WorldWideScience

Sample records for cardiac spect systems

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-10-01

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

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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...

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  9. A multiresolution restoration method for cardiac SPECT

    Science.gov (United States)

    Franquiz, Juan Manuel

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

  10. 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

  11. Feasibility study of segmented-parallel-hole collimator for stationary cardiac SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Yanfei [Utah Univ., Salt Lake City, UT (United States). Center for Advanced Imaging Research (UCAIR); Utah Univ., Salt Lake City, UT (United States). Dept. of Bioengineering; Zeng, Gengsheng L. [Utah Univ., Salt Lake City, UT (United States). Center for Advanced Imaging Research (UCAIR)

    2011-07-01

    The goal of this research is to propose a stationary cardiac SPECT system using the segmented parallel-beam collimator and to perform some computer simulations to test the feasibility. A stationary system has a benefit of acquiring temporally consistent projections. The most challenging issue in building a stationary system is to provide sufficient projection view-angles. A 2-detector, multi-segment collimator system with 14 view-angles over 180 in the transaxial direction and 3 view-angles in the axial directions was designed, where the two detectors are configured 90 apart in an L-shape. We applied the parallel-beam imaging geometry and used segmented parallel-hole collimator to acquire SPECT data. To improve the system condition due to data truncation, we measured more rays within the field-of-view (FOV) of the detector by using a relatively small detector bin-size. In image reconstruction, we used the maximum-likelihood expectation-maximization (ML-EM) algorithm. The criterion for evaluating the system is the summed pixel-to-pixel distance that measures the discrepancy between the 3D gold-standard image and the reconstructed 3D region of interest (ROI) with truncated data. Effects of limited number of view-angles, data truncation, varying body habitus, attenuation, and noise were considered in the system design. As a result, our segmented-parallel-beam stationary cardiac SPECT system is able to acquire sufficient data for cardiac imaging and has a high sensitivity gain. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-02-01

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

  14. 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.

  15. 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

  16. 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

  17. 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

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

    Science.gov (United States)

    Pretorius, P Hendrik; King, Michael A

    2009-01-01

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

  19. 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

  20. 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''.

  1. 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''.

  2. 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

  3. 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

  4. 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)

  5. 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)

  6. 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

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

    Science.gov (United States)

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

    2012-02-01

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

  8. 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)

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

  10. 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)

  11. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-02-01

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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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)

  19. 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.

  20. 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

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

    Science.gov (United States)

    Studenski, Matthew Thomas

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

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

    Science.gov (United States)

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

    2012-09-01

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

  3. SVD-Based Evaluation of Multiplexing in Multipinhole SPECT Systems

    Directory of Open Access Journals (Sweden)

    Aaron K. Jorgensen

    2008-01-01

    Full Text Available Multipinhole SPECT system design is largely a trial-and-error process. General principles can give system designers a general idea of how a system with certain characteristics will perform. However, the specific performance of any particular system is unknown before the system is tested. The development of an objective evaluation method that is not based on experimentation would facilitate the optimization of multipinhole systems. We derive a figure of merit for prediction of SPECT system performance based on the entire singular value spectrum of the system. This figure of merit contains significantly more information than the condition number of the system, and is therefore more revealing of system performance. This figure is then compared with simulated results of several SPECT systems and is shown to correlate well to the results of the simulations. The proposed figure of merit is useful for predicting system performance, but additional steps could be taken to improve its accuracy and applicability. The limits of the proposed method are discussed, and possible improvements to it are proposed.

  4. 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

    . 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...

  5. 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...

  6. 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

  7. Performance of a high-sensitivity dedicated cardiac SPECT scanner for striatal uptake quantification in the brain based on analysis of projection data

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mi-Ae; Moore, Stephen C.; McQuaid, Sarah J.; Kijewski, Marie Foley [Department of Radiology, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts 02115 (United States); Mueller, Stefan P. [Abteilung Nuklearmedizin, Universitaetsklinikum Essen, 45147 Essen (Germany)

    2013-04-15

    Purpose: The authors have previously reported the advantages of high-sensitivity single-photon emission computed tomography (SPECT) systems for imaging structures located deep inside the brain. DaTscan (Isoflupane I-123) is a dopamine transporter (DaT) imaging agent that has shown potential for early detection of Parkinson disease (PD), as well as for monitoring progression of the disease. Realizing the full potential of DaTscan requires efficient estimation of striatal uptake from SPECT images. They have evaluated two SPECT systems, a conventional dual-head gamma camera with low-energy high-resolution collimators (conventional) and a dedicated high-sensitivity multidetector cardiac imaging system (dedicated) for imaging tasks related to PD. Methods: Cramer-Rao bounds (CRB) on precision of estimates of striatal and background activity concentrations were calculated from high-count, separate acquisitions of the compartments (right striata, left striata, background) of a striatal phantom. CRB on striatal and background activity concentration were calculated from essentially noise-free projection datasets, synthesized by scaling and summing the compartment projection datasets, for a range of total detected counts. They also calculated variances of estimates of specific-to-nonspecific binding ratios (BR) and asymmetry indices from these values using propagation of error analysis, as well as the precision of measuring changes in BR on the order of the average annual decline in early PD. Results: Under typical clinical conditions, the conventional camera detected 2 M counts while the dedicated camera detected 12 M counts. Assuming a normal BR of 5, the standard deviation of BR estimates was 0.042 and 0.021 for the conventional and dedicated system, respectively. For an 8% decrease to BR = 4.6, the signal-to-noise ratio were 6.8 (conventional) and 13.3 (dedicated); for a 5% decrease, they were 4.2 (conventional) and 8.3 (dedicated). Conclusions: This implies that PD can

  8. 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.)

  9. 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

  10. Radiotracers for PET and SPECT studies of neurotransmitter systems

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.

    1991-01-01

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

  11. 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)

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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

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

    Science.gov (United States)

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

    2015-04-01

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

  20. 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.)

  1. 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...

  2. 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

  3. 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

  4. 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

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

    Science.gov (United States)

    Cao, Liji; Peter, Jörg

    2010-05-01

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

  6. 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.

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

    OpenAIRE

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

    2007-01-01

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

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

    Science.gov (United States)

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

    2011-03-01

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

  9. 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.

  10. 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.

  11. Cardiac hybrid imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

  12. 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

  13. 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

  14. 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

  15. 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)

  16. 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...

  17. 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).

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

    Science.gov (United States)

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

    2002-12-01

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

  19. 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...

  20. 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

  1. 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.)

  2. 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.

  3. 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

  4. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-15

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

  6. 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

  7. 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.)

  8. 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.)

  9. 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.)

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

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

  12. 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

  13. 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.

  14. 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)

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

    Science.gov (United States)

    Maeda, Hisatoshi

    2012-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-07

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

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

    Science.gov (United States)

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

    2011-03-01

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

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

  20. 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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chien-Chin Hsu

    2014-01-01

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

  3. 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

  4. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  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

    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

  7. 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)

  8. 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)

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

    Directory of Open Access Journals (Sweden)

    Shigeaki Higashiyama

    2014-05-01

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

  10. 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.)

  11. 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.

  12. 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

  13. 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.

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

    Science.gov (United States)

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

    2014-11-01

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

  15. 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)

  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

    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

  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. 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

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

    Science.gov (United States)

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

    2003-01-01

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

  20. 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

  1. 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

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

    Science.gov (United States)

    Brankov, Jovan G.

    2013-10-01

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

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  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. 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)

  9. 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)

  10. 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.

  11. 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

  12. 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

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

    Directory of Open Access Journals (Sweden)

    Cláudio Tinoco Mesquita

    2009-05-01

    scintigraphy (gated SPECT and cardiac magnetic 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.

  14. 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

  15. 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

  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. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  19. 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.

  20. 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

  1. 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)

  2. 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

  3. Electrical stimulation systems for cardiac tissue engineering.

    Science.gov (United States)

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

    2009-01-01

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

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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

  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. 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. 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) ...

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

    Science.gov (United States)

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

    2014-01-01

    A new multi-modality imaging tool is under development in the framework of the INSERT (INtegrated SPECT/MRI for Enhanced Stratification in Radio-chemo Therapy) project, supported by the European Community. The final goal is to develop a custom SPECT apparatus, that can be used as an insert for commercially available MRI systems such as 3 T MRI with 59 cm bore diameter. INSERT is expected to offer more effective and earlier diagnosis with potentially better outcome in survival for the treatment of brain tumors, primarily glioma. Two SPECT prototypes will be developed, one dedicated to preclinical imaging, the second one dedicated to clinical imaging. The basic building block of the SPECT detector ring is a small 5 cm×5 cm gamma camera, based on the well-established Anger architecture with a continuous scintillator readout by an array of silicon photodetectors. Silicon Drift Detectors (SDDs) and Silicon PhotoMultipliers (SiPM) are being considered as possible scintillator readout, considering that the detector choice plays a predominant role for the final performance of the system, such as energy and spatial resolution, as well as the useful field of view of the camera. Both solutions are therefore under study to evaluate their performances in terms of field of view (FOV), spatial and energy resolution. Preliminary simulations for both the preclinical and clinical systems have been carried out to evaluate resolution and sensitivity.

  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. 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

  16. 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.

  17. 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.)

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  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

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

  8. 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

  9. 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

  10. Development of the cardiac conduction system in zebrafish.

    Science.gov (United States)

    Poon, Kar-Lai; Liebling, Michael; Kondrychyn, Igor; Brand, Thomas; Korzh, Vladimir

    2016-07-01

    The cardiac conduction system (CCS) propagates and coordinates the electrical excitation that originates from the pacemaker cells, throughout the heart, resulting in rhythmic heartbeat. Its defects result in life-threatening arrhythmias and sudden cardiac death. Understanding of the factors involved in the formation and function of the CCS remains incomplete. By transposon assisted transgenesis, we have developed enhancer trap (ET) lines of zebrafish that express fluorescent protein in the pacemaker cells at the sino-atrial node (SAN) and the atrio-ventricular region (AVR), termed CCS transgenics. This expression pattern begins at the stage when the heart undergoes looping morphogenesis at 36 h post fertilization (hpf) and is maintained into adulthood. Using the CCS transgenics, we investigated the effects of perturbation of cardiac function, as simulated by either the absence of endothelium or hemodynamic stimulation, on the cardiac conduction cells, which resulted in abnormal compaction of the SAN. To uncover the identity of the gene represented by the EGFP expression in the CCS transgenics, we mapped the transposon integration sites on the zebrafish genome to positions in close proximity to the gene encoding fibroblast growth homologous factor 2a (fhf2a). Fhf2a is represented by three transcripts, one of which is expressed in the developing heart. These transgenics are useful tools for studies of development of the CCS and cardiac disease. PMID:27593944

  11. Cardiac and systemic haemodynamic complications of liver cirrhosis

    DEFF Research Database (Denmark)

    Henriksen, Jens H; Møller, Søren

    2009-01-01

    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...... by physical and pharmacological strain. Cardiac failure is an important cause of mortality after liver transplantation and stressful procedures as insertions of transjugular intrahepatic portal systemic shunt (TIPS), peritoneal venous shunting, and other types of surgery. Improvement of liver function has...... been shown to reverse the cardiovascular complications. The clinical significance is an important topic for future research. At present, no specific treatment can be recommended, and the cardiac failure in cirrhosis should be treated as in non-cirrhotic patients with sodium restriction, diuretics...

  12. 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.

  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. 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

  15. 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

  16. 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

  17. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-01

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

  20. 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.

  1. 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)

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

    Science.gov (United States)

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

    1996-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  5. 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.)

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

    Science.gov (United States)

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

  7. 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...

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. [Information system at Department of Cardiac Surgery Intensive Care Unit].

    Science.gov (United States)

    Dokozić, Josipa

    2014-03-01

    This paper analyzes the aspects of using computer technology in nursing practice. Transfer and managing of data, information and knowledge in nursing is enabled by using modern technology and suitable applications. Cardio applications at the Intensive Care Unit of Department of Cardiac Surgery in Osijek enables nurses/technicians to gain insight into patient personal data, medical history, microbiological findings, interventions that have been made as well as those scheduled in the field of health care, all this by using a few simple connections. Nurses/technicians are those who enter patient data into his/her Electronic Health Record. There are multiple contributions of cardiac system. In comparison with previous paper-based managing of nursing documentation, this program has considerably facilitated and improved nursing practice.

  13. 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

  14. 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.)

  15. 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 ...

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

    Science.gov (United States)

    O'Connor, M K; Cho, D S

    1992-06-01

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

  17. 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)

  18. 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....

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

    Science.gov (United States)

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

    1998-07-01

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

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

    Science.gov (United States)

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

    2015-05-01

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

  1. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  3. 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

  4. 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.)

  5. 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.)

  6. Quantitative SPECT techniques.

    Science.gov (United States)

    Watson, D D

    1999-07-01

    Quantitative imaging involves first, a set of measurements that characterize an image. There are several variations of technique, but the basic measurements that are used for single photon emission computed tomography (SPECT) perfusion images are reasonably standardized. Quantification currently provides only relative tracer activity within the myocardial regions defined by an individual SPECT acquisition. Absolute quantification is still a work in progress. Quantitative comparison of absolute changes in tracer uptake comparing a stress and rest study or preintervention and postintervention study would be useful and could be done, but most commercial systems do not maintain the data normalization that is necessary for this. Measurements of regional and global function are now possible with electrocardiography (ECG) gating, and this provides clinically useful adjunctive data. Techniques for measuring ventricular function are evolving and promise to provide clinically useful accuracy. The computer can classify images as normal or abnormal by comparison with a normal database. The criteria for this classification involve more than just checking the normal limits. The images should be analyzed to measure how far they deviate from normal, and this information can be used in conjunction with pretest likelihood to indicate the level of statistical certainty that an individual patient has a true positive or true negative test. The interface between the computer and the clinician interpreter is an important part of the process. Especially when both perfusion and function are being determined, the ability of the interpreter to correctly assimilate the data is essential to the use of the quantitative process. As we become more facile with performing and recording objective measurements, the significance of the measurements in terms of risk evaluation, viability assessment, and outcome should be continually enhanced. PMID:10433336

  7. 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

  8. 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.)

  9. 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

  10. 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

  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...

  12. 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...

  13. 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.

  14. Brain renin angiotensin system in cardiac hypertrophy and failure

    Directory of Open Access Journals (Sweden)

    Luciana eCampos

    2012-01-01

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

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. 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

  3. SPECT in epilepsies; SPECT bei Epilepsien

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  6. 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...

  7. 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.

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

    Institute of Scientific and Technical Information of China (English)

    孙涛; 严金川; 陈小节; 梁仪; 赵建伟; 张朝普; 李璇

    2011-01-01

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

  9. 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

  10. 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.

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

    Science.gov (United States)

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

    2014-10-01

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

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

    Science.gov (United States)

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

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

  13. [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

  14. [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.

  15. 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.)

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

    NARCIS (Netherlands)

    R. Due-Andersen (Rikke); T. Høi-Hansen (Thomas); N.V. Olsen; C.E. Larroude; J.K. Kanters; F. Boomsma (Frans); U. Pedersen-Bjergaard (Ullrik); B. Thorsteinsson (Birger)

    2008-01-01

    textabstractAims: 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 sub

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  18. 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.

  19. 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.)

  20. 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

  1. 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

  2. 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.)

  3. Rapid Circular Tomography System Suitable For Cardiac Imaging

    Science.gov (United States)

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

    1985-06-01

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

  4. 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

  5. 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

  6. 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.)

  7. 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

  8. Spect in epilepsy; SPECT bei Anfallsleiden

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-06-01

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

  9. 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)

  10. 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...

  11. 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.

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

    Science.gov (United States)

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

    2015-09-01

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

  13. 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...

  14. 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

  15. 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.

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

    OpenAIRE

    Végh, Anna M D; Duim, Sjoerd N; Smits, Anke M; Robert E Poelmann; Arend D. J. ten Harkel; DeRuiter, Marco C; Marie José Goumans; Monique R M Jongbloed

    2016-01-01

    The autonomic nervous system (cANS) is essential for proper heart function, and complications such as heart failure, arrhythmias and even sudden cardiac death are associated with an altered cANS function. A changed innervation state may underlie (part of) the atrial and ventricular arrhythmias observed after myocardial infarction. In other cardiac diseases, such as congenital heart disease, autonomic dysfunction may be related to disease outcome. This is also the case after heart transplantat...

  17. Brain pertechnetate SPECT in perinatal asphyxia

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

  18. High-resolution SPECT for small-animal imaging

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

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

    Science.gov (United States)

    Quail, Thomas; Shrier, Alvin; Glass, Leon

    2015-07-28

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

  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. 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...

  2. 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...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

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

  6. 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)

  7. 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.

  8. 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.)

  9. 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.)

  10. 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.)

  11. 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)

  12. 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

  13. 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

  14. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

  16. 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.)

  17. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Bernsen, Monique R.; Jong, Marion de [Erasmus MC, Department of Nuclear Medicine, Rotterdam (Netherlands); Erasmus MC, Department of Radiology, Rotterdam (Netherlands); Vaissier, Pieter E.B. [Delft University of Technology, Section Radiation Detection and Medical Imaging, Delft (Netherlands); Holen, Roel van [Ghent University, iMinds, ELIS Department, MEDISIP, Ghent (Belgium); Booij, Jan [University of Amsterdam, Department of Nuclear Medicine, Academic Medical Center, Amsterdam (Netherlands); Beekman, Freek J. [Delft University of Technology, Section Radiation Detection and Medical Imaging, Delft (Netherlands); MILabs B.V., Utrecht (Netherlands)

    2014-05-15

    Preclinical imaging with SPECT combined with CT or MRI is used more and more frequently and has proven to be very useful in translational research. In this article, an overview of current preclinical research applications and trends of SPECT combined with CT or MRI, mainly in tumour imaging and neuroscience imaging, is given and the advantages and disadvantages of the different approaches are described. Today SPECT and CT systems are often integrated into a single device (commonly called a SPECT/CT system), whereas at present combined SPECT and MRI is almost always carried out with separate systems and fiducial markers to combine the separately acquired images. While preclinical SPECT/CT is most widely applied in oncology research, SPECT combined with MRI (SPECT/MRI when integrated in one system) offers the potential for both neuroscience applications and oncological applications. Today CT and MRI are still mainly used to localize radiotracer binding and to improve SPECT quantification, although both CT and MRI have additional potential. Future technology developments may include fast sequential or simultaneous acquisition of (dynamic) multimodality data, spectroscopy, fMRI along with high-resolution anatomic MRI, advanced CT procedures, and combinations of more than two modalities such as combinations of SPECT, PET, MRI and CT all together. This will all strongly depend on new technologies. With further advances in biology and chemistry for imaging molecular targets and (patho)physiological processes in vivo, the introduction of new imaging procedures and promising new radiopharmaceuticals in clinical practice may be accelerated. (orig.)

  19. 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.)

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

    Science.gov (United States)

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

    2015-12-01

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

  1. 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.)

  2. Accelerated GPU based SPECT Monte Carlo simulations

    Science.gov (United States)

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

    2016-06-01

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

  3. Staging of moyamoya disease by perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-04-01

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

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

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

    NARCIS (Netherlands)

    Schomberg, H.

    2012-01-01

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

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

    NARCIS (Netherlands)

    R. Due-Andersen (Rikke); T. Høi-Hansen (Thomas); C.E. Larroude; N.V. Olsen; J.K. Kanters; F. Boomsma (Frans); U. Pedersen-Bjergaard (Ullrik); B. Thorsteinsson (Birger)

    2008-01-01

    textabstractAims: 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

  11. 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

  12. 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;

    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...

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. 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.)

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

    Directory of Open Access Journals (Sweden)

    Anna M. D. Végh

    2016-09-01

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

  2. 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

  3. '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.

  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. 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.

  6. 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.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-15

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

  9. Technetium-99m-labelled red blood cell imaging in the diagnosis of hepatic haemangiomas: the role of SPECT/CT with a hybrid camera

    International Nuclear Information System (INIS)

    Delayed liver single-photon emission computed tomography (SPECT) after 99mTc red blood cell (RBC) labelling is helpful in detecting hepatic haemangiomas; however, diagnosis can be difficult when lesions are situated adjacent to structures like the inferior vena cava, the heart or hepatic vessels, where blood activity persists. The aims of this study were to evaluate the usefulness of RBC SPECT and transmission computed tomography (RBC SPECT/CT) performed simultaneously with a hybrid imaging system for correct characterisation of hepatic lesions in patients with suspected haemangioma, and to assess the additional value of fused images compared with SPECT alone. Twelve patients with 24 liver lesions were studied. The acquisitions of both anatomical (CT) and functional (SPECT) data were performed during a single session. SPECT images were first interpreted alone and then re-evaluated after adding the transmission anatomical maps. Image fusion was successful in all patients, with perfect correspondence between SPECT and CT data, allowing the precise anatomical localisation of sites of increased blood pool activity. SPECT/CT had a significant impact on results in four patients (33.3%) with four lesions defined as indeterminate on SPECT images, accurately characterising the hot spot foci located near vascular structures. In conclusion, RBC SPECT/CT imaging using this hybrid SPECT/CT system is feasible and useful in the identification or exclusion of suspected hepatic haemangiomas located near regions with high vascular activity. (orig.)

  10. Technetium-99m-labelled red blood cell imaging in the diagnosis of hepatic haemangiomas: the role of SPECT/CT with a hybrid camera

    Energy Technology Data Exchange (ETDEWEB)

    Schillaci, Orazio; Danieli, Roberta; Manni, Carlo; Capoccetti, Francesca; Simonetti, Giovanni [Department of Biopathology and Diagnostic Imaging, University ' ' Tor Vergata' ' , Rome (Italy)

    2004-07-01

    Delayed liver single-photon emission computed tomography (SPECT) after {sup 99m}Tc red blood cell (RBC) labelling is helpful in detecting hepatic haemangiomas; however, diagnosis can be difficult when lesions are situated adjacent to structures like the inferior vena cava, the heart or hepatic vessels, where blood activity persists. The aims of this study were to evaluate the usefulness of RBC SPECT and transmission computed tomography (RBC SPECT/CT) performed simultaneously with a hybrid imaging system for correct characterisation of hepatic lesions in patients with suspected haemangioma, and to assess the additional value of fused images compared with SPECT alone. Twelve patients with 24 liver lesions were studied. The acquisitions of both anatomical (CT) and functional (SPECT) data were performed during a single session. SPECT images were first interpreted alone and then re-evaluated after adding the transmission anatomical maps. Image fusion was successful in all patients, with perfect correspondence between SPECT and CT data, allowing the precise anatomical localisation of sites of increased blood pool activity. SPECT/CT had a significant impact on results in four patients (33.3%) with four lesions defined as indeterminate on SPECT images, accurately characterising the hot spot foci located near vascular structures. In conclusion, RBC SPECT/CT imaging using this hybrid SPECT/CT system is feasible and useful in the identification or exclusion of suspected hepatic haemangiomas located near regions with high vascular activity. (orig.)

  11. 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.)

  12. 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.)

  13. 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 ...

  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. 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.

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

    OpenAIRE

    Baškot Branislav; Živković Miodrag; Tepić Sandra; Obradović Slobodan

    2009-01-01

    Background. The most important predictors of longterm survival in patients with cardiac ischemic disease are left ventricular ejection fraction, left ventricular volumes, infarction size, presence and extent of residual myocardial ischemia. One of the most important recent developments in single photon emission computed tomography (SPECT) myocardial perfusion imaging is the ability to acquire these studies in conjunction with electrocardiogram (ECG) gating (G-SPECT). The ability to asses radi...

  17. 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.

  18. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

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

    International Nuclear Information System (INIS)

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

  3. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

    Paulson, O.B.; Lassen, N.A.

    1997-01-01

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

  4. Targeted multi-pinhole SPECT

    NARCIS (Netherlands)

    Branderhorst, W.; Vastenhouw, B.; Van der Have, F.; Blezer, E.L.A.; Bleeker, W.K.; Beekman, F.J.

    2010-01-01

    Purpose: 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 o

  5. Few-view single photon emission computed tomography (SPECT) reconstruction based on a blurred piecewise constant object model

    Science.gov (United States)

    Wolf, Paul A.; Jørgensen, Jakob S.; Schmidt, Taly G.; Sidky, Emil Y.

    2013-08-01

    A sparsity-exploiting algorithm intended for few-view single photon emission computed tomography (SPECT) reconstruction is proposed and characterized. The algorithm models the object as piecewise constant subject to a blurring operation. To validate that the algorithm closely approximates the true object in the noiseless case, projection data were generated from an object assuming this model and using the system matrix. Monte Carlo simulations were performed to provide more realistic data of a phantom with varying smoothness across the field of view and a cardiac phantom. Reconstructions were performed across a sweep of two primary design parameters. The results demonstrate that the algorithm recovers the object in a noiseless simulation case. While the algorithm assumes a specific blurring model, the results suggest that the algorithm may provide high reconstruction accuracy even when the object does not match the assumed blurring model. Generally, increased values of the blurring parameter and total variation weighting parameters reduced streaking artifacts, while decreasing spatial resolution. The proposed algorithm demonstrated higher correlation with respect to the true phantom compared to maximum-likelihood expectation maximization (MLEM) reconstructions. Images reconstructed with the proposed algorithm demonstrated reduced streaking artifacts when reconstructing from few views compared to MLEM. The proposed algorithm introduced patchy artifacts in some reconstructed images, depending on the noise level and the selected algorithm parameters. Overall, the results demonstrate preliminary feasibility of a sparsity-exploiting reconstruction algorithm which may be beneficial for few-view SPECT.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

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

    International Nuclear Information System (INIS)

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

  9. 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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Nagara; Senda, Michio; Yonekura, Yoshiharu

    1985-02-01

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

  12. U-SPECT-BioFluo: an integrated radionuclide, bioluminescence, and fluorescence imaging platform

    NARCIS (Netherlands)

    Van Oosterom, M.N.; Kreuger, R.; Buckle, T.; Mahn, W.A.; Bunschoten, A.; Josephson, L.; Van Leeuwen, F.W.B.; Beekman, F.J.

    2014-01-01

    Background: In vivo bioluminescence, fluorescence, and single-photon emission computed tomography (SPECT) imaging provide complementary information about biological processes. However, to date these signatures are evaluated separately on individual preclinical systems. In this paper, we introduce a

  13. 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.

  14. 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

  15. [Cardiac amyloidosis].

    Science.gov (United States)

    Hoyer, Caroline; Angermann, Christiane E; Knop, Stefan; Ertl, Georg; Störk, Stefan

    2008-03-15

    Amyloidoses are a heterogeneous group of multisystem disorders, which are characterized by an extracellular deposition of amyloid fibrils. Typically affected are the heart, liver, kidneys, and nervous system. More than half of the patients die due to cardiac involvement. Clinical signs of cardiac amyloidosis are edema of the lower limbs, hepatomegaly, ascites and elevated jugular vein pressure, frequently in combination with dyspnea. There can also be chest pain, probably due to microvessel disease. Dysfunction of the autonomous nervous system or arrhythmias may cause low blood pressure, dizziness, or recurrent syncope. The AL amyloidosis caused by the deposition of immunoglobulin light chains is the most common form. It can be performed by monoclonal gammopathy. The desirable treatment therapy consists of high-dose melphalan therapy twice followed by autologous stem cell transplantation. Due to the high peritransplantation mortality, selection of appropriate patients is mandatory. The ATTR amyloidosis is an autosomal dominant disorder caused by the amyloidogenic form of transthyretin, a plasmaprotein that is synthesized in the liver. Therefore, liver transplantation is the only curative therapy. The symptomatic treatment of cardiac amyloidosis is based on the current guidelines for chronic heart failure according to the patient's New York Heart Association (NYHA) state. Further types of amyloidosis with possible cardiac involvement comprise the senile systemic amyloidosis caused by the wild-type transthyretin, secondary amyloidosis after chronic systemic inflammation, and the beta(2)-microglobulin amyloidosis after long-term dialysis treatment. PMID:18344065

  16. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-01

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

  17. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

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

  18. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    Science.gov (United States)

    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.

    2014-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake. PMID:23536223

  19. Optimization of detection geometry for industrial SPECT by Monte Carlo simulations

    Science.gov (United States)

    Park, J. G.; Kim, C. H.; Han, M. C.; Jung, S. H.; Kim, J. B.; Moon, J.

    2013-04-01

    The Korea Atomic Energy Research Institute (KAERI) has developed an industrial SPECT to investigate the fluid flow and mixing patterns in columns. It has been found that the industrial SPECT is indeed a very powerful tool to study the hydrodynamics in multiphase reactors. One of the practical issues in the development of industrial SPECTs is to achieve a required imaging resolution of an industrial SPECT with a minimum number of component detectors, the number of which is frequently limited by both the size of the detectors and the total cost of the imaging system. In the present study, a set of different geometries of industrial SPECTs were evaluated by Monte Carlo simulation using MCNPX to determine the minimum number of detectors that will provide a spatial resolution that corresponds to 10% of the cylindrical column diameter. Our results show that 11 and 12 detectors will satisfy the 10% resolution requirement for the 40 cm and 60 cm diameter columns, respectively, for the industrial SPECT and radioisotopes considered in the present study. The conclusion of this result is valid only for the case considered in the present study, but we believe that the same procedure can be applied to other industrial SPECTs for this kind of optimization.

  20. Fabrication of mouse embryonic stem cell-derived layered cardiac cell sheets using a bioreactor culture system.

    Directory of Open Access Journals (Sweden)

    Katsuhisa Matsuura

    Full Text Available Bioengineered functional cardiac tissue is expected to contribute to the repair of injured heart tissue. We previously developed cardiac cell sheets using mouse embryonic stem (mES cell-derived cardiomyocytes, a system to generate an appropriate number of cardiomyocytes derived from ES cells and the underlying mechanisms remain elusive. In the present study, we established a cultivation system with suitable conditions for expansion and cardiac differentiation of mES cells by embryoid body formation using a three-dimensional bioreactor. Daily conventional medium exchanges failed to prevent lactate accumulation and pH decreases in the medium, which led to insufficient cell expansion and cardiac differentiation. Conversely, a continuous perfusion system maintained the lactate concentration and pH stability as well as increased the cell number by up to 300-fold of the seeding cell number and promoted cardiac differentiation after 10 days of differentiation. After a further 8 days of cultivation together with a purification step, around 1 × 10(8 cardiomyocytes were collected in a 1-L bioreactor culture, and additional treatment with noggin and granulocyte colony stimulating factor increased the number of cardiomyocytes to around 5.5 × 10(8. Co-culture of mES cell-derived cardiomyocytes with an appropriate number of primary cultured fibroblasts on temperature-responsive culture dishes enabled the formation of cardiac cell sheets and created layered-dense cardiac tissue. These findings suggest that this bioreactor system with appropriate medium might be capable of preparing cardiomyocytes for cell sheet-based cardiac tissue.

  1. 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 ...

  2. Imaging recognition of multidrug resistance in human breast tumors using {sup 99m}Tc-labeled monocationic agents and a high-resolution stationary SPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhonglin E-mail: zliu@radiology.arizona.edu; Stevenson, Gail D.; Barrett, Harrison H.; Kastis, George A.; Bettan, Michael; Furenlid, Lars R.; Wilson, Donald W.; Woolfenden, James M

    2004-01-01

    Imaging recognition of multidrug-resistance by {sup 99m}Tc-labeled sestamibi, tetrofosmin and furifosmin in mice bearing human breast tumors was evaluated using a high-resolution SPECT, FASTSPECT. Imaging results showed that the washout rates in drug-resistant MCF7/D40 tumors were significantly greater than that in drug-sensitive MCF7/S tumors. Furifosmin exhibited greater washout from both MCF7/S and MCF7/D40 than sestamibi, while tetrofosmin washout was greater than sestamibi in MCF7/D40 only. Feasibility of the monocationic agents for characterizing MDR expression was well clarified with FASTSPECT imaging.

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

    Science.gov (United States)

    Goldstein, David S

    2003-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Maria de Fátima Monteitro Pereira Leite

    2003-11-01

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

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

    Science.gov (United States)

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

    2008-08-01

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

  6. 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.

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

  8. Design and performance of a multi-pinhole collimation device for small animal imaging with clinical SPECT and SPECT-CT scanners

    International Nuclear Information System (INIS)

    A multi-pinhole collimation device is developed that uses the gamma camera detectors of a clinical SPECT or SPECT-CT scanner to produce high-resolution SPECT images. The device consists of a rotating cylindrical collimator having 22 tungsten pinholes with 0.9 mm diameter apertures and an animal bed inside the collimator that moves linearly to provide helical or ordered-subsets axial sampling. CT images also may be acquired on a SPECT-CT scanner for purposes of image co-registration and SPECT attenuation correction. The device is placed on the patient table of the scanner without attaching to the detectors or scanner gantry. The system geometry is calibrated in-place from point source data and is then used during image reconstruction. The SPECT imaging performance of the device is evaluated with test phantom scans. Spatial resolution from reconstructed point source images is measured to be 0.6 mm full width at half maximum or better. Micro-Derenzo phantom images demonstrate the ability to resolve 0.7 mm diameter rod patterns. The axial slabs of a Micro-Defrise phantom are visualized well. Collimator efficiency exceeds 0.05% at the center of the field of view, and images of a uniform phantom show acceptable uniformity and minimal artifact. The overall simplicity and relatively good imaging performance of the device make it an interesting low-cost alternative to dedicated small animal scanners

  9. Design and performance of a multi-pinhole collimation device for small animal imaging with clinical SPECT and SPECT CT scanners

    Science.gov (United States)

    Di Filippo, Frank P.

    2008-08-01

    A multi-pinhole collimation device is developed that uses the gamma camera detectors of a clinical SPECT or SPECT-CT scanner to produce high-resolution SPECT images. The device consists of a rotating cylindrical collimator having 22 tungsten pinholes with 0.9 mm diameter apertures and an animal bed inside the collimator that moves linearly to provide helical or ordered-subsets axial sampling. CT images also may be acquired on a SPECT-CT scanner for purposes of image co-registration and SPECT attenuation correction. The device is placed on the patient table of the scanner without attaching to the detectors or scanner gantry. The system geometry is calibrated in-place from point source data and is then used during image reconstruction. The SPECT imaging performance of the device is evaluated with test phantom scans. Spatial resolution from reconstructed point source images is measured to be 0.6 mm full width at half maximum or better. Micro-Derenzo phantom images demonstrate the ability to resolve 0.7 mm diameter rod patterns. The axial slabs of a Micro-Defrise phantom are visualized well. Collimator efficiency exceeds 0.05% at the center of the field of view, and images of a uniform phantom show acceptable uniformity and minimal artifact. The overall simplicity and relatively good imaging performance of the device make it an interesting low-cost alternative to dedicated small animal scanners.

  10. SPECT/CT diagnostics for skeletal infections

    International Nuclear Information System (INIS)

    Skeletal infections are often a diagnostic and clinical challenge. Nuclear imaging modalities used in the diagnostic workup of acute and chronic skeletal infections include three-phase bone scintigraphy and scintigraphy with labelled leucocytes. The introduction of hybrid technologies, such as single photon emission computed tomography/computed tomography (SPECT/CT) has dramatically changed nuclear medical imaging of infections. In general SPECT/CT leads to a considerably more accurate diagnosis than planar or SPECT imaging. Given the integrated acquisition of metabolic, functional and morphological information, SPECT/CT has increased in particular the specificity of three-phase skeletal scanning and scintigraphy with labeled leucocytes. (orig.)

  11. Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chih-Jie; Kupinski, Matthew A.; Volokh, Lana [College of Optical Sciences, University of Arizona, Tucson, Arizona 85721 (United States); GE Healthcare, Haifa 39120 (Israel)

    2013-01-15

    Purpose: Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. Methods: Whitaker et al.'s study ['Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods,' Opt. Express 16(11), 8150-8173 (2008)] 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 with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Gary eTse

    2016-05-01

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

  14. SPECT of aged backache patients

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  16. The magnetic shielding for the neutron decay spectrometer aSPECT

    OpenAIRE

    Konrad, Gertrud; Guardia, Fidel Ayala; Baeßler, Stefan(Physics Department, University of Virginia, 382 McCormick Road, Charlottesville, VA 22904, USA); Borg, Michael; Glück, Ferenc; Heil, Werner; Hiebel, Stefan; Horta, Raquel Munoz; Sobolev, Yury

    2014-01-01

    Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magne...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  18. Cervical SPECT Camera for Parathyroid Imaging

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2012-08-31

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

  19. Assessment of anatomic relation between pulmonary perfusion and morphology in pulmonary emphysema with breath-hold SPECT-CT fusion images

    International Nuclear Information System (INIS)

    Anatomic relation between pulmonary perfusion and morphology in pulmonary emphysema was assessed on deep-inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images. Subjects were 38 patients with pulmonary emphysema and 11 non-smoker controls, who successfully underwent DIBrH and non-BrH perfusion SPECT using a dual-headed SPECT system during the period between January 2004 and June 2006. DIBrH SPECT was three-dimensionally co-registered with DIBrH CT to comprehend the relationship between lung perfusion defects and CT low attenuation areas (LAA). By comparing the appearance of lung perfusion on DIBrH with non-BrH SPECT, the correlation with the rate constant for the alveolar-capillary transfer of carbon monoxide (DLCO/VA) was compared between perfusion abnormalities on these SPECTs and LAA on CT. DIBrH SPECT provided fairly uniform perfusion in controls, but significantly enhanced perfusion heterogeneity when compared with non-BrH SPECT in pulmonary emphysema patients (P<0.001). The reliable DIBrH SPECT-CT fusion images confirmed more extended perfusion defects than LAA on CT in majority (73%) of patients. Perfusion abnormalities on DIBrH SPECT were more closely correlated with DLCO/VA than LAA on CT (P<0.05). DIBrH SPECT identifies affected lungs with perfusion abnormality better than does non-BrH SPECT in pulmonary emphysema. DIBrH SPECT-CT fusion images are useful for more accurately localizing affected lungs than morphologic CT alone in this disease. (author)

  20. Feasibility of a CdTe-based SPECT for high-resolution low-dose small animal imaging: a Monte Carlo simulation study

    International Nuclear Information System (INIS)

    Dedicated single-photon-emission computed tomography (SPECT) systems based on pixelated semiconductors such as cadmium telluride (CdTe) are in development to study small animal models of human disease. In an effort to develop a high-resolution, low-dose system for small animal imaging, we compared a CdTe-based SPECT system and a conventional NaI(Tl)-based SPECT system in terms of spatial resolution, sensitivity, contrast, and contrast-to-noise ratio (CNR). In addition, we investigated the radiation absorbed dose and calculated a figure of merit (FOM) for both SPECT systems. Using the conventional NaI(Tl)-based SPECT system, we achieved a spatial resolution of 1.66 mm at a 30 mm source-to-collimator distance, and a resolution of 2.4-mm hot-rods. Using the newly-developed CdTe-based SPECT system, we achieved a spatial resolution of 1.32 mm FWHM at a 30 mm source-to-collimator distance, and a resolution of 1.7-mm hot-rods. The sensitivities at a 30 mm source-to-collimator distance were 115.73 counts/sec/MBq and 83.38 counts/sec/MBq for the CdTe-based SPECT and conventional NaI(Tl)-based SPECT systems, respectively. To compare quantitative measurements in the mouse brain, we calculated the CNR for images from both systems. The CNR from the CdTe-based SPECT system was 4.41, while that from the conventional NaI(Tl)-based SPECT system was 3.11 when the injected striatal dose was 160 Bq/voxel. The CNR increased as a function of injected dose in both systems. The FOM of the CdTe-based SPECT system was superior to that of the conventional NaI(Tl)-based SPECT system, and the highest FOM was achieved with the CdTe-based SPECT at a dose of 40 Bq/voxel injected into the striatum. Thus, a CdTe-based SPECT system showed significant improvement in performance compared with a conventional system in terms of spatial resolution, sensitivity, and CNR, while reducing the radiation dose to the small animal subject. Herein, we discuss the feasibility of a CdTe-based SPECT system for high

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

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

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

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

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-05-01

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

  5. MRI and SPECT fusion for epilepsy lateralization

    Science.gov (United States)

    Jafari-Khouzani, Kourosh; Soltanian-Zadeh, Hamid; Elisevich, Kost

    2005-04-01

    This paper presents a study on the SPECT images of the brain with the aim of determining the hippocampus abnormality and consequently applying timely treatment. Intensity and volume features of the hippocampus from brain MRI have been shown to be useful in detecting the abnormal hippocampus in TLE. In this study, we evaluate the intensity information of the SPECT images of the brain for the purpose of early detection of abnormal hippocampus, before the brain tissue is damaged and MRI features change. The hippocampi are segmented manually by an expert from T1-weighted MR images. The segmented regions are mapped on the corresponding SPECT images using the mutual information technique. The mean and standard deviation of the hippocampi from SPECT images are used to determine abnormal hippocampus. The experimental results show that SPECT images analyzed along with MRI generate quantitative information useful for the treatment and evaluation of epileptic patients.

  6. SPECT/CT and pulmonary embolism

    DEFF Research Database (Denmark)

    Mortensen, Jann; Borgwardt, Henrik Gutte

    2014-01-01

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar...... technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had...... the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume...

  7. MR guided spatial normalization of SPECT scans

    International Nuclear Information System (INIS)

    Full text: In SPECT population studies where magnetic resonance (MR) scans are also available, the higher resolution of the MR scans allows for an improved spatial normalization of the SPECT scans. In this approach, the SPECT images are first coregistered to their corresponding MR images by a linear (affine) transformation which is calculated using SPM's mutual information maximization algorithm. Non-linear spatial normalization maps are then computed either directly from the MR scans using SPM's built in spatial normalization algorithm, or, from segmented TI MR images using DARTEL, an advanced diffeomorphism based spatial normalization algorithm. We compare these MR based methods to standard SPECT based spatial normalization for a population of 27 fibromyalgia patients and 25 healthy controls with spin echo T1 scans. We identify significant perfusion deficits in prefrontal white matter in FM patients, with the DARTEL based spatial normalization procedure yielding stronger statistics than the standard SPECT based spatial normalization. (author)

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  9. 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.

  10. PET and SPECT investigations in Alzheimer's disease

    International Nuclear Information System (INIS)

    Nuclear medicine offers a wide range of possibilities to investigate dementia. Various SPECT and PET tracers will be introduced in this article first. Different questions concerning evaluation of dementia are discussed taking Alzheimer's disease (AD) as an example. It is important to perform nuclear medicine investigations on high technical level, using standardized methods as statistical parametric mapping (SPM) for evaluation. If neuroprotective therapies are available, an early diagnosis, the determination of risk factors and longitudinal investigations will be the focus of interest and the main goal of nuclear medicine. Apart from measuring cerebral perfusion and glucose metabolism the development of new ligands, concerning the cholinergic system and the visualization of amyloid plaques, is of great importance. (orig.)

  11. Multichannel SQUID system detecting tangential components of the cardiac magnetic field

    Science.gov (United States)

    Tsukada, Keiji; Haruta, Yasuhiro; Adachi, Akira; Ogata, Hisanao; Komuro, Takanori; Ito, Tsuyoshi; Takada, Youichi; Kandori, Akihiko; Noda, Yasunaga; Terada, Yasushi; Mitsui, Toshio

    1995-10-01

    The 32-channel SQUID system described here is used for diagnosing heart disease by measuring the x and y components of the cardiac magnetic field. To detect a magnetic field parallel to the body surface, it uses a compact hybrid superconducting quantum interference device (SQUID) gradiometer consisting of a planar pickup coil (fabricated using thin-film techniques) and a square double-washer dc-SQUID having large voltage-flux transfer function. The SQUIDs are operated in a flux-locked mode using simple readout circuits connected directly to the preamplifier without additional positive feedback. The system is installed in a magnetically shielded room in a hospital. A low noise characteristics lower than 10 ft/√ Hz in a white noise is obtained in the hospital. Examples of tangential magnetocardiogram (MCG) measurements presented here show that the MCG obtained using this gradiometer makes it easy to visually estimate the electrophysiological behavior of the heart.

  12. A Real-Time Health Monitoring System for Remote Cardiac Patients Using Smartphone and Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Priyanka Kakria

    2015-01-01

    Full Text Available Online telemedicine systems are useful due to the possibility of timely and efficient healthcare services. These systems are based on advanced wireless and wearable sensor technologies. The rapid growth in technology has remarkably enhanced the scope of remote health monitoring systems. In this paper, a real-time heart monitoring system is developed considering the cost, ease of application, accuracy, and data security. The system is conceptualized to provide an interface between the doctor and the patients for two-way communication. The main purpose of this study is to facilitate the remote cardiac patients in getting latest healthcare services which might not be possible otherwise due to low doctor-to-patient ratio. The developed monitoring system is then evaluated for 40 individuals (aged between 18 and 66 years using wearable sensors while holding an Android device (i.e., smartphone under supervision of the experts. The performance analysis shows that the proposed system is reliable and helpful due to high speed. The analyses showed that the proposed system is convenient and reliable and ensures data security at low cost. In addition, the developed system is equipped to generate warning messages to the doctor and patient under critical circumstances.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Kondal'skaya Yu.O.

    2012-12-01

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

  15. Quantitative SPECT reconstruction using CT-derived corrections

    Science.gov (United States)

    Willowson, Kathy; Bailey, Dale L.; Baldock, Clive

    2008-06-01

    A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume effects in small volumes of interest. The accuracy of the quantitative technique has been evaluated with phantom experiments and clinical lung ventilation/perfusion SPECT/CT studies. A comparison of calculated values with the known total activities and concentrations in a mixed-material cylindrical phantom, and in liver and cardiac inserts within an anthropomorphic torso phantom, produced accurate results. The total activity in corrected ventilation-subtracted perfusion images was compared to the calibrated injected dose of [99mTc]-MAA (macro-aggregated albumin). The average difference over 12 studies between the known and calculated activities was found to be -1%, with a range of ±7%.

  16. Quantitative SPECT reconstruction using CT-derived corrections

    Energy Technology Data Exchange (ETDEWEB)

    Willowson, Kathy; Bailey, Dale L; Baldock, Clive [Institute of Medical Physics, School of Physics, University of Sydney, Camperdown, NSW 2006 (Australia)], E-mail: K.Willowson@physics.usyd.edu.au

    2008-06-21

    A method for achieving quantitative single-photon emission computed tomography (SPECT) based upon corrections derived from x-ray computed tomography (CT) data is presented. A CT-derived attenuation map is used to perform transmission-dependent scatter correction (TDSC) in conjunction with non-uniform attenuation correction. The original CT data are also utilized to correct for partial volume effects in small volumes of interest. The accuracy of the quantitative technique has been evaluated with phantom experiments and clinical lung ventilation/perfusion SPECT/CT studies. A comparison of calculated values with the known total activities and concentrations in a mixed-material cylindrical phantom, and in liver and cardiac inserts within an anthropomorphic torso phantom, produced accurate results. The total activity in corrected ventilation-subtracted perfusion images was compared to the calibrated injected dose of [{sup 99m}Tc]-MAA (macro-aggregated albumin). The average difference over 12 studies between the known and calculated activities was found to be -1%, with a range of {+-}7%.

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

    Directory of Open Access Journals (Sweden)

    Diego Lopes Mendes Barretti

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

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

  19. Anatomical reconstructions of the human cardiac venous system using contrast-computed tomography of perfusion-fixed specimens.

    Science.gov (United States)

    Spencer, Julianne; Fitch, Emily; Iaizzo, Paul A

    2013-01-01

    A detailed understanding of the complexity and relative variability within the human cardiac venous system is crucial for the development of cardiac devices that require access to these vessels. For example, cardiac venous anatomy is known to be one of the key limitations for the proper delivery of cardiac resynchronization therapy (CRT)(1) Therefore, the development of a database of anatomical parameters for human cardiac venous systems can aid in the design of CRT delivery devices to overcome such a limitation. In this research project, the anatomical parameters were obtained from 3D reconstructions of the venous system using contrast-computed tomography (CT) imaging and modeling software (Materialise, Leuven, Belgium). The following parameters were assessed for each vein: arc length, tortuousity, branching angle, distance to the coronary sinus ostium, and vessel diameter. CRT is a potential treatment for patients with electromechanical dyssynchrony. Approximately 10-20% of heart failure patients may benefit from CRT(2). Electromechanical dyssynchrony implies that parts of the myocardium activate and contract earlier or later than the normal conduction pathway of the heart. In CRT, dyssynchronous areas of the myocardium are treated with electrical stimulation. CRT pacing typically involves pacing leads that stimulate the right atrium (RA), right ventricle (RV), and left ventricle (LV) to produce more resynchronized rhythms. The LV lead is typically implanted within a cardiac vein, with the aim to overlay it within the site of latest myocardial activation. We believe that the models obtained and the analyses thereof will promote the anatomical education for patients, students, clinicians, and medical device designers. The methodologies employed here can also be utilized to study other anatomical features of our human heart specimens, such as the coronary arteries. To further encourage the educational value of this research, we have shared the venous models on our

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

    CERN Document Server

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

    1998-01-01

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

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

    Science.gov (United States)

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

    2014-04-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

    2015-11-01

    Cardiac involvement in systemic sclerosis (SSc) is considerably frequent in autopsy, but the early identification is clinically difficult. Recent advantages in cardiac magnetic resonance (CMR) enabled to detect myocardial fibrotic scar as late gadolinium enhancement (LGE). We aimed to examine the prevalence and distribution of LGE in patients with SSc, and associate them with clinical features, electrocardiographic abnormalities and cardiac function. Forty patients with SSc (58 ± 14 years-old, 35 females, limited/diffuse 25/15, disease duration 106 ± 113 months) underwent serological tests, 12-lead electrocardiogram (ECG) and CMR. Seven patients (17.5 %) showed LGE in 26 segments of left ventricle (LV). LGE distributed mainly in the basal to mid inter-ventricular septum and the right ventricular (RV) insertion points, but involved all the myocardial regions. More patients with LGE showed NYHA functional class II and more (71 vs. 21 %, p 125 pg/ml). When cardiac involvement of SSc was defined as low LVEF, ECG abnormalities or high NT-proBNP, the sensitivity, specificity positive and negative predictive values of LGE were 36, 92, 71 and 72 %, respectively. We could clarify the prevalence and distribution of LGE in Japanese patients with SSc. The presence of LGE was associated with cardiac symptom, conduction disturbance and impaired LV/RV contraction. PMID:24996373

  4. SPECT-T1-201 cardiac imaging

    International Nuclear Information System (INIS)

    Topics of discussion include: limitations of planar thallium-201 imaging; tomographic acquisition protocol; quantitative analysis involving slice selection, circumferential profile generation, comparison to normal limits and polar display of results; sensitivity and specificity; sources of error involving patient motion and upward creep; and clinical applications

  5. Cardiac remodeling during and after renin-angiotensin system stimulation in Cyp1a1-Ren2 transgenic rats

    DEFF Research Database (Denmark)

    Heijnen, Bart Fj; Pelkmans, Leonie Pj; Danser, Ah Jan;

    2013-01-01

    This study investigated renin-angiotensin system (RAS)-induced cardiac remodeling and its reversibility in the presence and absence of high blood pressure (BP) in Cyp1a1-Ren2 transgenic inducible hypertensive rats (IHR). In IHR (pro)renin levels and BP can be dose-dependently titrated by oral...... administration of indole-3-carbinol (I3C). Young (four-weeks old) and adult (30-weeks old) IHR were fed I3C for four weeks (leading to systolic BP >200 mmHg). RAS-stimulation was stopped and animals were followed-up for a consecutive period. Cardiac function and geometry was determined echocardiographically...... and the hearts were excised for molecular and immunohistochemical analyses. Echocardiographic studies revealed that four weeks of RAS-stimulation incited a cardiac remodeling process characterized by increased left ventricular (LV) wall thickness, decreased LV volumes, and shortening of the left ventricle...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    During moderate actual or simulated hemorrhage, as cardiac output decreases, reductions in systemic vascular conductance (SVC) maintain mean arterial pressure (MAP). Heat stress, however, compromises the control of MAP during simulated hemorrhage, and it remains unknown whether this response is d...

  7. Crossed cerebellar hyperperfusion in brain perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-10-01

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

  8. SPECT/CT and pulmonary embolism

    OpenAIRE

    Mortensen, Jann; Gutte, Henrik

    2013-01-01

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan i...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  11. Assessment of the value of 99Tcm-MIBI stress-rest SPECT imaging for evaluation of the outcomes of percutaneous transluminal coronary angioplasty

    International Nuclear Information System (INIS)

    Objective: To assess the value of stress-rest 99Tcm-MIBI (ST-RE) SPECT imaging for evaluation of perfusion improvement, prediction of restenosis (RS) and cardiac event rate in patients after percutaneous transluminal coronary angioplasty (PTCA). Methods: 99Tcm-MIBI ST-RE SPECT imaging was performed on 100 patients [(52 +- 9) years old] (14 +- 15) months after PTCA. On 30 of the 100 patients, ST-RE SPECT imaging were also performed before PTCA, and 30 patients underwent coronary angiography (CAG). The perfusion findings of myocardial segments were qualitatively classified into four patterns: normal (N), reversible defect (RD), partial reversible defect (PRD) and fixed defect (FD). Restenosis was predicted on the basis of RD or PRD. During the follow-up, cardiac death, myocardial infarction (MI), unstable angina and revascularization were considered as cardiac events. Results: 1) Among 100 patients, RD or PRD was observed in 28 patients, indicating myocardial ischemia (IS); FD was observed in 20 patients, indicating MI. The rate of occurrence of ischemic segments had no significant difference between patients with or without MI(P>0.05). 2) Among 30 patients, perfusion imaging was improved in 23 patients, the improved rate was 76.7%. The number of ischemic segments was decreased from 100 (37%) before PTCA to 10 (3.7%) after PTCA (P99Tcm-MIBI SPECT is a useful noninvasive method for evaluating the effect of PTCA and for predicting RS, and it is of high value for predicting cardiac events

  12. The usefulness of SPECT and MRI in the diagnosis of atypical parkinsonian syndromes; Diagnostisk nytte av SPECT- og MR-undersoekelse ved atypisk parkinsonisme

    Energy Technology Data Exchange (ETDEWEB)

    Skogseid, I.M.; Gerdts, R.; Nyberg-Hansen, R.; Rootwelt, K.; Bakke, S.J

    2001-07-01

    Clinico-pathological studies have shown that only three out of four patients with parkinsonism have idiopathic Parkinson's disease. In patients with so-called Parkinson plus syndrome, the degeneration in the brain is more widespread and the variety of neurological signs greater than in Parkinson's disease. The differentiation of these syndromes from Parkinson's disease can be difficult. Single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRl) can be of value in the differential diagnosis of parkinsonism. We present three patients with atypical parkinsonism in whom MRI and SPECT with {beta}-CIT and epidepride was performed in addition to the clinical evaluation. The three patients all had a rapidly developing symmetric akinetic-rigid syndrome that responded poorly to levodopa. MRI showed findings regarded as typical for multiple system atrophy in two patients, but only nonspecific findings in the third patient. SPECT with {beta}-CIT showed a pronounced bilateral and relatively symmetric reduction in the striatal dopaminergic activity in all patients. SPECT with epidepride showed a clearly reduced striatal D{sub 2}-receptor binding bilaterally in only one of the patients. In patients with atypical parkinsonism, MRI and SPECT with {beta}-CIT and epidepride can give valuable support to the clinical diagnosis of a Parkinson plus syndrome.

  13. Fusion imaging using a hybrid SPECT-CT camera improves port perfusion scintigraphy for control of hepatic arterial infusion of chemotherapy in colorectal cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Denecke, Timm; Lehmkuhl, Lukas; Peters, Nils; Pech, Maciej; Ricke, Jens; Felix, Roland; Amthauer, Holger [Charite-Universitatsmedizin Berlin - Klinik fur Strahlenheilkunde und PET-Zentrum Berlin, Campus Virchow-Klinikum, Berlin (Germany); Hildebrandt, Bert; Nicolaou, Annett; Riess, Hanno [Charite-Universitatsmedizin Berlin - Medizinische Klinik m.S. Haematologie Onkologie, Campus Virchow-Klinikum, Berlin (Germany)

    2005-09-01

    Exclusive and homogeneous perfusion of the liver is considered essential for the efficacy of hepatic arterial infusion of chemotherapy (HAI). The aim of this study was to evaluate port perfusion scintigraphy in colorectal cancer patients using a hybrid SPECT-CT system for control of minimally invasive intra-arterial port systems within the scope of a phase II trial. In 24 consecutive patients, the perfusion territories of intra-arterial hepatic port systems were assessed by port scintigraphy with{sup 99m}Tc-labelled macroaggregated albumin employing planar imaging, SPECT and SPECT-CT (acquired with a hybrid SPECT-CT camera). The results of blinded reading of the scintigraphic modalities concerning the intra- and extrahepatic perfusion pattern were compared with combined image analysis (angiography and contrast-enhanced dedicated CT) and patient history for validation. Extrahepatic perfusion was correctly seen in three patients, while suspected extrahepatic perfusion could be excluded in one. In 46 liver lobes, perfusion patterns were correctly visualised by SPECT-CT in 100% of cases (planar, 67%; SPECT, 86%). Assessing the perfusion pattern inside the liver on a segmental basis (segments, n=138), SPECT-CT revealed correct segmental assignment of tracer distribution in 100% and was significantly superior to SPECT alone (accuracy, 84%; p<0.001). The scintigraphic findings resulted in changes in therapeutic management in 8/24 patients (33%); in two of these the relevant findings were visualised only by SPECT-CT. In patients receiving HAI, port perfusion scintigraphy by fusion imaging with a hybrid SPECT-CT system provides important information for therapy optimisation and appears to be superior to SPECT alone. (orig.)

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

    Science.gov (United States)

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

    2006-01-20

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

  15. Effectiveness of Human Atrial Natriuretic Peptide Supplementation in Pulmonary Edema Patients Using the Pulse Contour Cardiac Output System

    OpenAIRE

    Sakamoto, Yuichiro; Mashiko, Kunihiro; Saito, Nobuyuki; Matsumoto, Hisashi; Hara, Yoshiaki; Kutsukata, Noriyoshi; Yokota, Hiroyuki

    2010-01-01

    Purpose Atrial natriuretic peptide (ANP) has a variety of pharmacologic effects, including natriuresis, diuresis, vasodilatation, and suppression of the renin-angiotensin system. A recent study showed that ANP infusion improved hypoxemia and pulmonary hypertension in a lung injury model. On the other hand, the pulse contour cardiac output (PiCCO™) system (Pulsion Medical Systems, Munich, Germany) allows monitoring of the intravascular volume status and may be used to guide volume therapy in s...

  16. Role of inflammation in the development of cardiac autonomic disfunction in patients with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    D. S. Novikova

    2008-01-01

    Full Text Available Objective. To evaluate role of inflammation in pathogenesis of cardiac autonomic dysfunction assessed by heart rate variability (HRV analyses, in patients (pts with systemic lupus erythematosus (SLE. Material and methods. 75 female pts with SLE aged before 55 years were included. Control group consisted of 32 healthy women of comparable age. Clinical symptoms, activity degree and main cardiovascular risk factors were assessed. Common carotid duplex scanning with measurement of intima-media thickness, echocardiography, 24 h ECG ambulatory recording with determination of time domain parameters, evaluation of serum inflammation markers level (CRP, IL-6, TNFa were performed. Results. HRV time domain parameters adjusted by McanNN - SDNNn%, SDNNin%, rMSSDn%, pNN50% in women with SLE were lower than in healthy control. HRV parameters inversely correlated with inflammation markers in SLE (p<0,05. SLE pts were divided into 4 groups: 1 (n=12 - pts with low HRV parameters and high level of IL-6; 2 (n=13 - low HRV and normal IL-6; 3 (n=6 - normal HRV and high IL-6; 4 (n=44 - normal HRV and IL-6. SLEDA1 2K, left atrium size, levels of markers of inflammation in group 1 were higher, then in group 4 (p<0,05. Hypertension, dyslipidemia, smoking and subclinical atherosclerosis of carotid arteries were more frequent in group 2 compared to group 4 (p<0,05. Conclusion. These results suggest important role of autoimmune inflammation in pathogenesis of cardiac autonomic dysfunction in SLE pts with high disease activity and traditional cardiovascular risk factor, atherosclerotic changes - in low SLE activity. HRV, traditional cardiovascular risk factors and inflammatory markers combined measurement can help to identify subjects at risk of cardiovascular mortality among SLE pts.

  17. Cardiac reflections and natural vibrations: Force-frequency relation recording system in the stress echo lab

    Directory of Open Access Journals (Sweden)

    Pianelli Mascia

    2007-11-01

    Full Text Available Abstract Background The inherent ability of ventricular myocardium to increase its force of contraction in response to an increase in contraction frequency is known as the cardiac force-frequency relation (FFR. This relation can be easily obtained in the stress echo lab, where the force is computed as the systolic pressure/end-systolic volume index ratio, and measured for increasing heart rates during stress. Ideally, the noninvasive, imaging independent, objective assessment of FFR would greatly enhance its practical appeal. Objectives 1 – To evaluate the feasibility of the cardiac force measurement by a precordial cutaneous sensor. 2 – To build the curve of force variation as a function of the heart rate. 3 – To compare the standard stress echo results vs. this sensor operator-independent built FFR. Methods The transcutaneous force sensor was positioned in the precordial region in 88 consecutive patients referred for exercise, dipyridamole, or pacing stress. The force was measured as the myocardial vibrations amplitude in the isovolumic contraction period. FFR was computed as the curve of force variation as a function of heart rate. Standard echocardiographic FFR measurements were performed. Results A consistent FFR was obtained in all patients. Both the sensor built and the echo built FFR identifiy pts with normal or abnormal contractile reserve. The best cut-off value of the sensor built FFR was 15.5 g * 10-3 (Sensitivity = 0.85, Specificity = 0.77. Sensor built FFR slope and shape mirror pressure/volume relation during stress. This approach is extendable to daily physiological exercise and could be potentially attractive in home monitoring systems.

  18. Early assessment of sub-clinical cardiac involvement in systemic sclerosis (SSc) using delayed enhancement cardiac magnetic resonance (CE-MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Di Cesare, Ernesto, E-mail: ernesto.dicesare@cc.univaq.it [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Battisti, Sara; Di Sibio, Alessandra [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy); Cipriani, Paola; Giacomelli, Roberto; Liakouli, Vasiliky; Ruscitti, Piero [Rheumatology Clinic, Department of Internal Medicine and Public Health, University of L’Aquila, L’Aquila (Italy); Masciocchi, Carlo [Department of Radiology, University of L’Aquila, Via Vetoio 1, 67100 L’Aquila (Italy)

    2013-06-15

    Objectives: Systemic sclerosis heart involvement (SHI) is one of systemic sclerosis (SSc) most frequent complications, both in diffuse (dcSSc) and limited (lcSSc) cutaneous forms of disease. Nowadays, SHI is a major factor decreasing SSc survival rate because, when clinically evident, is associated with 70% of mortality at 5 years. SHI shows different forms, primary and/or secondary. Primary myocardial SHI is characterized by fibrosis. Aim of our study is to assess the presence and pattern of fibrosis as detected by cardiac magnetic resonance (CMR) in systemic sclerosis. Methods: In this study, we used CE-MRI (contrast enhanced-MRI) in 58 female SSc patients. Images were evaluated to obtain functional parameters and to see presence, location and pattern (nodular, linear or diffuse) of myocardial LE, sign of fibrosis. CE-MRI findings were correlated with patients clinical setting. Results: Myocardial fibrosis was detected in 25 of 58 patients (43%). The main finding observed in 16 of these 25 patients was a late enhancement showing a linear pattern, without coronary distribution and sparing the sub-endocardial myocardial layers. A patchy nodular enhancement pattern was observed in 9 patients (36%). Patients with linear pattern presented dcSSc, on the contrary patients with nodular LE displayed the lcSSc form. Conclusions: This study shows that CE-MRI is a reliable technique to detect SHI earlier than other methods. SHI increase passive myocardial stiffness, proportional to collagen deposition degree, leading to cardiac remodelling with possible development of heart failure, even with normal ejection fraction. An early treatment of SHI might improve SSc patients outcome.

  19. A Soft Processor MicroBlaze-Based Embedded System for Cardiac Monitoring

    Directory of Open Access Journals (Sweden)

    El Hassan El Mimouni

    2013-10-01

    Full Text Available this paper aims to contribute to the efforts of design community to demonstrate the effectiveness of the state of the art Field Programmable Gate Array (FPGA, in the embedded systems development, taking a case study in the biomedical field. With this design approach, we have developed a System on Chip (SoC for cardiac monitoring based on the soft processor MicroBlaze and the Xilkernel Real Time Operating System (RTOS, both from Xilinx. The system permits the acquisition and the digitizing of the Electrocardiogram (ECG analog signal, displaying heart rate on seven segments module and ECG on Video Graphics Adapter (VGA screen, tracing the heart rate variability (HRV tachogram, and communication with a Personal Computer (PC via the serial port. We have used the MIT_BIH Database records to test and evaluate our implementation performance. In terms of the resources utilization, the implementation occupies around 70% of the used FPGA, namely the Xilinx Spartan 6 XC6SLX16. The accuracy of the QRS detection exceeds 96%.

  20. Three-dimensional tracking of cardiac catheters using an inverse geometry x-ray fluoroscopy system

    Energy Technology Data Exchange (ETDEWEB)

    Speidel, Michael A.; Tomkowiak, Michael T.; Raval, Amish N.; Van Lysel, Michael S. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Department of Medicine and Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States)

    2010-12-15

    Purpose: Scanning beam digital x-ray (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis at multiple planes. This study describes a tomosynthesis-based method for 3D tracking of high-contrast objects and present the first experimental investigation of cardiac catheter tracking using a prototype SBDX system. Methods: The 3D tracking algorithm utilizes the stack of regularly spaced tomosynthetic planes that are generated by SBDX after each frame period (15 frames/s). Gradient-filtered versions of the image planes are generated, the filtered images are segmented into object regions, and then a 3D coordinate is calculated for each object region. Two phantom studies of tracking performance were conducted. In the first study, an ablation catheter in a chest phantom was imaged as it was pulled along a 3D trajectory defined by a catheter sheath (10, 25, and 50 mm/s pullback speeds). SBDX tip tracking coordinates were compared to the 3D trajectory of the sheath as determined from a CT scan of the phantom after the registration of the SBDX and CT coordinate systems. In the second study, frame-to-frame tracking precision was measured for six different catheter configurations as a function of image noise level (662-7625 photons/mm{sup 2} mean detected x-ray fluence at isocenter). Results: During catheter pullbacks, the 3D distance between the tracked catheter tip and the sheath centerline was 1.0{+-}0.8 mm (mean {+-}one standard deviation). The electrode to centerline distances were comparable to the diameter of the catheter tip (2.3 mm), the confining sheath (4 mm outside diameter), and the estimated SBDX-to-CT registration error ({+-}0.7 mm). The tip position was localized for all 332 image frames analyzed and 83% of tracked positions were inside the 3D sheath volume derived from CT. The pullback speeds derived from the catheter trajectories were within 5% of the programed pullback speeds

  1. Simple suspension culture system of human iPS cells maintaining their pluripotency for cardiac cell sheet engineering.

    Science.gov (United States)

    Haraguchi, Yuji; Matsuura, Katsuhisa; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo

    2015-12-01

    In this study, a simple three-dimensional (3D) suspension culture method for the expansion and cardiac differentiation of human induced pluripotent stem cells (hiPSCs) is reported. The culture methods were easily adapted from two-dimensional (2D) to 3D culture without any additional manipulations. When hiPSCs were directly applied to 3D culture from 2D in a single-cell suspension, only a few aggregated cells were observed. However, after 3 days, culture of the small hiPSC aggregates in a spinner flask at the optimal agitation rate created aggregates which were capable of cell passages from the single-cell suspension. Cell numbers increased to approximately 10-fold after 12 days of culture. The undifferentiated state of expanded hiPSCs was confirmed by flow cytometry, immunocytochemistry and quantitative RT-PCR, and the hiPSCs differentiated into three germ layers. When the hiPSCs were subsequently cultured in a flask using cardiac differentiation medium, expression of cardiac cell-specific genes and beating cardiomyocytes were observed. Furthermore, the culture of hiPSCs on Matrigel-coated dishes with serum-free medium containing activin A, BMP4 and FGF-2 enabled it to generate robust spontaneous beating cardiomyocytes and these cells expressed several cardiac cell-related genes, including HCN4, MLC-2a and MLC-2v. This suggests that the expanded hiPSCs might maintain the potential to differentiate into several types of cardiomyocytes, including pacemakers. Moreover, when cardiac cell sheets were fabricated using differentiated cardiomyocytes, they beat spontaneously and synchronously, indicating electrically communicative tissue. This simple culture system might enable the generation of sufficient amounts of beating cardiomyocytes for use in cardiac regenerative medicine and tissue engineering.

  2. SPECT assay of radiolabeled monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1992-02-01

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

  3. Single Photon Emission Computed Tomography (SPECT)

    Science.gov (United States)

    ... Tools & Resources Stroke More Single Photon Emission Computed Tomography (SPECT) Updated:Sep 11,2015 What is a ... Heart Attack Myocardial Perfusion Imaging (MPI) Positron Emission Tomography (PET) Radionuclide Ventriculography, Radionuclide Angiography, MUGA Scan Heart ...

  4. SPECT assay of radiolabeled monoclonal antibodies

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Marco Antonio Gutierrez

    2010-01-01

    Full Text Available A method to compute three-dimension (3D left ventricle (LV motion and its color coded visualization scheme for the qualitative analysis in SPECT images is proposed. It is used to investigate some aspects of Cardiac Resynchronization Therapy (CRT. The method was applied to 3D gated-SPECT images sets from normal subjects and patients with severe Idiopathic Heart Failure, before and after CRT. Color coded visualization maps representing the LV regional motion showed significant difference between patients and normal subjects. Moreover, they indicated a difference between the two groups. Numerical results of regional mean values representing the intensity and direction of movement in radial direction are presented. A difference of one order of magnitude in the intensity of the movement on patients in relation to the normal subjects was observed. Quantitative and qualitative parameters gave good indications of potential application of the technique to diagnosis and follow up of patients submitted to CRT.

  6. D-SPECT, a semiconductor camera: Technical aspects and clinical applications;La camera a semi-conducteur D-Spect: aspects techniques et applications cliniques

    Energy Technology Data Exchange (ETDEWEB)

    Merlin, C.; Bertrand, S.; Kelly, A.; Veyre, A.; Mestas, D.; Cachin, F. [CLCC Jean-Perrin, Service de medecine nucleaire, 63 - Clermont-Ferrand (France); Motreff, P.; Levesque, S. [CHU Gabriel-Montpied, Service de cardiologie, 63 - Clermont-Ferrand (France); Cachin, F. [Universite d' Auvergne, UMR 990 Inserm, 63 - Clermont-Ferrand (France); Askienazy, S. [Cyclopharma, biopole Clermont-Limagne, 63 -Saint-Beauzire (France)

    2010-03-15

    Clinical practice in nuclear medicine has largely changed in the last decade, particularly with the arrival of PET/CT and SPECT/CT. New semiconductor cameras could represent the next evolution in our nuclear medicine practice. Due to the resolution and sensitivity improvement, this technology authorizes fast speed acquisitions, high contrast and resolution images performed with low activity injection. The dedicated cardiology D-SPECT camera (Spectrum Dynamics, Israel) is based on semiconductor technology and provides an original system for collimation and images reconstruction. We describe here our clinical experience in using the D-SPECT with a preliminary study comparing D-D.P.E.C.T. and conventional gamma camera. (authors)

  7. Brain SPECT imaging in temporal lobe epilepsy

    International Nuclear Information System (INIS)

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

  8. Precise fusion of MRI and dual energy 111In WBC/99mTc HDP SPECT/CT in the diabetic foot using companion CT: an example of SPECT/MRI imaging

    International Nuclear Information System (INIS)

    The purpose of our study was to correctly fuse MRI and SPECT 111In WBC and 99m Tc HDP images using companion CT images. The fused images could be used to assess proper surgical approach in treatment of the diabetic foot. Nine patients who had dual energy 111In WBC/ 99m Tc HDP SPECT/CT and MRI studies within a week were investigated in an ongoing project. A GE Infinia SPECT/CT camera and Siemens MAGNETOM 1.5T MR system were used in this study. First, the MRI and corresponding CT images were coregistrated using a transformation based on normalized mutual information. The transformation was saved and used for MRI and 111In WBC/ 99m Tc HDP SPECT fusion. A Jaszczak phantom study was also performed in order to estimate accuracy of MRI/ SPECT fusion. The Jaszczak phantom study with 3.7 MBq 111In hot sphere showed that MRI/SPECT alignment using the approach described above produced registration with 0.7±0.4 mm accuracy in all three dimensions (3D). The nine clinical cases were visually evaluated and showed 1-2 mm 3D fusion accuracy. MRI provides almost perfect anatomy of soft tissue and bony structures but it may exaggerate the extent of infection. 111In WBC/99m Tc HDP SPECT imaging is more accurate for infection detection but lacks anatomical reference. Combination of these images proved an essential adjunct to diagnosis. A clinical utility of the approach is illustrated in two clinical examples. In conclusion, the CT in dual energy 111In WBC/99m Tc HDP SPECT/CT studies can be used to accurately fuse and compare 111In WBC/99m Tc HDP SPECT and MRI images of the diabetic foot. This can significantly help in conservative treatment planning and limb salvage procedures in treatment of diabetic foot infections.

  9. Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient.

    Science.gov (United States)

    Jang, Yongwon; Noh, Hyung Wook; Lee, I B; Jung, Ji-Wook; Song, Yoonseon; Lee, Sooyeul; Kim, Seunghwan

    2012-01-01

    A patch type embedded cardiac function monitoring system was developed to detect arrhythmias such as PVC (Premature Ventricular Contraction), pause, ventricular fibrillation, and tachy/bradycardia. The overall system is composed of a main module including a dual processor and a Bluetooth telecommunication module. The dual microprocessor strategy minimizes power consumption and size, and guarantees the resources of embedded software programs. The developed software was verified with standard DB, and showed good performance.

  10. Usefulness of breath-hold cardiac cine MR imaging with a middle field MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Kentaro; Sato, Kiyoto; Aono, Masaki; Inoshita, Kenji; Utsumi, Naoko [Kagawa Inoshita Hospital, Ohnohara (Japan)

    1999-07-01

    To assess the accuracy of contrast-enhanced, single breath-hold cine MR imaging in calculating left ventricular volume and ejection fraction, we compared MR measurements with those obtained by using cine ventriculography in 60 patients. Fast cine MR images were acquired with a middle field MR system (0.5 T). A breath-hold single slice multi-phase fast gradient-echo (Fast Card) sequence was used to obtain fast cine MR images with the following parameters; TR of 16 ms, TE of 3 ms, flip angle of 30 degree, matrix elements of 256 x 128, view per segment of 6, field of view of 350 x 260 mm and one excitation. Left ventricular end-diastolic volume and ejection fraction obtained with contrast-enhanced Fast Card correlated well with those obtained with cine ventriculography (end-diastolic volume, y=1.00x+14.0, r=0.904, p<0.001; ejection fraction, y=0.961x+2.8, r=0.936, p<0.001). Our results show that contrast enhanced breath-hold cardiac cine MR imaging on horizontal long-axis view using a middle field MR system is an accurate method for evaluating left ventricular volume and ejection fraction. (author)

  11. Cardiac arrest

    Science.gov (United States)

    ... Article.jsp. Accessed June 16, 2014. Myerburg RJ, Castellanos A. Approach to cardiac arrest and life-threatening ... PA: Elsevier Saunders; 2011:chap 63. Myerburg RJ, Castellanos A. Cardiac arrest and audden aardiac death. In: ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

  13. Ectopic hyperfunctioning parathyroid tissue: the role of combined CT/SPECT technology

    International Nuclear Information System (INIS)

    Full text: Surgery is the therapeutic option for hyperparathyroidism and minimal invasive parathyroidectomy (MIP) has challenged the traditional approach of bilateral neck exploration. MIP provides the possibility of focal anesthesia, shorter operation time and length of hospital stay, better cosmetic results and lowered rates of operative morbidity. Ectopic parathyroid glands are relatively common and are often reasons for intervention failures. More than one reexploration is related with high surgical risk, therefore accurate preoperative localizing imaging is very essential. 99mTc-sestamibi dual-phase-scintigraphy (MIBI-SPECT) is a well established imaging modality in detecting (ectopic) hyperfunctioning parathyroid tissue, however, it lacks anatomical details. In case of ectopic tissue further morphological localization with CT/MRI is needed. Recently, SPECT/CT technology (GE Medical Systems Millennium VG with Hawkeye) has been presented which combines simultaneous acquisition of both transmission and emission tomography in a single device. We now report a successful use of this technology for exact preoperative localization of ectopic parathyroid tissue in order to facilitate MIP. SPECT/CT technology was used in three patients with hyperparathyroidism. One patient had primary and the remaining two renal hyperparathyroidism. The MIBI-SPECT study demonstrated in all patients a focal accumulation of the tracer in ectopic localization. For further anatomical details SPECT/CT technology has been used. SPECT/CT technology using a single device provided reliable anatomical details leading to a successful MIP. The success of the correct localization and resection of the hyperfunctioning parathyroid tissue was assessed by intraoperative parathyroid hormone measurement. Postoperative PTH levels and serum calcium are now in normal range. We conclude that preoperative localization of ectopic parathyroid tissue can be accurately achieved by combined use of SPECT (MIBI

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

    Directory of Open Access Journals (Sweden)

    Kowalczyk L.

    2014-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-04-01

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

  16. High Sensitivity SPECT for Small Animals and Plants

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Gregory S. [UC Davis

    2015-02-28

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

  17. Prototype Development of an Electrical Impedance Based Simultaneous Respiratory and Cardiac Monitoring System for Gated Radiotherapy

    OpenAIRE

    Kohli, Kirpal; Liu, Jeff; Schellenberg, Devin; Karvat, Anand; Parameswaran, Ash; Grewal, Parvind; Thomas, Steven

    2014-01-01

    Background In radiotherapy, temporary translocations of the internal organs and tumor induced by respiratory and cardiac activities can undesirably lead to significantly lower radiation dose on the targeted tumor but more harmful radiation on surrounding healthy tissues. Respiratory and cardiac gated radiotherapy offers a potential solution for the treatment of tumors located in the upper thorax. The present study focuses on the design and development of simultaneous acquisition of respira...

  18. An ECG Monitoring System For Prediction Of Cardiac Anomalies Using WBAN

    OpenAIRE

    Hadjem, Medina; Salem, Osman; Naït-Abdesselam, Farid

    2014-01-01

    International audience Cardiovascular diseases (CVD) are known to be the most widespread causes to death. Therefore, detecting earlier signs of cardiac anomalies is of prominent importance to ease the treatment of any cardiac complication or take appropriate actions. Electrocardiogram (ECG) is used by doctors as an important diagnosis tool and in most cases, it's recorded and analyzed at hospital after the appearance of first symptoms or recorded by patients using a device named holter ECG...

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

    Directory of Open Access Journals (Sweden)

    Gonca G. Bural

    2012-12-01

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

  20. Reliability of myocardial perfusion quantification in angiography using a digital flat panel cardiac system

    Science.gov (United States)

    Perrin, Muriel; Vaillant, Regis; Gavit-Houdant, Laurence; Lienard, Jean; Benali, Karim

    2002-04-01

    Discordance between lesion severity from angiocardiography and physiological effects has been reported elsewhere. Quantification of myocardial perfusion during the angiography procedure may supply additional information about short- and long-term outcomes and may be helpful for clinical decision making. In previous works, myocardial perfusion has been assessed using time density curves (TDC), which represent the contrast medium dilution over time in the myocardium. The mean transit time (MTT), derived from the TDC, has been reported as a good indicator of the regional myocardial perfusion. Our objective is to estimate the accuracy and reproducibility of MTT estimation on digital flat panel (DFP) images. We have simulated typical myocardium TDC obtained with a DFP cardiac system (Innova 2000, GE), taking into account scatter and noise. Logarithmic or linear subtractions have been applied to derive a contrast medium concentration proportional quantity from image intensity. A non-linear minimisation realises the model curve fitting. MTT estimates are more stable with linear subtraction in presence of scatter. However logarithmic subtraction presents smaller bias when scatter level is small. Both approaches are equally sensible to image noise. Linear subtraction should be preferred. Image noise has a high influence on MTT accuracy and we may reduce.

  1. [Non-invasive evaluation of the cardiac autonomic nervous system by PET]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    C-11 hydroxy ephedrine, introduced as the first clinically usable norepinephrine analogue, studies employing normal volunteers and patients with various cardiac disorders was found to valuable as a nonadreneric tracer. Simultaneously, animal studies been used to assess its use following ischemic injury in order to define neuronal damage. Current research focuses on the comparison of C-11 hydroxyephedrine with other neurotransmitters such as C-11 epinephrine and C-11 threohydroxyephedrine. Epinephrine is primarily stored in vesicles of the nerve terminal, while threo-hydroxyephedrine is only substrate to uptake I mechanism. Such a combination of radiotracers may allow the dissection of uptake I mechanism as well as vesicular storage. In parallel to the refinement of presynaptic tracers for the sympathetic nervous system, we are developing radiopharmaceuticals to delineate the adrenergic receptors in the heart. The combined evaluation of pre- and postsynaptic nerve function will improve our ability to identify abnormalides. We are currently developing a new radiosynthesis of the hydrophilic adrenergic receptor antagonist C-11 CGP-12177 which has been used by others for the visualization of adrenergic receptors in the heart. We are developing radiopharmaceuticals, for the delineation of presynaptic cholinergic nerve terminals. Derivatives of benzovesamicol have been labeled in our institution and are currently under investigation. The most promising agent is F-18 benzovesamicol (FEBOBV) which allows the visualization of parasympathetic nerve terminals in the canine heart as demonstrated by, preliminary PET data.

  2. [Non-invasive evaluation of the cardiac autonomic nervous system by PET

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    C-11 hydroxy ephedrine, introduced as the first clinically usable norepinephrine analogue, studies employing normal volunteers and patients with various cardiac disorders was found to valuable as a nonadreneric tracer. Simultaneously, animal studies been used to assess its use following ischemic injury in order to define neuronal damage. Current research focuses on the comparison of C-11 hydroxyephedrine with other neurotransmitters such as C-11 epinephrine and C-11 threohydroxyephedrine. Epinephrine is primarily stored in vesicles of the nerve terminal, while threo-hydroxyephedrine is only substrate to uptake I mechanism. Such a combination of radiotracers may allow the dissection of uptake I mechanism as well as vesicular storage. In parallel to the refinement of presynaptic tracers for the sympathetic nervous system, we are developing radiopharmaceuticals to delineate the adrenergic receptors in the heart. The combined evaluation of pre- and postsynaptic nerve function will improve our ability to identify abnormalides. We are currently developing a new radiosynthesis of the hydrophilic adrenergic receptor antagonist C-11 CGP-12177 which has been used by others for the visualization of adrenergic receptors in the heart. We are developing radiopharmaceuticals, for the delineation of presynaptic cholinergic nerve terminals. Derivatives of benzovesamicol have been labeled in our institution and are currently under investigation. The most promising agent is F-18 benzovesamicol (FEBOBV) which allows the visualization of parasympathetic nerve terminals in the canine heart as demonstrated by, preliminary PET data.

  3. Exercise training improves cardiac autonomic nervous system activity in type 1 diabetic children.

    Science.gov (United States)

    Shin, Ki Ok; Moritani, Toshio; Woo, Jinhee; Jang, Ki Soeng; Bae, Ju Yong; Yoo, Jaeho; Kang, Sunghwun

    2014-01-01

    [Purpose] We investigated the effect exercise training has on cardiac autonomic nervous system (ANS) and cardiovascular risk profiles in children with type 1 diabetes mellitus (DM). [Subjects] Fifteen type 1 DM children (all boys; 13.0±1.0 years of age) were enrolled in the study. [Methods] The subjects received exercise training three times a week in a 12-week program. Each child was asked to walk on a treadmill to achieve an exercise intensity of VO2max 60%. ANS activity was measured by power spectral analysis of the electrocardiogram (ECG). Blood samples were obtained for serum lipid profiles. To evaluate Doppler-shifted Fourier pulsatility index (PI) analysis, a 5-MHz continuous wave Doppler (VASCULAB D10) set was used to measure forward blood flow velocity (FLOW) in the radial artery. [Results] Total and low-frequency (LF) power of heart rate variability increased significantly after exercise intervention. Total cholesterol (TC) levels were significant lower after exercise intervention. Total and high-frequency (HF) power were significantly correlated with higher TC levels, but diastolic blood pressure and HF was significantly correlated with lower TC levels. [Conclusion] Regular exercise intervention should be prescribed for children with type 1 DM.

  4. Impact of changes in systemic vascular resistance on a novel non-invasive continuous cardiac output measurement system based on pulse wave transit time: a report of two cases

    OpenAIRE

    Ishihara, Hironori; Tsutsui, Masato

    2013-01-01

    The inaccuracy of arterial waveform analysis for measuring continuos cardiac output (CCO) associated with changes in systemic vascular resistance (SVR) has been well documented. A new non-invasive continuous cardiac output monitoring system (esCCO) mainly utilizing pulse wave transit time (PWTT) in place of arterial waveform analysis has been developed. However, the trending ability of esCCO to measure cardiac output during changes in SVR remains unclear. After a previous multicenter study on...

  5. Catecholamines, cardiac natriuretic peptides and chromogranin A: evolution and physiopathology of a 'whip-brake' system of the endocrine heart.

    Science.gov (United States)

    Tota, Bruno; Cerra, Maria Carmela; Gattuso, Alfonsina

    2010-09-15

    In the past 50 years, extensive evidence has shown the ability of vertebrate cardiac non-neuronal cells to synthesize and release catecholamines (CA). This formed the mindset behind the search for the intrinsic endocrine heart properties, culminating in 1981 with the discovery of the natriuretic peptides (NP). CA and NP, co-existing in the endocrine secretion granules and acting as major cardiovascular regulators in health and disease, have become of great biomedical relevance for their potent diagnostic and therapeutic use. The concept of the endocrine heart was later enriched by the identification of a growing number of cardiac hormonal substances involved in organ modulation under normal and stress-induced conditions. Recently, chromogranin A (CgA), a major constituent of the secretory granules, and its derived cardio-suppressive and antiadrenergic peptides, vasostatin-1 and catestatin, were shown as new players in this framework, functioning as cardiac counter-regulators in 'zero steady-state error' homeostasis, particularly under intense excitatory stimuli, e.g. CA-induced myocardial stress. Here, we present evidence for the hypothesis that is gaining support, particularly among human cardiologists. The actions of CA, NP and CgA, we argue, may be viewed as a hallmark of the cardiac capacity to organize 'whip-brake' connection-integration processes in spatio-temporal networks. The involvement of the nitric oxide synthase (NOS)/nitric oxide (NO) system in this configuration is discussed. The use of fish and amphibian paradigms will illustrate the ways that incipient endocrine-humoral agents have evolved as components of cardiac molecular loops and important intermediates during evolutionary transitions, or in a distinct phylogenetic lineage, or under stress challenges. This may help to grasp the old evolutionary roots of these intracardiac endocrine/paracrine networks and how they have evolved from relatively less complicated designs. The latter can also be used

  6. Microfluidic systems to examine intercellular coupling of pairs of cardiac myocytes.

    Science.gov (United States)

    Klauke, Norbert; Smith, Godfrey; Cooper, Jonathan M

    2007-06-01

    In this paper we describe a microfluidic environment that enables us to explore cell-to-cell signalling between longitudinally linked primary heart cells. We have chosen to use pairs (or doublets) of cardiac myocyte as a model system, not only because of the importance of cell-cell signalling in the study of heart disease but also because the single cardiomyocytes are both mechanically and electrically active and their synchronous activation due to the intercellular coupling within the doublet can be readily monitored on optical and electrical recordings. Such doublets have specialised intercellular contact structures in the form of the intercalated discs, comprising the adhesive junction (fascia adherens and macula adherens or desmosome) and the connecting junction (known as gap junction). The latter structure enables adjacent heart cells to share ions, second messengers and small metabolites (<1 kDa) between them and thus provides the structural basis for the synchronous (syncytical) behaviour of connected cardiomyocytes. Using the unique environment provided by the microfluidic system, described in this paper, we explore the local ionic conditions that enable the propagation of Ca(2+) waves between two heart cells. We observe that the ability of intracellular Ca(2+) waves to traverse the intercalated discs is dependent on the relative concentrations of diastolic Ca(2+) in the two adjacent cells. These experiments rely upon our ability to independently control both the electrical stimulation of each of the cells (using integrated microelectrodes) and to rapidly change (or switch) the local concentrations of ions and drugs in the extracellular buffer within the microfluidic channel (using a nanopipetting system). Using this platform, it is also possible to make simultaneous optical recordings (including fluorescence and cell contraction) to explore the effect of drugs on one or both cells, within the doublet.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

  8. Discrimination of the Healthy and Sick Cardiac Autonomic Nervous System by a New Wavelet Analysis of Heartbeat Intervals

    OpenAIRE

    Ashkenazy, Y.; Lewkowicz, M.; Levitan, J.; Moelgaard, H.; Thomsen, P. E. Bloch; Saermark, K.

    1998-01-01

    We demonstrate that it is possible to distinguish with a complete certainty between healthy subjects and patients with various dysfunctions of the cardiac nervous system by way of multiresolutional wavelet transform of RR intervals. We repeated the study of Thurner et al on different ensemble of subjects. We show that reconstructed series using a filter which discards wavelet coefficients related with higher scales enables one to classify individuals for which the method otherwise is inconclu...

  9. Non-neuronal cardiac cholinergic system influences CNS via the vagus nerve to acquire a stress-refractory propensity.

    Science.gov (United States)

    Oikawa, Shino; Kai, Yuko; Tsuda, Masayuki; Ohata, Hisayuki; Mano, Asuka; Mizoguchi, Naoko; Sugama, Shuei; Nemoto, Takahiro; Suzuki, Kenji; Kurabayashi, Atsushi; Muramoto, Kazuyo; Kaneda, Makoto; Kakinuma, Yoshihiko

    2016-11-01

    We previously developed cardiac ventricle-specific choline acetyltransferase (ChAT) gene-overexpressing transgenic mice (ChAT tgm), i.e. an in vivo model of the cardiac non-neuronal acetylcholine (NNA) system or non-neuronal cardiac cholinergic system (NNCCS). By using this murine model, we determined that this system was responsible for characteristics of resistance to ischaemia, or hypoxia, via the modulation of cellular energy metabolism and angiogenesis. In line with our previous study, neuronal ChAT-immunoreactivity in the ChAT tgm brains was not altered from that in the wild-type (WT) mice brains; in contrast, the ChAT tgm hearts were the organs with the highest expression of the ChAT transgene. ChAT tgm showed specific traits in a central nervous system (CNS) phenotype, including decreased response to restraint stress, less depressive-like and anxiety-like behaviours and anti-convulsive effects, all of which may benefit the heart. These phenotypes, induced by the activation of cardiac NNCCS, were dependent on the vagus nerve, because vagus nerve stimulation (VS) in WT mice also evoked phenotypes similar to those of ChAT tgm, which display higher vagus nerve discharge frequency; in contrast, lateral vagotomy attenuated these traits in ChAT tgm to levels observed in WT mice. Furthermore, ChAT tgm induced several biomarkers of VS responsible for anti-convulsive and anti-depressive-like effects. These results suggest that the augmentation of the NNCCS transduces an effective and beneficial signal to the afferent pathway, which mimics VS. Therefore, the present study supports our hypothesis that activation of the NNCCS modifies CNS to a more stress-resistant state through vagus nerve activity. PMID:27528769

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-02-01

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

  11. The usefulness of SPECT and MRI in the diagnosis of atypical parkinsonian syndromes

    International Nuclear Information System (INIS)

    Clinico-pathological studies have shown that only three out of four patients with parkinsonism have idiopathic Parkinson's disease. In patients with so-called Parkinson plus syndrome, the degeneration in the brain is more widespread and the variety of neurological signs greater than in Parkinson's disease. The differentiation of these syndromes from Parkinson's disease can be difficult. Single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRl) can be of value in the differential diagnosis of parkinsonism. We present three patients with atypical parkinsonism in whom MRI and SPECT with β-CIT and epidepride was performed in addition to the clinical evaluation. The three patients all had a rapidly developing symmetric akinetic-rigid syndrome that responded poorly to levodopa. MRI showed findings regarded as typical for multiple system atrophy in two patients, but only nonspecific findings in the third patient. SPECT with β-CIT showed a pronounced bilateral and relatively symmetric reduction in the striatal dopaminergic activity in all patients. SPECT with epidepride showed a clearly reduced striatal D2-receptor binding bilaterally in only one of the patients. In patients with atypical parkinsonism, MRI and SPECT with β-CIT and epidepride can give valuable support to the clinical diagnosis of a Parkinson plus syndrome

  12. Modelling photon transport in non-uniform media for SPECT with a vectorized Monte Carlo code.

    Science.gov (United States)

    Smith, M F

    1993-10-01

    A vectorized Monte Carlo code has been developed for modelling photon transport in non-uniform media for single-photon-emission computed tomography (SPECT). The code is designed to compute photon detection kernels, which are used to build system matrices for simulating SPECT projection data acquisition and for use in matrix-based image reconstruction. Non-uniform attenuating and scattering regions are constructed from simple three-dimensional geometric shapes, in which the density and mass attenuation coefficients are individually specified. On a Stellar GS1000 computer, Monte Carlo simulations are performed between 1.6 and 2.0 times faster when the vector processor is utilized than when computations are performed in scalar mode. Projection data acquired with a clinical SPECT gamma camera for a line source in a non-uniform thorax phantom are well modelled by Monte Carlo simulations. The vectorized Monte Carlo code was used to stimulate a 99Tcm SPECT myocardial perfusion study, and compensations for non-uniform attenuation and the detection of scattered photons improve activity estimation. The speed increase due to vectorization makes Monte Carlo simulation more attractive as a tool for modelling photon transport in non-uniform media for SPECT. PMID:8248288

  13. Development of the nSpect portable neutron spectrometer

    International Nuclear Information System (INIS)

    Portable instruments are particularly useful when a neutron spectrum is required for an area with limited space and accessibility. Portable instruments also offer a practical, cost-effective means by which areas that require infrequent surveying can be examined. This paper discusses the design and development of nSpect, a new, truly portable, neutron spectrometer. The nSpect spectrometer is a direct replacement for existing transportable neutron spectrometers, designed to perform equivalently or better. However, the use of bespoke electronic circuits and a more compact and lightweight design have reduced the typical mass of these instruments to approximately 15 kg. This weight falls within manual handling guidelines and makes nSpect truly portable. The nSpect spectrometer is fully-contained within two units, a sensor probe and a remote operator console. This allows the operator to be up to 40 m from the field while being much easier to carry than, for example, the significant bulk of a Bonner sphere set or less portable spectrometers. nSpect employs a variety of detectors which define six overlapping energy ranges to give nSpect an overall energy range from the thermal region (0.025 eV) to 10 MeV. Two BF3 proportional counters are used to assess the neutron flux at thermal and epi-thermal energies. A heavy metal sleeve has been used around one of the BF3 detectors in order to shield it from the thermal component of the flux. Hydrogen-filled proportional counters, with filling pressures of 1, 3 and 10 atm., have been used for the 50 keV - 1.4 MeV energy range. These spherical proportional counters, named SP10, have been adapted from the Centronic Ltd. SP9-type detector specifically for this project. A new approach to the energy calibration of spherical proportional counters has been developed and applied to the nSpect SP10 detectors. A small liquid scintillator cell, filled with EJ-301, is used for the 1 - 10 MeV energy range. High-speed digital electronics have

  14. Prognostic study of risk stratification among Japanese patients with ischemic heart disease using gated myocardial perfusion SPECT: J-ACCESS study

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Department of Radiology, Graduate School of Medical Science, Kyoto (Japan); Nakajima, Kenichi [Kanazawa University Graduate School of Medical Science, Department of Biotracer Medicine, Kanazawa (Japan); Kusuoka, Hideo [Osaka National Hospital, Osaka (Japan); Yamashina, Akira [Tokyo Medical University Hospital, Second Department of Internal Medicine, Tokyo (Japan); Nishimura, Shigeyuki [Saitama Medical School Hospital, Division of Cardiology, Saitama (Japan)

    2008-02-15

    Although the prognostic value of myocardial perfusion imaging using gated single photon emission computed tomography (SPECT) for predicting major cardiac events has been evaluated, little is known about the relevance of this procedure to the Japanese population. A total of 4,031 consecutive Japanese patients with suspected or confirmed ischemic heart diseases were registered at 117 hospitals in the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT investigation. Gated stress/rest myocardial perfusion SPECT was performed and the patients were followed up for 3 years. Segmental perfusion scores and quantitative gated SPECT results were calculated. Major cardiac events were defined as cardiac death, nonfatal myocardial infarction, and severe heart failure. During the 3-year follow-up, cardiac death (n = 57) and nonfatal myocardial infarction (n = 39) occurred in 96 patients (2.4%/3 years) when hard events were the endpoints. When severe heart failure was included as an endpoint, major cardiac events that developed in 175 patients (4.3%/3 years) comprised cardiac death (n = 45), nonfatal myocardial infarction (n = 37), and severe heart failure (n = 93). Normal and severely abnormal summed stress score values were associated with low (2.31%/3 years) and high (9.21%/3 years) rates of major cardiac events, respectively. Rates of major cardiac events were significantly higher in patients with ejection fraction (EF) <45% than in those with EF 45% or higher (16.55 vs 2.94%/3 years; P < 0.001). The incidence of major cardiac events within 3 years was also significantly higher among patients with high end-systolic volumes. The major event rates were similar among nondiabetic patients with and diabetic patients without prior myocardial infarction at 5.06% and 5.73%/3 years, respectively. Cardiac event rates were significantly lower in the Japanese than in the USA and European populations. However, large myocardial perfusion defects and

  15. Comparison of 99mTc-Technegas SPECT with 133Xe dynamic SPECT in pulmonary emphysema

    International Nuclear Information System (INIS)

    This study was undertaken to compare axial images of 99mTc-Technegas SPECT (Technegas) with those of 133Xe gas dynamic SPECT in patients with pulmonary emphysema. There were 20 patients, 19 males and 1 female. All patients except one ex-smoker were heavy smokers with a mean age of 68.1 years. For Technegas scintigraphy, the patients inhaled 505 MBq 99mTc-Technegas in several tidal volume breaths in the supine position without breath holding. For 133Xe gas scintigraphy, the patients inhaled 370 MBq 133Xe gas. 133Xe gas dynamic SPECT was performed in the equilibrium phase for the last minute of the 3 minute inhalation in a closed circuit, and in the washout phase for 6 minutes of inhalation in a semi-closed circuit, by means of a gamma camera with dual detectors (Picker model Prism 2000). Abnormal findings included heterogeneity, defects and hot spots on Technegas images and on retention images taken 3 minutes after 133Xe gas washout. In 2 of 20 patients, the degree of abnormal findings on Technegas images depended on the area of 133Xe gas retention in the washout phase. In 3 patients, the degrees of abnormal findings on both Technegas SPECT and 133Xe gas dynamic SPECT images were equivalent. In the remaining 15 patients, more detailed findings and a greater area were shown by Technegas SPECT than 133Xe gas dynamic SPECT. We conclude that in patients with pulmonary emphysema Technegas SPECT can demonstrate ventilation impairment more easily than 133Xe gas dynamic SPECT. (author)

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

    Directory of Open Access Journals (Sweden)

    Eylem Değirmenci

    2015-06-01

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

  17. Dual-Chamber Pacing for Cardiac Arrhythmias: Controversies in Cloning the Conduction System

    OpenAIRE

    Parsonnet, Victor; Bernstein, Alan D.; Norman, John C.

    1984-01-01

    From the outset, the art and science of cardiac pacing has been beset with a variety of problems. With the passage of time and concentrated effort in the interrelated sciences, many have been solved. We no longer are concerned with premature battery failure or leaking pulse-generator capsules, but now focus on an entirely new set of issues that beg for resolution. Foremost among these is the true role of dual-chamber pacing in the treatment of slow and fast cardiac arrhythmias of a multitude ...

  18. Evaluation of a real-time hybrid three-dimensional echo and X-ray imaging system for guidance of cardiac catheterisation procedures.

    Science.gov (United States)

    Housden, R J; Arujuna, A; Ma, Y; Nijhof, N; Gijsbers, G; Bullens, R; O'Neill, M; Cooklin, M; Rinaldi, C A; Gill, J; Kapetanakis, S; Hancock, J; Thomas, M; Razavi, R; Rhode, K S

    2012-01-01

    Minimally invasive cardiac surgery is made possible by image guidance technology. X-ray fluoroscopy provides high contrast images of catheters and devices, whereas 3D ultrasound is better for visualising cardiac anatomy. We present a system in which the two modalities are combined, with a trans-esophageal echo volume registered to and overlaid on an X-ray projection image in real-time. We evaluate the accuracy of the system in terms of both temporal synchronisation errors and overlay registration errors. The temporal synchronisation error was found to be 10% of the typical cardiac cycle length. In 11 clinical data sets, we found an average alignment error of 2.9 mm. We conclude that the accuracy result is very encouraging and sufficient for guiding many types of cardiac interventions. The combined information is clinically useful for placing the echo image in a familiar coordinate system and for more easily identifying catheters in the echo volume.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-09-01

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

  20. Anesthesia with propofol induces insulin resistance systemically in skeletal and cardiac muscles and liver of rats

    International Nuclear Information System (INIS)

    Highlights: ► Propofol, as a model anesthetic drug, induced whole body insulin resistance. ► Propofol anesthesia decreased glucose infusion rate to maintain euglycemia. ► Propofol decreased insulin-mediated glucose uptake in skeletal and cardiac muscles. ► Propofol increased hepatic glucose output confirming hepatic insulin resistance. -- Abstract: Hyperglycemia together with hepatic and muscle insulin resistance are common features in critically ill patients, and these changes are associated with enhanced inflammatory response, increased susceptibility to infection, muscle wasting, and worsened prognosis. Tight blood glucose control by intensive insulin treatment may reduce the morbidity and mortality in intensive care units. Although some anesthetics have been shown to cause insulin resistance, it remains unknown how and in which tissues insulin resistance is induced by anesthetics. Moreover, the effects of propofol, a clinically relevant intravenous anesthetic, also used in the intensive care unit for sedation, on insulin sensitivity have not yet been investigated. Euglycemic hyperinsulinemic clamp study was performed in rats anesthetized with propofol and conscious unrestrained rats. To evaluate glucose uptake in tissues and hepatic glucose output [3H]glucose and 2-deoxy[14C]glucose were infused during the clamp study. Anesthesia with propofol induced a marked whole-body insulin resistance compared with conscious rats, as reflected by significantly decreased glucose infusion rate to maintain euglycemia. Insulin-stimulated tissue glucose uptake was decreased in skeletal muscle and heart, and hepatic glucose output was increased in propofol anesthetized rats. Anesthesia with propofol induces systemic insulin resistance along with decreases in insulin-stimulated glucose uptake in skeletal and heart muscle and attenuation of the insulin-mediated suppression of hepatic glucose output in rats

  1. Anesthesia with propofol induces insulin resistance systemically in skeletal and cardiac muscles and liver of rats

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Yoshikazu; Fukushima, Yuji; Kaneki, Masao [Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Shriners Hospitals for Children, Harvard Medical School, Boston, MA 02114 (United States); Martyn, J.A. Jeevendra, E-mail: jmartyn@partners.org [Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Shriners Hospitals for Children, Harvard Medical School, Boston, MA 02114 (United States)

    2013-02-01

    Highlights: ► Propofol, as a model anesthetic drug, induced whole body insulin resistance. ► Propofol anesthesia decreased glucose infusion rate to maintain euglycemia. ► Propofol decreased insulin-mediated glucose uptake in skeletal and cardiac muscles. ► Propofol increased hepatic glucose output confirming hepatic insulin resistance. -- Abstract: Hyperglycemia together with hepatic and muscle insulin resistance are common features in critically ill patients, and these changes are associated with enhanced inflammatory response, increased susceptibility to infection, muscle wasting, and worsened prognosis. Tight blood glucose control by intensive insulin treatment may reduce the morbidity and mortality in intensive care units. Although some anesthetics have been shown to cause insulin resistance, it remains unknown how and in which tissues insulin resistance is induced by anesthetics. Moreover, the effects of propofol, a clinically relevant intravenous anesthetic, also used in the intensive care unit for sedation, on insulin sensitivity have not yet been investigated. Euglycemic hyperinsulinemic clamp study was performed in rats anesthetized with propofol and conscious unrestrained rats. To evaluate glucose uptake in tissues and hepatic glucose output [{sup 3}H]glucose and 2-deoxy[{sup 14}C]glucose were infused during the clamp study. Anesthesia with propofol induced a marked whole-body insulin resistance compared with conscious rats, as reflected by significantly decreased glucose infusion rate to maintain euglycemia. Insulin-stimulated tissue glucose uptake was decreased in skeletal muscle and heart, and hepatic glucose output was increased in propofol anesthetized rats. Anesthesia with propofol induces systemic insulin resistance along with decreases in insulin-stimulated glucose uptake in skeletal and heart muscle and attenuation of the insulin-mediated suppression of hepatic glucose output in rats.

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

    Directory of Open Access Journals (Sweden)

    Seunggyun Ha

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-15

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

  4. Development and optimization of SPECT gated blood pool cluster analysis for the prediction of CRT outcome

    Energy Technology Data Exchange (ETDEWEB)

    Lalonde, Michel, E-mail: mlalonde15@rogers.com; Wassenaar, Richard [Department of Physics, Carleton University, Ottawa, Ontario K1S 5B6 (Canada); Wells, R. Glenn; Birnie, David; Ruddy, Terrence D. [Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario K1Y 4W7 (Canada)

    2014-07-15

    Purpose: Phase analysis of single photon emission computed tomography (SPECT) radionuclide angiography (RNA) has been investigated for its potential to predict the outcome of cardiac resynchronization therapy (CRT). However, phase analysis may be limited in its potential at predicting CRT outcome as valuable information may be lost by assuming that time-activity curves (TAC) follow a simple sinusoidal shape. A new method, cluster analysis, is proposed which directly evaluates the TACs and may lead to a better understanding of dyssynchrony patterns and CRT outcome. Cluster analysis algorithms were developed and optimized to maximize their ability to predict CRT response. Methods: About 49 patients (N = 27 ischemic etiology) received a SPECT RNA scan as well as positron emission tomography (PET) perfusion and viability scans prior to undergoing CRT. A semiautomated algorithm sampled the left ventricle wall to produce 568 TACs from SPECT RNA data. The TACs were then subjected to two different cluster analysis techniques, K-means, and normal average, where several input metrics were also varied to determine the optimal settings for the prediction of CRT outcome. Each TAC was assigned to a cluster group based on the comparison criteria and global and segmental cluster size and scores were used as measures of dyssynchrony and used to predict response to CRT. A repeated random twofold cross-validation technique was used to train and validate the cluster algorithm. Receiver operating characteristic (ROC) analysis was used to calculate the area under the curve (AUC) and compare results to those obtained for SPECT RNA phase analysis and PET scar size analysis methods. Results: Using the normal average cluster analysis approach, the septal wall produced statistically significant results for predicting CRT results in the ischemic population (ROC AUC = 0.73;p < 0.05 vs. equal chance ROC AUC = 0.50) with an optimal operating point of 71% sensitivity and 60% specificity. Cluster

  5. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  6. Unsupervised learning of spect reconstruction

    International Nuclear Information System (INIS)

    An approach of image reconstruction from projection in single-photon emission computed tomography (SPECT), based on an unsupervised learning artificial Kohonen neural network, is developed. A kind of random sampling technique is used to generate sensory input from tomographic projections. It is proved that an adequate interpretation and representation of the synaptic strengths of the network can be used to obtain the tomographic image. A relevant numerical experiment is reported. To validate the method tests were performed using a typical phantom (simulated object) used in limited data sets tomography. At the end of the self-organizing process the synaptic strengths can be shown on x-y plane as a map of points. The density of points gives the reconstructed image. In order to obtain a usual representation of the image a grid of 32 x 32 pixels was superimposed on the map and the number of points in each pixel was counted in order to form the image function. As the number of points in each pixel (especially for pixels corresponding to the background of the phantom) is relatively small, the image function is spoiled by noise. Noise filtering was used to improve the quality of the image. The final result is presented as a 3D-surface plot and as a corresponding 8-level gray map. It can be concluded that a good reconstruction of sizes and shapes was obtained. Some artifacts spoil the region located around the spikes. This artifact can be reduced if an increased number of external stimuli are presented to the network. The price paid for this improvement is the increase of computation time. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-10-01

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

  8. Combined effect of diabetes mellitus and exercise training on cardiac function : a study of β-adrenergic system and intracellular calcium regulatory system

    OpenAIRE

    Le Douairon Lahaye, Solène

    2009-01-01

    The insulin treatment does not avoid long-term development of cardiomyopathy, regular physical activity is now offered as a complement to drug therapy of diabetes. Our primary aim was to determine long term respective effects of exercise training and insulin treatment on cardiac function with a focus on the β-adrenergic system and/or on the calcium intracellular regulatory system. In the long-term insulin treatment and exercise training were not able to decrease the troubles caused by diabete...

  9. Prognosis of patients with positive exercise test and normal myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Seo, J. H.; Jeong, S. Y.; Bae, J. H.; Ahn, B. C.; Lee, J.; Lee, K. B [College of Medicine, Kyungpook National University, Daegu (Korea, Republic of)

    2004-07-01

    Exercise SPECT myocardial perfusion imaging(Ex-MPI) is regarded as a predictive technique particularly in patients with coronary artery disease(CAD) capable of performing exercise testing. In clinical practice, we encounter equivocal situations of discordant findings between exercise ECG and MPI. We evaluated the prognosis of subjects with positive ECG and normal MPI findings, and predictive factors for cardiac events. 2571 Ex-MPI studies were reviewed over a period of 3 years. Subjects were followed for more than 2 years(24-56 months, mean 35{+-}10months) for cardiac events after study. The cardiac events were defined as hard events(cardiac death and nonfatal myocardial infarction(MI)) and soft events(aggravation of CAD necessitating revascularization, congestive heart failure necessitating hospital admission). We evaluated age, sex, typical angina pain, rest ECG, hypertension, diabetes mellitus(DM), serum levels of cholesterol and LDL, smoking history, history of cerebrovascular disease(CVD) and peripheral artery disease(PAD), and rest left ventricular ejection fraction(LVEF) as clinical variables. Of 83 subjects with positive ECG and normal MPS findings, 6 were considered as false negative results confirmed with coronary angiography. There were 77 patients (mean age 52{+-}10 years, 39 males) with positive ECG and normal MPI results. During the follow-up period, of 77 there were 3 cardiac events (annual rate 1.9%), no cardiac death, 2 nonfatal MIs (annual rate 1.3%) and 1 soft event (annual rate 0.6%). 2/39 males(5.1%), and 1/38 females(2.6%) had cardiac events. All cardiac events were observed within 2 years. 1-year cardiac event rate was 0.6% and 2-year cardiac event rate was 1.9%. Among clinical factors, male sex, typical chest pain and smoking history at the time of MPI were predictive of cardiac events. Patients with positive ECG and negative EX-MPI results have low risk for cardiac events. Nevertheless, the cardiac events cannot be excluded totally in some

  10. Prognosis of patients with positive exercise test and normal myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Exercise SPECT myocardial perfusion imaging(Ex-MPI) is regarded as a predictive technique particularly in patients with coronary artery disease(CAD) capable of performing exercise testing. In clinical practice, we encounter equivocal situations of discordant findings between exercise ECG and MPI. We evaluated the prognosis of subjects with positive ECG and normal MPI findings, and predictive factors for cardiac events. 2571 Ex-MPI studies were reviewed over a period of 3 years. Subjects were followed for more than 2 years(24-56 months, mean 35±10months) for cardiac events after study. The cardiac events were defined as hard events(cardiac death and nonfatal myocardial infarction(MI)) and soft