenning, C. (Christian); Vrachimis, A. (Alexis); Weckesser, J.M. (Jochen); Schober, O.

    2013-01-01

    Background: Freehand single photon emission computed tomography (fSPECT) is a three-dimensional (3-D) tomographic imaging modality based on data acquisition with a handheld detector that is moved freely, in contrast to conventional, gantry-mounted gamma camera systems. In this pilot study, we evaluated the feasibility of fSPECT for intraoperative 3-D mapping in patients with parathyroid adenomas. Methods: Three patients (range 30 to 45 years) diagnosed with hyperparathyroidism (one primary...

  19. Role of SPECT immunoscintigraphy with radiolabelled monoclonal antibodies for the early detection of malignancy and infection

    International Nuclear Information System (INIS)

    The study was undertaken to determine to what extent it is possible to improve immunoscintigraphic diagnosis by using single photon emission computed tomography (SPECT) imaging, in addition to the conventional planar method. Seventy-two patients (40 with infection, 17 with colorectal carcinoma and 15 with malignant melanoma) with 135 known lesions were studied using radiolabelled antibodies. Twenty-eight patients with 53 known lesions underwent additional SPECT imaging of the relevant body region. The overall sensitivity of the study was 86%. Sixteen sites (12%) were detected only by SPECT. Twenty occult lesions were diagnosed, 16 (80%) of them by SPECT. False negative results were mainly related to localization in organs with physiologically high count rates, such as kidneys, the urinary bladder, liver, stomach and the cardiac blood pool. False positive results were probably caused by normal tissue expressing the antigen. The results reveal that an 11% improvement in overall sensitivity can be attained by the utilization of the SPECT procedure with no false negative results. However, higher rates of false positive results were obtained by using SPECT, with an overall increase of the false positive studies by 11%. The planar method offers the advantage of an easier procedure, and is better suited for whole body studies. The SPECT method was of value in differentiating between overlapping physiological and pathological concentrations and in equivocal planar studies. In general, much better demonstration of the tumoral lesions was obtained by SPECT and it also enables sizing of the suspected lesion. However, owing to the prolonged imaging time and the higher rate of false positive studies, restriction of SPECT to selected body areas, after initial screening by planar whole body scintigraphy, is suggested. In conclusion, SPECT represents a useful supplement to the planar study. The combination of both studies seems to be promising for the early detection of tumoral

  20. 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.

  1. Quantitative High-Efficiency Cadmium-Zinc-Telluride SPECT with Dedicated Parallel-Hole Collimation System in Obese Patients: Results of a Multi-Center Study

    Science.gov (United States)

    Nakazato, Ryo; Slomka, Piotr J.; Fish, Mathews; Schwartz, Ronald G.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Lemley, Mark; Mackin, Maria L.; Peterson, Benjamin; Schwartz, Arielle M.; Doran, Jesse A.; Germano, Guido; Berman, Daniel S.

    2014-01-01

    Background Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride (CZT) parallel-hole SPECT-MPI for coronary artery disease (CAD) in obese patients. Methods and Results 118 consecutive obese patients at 3 centers (BMI 43.6±8.9 kg/m2, range 35–79.7 kg/m2) had upright/supine HE-SPECT and ICA >6 months (n=67) or low-likelihood of CAD (n=51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD) and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5=excellent; SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions. PMID:25388380

  2. A model of cardiac tissue as a conductive system with interacting pacemakers and refractory time

    OpenAIRE

    Loskutov, Alexander; Rybalko, Sergei; Zhuchkova, Ekaterina

    2002-01-01

    A model of the heart tissue as a conductive system with two interacting pacemakers and a refractory time, is proposed. In the parametric space of the model the phase locking areas are investigated in detail. Obtained results allow us to predict the behaviour of excitable systems with two pacemakers depending on the type and intensity of their interaction and the initial phase. Comparison of the described phenomena with intrinsic pathologies of cardiac rhythms is presented.

  3. A multiple-input multiple-output system for modeling the cardiac dynamics.

    Science.gov (United States)

    Monzon, Jorge E; Picaza, Carlos Alvarez; Pisarello, Maria I

    2011-01-01

    We describe the dynamics of the cardiovascular system by finding the input-output relationships in the state space of a functional cardiac model, based on state equations and observability criteria of control theory. The unit step response of the multiple-input multiple-output system model illustrates the damping effect of the arterial wall to the pulsatility of the heart. Our results show that hypertensive patients exhibit a lower inertia of the blood flow. PMID:22254491

  4. Construction of a computational anatomical model of the peripheral cardiac conduction system.

    Science.gov (United States)

    Sebastian, Rafael; Zimmerman, Viviana; Romero, Daniel; Frangi, Alejandro F

    2011-12-01

    A methodology is presented here for automatic construction of a ventricular model of the cardiac conduction system (CCS), which is currently a missing block in many multiscale cardiac electromechanic models. It includes the His bundle, left bundle branches, and the peripheral CCS. The algorithm is fundamentally an enhancement of a rule-based method known as the Lindenmayer systems (L-systems). The generative procedure has been divided into three consecutive independent stages, which subsequently build the CCS from proximal to distal sections. Each stage is governed by a set of user parameters together with anatomical and physiological constrains to direct the generation process and adhere to the structural observations derived from histology studies. Several parameters are defined using statistical distributions to introduce stochastic variability in the models. The CCS built with this approach can generate electrical activation sequences with physiological characteristics. PMID:21896384

  5. Dipyridamole thallium imaging for detecting cardiac involvement in patients with systemic sclerosis (scleroderma)

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Matsubara, Noboru; Tani, Akihiro; Morozumi, Takakazu; Hori, Masatsugu; Kitabatake, Akira; Kamada, Takenobu; Kimura, Kazufumi; Kozuka, Takahiro (Osaka Univ. (Japan). Faculty of Medicine)

    1990-02-01

    Dipyridamole thallium-201 imaging was carried out in 21 patients with progressive systemic sclerosis (PSS) to assess its value in detecting impaired myocardium and coronary microcirculation associated with PSS. Depending upon the degree of cardiac function, the patients were classified as having either ejection fraction of 50% or more (Group I, n=17) or less than 50% (Group II, n=4). In Group I, four patients had transient defect in which perfusion defects were seen on early images but not seen on delayed images; three had reverse redistribution in which defects were not seen on early images but seen on delayed images; and three had persistent defects which were seen on both early and delayed images. A decreased washout of thallium-201 was seen in 9 patients. In an analysis of both perfusion defects and washout rate, 13 patients (76%) in Group I were found to have abnormal findings. This suggests that disturbed coronary microcirculation or impaired myocardium may frequently develop even when EF is normal. All of the patients categorized as having a decreased cardiac function (Group II) had perfusion defect, suggesting the presence of myocardial fibrosis. In PSS, deterioration of cardiac function seemed to be associated with progression of myocardial fibrosis. Dipyridamole thallium imaging may be a sensitive method for detecting cardiac lesions in PSS. It also has the potential for detecting decreased coronary flow reserve or slightly impaired myocardium even without decreased EF. (N.K.).

  6. 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.

  7. Interest of the SPECT-CT hybrid imaging in the management of thyroid differentiated carcinomas

    International Nuclear Information System (INIS)

    Purpose: Images merging, associating SPECT and CT, integers functional and anatomical data. The purpose of our study was to evaluate the SPECT contribution coupled to CT in our daily practice of the management thyroid differentiated carcinomas. Conclusions: SPECT/CT merging got by a hybrid system allows a better anatomical location and improves the diagnostic value of examination in the extension assessment of thyroid differentiated carcinomas. (N.C.)

  8. A multiprocessor system for the analysis of cardiac arrhythmias

    International Nuclear Information System (INIS)

    The study presented here forms part of a real-time electrocardiographic signal analysis system project. The medical data analysis system consists of eight independent analyser units, all of which are connected to a controller unit by the standard IEEE-488 bus. Each bed is monitored by an arrhythmias analyser which has the facilities for analysing a patient's electrocardiogram automatically in real time. The measurements may be made in the presence of a pacemaker. The system described presents the technique of a separate and a simultaneous data analysis on two different ECG channels. This permit: a better diagnosis and an optimum use of the bus. (author)

  9. 123I-MIBG SPECT shows myocardial denervation after transmyocardial laser revascularisation

    International Nuclear Information System (INIS)

    Transmyocardial laser revascularization (TMLR) is an invasive therapy used to treat patients with severe refractory angina pectoris in whom standard treatment is insufficient or not possible. Randomized trials have reported a clear clinical benefit (relief of angina and improvement of Quality of Life (QOL)) of TMLR compared to maximal medical treatment. The post-TMLR clinical improvement has been suggested to be associated with myocardial sympathetic denervation. The aim of the present study was to investigate if TMLR induces myocardial sympathetic denervation. TMLR was performed in 8 patients with refractory angina pectoris. Pre- and post-TMLR myocardial perfusion scintigraphy (99mTc-Tetrofosmin SPECT) and sympathetic innervation (123I-MIBG SPECT) were semi-quantitatively assessed using an 18 segment model and a 5 point scoring system. Pre- and post-TMLR summed perfusion, denervation and difference scores were calculated. In all patients post-TMLR 123I-MIBG SPECT showed decreased uptake: summed denervation score pre-TMLR was 13.4±3.9 vs. 23.9±4.3 post-TMLR (P=0.00002). In 80% of segments the decreased uptake could be related to the TMLR treated area. Pre- and post TMLR myocardial perfusion scintigraphy did not show significant differences. In all patients angina reduced by ≥ 2 classes (NYHA classification) at 3 to 12 months follow up, and QOL significantly improved. Our results indicate that TMLR-induced improvement of angina and QOL can be explained by destruction of nociceptors or cardiac neural pathways, changing the perception of anginal pain

  10. SPECT and PET imaging in Parkinson's disease

    International Nuclear Information System (INIS)

    Parkinson disease (PD) is the second most common neurodegenerative disorder after Alzheimer's dementia (AD) with a prevalence of 2/1000 in the whole population. This number increases to 2/100 in the aging population and the total number of patients will rise further with increasing life expectancy. Modern imaging techniques such as SPECT (single photon emission tomography) and PET(positron emission tomography) can visualize function and molecular structures in the living human brain and are important clinical and research tools in the evaluation of FP. Because the brain dopamine (DA) system plays a pivotal role in the pathogenesis of PD and related disorders most SPECT and PET studies in PD deal with different aspects of DA-ergic function. However, PD also affects noradrenaline (NA) and serotonin (5HT) producing neurons which contribute to non-motor symptoms. Recent SPECT and PET studies also address this issue. SPECT is a technique which is widely available and is increasingly used in the clinical evaluation of PF patients. With SPECT and specific 123I labelled ligands pre- and postsynaptic structures of the nigrostriatal DA-ergic system can be labelled and visualized. Thus, it is possible to detect and to quantify lesions of the DA-ergic system on the one hand and lesions of the striatal output neurons on the other. This technique also enables studies of pharmacological interactions at the receptor level. With the help of β-CIT, a cocaine derivative, and other similar ligands DA transporters (DATs) can be labelled on DA-ergic nerve terminals. DAT imaging clearly differentiates between normal controls and PD patients even in early stages of the disease. Patients with subcortical vascular encephalopathy presenting with symptoms resembling PD ('lower body Parkinson') can be distinguished with high specificity and sensitivity. PET has the advantage of a better resolution and quantification and a larger number of tracers have mainly been used as a research tool. With

  11. Adaptive changes of the cardiac opioid system due to volume induced heart failure

    OpenAIRE

    Dehe, Lukas

    2016-01-01

    Knowledge about changes in the cardiac opioid system in congestive heart failure (CHF) is scarce. As such, this project investigated the cellular localization of the opioid receptors δ (DOR) and κ (KOR) in left ventricular (LV) myocardium. Opioid receptor (OR) binding sites were detected by radioligand binding. In addition, DOR and KOR localization was determined by double immunofluorescence confocal analysis in the left ventricle of male Wistar rats. DOR and KOR were colocalized with L-type ...

  12. Imaging of the atria and cardiac conduction system – from experiment to computer modelling

    OpenAIRE

    Hao, Guoliang

    2013-01-01

    Background: Experimental mapping and computer modelling provide important platforms to study the fundamental mechanisms underlying normal and abnormal activation of the heart. However, accurate computer modelling requires detailed anatomical models and needs support and validation from experimental data. Aims: 1) Construction of detailed anatomical heart models with the cardiac conduction system (CCS). 2) Mapping of the electrical activation sequence in rabbit atria to support and validate co...

  13. Physiological consequences of ionic concentration changes in cardiac cell tubular system

    Czech Academy of Sciences Publication Activity Database

    Pásek, Michal; Christé, G.; Šimurda, J.

    Plzeň : Západočeká universita v Plzni, 2004 - (Horák, M.), s. 1-4 ISBN 80-7043-315-9. [Biomechanics of Man 2004. hotel Horizont, Šumava (CZ), 16.11.2004-19.11.2004] R&D Projects: GA ČR GP204/02/D129 Institutional research plan: CEZ:AV0Z2076919 Keywords : cardiac cell * tubular system * quantitative modelling Subject RIV: BO - Biophysics

  14. Elevated Cardiac Troponins in Setting of Systemic Inflammatory Response Syndrome, Sepsis, and Septic Shock

    OpenAIRE

    Nasir Hussain

    2013-01-01

    Elevation of cardiac troponins and creatinine kinase is frequently observed in setting of systemic inflammatory response syndrome (SIRS), sepsis, or septic shock. Underlying pathophysiologic mechanism for such troponin leak, its clinical significance, and what different could be done in such settings remain elusive. In this paper we have briefly overviewed the proposed pathogenic mechanisms for SIRS, sepsis, or septic shock-related troponin elevation (SRTE) and have provided brief overview on...

  15. Clinical results of neurotransmission SPECT in extra-pyramidal diseases

    International Nuclear Information System (INIS)

    We present some methodological aspects and clinical applications of dopamine D2 receptor and transporter SPECT using new radiotracers radiolabeled with iodine 123. The gamma camera quality control and standardisation has to be adapted to the small volume and deep location of striata, where receptors and transporters are present. Phantom containing hollow spheres of different diameters which can be filled with different amounts of 99mTc or 123I. The semi quantitation of receptor and transporter molecular concentration is based on an equilibrium binding model. According to this model, the binding potential (Bmax. Ka) is equal to the ratio between specific binding in the striatum and circulating activity in a reference region of interest in the occipital cortex. By comparing ECD and ILIS SPECT, it has been shown that striatal ILIS binding does not depend on the local perfusion. The clinical applications mainly concern the extra-pyramidal pathology: ILIS and IBZM SPECT are able to differentiate pre- and post-synaptic lesions. In Parkinson disease the nigrostriatal pathway is damaged and D2 receptors are normal or increased, as shown by normal or elevated IBZM or ILIS uptake. In other extra pyramidal degenerative diseases as progressive supra nuclear palsy or multiple system atrophy striatal D2 receptors are damaged as shown by decreased IBZM or ILIS uptake. In our experience, 88 per cent of patients are correctly classified by ILIS SPECT and 86 per cent with IBZM SPECT. Dopamine transporter SPECT with βCIT and PE2I provides an evaluation of the presynaptic neuronal density in the striatum. One can expect an help for the early diagnosis and the evaluation of Parkinson disease. Another potential application of dopaminergic neurotransmission SPECT is the evaluation of neuronal loss after hypoxo-ischemia. We conclude that dopaminergic neurotransmission SPECT using specific ligands should become a useful diagnosis tool to study a large number of brain dysfunctions. (author)

  16. New SPECT and PET dementia tracers

    International Nuclear Information System (INIS)

    Single photon emission tomography (SPECT) and positron emission tomography (PET) are techniques to study in vivo neurotransmitter systems, neuro inflammation and amyloid deposits in normal human brain and in dementia. These methods used to explore the integrity of dopaminergic, cholinergic and serotonergic systems in Alzheimer's disease and in other dementias allowed to understand how the neurotransmission was modified in these disorders. Progress in the understanding of pathophysiological and clinical signs of dementia requires an evolution of the radioligands used to carry out an increasingly early and differential diagnosis in addition to monitoring the progression of disease and the effects of therapies. New emerging radiotracers for neuro inflammation or amyloid deposits are essential. In this article, new SPECT and PET tracers are presented. (authors)

  17. Hybrid cardiac imaging: Insights in the dilemma of the appropriate clinical management of patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    Aim: To evaluate the potential of SPECT myocardial perfusion imaging (MPI)–computed tomography coronary angiography (CTCA) hybrid fusion imaging to improve the diagnostic performance of cardiac SPECT/MPI and CTCA alone in order to act as more accurate gate keeper to further investigation invasive or not. Methods and results: Twenty-five patients were subjected to SPECT/MPI and CTCA within a period of 1 month without any medical treatment modification. A fusion software package was used for cardiac SPECT–CTCA image fusion. Semiquantitative analysis was performed for cardiac SPECT, CTCA and SPECT/MPI–CTCA fusion images. Patients were classified in 2 groups according to the clinical decision for further investigation (group A), or not (group B). Statistically significant differences were observed when SPECT/MPI–CTCA fusion images were used instead of cardiac SPECT alone (p < 0.05). No statistically significant differences were observed comparing CTCA alone to SPECT/MPI–CTCA fusion images (p = 0.25). A mid-term follow-up (mean 3.58 ± 0.24 years) showed that all patients classified in group A based on the interpretation of SPECT MPI–CTCA fused images underwent conventional coronary angiography with further necessity for PTCA or CABG whereas absence of major or minor cardiac events was revealed for all patients of group B. Conclusion: In patients suspected for coronary artery disease, cardiac SPECT/MPI–CTCA fusion imaging was found to considerably alter the clinical decision for referral to further investigation derived from SPECT/MPI

  18. Progression of dopamine transporter decline in patients with the Parkinson variant of multiple system atrophy: a voxel-based analysis of [123I]β-CIT SPECT

    International Nuclear Information System (INIS)

    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 [123I]β-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 [123I]β-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.)

  19. 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.)

  20. SPECT/CT in diagnostics of the hand joint

    International Nuclear Information System (INIS)

    Hand and wrist pain remains a diagnostic challenge, both for hand surgeons and for radiologists. Especially chronic wrist pain is often hard to localize clinically and further cross-sectional imaging is often indispensable. The well-established standard for non-invasive diagnostic imaging in chronic wrist pain is magnetic resonance imaging (MRI). Recently, state-of-the-art single photon emission computed tomography/computed tomography (SPECT/CT) systems have been introduced into the diagnostic array for musculoskeletal conditions. Besides morphological data SPECT/CT also provides metabolic information. SPECT/CT allows an exact detection and precise anatomical mapping of different pathologies of the wrist, which is often crucial for therapy. In patients with chronic wrist pain, SPECT/CT is more specific than MRI. It is also beneficial in patients with posttraumatic conditions and metal implants and may serve as a problem-solving tool in difficult cases. It is considered that SPECT/CT imaging is useful if MRI results are equivocal or present no clearly leading pathology. A primary examination with SPECT/CT seems to be a reasonable option for patients with certain bone pathologies, metal implants and non-specific wrist pain. (orig.)

  1. 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.

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

    International Nuclear Information System (INIS)

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

  3. Role of myocardial perfusion SPECT in asymptomatic diabetic patients

    International Nuclear Information System (INIS)

    Purpose: It is important that early diagnosis and treatment of coronary artery disease in diabetic patients, but there are few reports on the prevalence of stress-induced myocardial perfusion abnormalities and the rates of cardiac event in patients with type 2 diabetes. We evaluated the scan findings on gated myocardial perfusion SPECT in asymptomatic diabetic patients. Methods: We performed pharmacological stress test and gated perfusion SPECT in 69 diabetic patients without cardiovascular symptom (mean age: 65 year, male 31 and female 38). Patients underwent two-day imaging protocol and stress study was performed injection of Tc-99m MIBI during adenosine infusion. We followed up these patients by reviewing medical records. Results: Fifty-two of 69 patients (74.5%) showed normal scan findings and 17 patients (24.6%) showed reversible or fixed perfusion defects. Three of 52 patients with normal scan findings showed decreased LV ejection fraction and decreased wall motion. Twenty-three patients with normal scan findings were possible to follow up for more than 1yr (mean time: 18.3±3.3 mo.) and they all had no cardiac event. Three patients with reversible perfusion defects were performed coronary angioplasty. Conclusion: Myocardial perfusion SPECT is a noninvasive method and maybe useful in early diagnosis and predicting prognosis in diabetic patients

  4. Intelligent Cardiac Monitoring System using Virtual Instrumentation Techniques

    Directory of Open Access Journals (Sweden)

    Sharva Kant

    2011-07-01

    Full Text Available This paper describes the design of a portable, cheap and easy to handle microcontroller-based heart monitoring system using a Atmega32 model-based microcontroller and GLCD. The project is capable of detecting and distinguishing the normal heart signal from an abnormal one. A circuit was designed to convert the sound signals from the heart into electrical signals. The signal so obtained was then processed and conditioned to get a Phonocardiogram (PCG. The design considerations of this project are influenced by its target users. Its major application lies with medical practitioners in remote areas and army units in warzones where technical help is usually difficult. This project will facilitate a PCG read in such areas resulting in preventive timely measures being taken. This paper also gives solution to display the graphs and results on a GLCD which would further enhance the portability of this system.

  5. 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.

  6. Effects of Aerobic Exercise Training on Cardiac Renin-Angiotensin System in an Obese Zucker Rat Strain

    OpenAIRE

    Diego Lopes Mendes Barretti; Flávio de Castro Magalhães; Tiago Fernandes; Everton Crivoi do Carmo; Kaleizu Teodoro Rosa; Maria Claudia Irigoyen; Carlos Eduardo Negrão; Edilamar Menezes Oliveira

    2012-01-01

    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 Zu...

  7. Parallel-hole collimator concept for stationary SPECT imaging.

    Science.gov (United States)

    Pato, Lara R V; Vandenberghe, Stefaan; Zedda, Tiziana; Van Holen, Roel

    2015-11-21

    Parallel-hole SPECT collimators have traditionally been manufactured by stacking sheets of lead foil or by casting. These techniques significantly restrict our options in terms of collimator geometry. However, recent developments in metal additive manufacturing are making novel collimator designs possible, giving rise to new opportunities in SPECT imaging. In this paper we propose an innovative type of collimator for stationary SPECT, using parallel-holes whose collimation direction depends on their axial position. Its main advantage compared to current stationary SPECT systems (which are based on pinholes) is that, using only axial bed translations, we can achieve complete angular sampling of an increased portion of the transaxial area of the collimator bore. This allows the system to be much more compact than current stationary SPECT systems that image objects of the same size. We describe three possible designs, for full-body, brain and small-animal imaging, respectively, and test their feasibility using simulations. The system modeling method is validated against realistic Monte Carlo simulations, and then used in the evaluation of the systems' performances and reconstructions. The simulations show that the system is able to reconstruct objects occupying the predicted field of view ([Formula: see text] of the transaxial area of the bore) without sampling artifacts. In particular, we perform reconstructions from noisy projection data obtained for an activity and scanning time similar to standard protocols for the three applications, and the resulting images indicate the possibility of using the proposed systems in practice. PMID:26528908

  8. Quantitative simultaneous {sup 99m}Tc-ECD/{sup 123}I-FP-CIT SPECT in Parkinson's disease and multiple system atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, Georges El; Kijewski, Marie Foley [Harvard Medical School and Brigham and Women' s Hospital, Division of Nuclear Medicine, Department of Radiology, Boston, MA (United States); Habert, Marie-Odile; Maksud, Philippe; Malek, Zoulikha [CHU Pitie-Salpetriere, U678 INSERM - UPMC, Paris (France); CHU Pitie-Salpetriere, Department of Nuclear Medicine, Paris (France); Kas, Aurelie [CHU Pitie-Salpetriere, Department of Nuclear Medicine, Paris (France); Lacomblez, Lucette [CHU Pitie-Salpetriere, Federation des Maladies du Systeme Nerveux, Paris (France); CHU Pitie-Salpetriere, Department of Pharmacology, Paris (France)

    2006-01-01

    The purpose of this study was to investigate the feasibility and utility of dual-isotope SPECT for differential diagnosis of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA). Simultaneous {sup 99m}Tc-ECD/{sup 123}I-FP-CIT studies were performed in nine normal controls, five IPD patients, and five MSA patients. Projections were corrected for scatter, cross-talk, and high-energy penetration, and iteratively reconstructed while correcting for patient-specific attenuation and variable collimator response. Perfusion and dopamine transporter (DAT) function were assessed using voxel-based statistical parametric mapping (SPM2) and volume of interest quantitation. DAT binding potential (BP) and asymmetry index (AI) were estimated in the putamen and caudate nucleus. Striatal BP was lower in IPD (55%) and MSA (23%) compared to normal controls (p<0.01), and in IPD compared to MSA (p<0.05). AI was greater for IPD than for MSA and controls in both the caudate nucleus and the putamen (p<0.05). There was significantly decreased perfusion in the left and right nucleus lentiformis in MSA compared to IPD and controls (p<0.05). Dual-isotope studies are both feasible in and promising for the diagnosis of parkinsonian syndromes. (orig.)

  9. Cerebral blood flow assessed by brain SPECT with 99mTc-HMPAO utilising the acetazolamide test in systemic lupus erythematosus

    International Nuclear Information System (INIS)

    Background: Cerebrovascular diseases are one of the most important complications of systemic lupus erythematosus (SLE). The diagnostic imaging of neuropsychiatric SLE complications presents many problems. This study was undertaken to investigate cerebral blood flow char s and its reactivity to hypercapnia by means of acetazolamide test in SLE patients. Methods: Brain SPECT studies using 99mTc-HMPAO were performed in 50 patients with SLE. Acetazolamide test was performed in 35 patients 3 days after the baseline study by means of repetitive scanning 20 min after i.v. injection of 1.0 g of acetazolamide. Results: Significant interhemispheric hypoperfusion areas were shown in 76.3% of all patients, 83.8% symptomatic and 63.1% asymptomatic. Patients with antiphospholipid syndrome showed multifocal perfusion deficits. The reaction of cerebral perfusion to acetazolamide was heterogenous and showed increase, decrease, no change or mixed reaction of baseline-study-found focal hypoperfusion. Acetazolamide test revealed hypoperfusion in two patients with normal baseline study. MRI scanning revealed cerebral lesions in 41% of patients. Conclusions: CBF asymmetries in symptomatic and asymptomatic patients with SLE are frequent. Regional CBF alterations seem to be different in patients with and without antiphospholipid syndrome. The part of the patients with SLE shows no or paradoxically inversed reaction to acetazolamide. (author)

  10. Neuropharmacological studies with SPECT in neuropsychiatric disorders

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-10-01

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

  11. 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 of...... patients were using non-sedating antihistamines. In general non-sedating antihistamines are associated with cardiac arrhythmia to a higher extent in comparison with other drugs (ADR reporting odds ratio 2.05 [95% CI: 1.45, 2.89]). The association between arrhythmias and non-sedating antihistamine drugs...... calculated before 1998 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...

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

    International Nuclear Information System (INIS)

    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-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

  13. 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.

  14. Dynamic model of the left ventricle for use in simulation of myocardial perfusion SPECT and gated SPECT

    International Nuclear Information System (INIS)

    Simulation is a useful tool in cardiac SPECT to assess quantification algorithms. However, simple equation-based models are limited in their ability to simulate realistic heart motion and perfusion. We present a numerical dynamic model of the left ventricle, which allows us to simulate normal and anomalous cardiac cycles, as well as perfusion defects. Bicubic splines were fitted to a number of control points to represent endocardial and epicardial surfaces of the left ventricle. A transformation from each point on the surface to a template of activity was made to represent the myocardial perfusion. Geometry-based and patient-based simulations were performed to illustrate this model. Geometry-based simulations modeled (1) a normal patient, (2) a well-perfused patient with abnormal regional function, (3) an ischaemic patient with abnormal regional function, and (4) a patient study including tracer kinetics. Patient-based simulation consisted of a left ventricle including a realistic shape and motion obtained from a magnetic resonance study. We conclude that this model has the potential to study the influence of several physical parameters and the left ventricle contraction in myocardial perfusion SPECT and gated-SPECT studies

  15. 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.)

  16. 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

    International Nuclear Information System (INIS)

    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 [123I]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 (BPNP) 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 BPNP 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.)

  17. Parallel-hole collimator concept for stationary SPECT imaging

    Science.gov (United States)

    Pato, Lara R. V.; Vandenberghe, Stefaan; Zedda, Tiziana; Van Holen, Roel

    2015-11-01

    Parallel-hole SPECT collimators have traditionally been manufactured by stacking sheets of lead foil or by casting. These techniques significantly restrict our options in terms of collimator geometry. However, recent developments in metal additive manufacturing are making novel collimator designs possible, giving rise to new opportunities in SPECT imaging. In this paper we propose an innovative type of collimator for stationary SPECT, using parallel-holes whose collimation direction depends on their axial position. Its main advantage compared to current stationary SPECT systems (which are based on pinholes) is that, using only axial bed translations, we can achieve complete angular sampling of an increased portion of the transaxial area of the collimator bore. This allows the system to be much more compact than current stationary SPECT systems that image objects of the same size. We describe three possible designs, for full-body, brain and small-animal imaging, respectively, and test their feasibility using simulations. The system modeling method is validated against realistic Monte Carlo simulations, and then used in the evaluation of the systems’ performances and reconstructions. The simulations show that the system is able to reconstruct objects occupying the predicted field of view (75% of the transaxial area of the bore) without sampling artifacts. In particular, we perform reconstructions from noisy projection data obtained for an activity and scanning time similar to standard protocols for the three applications, and the resulting images indicate the possibility of using the proposed systems in practice.

  18. Effects of cardiac sympathetic nervous system on the stunned myocardium

    International Nuclear Information System (INIS)

    123I-Metaiodobenzylguanidine (123I-MIBG) uptake in the stunned myocardium was investigated in open chest dogs. 123I-MIBG is a tracer taken up in presynaptic adrenergic vesicles and reflects the function of the myocardial sympathetic nervous system. This study revealed that in the stunned myocardium without infarct, 123I-MIBG uptake was normal up to 40 minutes of ischemia and that exogenous noradrenaline improved deteriolated regional wall motion with increased uptake of 123I-MIBG. However, uptake of 123I-MIBG per flow decreased with infarct in ischemic areas, and it showed a linear relation with regional wall motion. Thus, in the absence of infarction 123I-MIBG is a tracer to differentiate stunning from more severe ischemia with persistent wall motion abnormality. Normal uptake and storage of 123I-MIBG in the stunned condition suggests that catecholamine release or second effector mechanism may relate to the mechanism. (author)

  19. Hybrid SPECT/CT imaging in neurology.

    Science.gov (United States)

    Ciarmiello, Andrea; Giovannini, Elisabetta; Meniconi, Martina; Cuccurullo, Vincenzo; Gaeta, Maria Chiara

    2014-01-01

    In recent years, the SPECT/CT hybrid modality has led to a rapid development of imaging techniques in nuclear medicine, opening new perspectives for imaging staff and patients as well. However, while, the clinical role of positron emission tomography-computed tomography (PET-CT) is well consolidated, the diffusion and the consequent value of single-photon emission tomography-computed tomography (SPECT-CT) has yet to be weighed, Hence, there is a need for a careful analysis, comparing the "potential" benefits of the hybrid modality with the "established" ones of the standalone machine. The aim of this article is to analyze the impact of this hybrid tool on the diagnosis of diseases of the central nervous system, comparing strengths and weaknesses of both modalities through the use of SWOT analysis. PMID:25143053

  20. Spect in epilepsy

    International Nuclear Information System (INIS)

    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.)

  1. Neuropsychiatry: PET and SPECT

    International Nuclear Information System (INIS)

    Functional brain imaging with PET and SPECT have a definitive and well established role in the investigation of a variety of conditions such as dementia, epilepsy and drug addiction. With these methods it is possible to detect early rCBF (regional Cerebral Blood Flow) changes seen in dementia (even before clinical symptoms) and differentiate Alzheimer's disease from other dementias by means of the rCBF pattern change. 18-F-FDG PET imaging is a useful tool in partial epilepsy because both rCBF and brain metabolism are compromised at the epileptogenic focus. During the seizure, rCBF dramatically increases locally. Using SPECT it is possible to locate such foci with 97% accuracy. In drug addiction, particularly with cocaine, functional imaging has proven to be very sensitive to detect brain flow and metabolism derangement early in the course of this condition. These findings are important in many ways: prognostic value, they are used as a powerful reinforcement tool and to monitor functional recovery with rehabilitation. There are many other conditions in which functional brain imaging is of importance such as acute stroke treatment assessment, trauma rehabilitation and in psychiatric and abnormal movement diseases specially with the development of receptor imaging (au)

  2. Culturing Mouse Cardiac Valves in the Miniature Tissue Culture System.

    Science.gov (United States)

    Kruithof, Boudewijn P T; Lieber, Samuel C; Kruithof-de Julio, Marianna; Gaussin, Vincian; Goumans, Marie José

    2015-01-01

    Heart valve disease is a major burden in the Western world and no effective treatment is available. This is mainly due to a lack of knowledge of the molecular, cellular and mechanical mechanisms underlying the maintenance and/or loss of the valvular structure. Current models used to study valvular biology include in vitro cultures of valvular endothelial and interstitial cells. Although, in vitro culturing models provide both cellular and molecular mechanisms, the mechanisms involved in the 3D-organization of the valve remain unclear. While in vivo models have provided insight into the molecular mechanisms underlying valvular development, insight into adult valvular biology is still elusive. In order to be able to study the regulation of the valvular 3D-organization on tissue, cellular and molecular levels, we have developed the Miniature Tissue Culture System. In this ex vivo flow model the mitral or the aortic valve is cultured in its natural position in the heart. The natural configuration and composition of the leaflet are maintained allowing the most natural response of the valvular cells to stimuli. The valves remain viable and are responsive to changing environmental conditions. This MTCS may provide advantages on studying questions including but not limited to, how does the 3D organization affect valvular biology, what factors affect 3D organization of the valve, and which network of signaling pathways regulates the 3D organization of the valve. PMID:26555276

  3. Cardiac sarcoidosis

    Science.gov (United States)

    Smedema, J.P.; Zondervan, P.E.; van Hagen, P.; ten Cate, F.J.; Bresser, P.; Doubell, A.F.; Pattynama, P.; Hoogsteden, H.C.; Balk, A.H.M.M.

    2002-01-01

    Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology. Symptomatic cardiac involvement occurs in approximately 5% of patients. The prevalence of sarcoidosis in the Netherlands is unknown, but estimated to be approximately 20 per 100,000 population (3200 patients). We report on five patients who presented with different manifestations of cardiac sarcoidosis, and give a brief review on the current management of this condition. Magnetic Resonance Imaging (MRI) can be of great help in diagnosing this condition as well as in the follow-up of the response to therapy. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:25696121

  4. The role of preclinical SPECT in oncological and neurological research in combination with either CT or MRI

    International Nuclear Information System (INIS)

    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.)

  5. 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.)

  6. Evaluation of the acute cardiac and central nervous system effects of the fluorocarbon trifluoromethane in baboons

    Energy Technology Data Exchange (ETDEWEB)

    Branch, C.A.; Goldberg, D.A.; Ewing, J.R.; Butt, S.S.; Gayner, J. [Henry Ford Hospital, Detroit, MI (United States); Fagan, S.C. [Wayne State Univ., Detroit, MI (United States)

    1994-12-31

    The gaseous fluorocarbon trifluoromethane has recently been investigated for its potential as an in vivo gaseous indicator for nuclear magnetic resonance studies of brain perfusion. Trifluoromethane may also have significant value as a replacement for chlorofluorocarbon fire retardants. Because of possible species-specific cardiotoxic and anesthetic properties, the toxicological evaluation of trifluoromethane in primates (Papio anubis) is necessary prior to its evaluation in humans. We report the acute cardiac and central nervous system effects of trifluoromethane in eight anesthetized baboons. A dose-response effect was established for respiratory rate, electroencephalogram, and cardiac sinus rate, which exhibited a stepwise decrease from 10% trifluoromethane. No spontaneous arrhythmias were noted, and arterial blood pressure remained unchanged at any inspired level. Intravenous epinephrine infusions (1 {mu}g/kg) induced transient cardiac arrhythmia in 1 animal only at 70% FC-23 (v/v) trifluoromethane. Trifluoromethane appears to induce mild dose-related physiological changes at inspired levels of 30% or more, indicative of an anesthetic effect. These data suggest that trifluoromethane may be safe to use in humans, without significant adverse acute effects, at an inspired level of 30%. 23 refs., 3 figs., 3 tabs.

  7. An interoperable system for automated diagnosis of cardiac abnormalities from electrocardiogram data.

    Science.gov (United States)

    Tinnakornsrisuphap, Thidarat; Billo, Richard E

    2015-03-01

    Electrocardiogram (ECG) data are stored and analyzed in different formats, devices, and computer platforms. As a result, ECG data from different monitoring devices cannot be displayed unless the user has access to the proprietary software of each particular device. This research describes an ontology and encoding for representation of ECG data that allows open exchange and display of ECG data in a web browser. The ontology is based on the Health Level Seven (HL7) medical device communication standard. It integrates ECG waveform data, HL7 standard ECG data descriptions, and cardiac diagnosis rules, providing a capability to both represent ECG waveforms as well as perform automated diagnosis of 37 different cardiac abnormalities. The ECG ontology is encoded in XML, thus allowing ECG data from any digital ECG device that maps to it to be displayed in a general-purpose Internet browser. An experiment was conducted to test the interoperability of the system (ability to openly share ECG data without error in a web browser) and also to assess the accuracy of the diagnosis model. Results showed 100% interoperability using 276 ECG data files and 93% accuracy in diagnosis of abnormal cardiac conditions. PMID:24808416

  8. 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.

  9. Procalcitonin for the differential diagnosis of infectious and non-infectious systemic inflammatory response syndrome after cardiac surgery

    OpenAIRE

    Zhao, Dong; Zhou, Jianxin; Haraguchi, Go; Arai, Hirokuni; Mitaka, Chieko

    2014-01-01

    Background This study was performed to assess the value of procalcitonin (PCT) for the differential diagnosis between infectious and non-infectious systemic inflammatory response syndrome (SIRS) after cardiac surgery. Methods Patients diagnosed with SIRS after cardiac surgery between April 1, 2011 and March 31, 2013 were retrospectively studied. A total of 142 patients with SIRS, infectious (n = 47) or non-infectious (n = 95), were included. The patients with infectious SIRS included 11 with ...

  10. 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, (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

  11. 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

  12. Voxel-based investigations of regional cerebral blood flow abnormalities in Alzheimer's disease using a single-detector SPECT system Investigações voxel-a-voxel de anormalidades de fluxo sanguíneo cerebral regional na doença de Alzheimer usando equipamento de SPECT de detector único

    Directory of Open Access Journals (Sweden)

    Fabio L. S. Duran

    2007-01-01

    Full Text Available PURPOSE: To evaluate the feasibility of using the Statistical Parametric Mapping (SPM program for an automated, voxel-by-voxel assessment of regional cerebral blood flow (rCBF deficits in Alzheimer's disease (AD subjects relative to age-matched controls studied with a conventional, single-detector SPECT system. METHODS: We used a databank of 99mTc-HMPAO images of 19 patients with a diagnosis of probable AD and 15 elderly healthy volunteers; data were acquired using an Orbiter-Siemens single-detector SPECT system. Using SPM, images were transformed spatially, smoothed (12mm, and the data were compared on a voxel-by-voxel basis with t-tests. RESULTS: There were significant rCBF reductions in AD patients relative to controls involving regions predicted a priori to be affected in AD, namely the left temporal and parietal neocortices, and the right posterior cingulate gyrus (pOBJETIVO: Avaliar a viabilidade de emprego do programa Statistical Parametric Mapping (SPM para investigar de forma automatizada, voxel-a-voxel, a presença de déficits de fluxo sanguíneo cerebral regional (FSCr em pacientes com doença de Alzheimer (DA comparados a sujeitos-controle pareados para idade, usando imagens de SPECT adquiridas com um equipamento convencional de detector único. MÉTODOS: Foi utilizado um banco de imagens adquiridas após injeção de 99mTc-HMPAO em 19 pacientes com diagnóstico provável de DA e 15 voluntários idosos saudáveis, usando um equipamento de SPECT Orbiter-Siemens de detector único. Empregando o programa SPM, as imagens foram transformadas espacialmente, suavizadas (12mm FWHM, e comparadas estatisticamente voxel-a-voxel entre os dois grupos, usando o teste de T. RESULTADOS: Foram identificadas reduções significativas de FSCr nos pacientes com DA comparados aos controles em regiões previstas a priori como afetadas por esta forma de demência, quais sejam os neocórtices temporal e parietal em hemisfério esquerdo e o c

  13. NEUROPSIQUIATRIA: PET Y SPECT

    Directory of Open Access Journals (Sweden)

    Juan Carlos Quintana F

    2002-01-01

    Full Text Available Existen numerosas indicaciones claramente establecidas para el uso del SPECT y PET en patología neuro-psiquiátrica, particularmente en el estudio de demencias, epilepsia y adicción a drogas. Estos métodos permiten detectar precozmente (aun antes de las manifestaciones clínicas cambios en la perfusión y metabolismo cerebral en pacientes con demencias. Es posible además diferenciar la enfermedad de Alzheimer de otras causas de demencia, analizando el patrón de la alteración neuro- funcional. En epilepsia parcial, tanto el metabolismo como la perfusión están alterados en el foco epileptogénico, lo que puede ser detectado con F-18FDG PET. Durante la crisis epiléptica, el flujo sanguíneo puede aumentar dramáticamente en el foco epileptogénico, lo que puede ser detectado con SPECT con 97% de certeza. En pacientes drogadictos, especialmente a la cocaína, estos métodos han demostrado ser muy sensibles para la detección precoz de cambios en el flujo y metabolismo cerebral, lo que es clínicamente importante en varios aspectos: 1 Tiene valor pronóstico (neuro-funcional, 2 Se puede usar para aumentar la adherencia a la terapia y 3 Permite evaluar objetivamente la recuperación funcional. Existen muchas otras indicaciones presentes y futuras, por ejemplo: en la monitorización de la revascularización en accidentes vasculares cerebrales agudos, rehabilitación post TEC, estudio de patología psiquiátrica y movimientos anormales especialmente con el desarrollo de radioligandosFunctional brain imaging with PET and SPECT have a definitive and well established role in the investigation of a variety of conditions such as dementia, epilepsy and drug addiction. With these methods it is possible to detect early rCBF (regional Cerebral Blood Flow changes seen in dementia (even before clinical symptoms and differentiate Alzheimer's disease from other dementias by means of the rCBF pattern change. 18-F-FDG PET imaging is a useful tool in partial

  14. 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.

  15. The SPECT imaging shows the accumulation of neural progenitor cells into internal organs after systemic administration in middle cerebral artery occlusion rats.

    Science.gov (United States)

    Lappalainen, Riikka S; Narkilahti, Susanna; Huhtala, Tuulia; Liimatainen, Timo; Suuronen, Tiina; Närvänen, Ale; Suuronen, Riitta; Hovatta, Outi; Jolkkonen, Jukka

    2008-08-01

    The regenerative potential of stem cells from various sources has been under intense investigation in the experimental models of cerebral ischemia. To end up with a restorative therapeutic treatment, it is crucial to get the cell transplants to the site of injury. Here, we evaluated the feasibility of small animal SPECT/CT in assessing the definite accumulation of (111)In-oxine-labeled human embryonic stem (ES) cell-derived neural progenitors and rat hippocampal progenitors after intravenous or intra-arterial administration (femoral vein vs. common carotid artery) in middle cerebral artery occlusion (MCAO) and sham-operated rats. Cell detection was carried out immediately and 24h after the infusion using a SPECT/CT device. The results showed that after intravenous injections both cell types accumulated primarily into internal organs, instead of brain. In contrast, after intra-arterial injection, a weak signal was detected in the ischemic hemisphere. Additional studies showed that the detection sensitivity of SPECT/CT device was approximately 1000 (111)In-oxine-labeled cells and labeling did not affect the cell viability. In conclusion, a small animal SPECT is powerful technique to study the whole body biodistribution of cell-based therapies. Our data showed that intravenous administration is not an optimal route to deliver neural progenitor cell-containing transplants into the brain after MCAO in rats. PMID:18572314

  16. Complex Nonlinear Autonomic Nervous System Modulation Link Cardiac Autonomic Neuropathy and Peripheral Vascular Disease

    Directory of Open Access Journals (Sweden)

    Kinda eKhalaf

    2015-03-01

    Full Text Available Background: Physiological interactions are abundant within, and between, body systems. These interactions may evolve into discrete states during pathophysiological processes resulting from common mechanisms. An association between arterial stenosis, identified by low ankle-brachial pressure index (ABPI and cardiovascular disease (CVD as been reported. Whether an association between vascular calcification - characterized by high ABPI and a different pathophysiology - is similarly associated with CVD, has not been established. The current study aims to investigate the association between ABPI, and cardiac rhythm, as an indicator of cardiovascular health and functionality, utilising heart rate variability (HRV.Methods and Results: Two hundred and thirty six patients underwent ABPI assessment. Standard time and frequency domain, and non-linear HRV measures were determined from 5-minute electrocardiogram. ABPI data were divided into normal (n=101, low (n=67 and high (n=66 and compared to HRV measures.(DFAα1 and SampEn were significantly different between the low ABPI, high ABPI and control groups (p<0.05.Conclusion: A possible coupling between arterial stenosis and vascular calcification with decreased and increased HRV respectively was observed. Our results suggest a model for interpreting the relationship between vascular pathophysiology and cardiac rhythm. The cardiovascular system may be viewed as a complex system comprising a number of interacting subsystems. These cardiac and vascular subsystems/networks may be coupled and undergo transitions in response to internal or external perturbations. From a clinical perspective, the significantly increased sample entropy compared to the normal ABPI group and the decreased and increased complex correlation properties measured by DFA for the low and high ABPI groups respectively, may be useful indicators that a more holistic treatment approach in line with this more complex clinical picture is required.

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

    International Nuclear Information System (INIS)

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

  18. 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

    International Nuclear Information System (INIS)

    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.)

  19. 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.)

  20. Assessment of brain SPECT neuropsychiatric involvement in collagen-vascular diseases

    International Nuclear Information System (INIS)

    Objective: To study the value of brain SPECT in the diagnosis and follow up of SNC involvement in systemic connective tissue diseases (SCTD) with neuropsychiatric symptoms (NPS). Materials and methods: We retrospectively analyzed 31 consecutive patients with SCTD presenting with NPS who underwent 99mTc-ECD SPECT and statistical surface maps. 21 patients had systemic lupus erythematosus and 3 had Behcet disease. Results were compared to those of CT (18/31), MRI (8/31) and neuropsychological examination (NPE). 6 patients had follow-up SPECT scans. Results: Twenty-eight patients had abnormal SPECT studies. CT was abnormal in 3/18 patients (sensitivity 90.3% vs. 16.7%; p<0.001). MRI showed alterations in 5/8 patients and NPE in 7/10. Although all these patients presented abnormal SPECT scans, sensitivity values were not statistically different. Patients with major NPS presented more extensive perfusion defects (p<0.035). Patients with follow-up SPECT scans showed perfusion improvement with response to treatment and progression of the alterations when symptoms relapsed. Conclusion:Brain SPECT presents high sensitivity for the detection of neurological involvement in SCTD. SPECT usefulness may extend to follow-up and evaluation of response to treatment

  1. 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, 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.

  2. 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

  3. SPM analysis of cerebrovascular reserve capacity after stimulation with acetazolamide measured by Tc-99m ECD SPECT in normal brain MRI patient

    International Nuclear Information System (INIS)

    This study was undertaken to evaluate normal response of acetazolamide in normal individuals, whose brain MRI is normal, using SPM99. In total, 10 Tc- 99m ECD brain SPECT were evaluated retrospectively. The half of the patients were male. Their mean age was 47.1 years old with a range of 33-61 years. They all visited our neurology department to evaluate stroke symptom. Their brain MRI was normal. Rest/acetazolamide brain SPECT was perfomed using Tc-99m ECD and the sequential injection and subtraction method. SPECT was acquired using fanbeam collimators and triple-head gamma camera (MultiSPECT III, Siemens medical systems, Inc. Hoffman Estates, III, USA). Chang's attenuation correction was applied their brain SPECT revealed normal rCBF pattern in visual analysis by two nuclear physician and they were diagnosed clinically normal. Using SPM method, we compared rest brain SPECT images with those of acetazolamide brain SPECT and measured the extent of the area with significant perfusion change (P<0.05) in predefined 34 cerebral regions. Acetazolamide brain SPECT showed no significant decreased region in comparison to rest brain SPECT. Only small portion of left mid temporal gyrus revealed increased rCBF on acetazolamide brain SPECT in comparison to rest brain SPECT. It apperas that there is no significant change in rCBF between rest and acetazolamide brain SPECT using Tc-99m ECD. The small number of this study is limitation of our study

  4. 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.)

  5. Evaluation of quantitative accuracy in CZT-based pre-clinical SPECT for various isotopes

    International Nuclear Information System (INIS)

    In vivo pre-clinical single-photon emission computed tomography (SPECT) is a valuable tool for functional small animal imaging, but several physical factors, such as scatter radiation, limit the quantitative accuracy of conventional scintillation crystal-based SPECT. Semiconductor detectors such as CZT overcome these deficiencies through superior energy resolution. To our knowledge, little scientific information exists regarding the accuracy of quantitative analysis in CZT-based pre-clinical SPECT systems for different isotopes. The aim of this study was to assess the quantitative accuracy of CZT-based pre-clinical SPECT for four isotopes: 201Tl, 99mTc, 123I, and 111In. The quantitative accuracy of the CZT-based Triumph X-SPECT (Gamma-Medica Ideas, Northridge, CA, U.S.A.) was compared with that of a conventional SPECT using GATE simulation. Quantitative errors due to the attenuation and scatter effects were evaluated for all four isotopes with energy windows of 5%, 10%, and 20%. A spherical source containing the isotope was placed at the center of the air-or-water-filled mouse-sized cylinder phantom. The CZT-based pre-clinical SPECT was more accurate than the conventional SPECT. For example, in the conventional SPECT with an energy window of 10%, scatter effects degraded quantitative accuracy by up to 11.52%, 5.10%, 2.88%, and 1.84% for 201Tl, 99mTc, 123I, and 111In, respectively. However, with the CZT-based pre-clinical SPECT, the degradations were only 9.67%, 5.45%, 2.36%, and 1.24% for 201Tl, 99mTc, 123I, and 111In, respectively. As the energy window was increased, the quantitative errors increased in both SPECT systems. Additionally, the isotopes with lower energy of photon emissions had greater quantitative error. Our results demonstrated that the CZT-based pre-clinical SPECT had lower overall quantitative errors due to reduced scatter and high detection efficiency. Furthermore, the results of this systematic assessment quantifying the accuracy of these SPECT

  6. Evaluation of quantitative accuracy in CZT-based pre-clinical SPECT for various isotopes

    Science.gov (United States)

    Park, S.-J.; Yu, A. R.; Kim, Y.-s.; Kang, W.-S.; Jin, S. S.; Kim, J.-S.; Son, T. J.; Kim, H.-J.

    2015-05-01

    In vivo pre-clinical single-photon emission computed tomography (SPECT) is a valuable tool for functional small animal imaging, but several physical factors, such as scatter radiation, limit the quantitative accuracy of conventional scintillation crystal-based SPECT. Semiconductor detectors such as CZT overcome these deficiencies through superior energy resolution. To our knowledge, little scientific information exists regarding the accuracy of quantitative analysis in CZT-based pre-clinical SPECT systems for different isotopes. The aim of this study was to assess the quantitative accuracy of CZT-based pre-clinical SPECT for four isotopes: 201Tl, 99mTc, 123I, and 111In. The quantitative accuracy of the CZT-based Triumph X-SPECT (Gamma-Medica Ideas, Northridge, CA, U.S.A.) was compared with that of a conventional SPECT using GATE simulation. Quantitative errors due to the attenuation and scatter effects were evaluated for all four isotopes with energy windows of 5%, 10%, and 20%. A spherical source containing the isotope was placed at the center of the air-or-water-filled mouse-sized cylinder phantom. The CZT-based pre-clinical SPECT was more accurate than the conventional SPECT. For example, in the conventional SPECT with an energy window of 10%, scatter effects degraded quantitative accuracy by up to 11.52%, 5.10%, 2.88%, and 1.84% for 201Tl, 99mTc, 123I, and 111In, respectively. However, with the CZT-based pre-clinical SPECT, the degradations were only 9.67%, 5.45%, 2.36%, and 1.24% for 201Tl, 99mTc, 123I, and 111In, respectively. As the energy window was increased, the quantitative errors increased in both SPECT systems. Additionally, the isotopes with lower energy of photon emissions had greater quantitative error. Our results demonstrated that the CZT-based pre-clinical SPECT had lower overall quantitative errors due to reduced scatter and high detection efficiency. Furthermore, the results of this systematic assessment quantifying the accuracy of these SPECT

  7. 'Double-layer' method to improve image quality of industria SPECT

    International Nuclear Information System (INIS)

    Recently a lab-scale single photon emission computed tomography (SPECT) system was constructed to study the details of the image formation process in an industrial SPECT system. The industrial SPECT system differs from a medical SPECT system in that it uses relatively large detectors and collimators in order to effectively detect high-energy gammas with enough collimation power, resulting always, however, in low-quality images. In this paper, a simple but very effective 'double-layer' method is proposed as a means of improving the image quality of the industrial SPECT system. The rationale of the double-layer method is to simultaneously employ two layers of identical SPECT systems to increase the number of measurements points and, thereby, increase the image quality. The performance results of the double-layer method, as evaluated by Geant4 Monte Carlo simulations, showed dramatic improvement in image quality over those offered by the single-layer SPECT system. The improvement, additionally, was more marked for more complicated and higher-energy gamma sources.

  8. 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.

  9. Myocyte-fibroblast communication in cardiac fibrosis and arrhythmias: Mechanisms and model systems.

    Science.gov (United States)

    Pellman, Jason; Zhang, Jing; Sheikh, Farah

    2016-05-01

    Development of cardiac fibrosis and arrhythmias is controlled by the activity of and communication between cardiomyocytes and fibroblasts in the heart. Myocyte-fibroblast interactions occur via both direct and indirect means including paracrine mediators, extracellular matrix interactions, electrical modulators, mechanical junctions, and membrane nanotubes. In the diseased heart, cardiomyocyte and fibroblast ratios and activity, and thus myocyte-fibroblast interactions, change and are thought to contribute to the course of disease including development of fibrosis and arrhythmogenic activity. Fibroblasts have a developing role in modulating cardiomyocyte electrical and hypertrophic activity, however gaps in knowledge regarding these interactions still exist. Research in this field has necessitated the development of unique approaches to isolate and control myocyte-fibroblast interactions. Numerous methods for 2D and 3D co-culture systems have been developed, while a growing part of this field is in the use of better tools for in vivo systems including cardiomyocyte and fibroblast specific Cre mouse lines for cell type specific genetic ablation. This review will focus on (i) mechanisms of myocyte-fibroblast communication and their effects on disease features such as cardiac fibrosis and arrhythmias as well as (ii) methods being used and currently developed in this field. PMID:26996756

  10. Optimization of detector size and collimator for PG-SPECT

    International Nuclear Information System (INIS)

    A current absorbed dose evaluation method in a Boron Neutron Capture Therapy demands boron reaction rate from a boron concentration of an affected part supposed from a neutron flux and a boron concentration in blood measured by an activation method of a gold wire indirectly and converts it into an absorbed dose. So we devised a PG-SEPCT (Prompt Gamma-ray Single Photon Emission Computed Tomography) system to evaluate an absorbed dose directly by measuring prompt gamma-rays. Ordinary SPECT system uses a big NaI scintillator for detector so that measurement is done in low background gamma-ray environment. However, a conventional detector and collimator system cannot be just applied to PG-SPECT system because a background radiation coexists abundantly (PG-SPECT system is set in irradiation room). Accordingly PG-SPECT system requires a dedicated detector and collimator system. In order to reduce efficiency for background gamma-rays, we arranged detectors in a collimator to shield from background gamma-rays. We examined the most suitable collimator shape. The optimization condition of a dedicated collimator system is as follows: 1) the smallest particle size that can be distinguished is 1 cm. 2) necessary counts at measurement target center is not less than 10,000. (author)

  11. SPECT of brain blood flow

    International Nuclear Information System (INIS)

    Morphological observation of the brain became possible by CT and various informations on vascularity and damages in brain blood barrier (BBB) became obtainable by the combined use of contrast medium. Then the appearance of MRI had enabled to discriminate the cortex and the medula of the brain and to perform MR angiography. However, it was still difficult to observe the cerebral tissue in detail. Recently, nuclear medical procedures have been developed and applied to diagnosis. SPECT images attributable to the distribution of γ-ray from a tracer, which monitors the blood flow and various metabolisms. Thus, investigations of cerebral functions including blood flow metabolism and neural transmission etc. became possible by the technique. Here, SPECT by Xe-133 clearance and 99mTc HMPAO methods were reviewed. For Xe-133 method, subjects positioned in SPECT instrument underwent bolus inhalation of Xe-133, 1850 Mbq followed by washout respiration of room air. During these treatment, cerebral projection and determination of the concentration of Xe-133 CO2 in the expired air were continuously carried out. And the blood flow level per pixel was estimated from SPECT images and the end-tidal Xe-133 concentration curve. This method was thought to be the most excellent method for the determination of local blood flow in respect of accuracy and reproducibility. The tracer distribution expressed the functional level of the stagnant state of blood flow. SPECT provides useful informations to investigate the physiological functions and pathology in the brain. (M.N.)

  12. Myocardial viability assessed by Tl-201 SPECT. Redistribution versus reinjection; Estudo da viabilidade miocardica atraves do SPECT-talio-201. Redistribuicao convencional versus reinjecao

    Energy Technology Data Exchange (ETDEWEB)

    Chalela, William Azem; Pimentel, Flavio Ferrarini de Oliveira; Uchida, Augusto Hiroshi; Bottega, Augusto; Ramires, Jose Antonio Franchine; Izaki, Marisa; Moraes, Aguinaldo Pereira; Soares Junior, Jose; Giorgi, Maria C. Pinto; Moffa, Paulo Jorge; Bellotti, Giovanni; Giovanni Guido Cerri; Meneghetti, Jose Claudio [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Instituto do Coracao

    1994-07-01

    The purpose of this study was to verify if a third series of images acquired by reinjection thallium-201, 24 h after conventional myocardial perfusion with the radioisotope, improves the identification of myocardial viability segments. The methods: we studied 30 patients, mean age 57.7 {+-}9.4 years, with old myocardial infarction using thallium (Tl)-201 SPECT, and we obtained three series of images (stress, redistribution after 4 h and reinjection after 24 h). Cardiac images were divided in 5 segments (apical, lateral, anterior, septal and inferior) and each one received a value by a score system according to the Tl-201 myocardial uptake (0=normal uptake; 1=mild hypoperfusion; 2=moderate hypoperfusion; 3=severe hypoperfusion or no myocardial uptake). We considered viable myocardium when the uptake of Tl-201 in the segment related to the myocardial infarction increases at least 1 point in two different axis of Tl-201 SPECT. The results: seven (23,3%) patients demonstrated increase of Tl-201 uptake only at reinjection images, showing a high efficacy of the method. Nine (30%) patients showed persistent hypoperfusion at all series of images suggesting only fibrosis in the are related to the infarction. Fourteen (46,7%) patients showed increase of Tl-201 concentration at redistribution images; among these patients, six showed improvement of myocardial uptake at reinjection. This condition was interpreted as regional chronic ischemic process: hibernating myocardium. The conclusion was that Tl-201 hypoperfusion at redistribution images without significant changes in relation to the stress images do not represent fibrosis at all. The reinjection technic was better than conventional redistribution in the detection of viable myocardium. This data allows a better therapeutic orientation. (author)

  13. The application of PET, SPECT and MRS in Parkinson's disease

    International Nuclear Information System (INIS)

    PET and SPECT provide the means to studying in vivo the neurochemical, hemodynamic or metabolic consequences of the degeneration of the nigrostriatal dopamineric system in Parkinson's disease (PD). Activation studies using cerebral blood flow and metabolism measurements during a motor task reveal an impaired ability to activate the supplementary motor area and dorsolateral prefrontal cortex in PD. The extent of striatal dopaminergic denervation can be quantified with PET and SPECT. Striatal uptake of 18F-dopa is markedly decreased in PD, more in the putamen than in the caudate nucleus, and inversely correlates with the severity of motor signs and with duration of disease. PET and SPECT make possible the assessment by noninvasive means of the changes in dopamine receptor density. Meanwhile, MRS can reveal changes in concentration of several hydrogenate and phosphoric compounds in the brain. The functional information of brain in PD can be obtained with these complementary techniques. (authors)

  14. 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.

  15. 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.