WorldWideScience

Sample records for quantitative gated spect

  1. The additive prognostic value of perfusion and functional data assessed by quantitative gated SPECT in women

    NARCIS (Netherlands)

    Y.G.C.J. America (Yves); J.J. Bax (Jeroen); H. Boersma (Eric); M. Stokkel (Marcel); E.E. van der Wall (Ernst)

    2009-01-01

    textabstractBackground: The aim of this study was to assess the prognostic value of technetium-99m tetrofosmin gated SPECT imaging in women using quantitative gated single photon emission computed tomography (SPECT) imaging. Methods: We followed 453 consecutive female patients. Average follow-up was

  2. The impact of hypertension on diastolic left ventricular function, evaluated by quantitative ECG-gated myocardial perfusion SPECT

    Directory of Open Access Journals (Sweden)

    Mohamed H.M. Sayed

    2015-09-01

    Conclusions: Quantitative ECG-gated Tc-99m tetrofosmin SPECT reveals that hypertensive patients with preserved global LV systolic function may have significant changes in diastolic LV function. Gated myocardial perfusion SPECT reports are always lacking in these changes in diastolic function. We recommend inclusion of such changes in diastolic function in gated myocardial perfusion SPECT reports that can help in proper management of hypertensive patients.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  4. Automated quantitative coronary computed tomography correlates of myocardial ischaemia on gated myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Graaf, Michiel A. de; Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of The Netherlands, Utrecht (Netherlands); El-Naggar, Heba M.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Broersen, Alexander; Kitslaar, Pieter H.; Dijkstra, Jouke [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Kroft, Lucia J. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Younis, Imad Al [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Reiber, Johan H. [Leiden University Medical Center, Department of Radiology, Division of Image Processing, Leiden (Netherlands); Medis medical imaging systems B.V., Leiden (Netherlands); Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

    2013-08-15

    Automated software tools have permitted more comprehensive, robust and reproducible quantification of coronary stenosis, plaque burden and plaque location of coronary computed tomography angiography (CTA) data. The association between these quantitative CTA (QCT) parameters and the presence of myocardial ischaemia has not been explored. The aim of the present investigation was to evaluate the association between QCT parameters of coronary artery lesions and the presence of myocardial ischaemia on gated myocardial perfusion single-photon emission CT (SPECT). Included in the study were 40 patients (mean age 58.2 {+-} 10.9 years, 27 men) with known or suspected coronary artery disease (CAD) who had undergone multidetector row CTA and gated myocardial perfusion SPECT within 6 months. From the CTA datasets, vessel-based and lesion-based visual analyses were performed. Consecutively, lesion-based QCT was performed to assess plaque length, plaque burden, percentage lumen area stenosis and remodelling index. Subsequently, the presence of myocardial ischaemia was assessed using the summed difference score (SDS {>=}2) on gated myocardial perfusion SPECT. Myocardial ischaemia was seen in 25 patients (62.5 %) in 37 vascular territories. Quantitatively assessed significant stenosis and quantitatively assessed lesion length were independently associated with myocardial ischaemia (OR 7.72, 95 % CI 2.41-24.7, p < 0.001, and OR 1.07, 95 % CI 1.00-1.45, p = 0.032, respectively) after correcting for clinical variables and visually assessed significant stenosis. The addition of quantitatively assessed significant stenosis ({chi} {sup 2} = 20.7) and lesion length ({chi} {sup 2} = 26.0) to the clinical variables and the visual assessment ({chi} {sup 2} = 5.9) had incremental value in the association with myocardial ischaemia. Coronary lesion length and quantitatively assessed significant stenosis were independently associated with myocardial ischaemia. Both quantitative parameters have

  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. Evaluation of global and regional left ventricular function obtained by quantitative gated SPECT using {sup 99m}Tc-tetrofosmin for left ventricular dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Ban, Kazunobu; Nakajima, Tohru; Iseki, Harukazu; Abe, Sumihisa; Handa, Shunnosuke; Suzuki, Yutaka [Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine

    2000-08-01

    The quantitative gated SPECT (QGS) software is able to calculate LV volumes and visualize LV wall motion and perfusion throughout the cardiac cycle using an automatic edge detection algorithm of the left ventricle. We evaluated the reliability of global and regional LV function assessment derived from QGS by comparing it with the results from left ventriculo-cineangiography (LVG). In 20 patients with left ventricular dysfunction who underwent ECG gated {sup 99m}Tc-tetrofosmin SPECT, the end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were calculated. The QGS-assessed regional wall motion was determined using the cinematic display. QGS-derived EDV, ESV and LVEF correlated well with those by LVG (p<0.001 for each). There was a good correlation between wall motion score (WMS) derived from the QGS and the LVG (r=0.40, p<0.05). In some patients with extensive myocardial infarction, there was a discrepancy in the regional wall motion results between QGS and LVG. The ECG-gated SPECT using QGS is useful to evaluate global and regional LV functions in left ventricular dysfunction. (author)

  7. SU-C-201-06: Utility of Quantitative 3D SPECT/CT Imaging in Patient Specific Internal Dosimetry of 153-Samarium with GATE Monte Carlo Package

    Energy Technology Data Exchange (ETDEWEB)

    Fallahpoor, M; Abbasi, M [Tehran University of Medical Sciences, Vali-Asr Hospital, Tehran, Tehran (Iran, Islamic Republic of); Sen, A [University of Houston, Houston, TX (United States); Parach, A [Shahid Sadoughi University of Medical Sciences, Yazd, Yazd (Iran, Islamic Republic of); Kalantari, F [UT Southwestern Medical Center, Dallas, TX (United States)

    2015-06-15

    Purpose: Patient-specific 3-dimensional (3D) internal dosimetry in targeted radionuclide therapy is essential for efficient treatment. Two major steps to achieve reliable results are: 1) generating quantitative 3D images of radionuclide distribution and attenuation coefficients and 2) using a reliable method for dose calculation based on activity and attenuation map. In this research, internal dosimetry for 153-Samarium (153-Sm) was done by SPECT-CT images coupled GATE Monte Carlo package for internal dosimetry. Methods: A 50 years old woman with bone metastases from breast cancer was prescribed 153-Sm treatment (Gamma: 103keV and beta: 0.81MeV). A SPECT/CT scan was performed with the Siemens Simbia-T scanner. SPECT and CT images were registered using default registration software. SPECT quantification was achieved by compensating for all image degrading factors including body attenuation, Compton scattering and collimator-detector response (CDR). Triple energy window method was used to estimate and eliminate the scattered photons. Iterative ordered-subsets expectation maximization (OSEM) with correction for attenuation and distance-dependent CDR was used for image reconstruction. Bilinear energy mapping is used to convert Hounsfield units in CT image to attenuation map. Organ borders were defined by the itk-SNAP toolkit segmentation on CT image. GATE was then used for internal dose calculation. The Specific Absorbed Fractions (SAFs) and S-values were reported as MIRD schema. Results: The results showed that the largest SAFs and S-values are in osseous organs as expected. S-value for lung is the highest after spine that can be important in 153-Sm therapy. Conclusion: We presented the utility of SPECT-CT images and Monte Carlo for patient-specific dosimetry as a reliable and accurate method. It has several advantages over template-based methods or simplified dose estimation methods. With advent of high speed computers, Monte Carlo can be used for treatment planning

  8. 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.

  9. Examining a hypothetical quantitative model for better approximation of culprit coronary artery and site of stenosis on 99mTc-sestamibi gated myocardial perfusion SPECT.

    Science.gov (United States)

    Pal, Sushanta; Sen, Srabani; Das, Debasis; Basu, Sandip

    2016-10-01

    A hypothetical quantitative model of analyzing gated myocardial perfusion SPECT is proposed and examined for the feasibility of its use as a predictor of diseased coronary artery and approximating the site of stenosis to determine whether it could serve as a useful noninvasive complement for coronary angiography. The extent and severity of perfusion defects on rest gated myocardial perfusion imaging SPECT-images were assessed on a five-point scale in a standard 17-segment model and total perfusion deficit was quantified by automated software. The first step was to locate the diseased coronary artery using a quantitative method: for this, the score of each segment belonging to a particular coronary artery was determined using a systematic presumptive approach. After determination of specific coronary artery segments, the scores of the contiguous segments in three short axis slices (apical, middle, and basal) were summed for six subdivisions (anterior, anterolateral, inferolateral, inferior, anteroseptal, and inferoseptal). The site of stenosis was determined from (a) the initial approximation of the involved segments with a defect score of 2-4 and (b) subsequent calculation of the defect score of each of the six subdivisions and allocating the site through a preassigned number for each coronary artery. For each coronary artery, only the subdivision with the highest defect score was considered. Proximal, middle, and distal segments of left anterior descending artery (LAD) were considered to be represented when the summed value of a subdivision within a particular arterial territory was more than or equal to 7, between 5 and 7, 5 and 3, respectively. For the left circumflex and right coronary artery, summed scores (of respective subdivisions) of more than or equal to 5 and between 3 and 5 were preassigned to proximal and distal stenosis, respectively. The results were then correlated with the coronary angiographic data. On coronary angiography, proximal LAD occlusion

  10. 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

  11. 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

  12. [Variables that influence the indication of a second myocardial perfusion gated-SPECT after a normal stress-rest gated SPECT].

    Science.gov (United States)

    Romero-Farina, G; Candell-Riera, J; Aguadé-Bruix, S; Cuberas-Borrós, G; Pizzi, M N; Santos, A; de León, G; García-Dorado, D

    2014-01-01

    The objective of this study was to investigate predictor variables at the moment of normal stress-rest myocardial perfusion gated SPECT for indication of a second gated SPECT. A prospective, single center cohort study was conducted. We evaluated 2326 consecutive patients (age 63.6 ± 13 years, 57.3% females) without perfusion defects and with normal left ventricular ejection fraction on a myocardial perfusion gated SPECT. Clinical and stress test variables were studied to predict indication of a second gated SPECT and presence of reversible perfusion defects in the second gated SPECT. During a mean follow-up of 3.6 ± 2 years a second gated SPECT was performed in 286 patients (12.3%). Independent predictor variables of a second gated SPECT were presence of three or more cardiovascular risk factors (χ(2): 5.510; HR: 1.4; p=0.019), previous acute myocardial infarction (χ(2): 3.867; HR: 1.4; p=0.049), previous coronary revascularization (χ(2): 41.081; HR: 2.5; p<0.001), and a positive stress test (χ(2): 8.713; HR: 1.5; p=0.003). Observation of perfusion defects in the 280 patients in whom a second stress-rest gated SPECT was performed was more likely in male patients (χ(2): 4.322; HR: 1.9; p=0.038) who had a first pure pharmacological gated-SPECT (χ(2): 7.182; HR: 2.6; p=0.007). In patients with a first normal myocardial perfusion gated SPECT, various clinical factors and variables derived from the stress test affect the indication of a second gated SPECT and the presence of ischemia in the latter. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

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

    Science.gov (United States)

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

    2015-05-01

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

  14. Impact of reconstruction parameters on quantitative I-131 SPECT

    NARCIS (Netherlands)

    van Gils, C A J; Beijst, C; van Rooij, R; de Jong, H W A M

    2016-01-01

    Radioiodine therapy using I-131 is widely used for treatment of thyroid disease or neuroendocrine tumors. Monitoring treatment by accurate dosimetry requires quantitative imaging. The high energy photons however render quantitative SPECT reconstruction challenging, potentially requiring accurate cor

  15. Impact of reconstruction parameters on quantitative I-131 SPECT

    NARCIS (Netherlands)

    van Gils, C A J; Beijst, C; van Rooij, R; de Jong, H W A M

    2016-01-01

    Radioiodine therapy using I-131 is widely used for treatment of thyroid disease or neuroendocrine tumors. Monitoring treatment by accurate dosimetry requires quantitative imaging. The high energy photons however render quantitative SPECT reconstruction challenging, potentially requiring accurate

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-05-07

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

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

    Science.gov (United States)

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

    2010-05-01

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

  18. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Elschot, Mattijs; Smits, Maarten L. J.; Nijsen, Johannes F. W.; Lam, Marnix G. E. H.; Zonnenberg, Bernard A.; Bosch, Maurice A. A. J. van den; Jong, Hugo W. A. M. de [Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Viergever, Max A. [Image Sciences Institute, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands)

    2013-11-15

    Purpose: Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ({sup 166}Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative {sup 166}Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum.Methods: A fast Monte Carlo (MC) simulator was developed for simulation of {sup 166}Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full {sup 166}Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A{sup est}) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six {sup 166}Ho RE patients.Results: At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96–106.21 ml were improved from 32%–63% (SPECT-DSW) and 50%–80

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

    Science.gov (United States)

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

    2009-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

  1. Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Acampa, Wanda; Liuzzi, Raffaele; De Luca, Serena; Capasso, Enza; Luongo, Luca; Cuocolo, Alberto [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages, National Council of Research, Naples (Italy); Caprio, Maria Grazia [University Federico II, Department of Biomorphological and Functional Sciences, Institute of Biostructures and Bioimages, National Council of Research, Naples (Italy); SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Nicolai, Emanuele [SDN Foundation, Institute of Diagnostic and Nuclear Development, Naples (Italy); Petretta, Mario [University Federico II, Department of Clinical Medicine, Cardiovascular and Immunological Sciences, Naples (Italy)

    2010-02-15

    We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients. Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest {sup 99m}Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest. In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress. In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography. (orig.)

  2. Measurement of left ventricular chamber and myocardial volume in hypertrophic cardiomyopathy patients by ECG-gated myocardial perfusion SPECT. Application of a newly developed edge-detection algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Yoshihiro; Katafuchi, Tetsuro; Hirase, Yoshinori; Sagoh, Masayoshi; Oka, Hisashi [National Cardiovascular Center, Suita, Osaka (Japan); Mori, Hideaki [Siemens-Asahi Medical Technologies, Ltd., Tokyo (Japan); Murase, Kenya [Osaka Univ., Suita (Japan). Medical School

    2002-12-01

    Quantitative gated SPECT (QGS) software has been reported to demonstrate inaccurate edge detection in the left ventricular chamber in hypertrophic cardiomyopathy patients. In this study we developed a method to calculate left ventricular volume (LVV) and left myocardial volume (LMV) from gated SPECT data using a newly developed edge-detection algorithm, and we compared it with the QGS method of calculating LVV and LMV in a phantom study. Our method gave more accurate measurements LVV and LMV whereas the QGS method underestimated LMV. Compared with QGS LVV and LMV, our method yielded better results in the phantom study. (author)

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

    Science.gov (United States)

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

    2016-03-01

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

  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. Accuracy of quantitative reconstructions in SPECT/CT imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-07

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

  6. Impact of reconstruction parameters on quantitative I-131 SPECT

    Science.gov (United States)

    van Gils, C. A. J.; Beijst, C.; van Rooij, R.; de Jong, H. W. A. M.

    2016-07-01

    Radioiodine therapy using I-131 is widely used for treatment of thyroid disease or neuroendocrine tumors. Monitoring treatment by accurate dosimetry requires quantitative imaging. The high energy photons however render quantitative SPECT reconstruction challenging, potentially requiring accurate correction for scatter and collimator effects. The goal of this work is to assess the effectiveness of various correction methods on these effects using phantom studies. A SPECT/CT acquisition of the NEMA IEC body phantom was performed. Images were reconstructed using the following parameters: (1) without scatter correction, (2) with triple energy window (TEW) scatter correction and (3) with Monte Carlo-based scatter correction. For modelling the collimator-detector response (CDR), both (a) geometric Gaussian CDRs as well as (b) Monte Carlo simulated CDRs were compared. Quantitative accuracy, contrast to noise ratios and recovery coefficients were calculated, as well as the background variability and the residual count error in the lung insert. The Monte Carlo scatter corrected reconstruction method was shown to be intrinsically quantitative, requiring no experimentally acquired calibration factor. It resulted in a more accurate quantification of the background compartment activity density compared with TEW or no scatter correction. The quantification error relative to a dose calibrator derived measurement was found to be  Gaussian or no CDR modelling. Scatter correction showed a small effect on quantification of small volumes. When using a weighting factor, TEW correction was comparable to Monte Carlo reconstruction in all measured parameters, although this approach is clinically impractical since this factor may be patient dependent. Monte Carlo based scatter correction including accurately simulated CDR modelling is the most robust and reliable method to reconstruct accurate quantitative iodine-131 SPECT images.

  7. GATE - Geant4 Application for Tomographic Emission: a simulation toolkit for PET and SPECT

    Science.gov (United States)

    Jan, S.; Santin, G.; Strul, D.; Staelens, S.; Assié, K.; Autret, D.; Avner, S.; Barbier, R.; Bardiès, M.; Bloomfield, P. M.; Brasse, D.; Breton, V.; Bruyndonckx, P.; Buvat, I.; Chatziioannou, A. F.; Choi, Y.; Chung, Y. H.; Comtat, C.; Donnarieix, D.; Ferrer, L.; Glick, S. J.; Groiselle, C. J.; Guez, D.; Honore, P.-F.; Kerhoas-Cavata, S.; Kirov, A. S.; Kohli, V.; Koole, M.; Krieguer, M.; van der Laan, D. J.; Lamare, F.; Largeron, G.; Lartizien, C.; Lazaro, D.; Maas, M. C.; Maigne, L.; Mayet, F.; Melot, F.; Merheb, C.; Pennacchio, E.; Perez, J.; Pietrzyk, U.; Rannou, F. R.; Rey, M.; Schaart, D. R.; Schmidtlein, C. R.; Simon, L.; Song, T. Y.; Vieira, J.-M.; Visvikis, D.; Van de Walle, R.; Wieërs, E.; Morel, C.

    2012-01-01

    Monte Carlo simulation is an essential tool in emission tomography that can assist in the design of new medical imaging devices, the optimization of acquisition protocols, and the development or assessment of image reconstruction algorithms and correction techniques. GATE, the Geant4 Application for Tomographic Emission, encapsulates the Geant4 libraries to achieve a modular, versatile, scripted simulation toolkit adapted to the field of nuclear medicine. In particular, GATE allows the description of time-dependent phenomena such as source or detector movement, and source decay kinetics. This feature makes it possible to simulate time curves under realistic acquisition conditions and to test dynamic reconstruction algorithms. This paper gives a detailed description of the design and development of GATE by the OpenGATE collaboration, whose continuing objective is to improve, document, and validate GATE by simulating commercially available imaging systems for PET and SPECT. Large effort is also invested in the ability and the flexibility to model novel detection systems or systems still under design. A public release of GATE licensed under the GNU Lesser General Public License can be downloaded at the address http://www-lphe.ep.ch/GATE/. Two benchmarks developed for PET and SPECT to test the installation of GATE and to serve as a tutorial for the users are presented. Extensive validation of the GATE simulation platform has been started, comparing simulations and measurements on commercially available acquisition systems. References to those results are listed. The future prospects toward the gridification of GATE and its extension to other domains such as dosimetry are also discussed. PMID:15552416

  8. Assessment of myocardial perfusion and function in victims of scorpion envenomation using gated-SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Alexandre Baldini de; Cupo, Palmira; Pintya, Antonio O.; Caligaris, Fabio; Marin-Neto, Jose A; Hering, Sylvia E.; Simoes, Marcus Vinicius, E-mail: simoesmv@yahoo.co [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas

    2010-04-15

    Background: cardiogenic shock and acute pulmonary edema are the major causes of death of patients with scorpion envenomation, whose pathophysiological mechanism remains controversial. Objective: to investigate the correlation between myocardial perfusion abnormalities and left ventricular contractile function in victims of scorpion envenomation. Methods: fifteen patients underwent ECG-gated myocardial perfusion scintigraphy (gated SPECT) within 72 hours of, and 15 days after scorpion envenomation. Images were analyzed by means of a semi-quantitative visual perfusion score (0 = normal, 4 = absent) and motion score (0 = normal, 4 akinesia), using the 17-segment model. Summed perfusion (SPS) and summed motion (SMS) scores were calculated for each patient. Ejection fraction (LVEF) was calculated by a commercially available software. Results: at baseline, 12 out of the 15 patients presented abnormal myocardial perfusion and contractility. Mean values of SPS, SMS and LVEF were 12.5 +- 7.3, 17.0 +- 12.8, and 44.6 +- 16.0%, respectively. A positive correlation between SPS and SMS (r = 0.68; p = 0.005) and negative correlation between SPS and LVEF (r -0.75; p = 0.0021) were found. The follow-up studies showed recovery of global contractility (LVEF of 68.9 +- 9.5, p = 0.0002), segmental contractility (SMS of 2.6 +- 3.1, p = 0.0009) and perfusion (SPS of 3.7 +- 3.3, p = 0.0003). Improvement of LVEF correlated positively with improvement of SPS (r = 0.72; p = 0.0035). Conclusions: myocardial perfusion abnormalities are common in scorpion envenomation and correlate topographically with the contractile dysfunction. Recovery of contractility correlates with reversibility of perfusion defects. These findings suggest the participation of myocardial perfusion abnormalities in the pathophysiology of this form of acute ventricular failure. (author)

  9. GATED SPECT TO EVALUATE LEFT VENTRICULAR MYOCARDIAL PERFUSION, FUNCTION AND DYSSYNCHRONY FOR RESYNCHRONIZATION THERAPY

    Directory of Open Access Journals (Sweden)

    E.N. Ostroumov

    2009-01-01

    Full Text Available The study included 15 consecutive patients with heart failure and substantial LV dyssynchrony undergoing CRT. Clinical and phase analysis of gated myocardial perfusion SPECT assessed at baseline, after 2–3 days and after 3–4 months of CRT. The results demonstrated inversely relationship between the response to CRT and the nonviable myocardium. Evaluation of myocardial viability is necessary to considered in the selection process for CRT.

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

    OpenAIRE

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

    2009-01-01

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

  11. About myocardial gated-SPECT; Autour de la tomoscintigraphie myocardique synchronisee

    Energy Technology Data Exchange (ETDEWEB)

    Halley, A. [Centre Havrais d' Imagerie Scintigraphique, 76 - Montivilliers (France); Agostini, D. [Centre Hospitalier Universitaire, Service de Medecine Nucleaire 14 - Caen (France)

    2007-12-15

    Over the last decades, myocardial perfusion SPECT has become central in the management of patients with known or suspected coronary artery disease. Ecg-Gating, which allows non only the calculation of left ventricular ejection fraction and ventricular volumes but the analysis of regional wall motion, has become a routine part of clinical protocols. Through several examples, we illustrate the usefulness of this imaging modality and present technical pitfalls. (authors)

  12. 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

  13. Impact of attenuation correction and gated acquisition in SPECT myocardial perfusion imaging: results of the multicentre SPAG (SPECT Attenuation Correction vs Gated) study

    Energy Technology Data Exchange (ETDEWEB)

    Genovesi, Dario; Giorgetti, Assuero; Gimelli, Alessia; Kusch, Annette; D' Aragona Tagliavia, Irene; Casagranda, Mirta; Marzullo, Paolo [Fondazione CNR-Regione Toscana ' ' G. Monasterio' ' , Nuclear Medicine, Pisa (Italy); Cannizzaro, Giorgio [A.O.V. Cervello, Nuclear Medicine, Palermo (Italy); Giubbini, Raffaele; Bertagna, Francesco [Spedali Civili, Nuclear Medicine, Brescia (Italy); Fagioli, Giorgio; Rossi, Massimiliano; Romeo, Annadina [Ospedale Maggiore, Nuclear Medicine, Bologna (Italy); Bertolaccini, Pietro; Bonini, Rita [Ospedale SS Giacomo e Cristoforo, Nuclear Medicine, Massa (Italy)

    2011-10-15

    In clinical myocardial single photon emission computed tomography (SPECT), attenuation artefacts may cause a loss of specificity in the identification of diseased vessels that can be corrected by means of gated SPECT (GSPECT) acquisition or CT attenuation correction (AC). The purpose of this multicentre study was to assess the impact of GSPECT and AC on the diagnostic performance of myocardial scintigraphy, according to patient's sex, body mass index (BMI) and site of coronary artery disease (CAD). We studied a group of 104 patients who underwent coronary angiography within 1 month before or after the SPECT study. Patients with a BMI > 27 were considered ''overweight''. Attenuation-corrected and standard GSPECT early images were randomly interpreted by three readers blinded to the clinical data. In the whole group, GSPECT and AC showed a diagnostic accuracy of 86.5% (sensitivity 82%, specificity 93%) and 77% (sensitivity 75.4%, specificity 81.4%), respectively (p < 0.05). In women, when anterior ischaemia was matched with CAD, AC failed to show any increase in specificity (AC 63.6% vs GSPECT 63.6%) with evident loss of sensitivity (AC 72.7% vs GSPECT 90.9%). AC significantly improved SPECT specificity in the identification of right CAD in overweight men (AC 100% vs GSPECT 66.7%, p <0.05). AC improved specificity in the evaluation of right CAD in overweight men. In the other evaluable subgroups specificity was not significantly affected while sensitivity was frequently reduced. (orig.)

  14. Assessment of left ventricular performance by ECG-gated SPECT. Comparison with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tadamura, Eiji; Inubushi, Masayuki; Kubo, Shigeto; Matsumoto, Keiichi; Yokoyama, Hiroshi; Fujita, Toru; Konishi, Junji [Kyoto Univ. (Japan). Faculty of Medicine

    1999-10-01

    In the measurement of a left ventricular volume, MIBI-QGS was compared with MRI. Because it became clear by the experiment using phantom that a volume calculated with QGS was smaller than the actual volume, data of clinical study were corrected. Subjects were 20 patients with coronary artery disease. Fourteen patients had anamnesis of myocardial infarct. ECG-gated SPECT was performed one hour after intravenous injection of MIBI (600 MBq) in rest. End diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) were calculated using QGS. Cine-MR image was obtained by using MR system of 1.5 Tesla within 1 week after SPECT. A condition was as follows; segmented k-space gradient echo with view sharing, TR=11 ms, TE=1.4 ms, flip angle 20 degree, field of view 32 cm, matrix 256 x 196, 8 lines per segment. LVEF, ESV and EF were analysed by Bland-Altman method, and the difference between MIBI-gated-SPECT and MRI was no problem. Horizontal dislocation image and vertical major axis dislocation image were provided. Minor axis crossing images of 10-12 slice were also filmed in order to cover all left ventricles. As a result, availability of MIBI-QGS became clear. Some factors which produces the measurement error are examined. (K.H.)

  15. Quantitative multi-pinhole small-animal SPECT : uniform versus non-uniform Chang attenuation correction

    NARCIS (Netherlands)

    Wu, C.; de Jong, J. R.; van Andel, H. A. Gratama; van der Have, F.; Vastenhouw, B.; Laverman, P.; Boerman, O. C.; Dierckx, R. A. J. O.; Beekman, F. J.

    2011-01-01

    Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusi

  16. Quantitative multi-pinhole small-animal SPECT: uniform versus non-uniform Chang attenuation correction

    NARCIS (Netherlands)

    Wu, C.; Jong, J.R. de; Gratama van Andel, H.A.; Have, F. van der; Vastenhouw, B.; Laverman, P.; Boerman, O.C.; Dierckx, R.A.; Beekman, F.J.

    2011-01-01

    Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusi

  17. GATE simulation of a LYSO-based SPECT imager: Validation and detector optimization

    Energy Technology Data Exchange (ETDEWEB)

    Li, Suying [Department of Biomedicine and Engineering, College of Engineering, Peking University, No. 5 Yiheyuan Road, Beijing 100871 (China); Zhang, Qiushi [Institute for Drug and Instrument Control of Health Department GLD of PLA, No. 17 Fengtai West Road, Beijing 100071 (China); Xie, Zhaoheng; Liu, Qi [Department of Biomedicine and Engineering, College of Engineering, Peking University, No. 5 Yiheyuan Road, Beijing 100871 (China); Xu, Baixuan [The General Hospital of Chinese People’s Liberation Army, No. 28 Fuxing Road, Beijing 100039 (China); Yang, Kun; Li, Changhui [Department of Biomedicine and Engineering, College of Engineering, Peking University, No. 5 Yiheyuan Road, Beijing 100871 (China); Ren, Qiushi, E-mail: renqsh@coe.pku.edu.cn [Department of Biomedicine and Engineering, College of Engineering, Peking University, No. 5 Yiheyuan Road, Beijing 100871 (China)

    2015-02-11

    This paper presents a small animal SPECT system that is based on cerium doped lutetium–yttrium oxyorthosilicate (LYSO) scintillation crystal, position sensitive photomultiplier tubes (PSPMTs) and parallel hole collimator. Spatial resolution test and animal experiment were performed to demonstrate the imaging performance of the detector. Preliminary results indicated a spatial resolution of 2.5 mm at FWHM that cannot meet our design requirement. Therefore, we simulated this gamma camera using GATE (GEANT 4 Application for Tomographic Emission) aiming to make detector spatial resolution less than 2 mm. First, the GATE simulation process was validated through comparison between simulated and experimental data. This also indicates the accuracy and effectiveness of GATE simulation for LYSO-based gamma camera. Then the different detector sampling methods (crystal size with 1.5, and 1 mm) and collimator design (collimator height with 30, 34.8, 38, and 43 mm) were studied to figure out an optimized parameter set. Detector sensitivity changes were also focused on with different parameters set that generated different spatial resolution results. Tradeoff curves of spatial resolution and sensitivity were plotted to determine the optimal collimator height with different sampling methods. Simulation results show that scintillation crystal size of 1 mm and collimator height of 38 mm, which can generate a spatial resolution of ∼1.8 mm and sensitivity of ∼0.065 cps/kBq, can be an ideal configuration for our SPECT imager design.

  18. 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

    2015-02-21

    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 (99m)Tc 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

  19. 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

  20. Quantitation of myocardial blood flow and myocardial flow reserve with {sup 99m}Tc-sestamibi dynamic SPECT/CT to enhance detection of coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Bailing [University of Missouri-Columbia, Nuclear Science and Engineering Institute, Columbia, MO (United States); Chen, Fu-Chung; Chen, Chien-Cheng [Show Chwan Memorial Hospital, Section of Cardiology, Department of Internal Medicine, Changhua (China); Wu, Tao-Cheng [Taipei Veterans General Hospital, Section of Cardiology, Department of Internal Medicine, Taipei (China); Huang, Wen-Sheng [Changhua Christian Hospital, Department of Medical Research and Department of Nuclear Medicine, Changhua (China); Hou, Po-Nien [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Lukong Town, Changhua Shien (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Lukong Town, Changhua Shien (China); Central Taiwan University of Science and Technology, Department of Medical Imaging and Radiological Science, Taichung (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China)

    2014-12-15

    Conventional dual-head single photon emission computed tomography (SPECT)/CT systems capable of fast dynamic SPECT (DySPECT) imaging have a potential for flow quantitation. This study introduced a new method to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR) with DySPECT scan and evaluated the diagnostic performance of detecting coronary artery disease (CAD) compared with perfusion using invasive coronary angiography (CAG) as the reference standard. This study included 21 patients with suspected or known CAD who had received DySPECT, ECG-gated SPECT (GSPECT), and CAG (13 with ≥50 % stenosis in any vessel; non-CAD group: 8 with patent arteries or <50 % stenosis). DySPECT and GSPECT scans were performed on a widely used dual-head SPECT/CT scanner. The DySPECT imaging protocol utilized 12-min multiple back-and-forth gantry rotations during injections of {sup 99m}Tc-sestamibi (MIBI) tracer at rest or dipyridamole-stress stages. DySPECT images were reconstructed with full physical corrections and converted to the physical unit of becquerels per milliliter. Stress MBF (SMBF), rest MBF (RMBF), and MFR were quantified by a one-tissue compartment flow model using time-activity curves derived from DySPECT images. Perfusion images were processed for GSPECT scan and interpreted to obtain summed stress score (SSS) and summed difference score (SDS). Receiver-operating characteristic (ROC) analyses were conducted to evaluate the diagnostic performance of flow and perfusion. Using the criteria of ≥50 % stenosis as positive CAD, areas under the ROC curve (AUCs) of flow assessment were overall significantly greater than those of perfusion. For patient-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.91 ± 0.07, 0.86 ± 0.09, 0.64 ± 0.12, and 0.59 ± 0.13. For vessel-based analysis, AUCs for MFR, SMBF, SSS, and SDS were 0.81 ± 0.05, 0.76 ± 0.06, 0.62 ± 0.07, and 0.56 ± 0.08, respectively. The preliminary data suggest that MBF quantitation with a

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

    NARCIS (Netherlands)

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

    2010-01-01

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

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  3. Noninvasive Nuclear SPECT Myocardial Blood Flow Quantitation to Guide Management for Coronary Artery Disease.

    Science.gov (United States)

    Chen, Lung-Ching; Jong, Bor-Hsin; Lin, Sheng-Che; Ku, Chi-Tai; Chen, Ing-Jou; Chen, Yen-Kung; Hsu, Bailing

    2017-09-01

    Recently, myocardial blood flow quantitation with dynamic SPECT has been validated to enhance the detection of multivessel coronary artery disease (CAD) and conclude equivocal SPECT myocardial perfusion study. This advance opened an important clinical application to utilize the tool in guiding CAD management for area where myocardial perfusion tracers for PET are unavailable or unaffordable. We present a clinical patient with ongoing recursive angina who underwent multiple nuclear stress tests for a sequence of CAD evaluation in 26 months and demonstrated that SPECT myocardial blood flow quantitation properly guided CAD management to warrant patient outcome.

  4. 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.

  5. Agreement of left ventricular ejection fraction and volumes between adenosine stress TL-201 gated SPECT and echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Pai, M. S. [College of Medicine, Univ. of Ewha, Seoul (Korea, Republic of); Moon, D. H.; Kim, H. M.; Yang, Y. J.; Kang, D. H. [Asan Medical Center, Seoul (Korea, Republic of)

    2003-07-01

    Electrocardiogram-gated TI-201 SPECT measurements of left ventricular ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) have shown high correlation with conventional methods. However, how much these parameters measured by TI-201 gated SPECT differ from those by echocardiography has not been assessed. Adenosine stress (Ad-G) and redistribution TI-201 gated SPECT (Re-G) and resting echocardiography were conducted in 337 patients (184 male, 153 female). EDV, ESV and LVEF measured by QGS software were compared with the results by echocardiography. Patients with arrhythmia (atrial fibrillation or frequent premature contractions) or evidence of fixed or reversible perfusion defects on TI-201 SPECT were excluded. EF, EDV and ESV measured by Ad-G (63.3{+-}9.8,73.8{+-}30.2,29.1{+-}20.1) and Re-G (65.2{+-}11.6,69.1{+-}30.1,26.5{+-}20.3) correlated well with those by Echo (61.4{+-}7.9,78.3{+-}2.7, 30.7{+-} 17.5 ; r of Ad-G=0.547, 0.850, 0.827, p<0.001 ; r of Re-G=0.585, 0.838, 0.819, p<0.001). However the difference (mean, SD, SEE of Echo - gated SPECT) was statistically significant (EF: Ad-G=1.71, 8.92, 0.48, Re-G=3.59, 10.39, 0.56, p<0.001 ; EDV: Ad-G=4.75, 16.21, 0.88, Re-G=9.53, 16.77, 0.91, p<0.001 ; ESV: Ad-G=1.75, 11.35, 0.61, p<0.05, Re-G=4.29, 11.7, 0.63, p<0.001). Bland-Altman plots showed that the difference of EDV and ESV did not vary in any systematic way over the range of measurement, whereas the difference of EF increased with increasing average EF by Echo and gated-SPECT. The difference of EF, EDV, and ESV between Ad-G and Echo was significantly smaller than those between Re-G and Echo (p<0.001). Gated TI-201 SPECT underestimates EDV and ESV over a wide range of volume. As a result, EF by gated TI-201 SPECT is overestimated especially in patients with small LV volume. Ad-G is preferable to Re-G in assessing left ventricular ejection fraction and volume in place of Echo because of smaller bias.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-15

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

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

    DEFF Research Database (Denmark)

    Lomsky, Milan; Richter, Jens; Johansson, Lena

    2005-01-01

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

  8. Left-ventricular dyssynchrony evaluated by Tl-201 gated SPECT myocardial perfusion imaging: a comparison with Tc-99m sestamibi.

    Science.gov (United States)

    Chen, Chien-Cheng; Huang, Wen-Sheng; Hung, Guang-Uei; Chen, Wan-Chen; Kao, Chia-Hung; Chen, Ji

    2013-03-01

    Phase analysis of gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has been validated as a reliable tool to assess left-ventricular (LV) mechanical dyssynchrony. The initial results were all confirmed from studies using technetium-99m (Tc-99m) sestamibi or tetrofosmin as the radiotracers. The purpose of this study was to evaluate the feasibility of phase analysis in thallium-201 (Tl-201) gated SPECT MPI. Seventeen patients referred from a cardiology clinic for evaluation of coronary artery disease were studied. All patients underwent both Tl-201 and Tc-99m sestamibi gated SPECT MPI within 1 week. An additional 34 patients with Tl-201 gated SPECT and 22 patients with Tc-99m sestamibi gated SPECT, who had a low likelihood of coronary artery disease, normal LV function, and normal perfusion on MPI, were used as normal controls. LV dyssynchrony parameters, including phase standard deviation (PSD) and phase histogram bandwidth (PHB), were measured using a standard phase analysis tool and compared between Tl-201 and Tc-99m sestamibi images. The LV dyssynchrony parameters correlated well (r=0.93 for PSD and r=0.84 for PHB) between Tl-201 and Tc-99m sestamibi images. The dyssynchrony parameters of Tl-201 were significantly larger than those of Tc-99m sestamibi (PSD: 24.5±12.0 vs. 17.4±9.7, PTl-201 and Tc-99m sestamibi images showed concordant results. LV dyssynchrony parameters correlated well between Tl-201 and Tc-99m sestamibi images, even though the values were significantly larger for Tl-201 than for Tc-99m sestamibi. Tl-201 images showed results similar to those of Tc-99m sestamibi in the diagnosis of LV dyssynchrony.

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

    OpenAIRE

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

    2010-01-01

    Purpose: In pinhole SPECT, attenuation of the photon flux on trajectories between source and pinholes affects quantitative accuracy of reconstructed images. Previously we introduced iterative methods that compensate for image degrading effects of detector and pinhole blurring, pinhole sensitivity and scatter for multi-pinhole SPECT. The aim of this paper is (1) to investigate the accuracy of the Chang algorithm in rodents and (2) to present a practical Changbased method using body outline con...

  10. Combining SPECT and Quantitative EEG Analysis for the Automated Differential Diagnosis of Disorders with Amnestic Symptoms

    Directory of Open Access Journals (Sweden)

    Yvonne Höller

    2017-09-01

    Full Text Available Single photon emission computed tomography (SPECT and Electroencephalography (EEG have become established tools in routine diagnostics of dementia. We aimed to increase the diagnostic power by combining quantitative markers from SPECT and EEG for differential diagnosis of disorders with amnestic symptoms. We hypothesize that the combination of SPECT with measures of interaction (connectivity in the EEG yields higher diagnostic accuracy than the single modalities. We examined 39 patients with Alzheimer's dementia (AD, 69 patients with depressive cognitive impairment (DCI, 71 patients with amnestic mild cognitive impairment (aMCI, and 41 patients with amnestic subjective cognitive complaints (aSCC. We calculated 14 measures of interaction from a standard clinical EEG-recording and derived graph-theoretic network measures. From regional brain perfusion measured by 99mTc-hexamethyl-propylene-aminoxime (HMPAO-SPECT in 46 regions, we calculated relative cerebral perfusion in these patients. Patient groups were classified pairwise with a linear support vector machine. Classification was conducted separately for each biomarker, and then again for each EEG- biomarker combined with SPECT. Combination of SPECT with EEG-biomarkers outperformed single use of SPECT or EEG when classifying aSCC vs. AD (90%, aMCI vs. AD (70%, and AD vs. DCI (100%, while a selection of EEG measures performed best when classifying aSCC vs. aMCI (82% and aMCI vs. DCI (90%. Only the contrast between aSCC and DCI did not result in above-chance classification accuracy (60%. In general, accuracies were higher when measures of interaction (i.e., connectivity measures were applied directly than when graph-theoretical measures were derived. We suggest that quantitative analysis of EEG and machine-learning techniques can support differentiating AD, aMCI, aSCC, and DCC, especially when being combined with imaging methods such as SPECT. Quantitative analysis of EEG connectivity could become

  11. Combining SPECT and Quantitative EEG Analysis for the Automated Differential Diagnosis of Disorders with Amnestic Symptoms

    Science.gov (United States)

    Höller, Yvonne; Bathke, Arne C.; Uhl, Andreas; Strobl, Nicolas; Lang, Adelheid; Bergmann, Jürgen; Nardone, Raffaele; Rossini, Fabio; Zauner, Harald; Kirschner, Margarita; Jahanbekam, Amirhossein; Trinka, Eugen; Staffen, Wolfgang

    2017-01-01

    Single photon emission computed tomography (SPECT) and Electroencephalography (EEG) have become established tools in routine diagnostics of dementia. We aimed to increase the diagnostic power by combining quantitative markers from SPECT and EEG for differential diagnosis of disorders with amnestic symptoms. We hypothesize that the combination of SPECT with measures of interaction (connectivity) in the EEG yields higher diagnostic accuracy than the single modalities. We examined 39 patients with Alzheimer's dementia (AD), 69 patients with depressive cognitive impairment (DCI), 71 patients with amnestic mild cognitive impairment (aMCI), and 41 patients with amnestic subjective cognitive complaints (aSCC). We calculated 14 measures of interaction from a standard clinical EEG-recording and derived graph-theoretic network measures. From regional brain perfusion measured by 99mTc-hexamethyl-propylene-aminoxime (HMPAO)-SPECT in 46 regions, we calculated relative cerebral perfusion in these patients. Patient groups were classified pairwise with a linear support vector machine. Classification was conducted separately for each biomarker, and then again for each EEG- biomarker combined with SPECT. Combination of SPECT with EEG-biomarkers outperformed single use of SPECT or EEG when classifying aSCC vs. AD (90%), aMCI vs. AD (70%), and AD vs. DCI (100%), while a selection of EEG measures performed best when classifying aSCC vs. aMCI (82%) and aMCI vs. DCI (90%). Only the contrast between aSCC and DCI did not result in above-chance classification accuracy (60%). In general, accuracies were higher when measures of interaction (i.e., connectivity measures) were applied directly than when graph-theoretical measures were derived. We suggest that quantitative analysis of EEG and machine-learning techniques can support differentiating AD, aMCI, aSCC, and DCC, especially when being combined with imaging methods such as SPECT. Quantitative analysis of EEG connectivity could become an

  12. Quantitative assessment of regional myocardial blood flow with thallium-201 and SPECT.

    Science.gov (United States)

    Iida, H; Eberl, S

    1998-01-01

    Thallium-201 has been used extensively as a myocardial perfusion agent and to assess myocardial viability. Unlike other 99mTc-labeled agents such as 99mTc-sestamibi and 99mTc-tetrofosmine, the regional concentration of 201Tl varies with time, and its kinetics make it a potential candidate for estimating absolute physiologic parameters with kinetic model analysis. This article outlines a strategy for quantitative assessment of regional myocardial blood flow in man using 201Tl and dynamic single photon emission computed tomography (SPECT). Quantitatively accurate SPECT images that are proportional to the true radioactivity distribution are prerequisites for model-based kinetic analysis. Our technique for quantitative SPECT includes ordered-subset maximum likelihood-expectation maximization (ML-EM) reconstruction with transmission data-based attenuation correction and transmission-dependent convolution subtraction scatter correction. A three-compartment model was found to reproduce the observed regional time-activity curves well, and dog experiments demonstrated that influx rate constant (K1) values estimated from the dynamic SPECT data correlated well with absolute myocardial blood flow determined by in vitro microspheres for a physiologically wide range of flows. Several possible strategies for simplifying the study procedures, without compromising accuracy, are also presented, which should make absolute quantitation of regional myocardial blood flow feasible using 201Tl and a conventional SPECT camera in a clinical setting.

  13. [Automatic calculation of left ventricular volume and ejection fraction from gated myocardial perfusion SPECT--basic evaluation using phantom].

    Science.gov (United States)

    Kinoshita, Y; Nanbu, I; Tohyama, J; Ooba, S

    1998-02-01

    We evaluated accuracy of Quantitative Gated SPECT Program that enabled calculation of the left ventricular (LV) volume and ejection fraction by automatically tracing the contour of the cardiac surface. Cardiac phantoms filled with 99mTc-solution were used. Data acquisition was made by 180-degree projection in L type and 360-degree projection in opposed type. Automatic calculation could be done in all processes, which required 3-4 minutes. Reproducibility was sufficient. The adequate cut off value of a prefilter was 0.45. At this value LV volume was 93% of the actual volume in L type acquisition and 95.9% in opposed type acquisition. The LV volume obtained in L type was smaller than that obtained in opposed type (p defects was fair, on the cardiac phantoms with all of 90-degree defects and 180-degree defects of the septal and lateral wall. The LV volume was estimated to be larger on the phantom with 180-degree defect of the anterior wall, and to be smaller on the phantom of 180-degree defect of the inferoposterior wall. Because tracing was deviated anteriorly at the defects. In the patients with similar conditions to 180-degree defect of the anterior wall or inferoposterior wall, the LV volume should be carefully evaluated.

  14. Automatic calculation of left ventricular volume and ejection fraction from gated myocardial perfusion SPECT. Basic evaluation using phantom

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Yoshimi; Nanbu, Ichirou [Nagoya Daini Red Cross Hospital (Japan); Tohyama, Junko; Ooba, Satoru

    1998-02-01

    We evaluated accuracy of Quantitative Gated SPECT Program that enabled calculation of the left ventricular (LV) volume and ejection fraction by automatically tracing the contour of the cardiac surface. Cardiac phantoms filled with {sup 99m}Tc-solution were used. Data acquisition was made by 180-degree projection in L type and 360-degree projection in opposed type. Automatic calculation could be done in all processes, which required 3-4 minutes. Reproducibility was sufficient. The adequate cut off value of a prefilter was 0.45. At this value LV volume was 93% of the actual volume in L type acquisition and 95.9% in opposed type acquisition. The LV volume obtained in L type was smaller than that obtained in opposed type (p<0.05). The tracing of the defects was fair, on the cardiac phantoms with all of 90-degree defects and 180-degree defects of the septal and lateral wall. The LV volume was estimated to be larger on the phantom with 180-degree defect of the anterior wall, and to be smaller on the phantom of 180-degree defect of the inferoposterior wall. Because tracing was deviated anteriorly at the defects. In the patients with similar conditions to 180-degree defect of the anterior wall or inferoposterior wall, the LV volume should be carefully evaluated. (author)

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

    Science.gov (United States)

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

    2017-08-03

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

  16. Relationship between myocardial perfusion-gated SPECT and the performance of coronary revascularization in patients with ischemic cardiomyopathy.

    Science.gov (United States)

    Romero-Farina, Guillermo; Candell-Riera, Jaume; Aguadé-Bruix, Santiago; Ferreira-Gonzalez, Ignacio; Igual, Albert; García-Dorado, David

    2012-10-01

    Ischemic cardiomyopathy (ICM) is a disease with high morbidity and mortality. There are several published studies on the evolution and prognosis of patients with ICM. However, reports on the therapeutic management in clinical practice are scarce. The aim of this study was to analyze coronary revascularization (CR) performance in patients with ICM and suitable coronary anatomy according to myocardial perfusion stress-rest gated SPECT results. Eighty-seven consecutive patients (mean age, 62.4 y; 20 women), with ischemic heart disease, left ventricular ejection fraction of 40% or less, coronary anatomy suitable for CR, and without previous CR, were evaluated by means of stress-rest gated SPECT. Sixty-four percent of patients had scintigraphic criteria of viability and 62.1% showed scintigraphic ischemia in stress-rest gated SPECT. Forty-five percent of patients were revascularized, and the remainder received medical treatment only. Coronary revascularization was more frequent in patients with scintigraphic viability (P = 0.012), in those with scintigraphic ischemia (P = 0.007), and in those with low left ventricular end-systolic volume (P = 0.006). Cox regression analysis identified multivessel disease [hazard ratio (HR), 3.3; 95% confidence interval (CI), 4-7.8], summed difference score greater than 4 (HR, 3.9; 95% CI, 1.5-9.8), and left ventricular end-systolic volume less than 120 mL (HR, 3.2; 95% CI, 1.3-8.2) as the best independent predictors of CR treatment. In patients with ICM and suitable coronary arteries who are able to perform a stress myocardial perfusion-gated SPECT, the presence of multivessel disease and myocardial ischemia and the absence of severely increased left ventricular volume were associated to a decision of CR.

  17. Optimal energy window selection of a CZT-based small-animal SPECT for quantitative accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Su-Jin [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju 220-710 (Korea, Republic of); Yu, A. Ram [Laboratory animal center, OSONG Medical Innovation Foundation, Chunguk 363-951 (Korea, Republic of); Department of Nuclear Medicine, College of Medicine, Hanyang University Hospital, Seoul 133-792 (Korea, Republic of); Choi, Yun Young [Department of Nuclear Medicine, College of Medicine, Hanyang University Hospital, Seoul 133-792 (Korea, Republic of); Kim, Kyeong Min [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Kim, Hee-Joung, E-mail: hjk1@yonsei.ac.kr [Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju 220-710 (Korea, Republic of)

    2015-05-11

    Cadmium zinc telluride (CZT)-based small-animal single-photon emission computed tomography (SPECT) has desirable characteristics such as superior energy resolution, but data acquisition for SPECT imaging has been widely performed with a conventional energy window. The aim of this study was to determine the optimal energy window settings for technetium-99 m ({sup 99m}Tc) and thallium-201 ({sup 201}Tl), the most commonly used isotopes in SPECT imaging, using CZT-based small-animal SPECT for quantitative accuracy. We experimentally investigated quantitative measurements with respect to primary count rate, contrast-to-noise ratio (CNR), and scatter fraction (SF) within various energy window settings using Triumph X-SPECT. The two ways of energy window settings were considered: an on-peak window and an off-peak window. In the on-peak window setting, energy centers were set on the photopeaks. In the off-peak window setting, the ratios of energy differences between the photopeak from the lower- and higher-threshold varied from 4:6 to 3:7. In addition, the energy-window width for {sup 99m}Tc varied from 5% to 20%, and that for {sup 201}Tl varied from 10% to 30%. The results of this study enabled us to determine the optimal energy windows for each isotope in terms of primary count rate, CNR, and SF. We selected the optimal energy window that increases the primary count rate and CNR while decreasing SF. For {sup 99m}Tc SPECT imaging, the energy window of 138–145 keV with a 5% width and off-peak ratio of 3:7 was determined to be the optimal energy window. For {sup 201}Tl SPECT imaging, the energy window of 64–85 keV with a 30% width and off-peak ratio of 3:7 was selected as the optimal energy window. Our results demonstrated that the proper energy window should be carefully chosen based on quantitative measurements in order to take advantage of desirable characteristics of CZT-based small-animal SPECT. These results provided valuable reference information for the

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

    Science.gov (United States)

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

    2015-03-01

    Quantitative single-photon emission computed tomography (SPECT) imaging is emerging as an important tool in clinical studies and biomedical research. There is thus a need for optimization and evaluation of systems and algorithms that are being developed for quantitative SPECT imaging. An appropriate objective method to evaluate these systems is by comparing their performance in the end task that is required in quantitative SPECT imaging, such as estimating the mean activity concentration in a volume of interest (VOI) in a patient image. This objective evaluation can be performed if the true value of the estimated parameter is known, i.e. we have a gold standard. However, very rarely is this gold standard known in human studies. Thus, no-gold-standard techniques to optimize and evaluate systems and algorithms in the absence of gold standard are required. In this work, we developed a no-gold-standard technique to objectively evaluate reconstruction methods used in quantitative SPECT when the parameter to be estimated is the mean activity concentration in a VOI. We studied the performance of the technique with realistic simulated image data generated from an object database consisting of five phantom anatomies with all possible combinations of five sets of organ uptakes, where each anatomy consisted of eight different organ VOIs. Results indicate that the method pro- vided accurate ranking of the reconstruction methods. We also demonstrated the application of consistency checks to test the no-gold-standard output.

  19. The consequences of a new software package for the quantification of gated-SPECT myocardial perfusion studies

    Energy Technology Data Exchange (ETDEWEB)

    Veen, Berlinda J. van der; Dibbets-Schneider, Petra; Stokkel, Marcel P.M. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Scholte, Arthur J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands)

    2010-09-15

    Semiquantitative analysis of myocardial perfusion scintigraphy (MPS) has reduced inter- and intraobserver variability, and enables researchers to compare parameters in the same patient over time, or between groups of patients. There are several software packages available that are designed to process MPS data and quantify parameters. In this study the performances of two systems, quantitative gated SPECT (QGS) and 4D-MSPECT, in the processing of clinical patient data and phantom data were compared. The clinical MPS data of 148 consecutive patients were analysed using QGS and 4D-MSPECT to determine the end-diastolic volume, end-systolic volume and left ventricular ejection fraction. Patients were divided into groups based on gender, body mass index, heart size, stressor type and defect type. The AGATE dynamic heart phantom was used to provide reference values for the left ventricular ejection fraction. Although the correlations were excellent (correlation coefficients 0.886 to 0.980) for all parameters, significant differences (p < 0.001) were found between the systems. Bland-Altman plots indicated that 4D-MSPECT provided overall higher values of all parameters than QGS. These differences between the systems were not significant in patients with a small heart (end-diastolic volume <70 ml). Other clinical factors had no direct influence on the relationship. Additionally, the phantom data indicated good linear responses of both systems. The discrepancies between these software packages were clinically relevant, and influenced by heart size. The possibility of such discrepancies should be taken into account when a new quantitative software system is introduced, or when multiple software systems are used in the same institution. (orig.)

  20. Global scaling for semi-quantitative analysis in FP-CIT SPECT.

    Science.gov (United States)

    Kupitz, D; Apostolova, I; Lange, C; Ulrich, G; Amthauer, H; Brenner, W; Buchert, R

    2014-01-01

    Semi-quantitative characterization of dopamine transporter availability from single photon emission computed tomography (SPECT) with 123I-ioflupane (FP-CIT) is based on uptake ratios relative to a reference region. The aim of this study was to evaluate the whole brain as reference region for semi-quantitative analysis of FP-CIT SPECT. The rationale was that this might reduce statistical noise associated with the estimation of non-displaceable FP-CIT uptake. 150 FP-CIT SPECTs were categorized as neurodegenerative or non-neurodegenerative by an expert. Semi-quantitative analysis of specific binding ratios (SBR) was performed with a custom-made tool based on the Statistical Parametric Mapping software package using predefined regions of interest (ROIs) in the anatomical space of the Montreal Neurological Institute. The following reference regions were compared: predefined ROIs for frontal and occipital lobe and whole brain (without striata, thalamus and brainstem). Tracer uptake in the reference region was characterized by the mean, median or 75th percentile of its voxel intensities. The area (AUC) under the receiver operating characteristic curve was used as performance measure. The highest AUC of 0.973 was achieved by the SBR of the putamen with the 75th percentile in the whole brain as reference. The lowest AUC for the putamen SBR of 0.937 was obtained with the mean in the frontal lobe as reference. We recommend the 75th percentile in the whole brain as reference for semi-quantitative analysis in FP-CIT SPECT. This combination provided the best agreement of the semi-quantitative analysis with visual evaluation of the SPECT images by an expert and, therefore, is appropriate to support less experienced physicians.

  1. Quantitative comparison of PET and Bremsstrahlung SPECT for imaging the in vivo yttrium-90 microsphere distribution after liver radioembolization.

    Directory of Open Access Journals (Sweden)

    Mattijs Elschot

    Full Text Available BACKGROUND: After yttrium-90 ((90Y microsphere radioembolization (RE, evaluation of extrahepatic activity and liver dosimetry is typically performed on (90Y Bremsstrahlung SPECT images. Since these images demonstrate a low quantitative accuracy, (90Y PET has been suggested as an alternative. The aim of this study is to quantitatively compare SPECT and state-of-the-art PET on the ability to detect small accumulations of (90Y and on the accuracy of liver dosimetry. METHODOLOGY/PRINCIPAL FINDINGS: SPECT/CT and PET/CT phantom data were acquired using several acquisition and reconstruction protocols, including resolution recovery and Time-Of-Flight (TOF PET. Image contrast and noise were compared using a torso-shaped phantom containing six hot spheres of various sizes. The ability to detect extra- and intrahepatic accumulations of activity was tested by quantitative evaluation of the visibility and unique detectability of the phantom hot spheres. Image-based dose estimates of the phantom were compared to the true dose. For clinical illustration, the SPECT and PET-based estimated liver dose distributions of five RE patients were compared. At equal noise level, PET showed higher contrast recovery coefficients than SPECT. The highest contrast recovery coefficients were obtained with TOF PET reconstruction including resolution recovery. All six spheres were consistently visible on SPECT and PET images, but PET was able to uniquely detect smaller spheres than SPECT. TOF PET-based estimates of the dose in the phantom spheres were more accurate than SPECT-based dose estimates, with underestimations ranging from 45% (10-mm sphere to 11% (37-mm sphere for PET, and 75% to 58% for SPECT, respectively. The differences between TOF PET and SPECT dose-estimates were supported by the patient data. CONCLUSIONS/SIGNIFICANCE: In this study we quantitatively demonstrated that the image quality of state-of-the-art PET is superior over Bremsstrahlung SPECT for the

  2. Comparison of contrast enhanced three dimensional echocardiography with MIBI gated SPECT for the evaluation of left ventricular function

    Directory of Open Access Journals (Sweden)

    Cosyns Bernard

    2009-06-01

    Full Text Available Abstract Background In clinical practice and in clinical trials, echocardiography and scintigraphy are used the most for the evaluation of global left ejection fraction (LVEF and left ventricular (LV volumes. Actually, poor quality imaging and geometrical assumptions are the main limitations of LVEF measured by echocardiography. Contrast agents and 3D echocardiography are new methods that may alleviate these potential limitations. Methods Therefore we sought to examine the accuracy of contrast 3D echocardiography for the evaluation of LV volumes and LVEF relative to MIBI gated SPECT as an independent reference. In 43 patients addressed for chest pain, contrast 3D echocardiography (RT3DE and MIBI gated SPECT were prospectively performed on the same day. The accuracy and the variability of LV volumes and LVEF measurements were evaluated. Results Due to good endocardial delineation, LV volumes and LVEF measurements by contrast RT3DE were feasible in 99% of the patients. The mean LV end-diastolic volume (LVEDV of the group by scintigraphy was 143 ± 65 mL and was underestimated by triplane contrast RT3DE (128 ± 60 mL; p Conclusion Contrast RT3DE allows an accurate assessment of LVEF compared to the LVEF measured by SPECT, and shows low variability between observers. Although RT3DE triplane provides accurate evaluation of left ventricular function, RT3DE full-volume is superior to triplane modality in patients with suspected coronary artery disease.

  3. Visual and semi-quantitative assessment of brain tumors using (201)Tl-SPECT.

    Science.gov (United States)

    Nose, Ayumi; Otsuka, Hideki; Nose, Hayato; Otomi, Yoichi; Terazawa, Kaori; Harada, Masafumi

    2013-01-01

    To evaluate the usefulness of (201)Tl-SPECT in differentiating benign from malignant brain tumors. Eighty-eight patients (44 males and 44 females) with 58 high-grade (WHO grade III-IV) and 30 low-grade (WHO grade I-II) tumors were evaluated with (201)Tl-SPECT. (1) Visual assessment was performed by board-certificated radiologists using (201)Tl-SPECT. Tumors were classified in two groups (Tl-positive and Tl-negative) and scored using the five grade evaluation system. Receiver operating characteristic (ROC) analysis was performed in the Tl-positive group. (2) Semi-quantitative assessment involved measurement of early and delayed (201)Tl uptake, and the retention index (RI) was applied as follows: RI=delayed uptake ratio/early uptake ratio. Three combinations of RI using mean and maximum values of the region of interest were calculated. (1) Seventy-four Tl-positive and 14 Tl-negative tumors. The area under the ROC curve (AUC) estimated by three radiologists exceeded a value of 0.7. The value was greater when estimated by the more experienced radiologist. (2) In all RIs, the difference of RI between high-grade tumors and low-grade tumors was statistically significant. A visual and semi-quantitative assessment using (201)Tl-SPECT was found to be useful for differentiating benign from malignant brain tumors.

  4. Assessment of the sources of error affecting the quantitative accuracy of SPECT imaging in small animals

    Science.gov (United States)

    Hwang, Andrew B.; Franc, Benjamin L.; Gullberg, Grant T.; Hasegawa, Bruce H.

    2008-05-01

    Small animal SPECT imaging systems have multiple potential applications in biomedical research. Whereas SPECT data are commonly interpreted qualitatively in a clinical setting, the ability to accurately quantify measurements will increase the utility of the SPECT data for laboratory measurements involving small animals. In this work, we assess the effect of photon attenuation, scatter and partial volume errors on the quantitative accuracy of small animal SPECT measurements, first with Monte Carlo simulation and then confirmed with experimental measurements. The simulations modeled the imaging geometry of a commercially available small animal SPECT system. We simulated the imaging of a radioactive source within a cylinder of water, and reconstructed the projection data using iterative reconstruction algorithms. The size of the source and the size of the surrounding cylinder were varied to evaluate the effects of photon attenuation and scatter on quantitative accuracy. We found that photon attenuation can reduce the measured concentration of radioactivity in a volume of interest in the center of a rat-sized cylinder of water by up to 50% when imaging with iodine-125, and up to 25% when imaging with technetium-99m. When imaging with iodine-125, the scatter-to-primary ratio can reach up to approximately 30%, and can cause overestimation of the radioactivity concentration when reconstructing data with attenuation correction. We varied the size of the source to evaluate partial volume errors, which we found to be a strong function of the size of the volume of interest and the spatial resolution. These errors can result in large (>50%) changes in the measured amount of radioactivity. The simulation results were compared with and found to agree with experimental measurements. The inclusion of attenuation correction in the reconstruction algorithm improved quantitative accuracy. We also found that an improvement of the spatial resolution through the use of resolution

  5. Assessment of the sources of error affecting the quantitative accuracy of SPECT imaging in small animals

    Energy Technology Data Exchange (ETDEWEB)

    Joint Graduate Group in Bioengineering, University of California, San Francisco and University of California, Berkeley; Department of Radiology, University of California; Gullberg, Grant T; Hwang, Andrew B.; Franc, Benjamin L.; Gullberg, Grant T.; Hasegawa, Bruce H.

    2008-02-15

    Small animal SPECT imaging systems have multiple potential applications in biomedical research. Whereas SPECT data are commonly interpreted qualitatively in a clinical setting, the ability to accurately quantify measurements will increase the utility of the SPECT data for laboratory measurements involving small animals. In this work, we assess the effect of photon attenuation, scatter and partial volume errors on the quantitative accuracy of small animal SPECT measurements, first with Monte Carlo simulation and then confirmed with experimental measurements. The simulations modeled the imaging geometry of a commercially available small animal SPECT system. We simulated the imaging of a radioactive source within a cylinder of water, and reconstructed the projection data using iterative reconstruction algorithms. The size of the source and the size of the surrounding cylinder were varied to evaluate the effects of photon attenuation and scatter on quantitative accuracy. We found that photon attenuation can reduce the measured concentration of radioactivity in a volume of interest in the center of a rat-sized cylinder of water by up to 50percent when imaging with iodine-125, and up to 25percent when imaging with technetium-99m. When imaging with iodine-125, the scatter-to-primary ratio can reach up to approximately 30percent, and can cause overestimation of the radioactivity concentration when reconstructing data with attenuation correction. We varied the size of the source to evaluate partial volume errors, which we found to be a strong function of the size of the volume of interest and the spatial resolution. These errors can result in large (>50percent) changes in the measured amount of radioactivity. The simulation results were compared with and found to agree with experimental measurements. The inclusion of attenuation correction in the reconstruction algorithm improved quantitative accuracy. We also found that an improvement of the spatial resolution through the

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

    Science.gov (United States)

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

    2017-01-01

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

  7. Optimal left ventricular lead position assessed with phase analysis on gated myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Boogers, Mark J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); The Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands); Chen, Ji; Garcia, Ernest V. [Emory University School of Medicine, Department of Radiology, Atlanta, GA (United States); Bommel, Rutger J. van; Borleffs, C.J.W.; Schalij, Martin J.; Wall, Ernst E. van der; Bax, Jeroen J. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Dibbets-Schneider, Petra; Hiel, Bernies van der; Younis, Imad Al [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands)

    2011-02-15

    The aim of the current study was to evaluate the relationship between the site of latest mechanical activation as assessed with gated myocardial perfusion SPECT (GMPS), left ventricular (LV) lead position and response to cardiac resynchronization therapy (CRT). The patient population consisted of consecutive patients with advanced heart failure in whom CRT was currently indicated. Before implantation, 2-D echocardiography and GMPS were performed. The echocardiography was performed to assess LV end-systolic volume (LVESV), LV end-diastolic volume (LVEDV) and LV ejection fraction (LVEF). The site of latest mechanical activation was assessed by phase analysis of GMPS studies and related to LV lead position on fluoroscopy. Echocardiography was repeated after 6 months of CRT. CRT response was defined as a decrease of {>=}15% in LVESV. Enrolled in the study were 90 patients (72% men, 67{+-}10 years) with advanced heart failure. In 52 patients (58%), the LV lead was positioned at the site of latest mechanical activation (concordant), and in 38 patients (42%) the LV lead was positioned outside the site of latest mechanical activation (discordant). CRT response was significantly more often documented in patients with a concordant LV lead position than in patients with a discordant LV lead position (79% vs. 26%, p<0.01). After 6 months, patients with a concordant LV lead position showed significant improvement in LVEF, LVESV and LVEDV (p<0.05), whereas patients with a discordant LV lead position showed no significant improvement in these variables. Patients with a concordant LV lead position showed significant improvement in LV volumes and LV systolic function, whereas patients with a discordant LV lead position showed no significant improvements. (orig.)

  8. Clinical Significance of Quantitative 123I-MIBG SPECT/CT Analysis of Pheochromocytoma and Paraganglioma.

    Science.gov (United States)

    Nakamoto, Ryusuke; Nakamoto, Yuji; Ishimori, Takayoshi; Togashi, Kaori

    2016-11-01

    This retrospective study compared the diagnostic performances of quantitative versus visual analyses of I-MIBG scintigraphy in patients with suspected pheochromocytoma and paraganglioma (PPGL). SPECT images were obtained 6 and/or 24 h after MIBG injection from 68 patients with clinically suspected PPGL, with attenuation correction by low-dose unenhanced CT. Planar images were also obtained at each time point. SUVs of retroperitoneal tumors, including PPGLs, and physiological uptake by normal organs were measured using the SPECT images. The diagnostic performance of the quantitative assessment in differentiating PPGLs from other lesions or normal adrenal glands was assessed using receiver operating characteristic analysis. The planar scans and 6-h and 24-h SPECT/CT images were also assessed visually. PPGLs showed a significantly higher SUVmax (mean ± SD = 9.97 ± 3.86) than other retroperitoneal lesions (3.85 ± 1.51) or normal adrenal glands (3.91 ± 1.20). At an optimal cut-off of 6.57, the sensitivity, specificity, and accuracy of the quantitative assessment for 6-h SPECT/CT in differentiating PPGLs was 78.6%, 96.3%, and 92.6%, respectively; the area under the curve was 0.878. The diagnostic performance did not significantly differ between the quantitative and visual analyses, but the specificity of the former tended to be higher at 6 h (96.3% vs. 90.7%) and at 24 h (91.2% vs. 82.4%). The specificity, but not the sensitivity, of the quantitative approach was higher than that of visual assessment in differentiating PPGLs from other retroperitoneal pathologies and from physiological uptake in the normal adrenal gland.

  9. Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT.

    Science.gov (United States)

    Lee, Taek-Soo; Frey, Eric C; Tsui, Benjamin M W

    2015-04-07

    This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of (99m)Tc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman's rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

  10. Development of 4D mathematical observer models for the task-based evaluation of gated myocardial perfusion SPECT

    Science.gov (United States)

    Lee, Taek-Soo; Frey, Eric C.; Tsui, Benjamin M. W.

    2015-04-01

    This paper presents two 4D mathematical observer models for the detection of motion defects in 4D gated medical images. Their performance was compared with results from human observers in detecting a regional motion abnormality in simulated 4D gated myocardial perfusion (MP) SPECT images. The first 4D mathematical observer model extends the conventional channelized Hotelling observer (CHO) based on a set of 2D spatial channels and the second is a proposed model that uses a set of 4D space-time channels. Simulated projection data were generated using the 4D NURBS-based cardiac-torso (NCAT) phantom with 16 gates/cardiac cycle. The activity distribution modelled uptake of 99mTc MIBI with normal perfusion and a regional wall motion defect. An analytical projector was used in the simulation and the filtered backprojection (FBP) algorithm was used in image reconstruction followed by spatial and temporal low-pass filtering with various cut-off frequencies. Then, we extracted 2D image slices from each time frame and reorganized them into a set of cine images. For the first model, we applied 2D spatial channels to the cine images and generated a set of feature vectors that were stacked for the images from different slices of the heart. The process was repeated for each of the 1,024 noise realizations, and CHO and receiver operating characteristics (ROC) analysis methodologies were applied to the ensemble of the feature vectors to compute areas under the ROC curves (AUCs). For the second model, a set of 4D space-time channels was developed and applied to the sets of cine images to produce space-time feature vectors to which the CHO methodology was applied. The AUC values of the second model showed better agreement (Spearman’s rank correlation (SRC) coefficient = 0.8) to human observer results than those from the first model (SRC coefficient = 0.4). The agreement with human observers indicates the proposed 4D mathematical observer model provides a good predictor of the

  11. Three modality image registration of brain SPECT/CT and MR images for quantitative analysis of dopamine transporter imaging

    Science.gov (United States)

    Yamaguchi, Yuzuho; Takeda, Yuta; Hara, Takeshi; Zhou, Xiangrong; Matsusako, Masaki; Tanaka, Yuki; Hosoya, Kazuhiko; Nihei, Tsutomu; Katafuchi, Tetsuro; Fujita, Hiroshi

    2016-03-01

    Important features in Parkinson's disease (PD) are degenerations and losses of dopamine neurons in corpus striatum. 123I-FP-CIT can visualize activities of the dopamine neurons. The activity radio of background to corpus striatum is used for diagnosis of PD and Dementia with Lewy Bodies (DLB). The specific activity can be observed in the corpus striatum on SPECT images, but the location and the shape of the corpus striatum on SPECT images only are often lost because of the low uptake. In contrast, MR images can visualize the locations of the corpus striatum. The purpose of this study was to realize a quantitative image analysis for the SPECT images by using image registration technique with brain MR images that can determine the region of corpus striatum. In this study, the image fusion technique was used to fuse SPECT and MR images by intervening CT image taken by SPECT/CT. The mutual information (MI) for image registration between CT and MR images was used for the registration. Six SPECT/CT and four MR scans of phantom materials are taken by changing the direction. As the results of the image registrations, 16 of 24 combinations were registered within 1.3mm. By applying the approach to 32 clinical SPECT/CT and MR cases, all of the cases were registered within 0.86mm. In conclusions, our registration method has a potential in superimposing MR images on SPECT images.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  13. Patient-specific dosimetry based on quantitative SPECT imaging and 3D-DFT convolution

    Energy Technology Data Exchange (ETDEWEB)

    Akabani, G.; Hawkins, W.G.; Eckblade, M.B.; Leichner, P.K. [Univ. of Nebraska Medical Center, Omaha, NE (United States)

    1999-01-01

    The objective of this study was to validate the use of a 3-D discrete Fourier Transform (3D-DFT) convolution method to carry out the dosimetry for I-131 for soft tissues in radioimmunotherapy procedures. To validate this convolution method, mathematical and physical phantoms were used as a basis of comparison with Monte Carlo transport (MCT) calculations which were carried out using the EGS4 system code. The mathematical phantom consisted of a sphere containing uniform and nonuniform activity distributions. The physical phantom consisted of a cylinder containing uniform and nonuniform activity distributions. Quantitative SPECT reconstruction was carried out using the Circular Harmonic Transform (CHT) algorithm.

  14. Beneficial effect of coronary artery bypass grafting as assessed by quantitative gated single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hida, Satoshi; Chikamori, Taishiro; Hirayama, Tetsuzo; Usui, Yasuhiro; Yanagisawa, Hidefumi; Morishima, Takayuki; Ishimaru, Shin; Yamashina, Akira [Tokyo Medical Coll. (Japan)

    2003-06-01

    The development of quantitative gated single-photon emission computed tomography (SPECT) has enabled the assessment of left ventricular perfusion, function and wall thickness in a single examination. Accordingly, the present study used gated SPECT to assess the benefit of coronary artery bypass grafting (CABG) in patients with coronary artery disease; 47 of those patients were evaluated before and 5 months after CABG. As a result of coronary revascularization, a significant improvement was observed in global ejection fraction (50{+-}12{yields}53{+-}11%; p<0.05). In 107 revascularized territories, the average regional reversible defect score (0.8{+-}0.5{yields}0.2{+-}0.3; p<0.0001), average regional perfusion score at rest (0.6{+-}0.6{yields}0.3{+-}0.4; p<0.0001), average regional wall motion score (0.9{+-}0.7{yields}0.7{+-}0.5; p<0.05), and end-diastolic wall thickness (8.1{+-}1.3{yields}8.6{+-}1.5 mm; p<0.0005) all improved significantly. Even in 34 non-revascularized territories, the average regional reversible defect score (0.5{+-}0.7{yields}0.2{+-}0.5; p<0.03), average regional wall motion score (0.8{+-}1.1{yields}0.5{+-}1.0; p<0.03) and end-diastolic wall thickness (8.0{+-}1.4{yields}9.1{+-}2.0 mm; p<0.03) all improved significantly. These results indicate that improvement in myocardial ischemia, hibernation and left ventricular function with CABG can be assessed in detail with gated SPECT. (author)

  15. Quantitative evaluation of right ventricular overload in cor pulmonale using sup 201 Tl myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Hiroshi; Misawa, Toshihiro; Kutsumi, Yasunori (Fukui Medical School, Matsuoka (Japan)) (and others)

    1991-01-01

    To determine quantitatively the discriminant and characteristics of cor pulmonale, {sup 201}Tl myocardial perfusion SPECT was performed in 16 patients with chronic obstructive pulmonary disease (COPD) and 7 with restrictive pulmonary disease (RPD). One section of the short-axis SPECT image in which the right ventricle was most clearly visualized was selected. Tl-score was defined as the ratio of the sum of counts in the region of interest (ROI) at the anterior, mid, and posterior regions of the right ventricular free wall to the sum of counts in ROI at the posterior, lateral, and anterior walls of the left ventricle, and the anterior and posterior regions of the interventricular septum. In the group of COPD patients, Tl-score was positively correlated with mean pulmonary arterial pressure (mPAP), total pulmonary vascular resistance (TPR), and arterial carbon dioxide tension (PaCO{sub 2}), while it was inversely correlated with arterial oxygen tension (PaO{sub 2}). However, there was no significant correlation between Tl-score and mPAP, TPR, PaCO{sub 2}, and PaO{sub 2} in the group of RPD patients. In assessing pulmonary hypertension as defined by mPAP over 20 mmHg, a Tl-score greater than 0.25 was useful with a sensitivity of 69% and a specificity of 90%. The occurrence of cor pulmonale is a major factor in determining the prognosis of COPD patients. It was concluded that {sup 201}Tl myocardial SPECT is useful for evaluating right ventricular overload quantitatively, as well as for assessing core pulmonale, especially in COPD patients, since the ratio of Tl counts in the right and left ventricles was significantly correlated with right cardiopulmonary hemodynamic parameters. (N.K.).

  16. Quantitation of renal uptake of technetium-99m DMSA using SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Groshar, D.; Frankel, A.; Iosilevsky, G.; Israel, O.; Moskovitz, B.; Levin, D.R.; Front, D.

    1989-02-01

    Quantitative single photon emission computed tomography (SPECT) methodology based on calibration with kidney phantoms has been applied for the assessment of renal uptake of (/sup 99m/Tc)DMSA in 25 normals; 16 patients with a single normal kidney; 30 patients with unilateral nephropathy; and 17 patients with bilateral nephropathy. An excellent correlation (r = 0.99, s.e.e. = 152) was found between SPECT measured concentration and actual concentration in kidney phantoms. Kidney uptake at 6 hr after injection in normals was 20.0% +/- 4.6% for the left and 20.8% +/- 4.4% for the right. Patients with unilateral nephropathy had a statistically significant (p less than 0.001) low uptake in the diseased kidney (7.0% +/- 4.7%), but the contralateral kidney uptake did not differ from the normal group (20.0% +/- 7.0%). The method was especially useful in patients with bilateral nephropathy. Significantly (p less than 0.001) decreased uptake was found in both kidneys (5.1% +/- 3.4% for the left and 6.7% +/- 4.2% for the right). The total kidney uptake (right and left) in this group showed to be inversely correlated (r = 0.83) with serum creatinine. The uptake of (/sup 99m/Tc)DMSA in single normal kidney was higher (p less than 0.001) than in a normal kidney (34.7% +/- 11.9%), however, it was lower than the total absolute uptake (RT + LT = 41.5% +/- 8.8%) in the normal group. The results indicate that SPECT is a reliable and reproducible technique to quantitate absolute kidney uptake of (/sup 99m/Tc)DMSA.

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

    Science.gov (United States)

    Lalonde, Michel; Wells, R Glenn; Birnie, David; Ruddy, Terrence D; Wassenaar, Richard

    2014-07-01

    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. 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. 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 Cluster analysis results were similar to SPECT RNA phase analysis (ROC AUC = 0.78, p = 0.73 vs cluster AUC; sensitivity/specificity = 59%/89%) and

  18. 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

  19. SPECT myocardial blood flow quantitation toward clinical use: a comparative study with {sup 13}N-Ammonia PET myocardial blood flow quantitation

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Bailing [University of Missouri-Columbia, Nuclear Science and Engineering Institute, Columbia, Missouri (United States); Hu, Lien-Hsin; Yang, Bang-Hung; Ting, Chien-Hsin; Huang, Wen-Sheng [Taipei Veterans General Hospital, Department of Nuclear Medicine, Taipei (China); Chen, Lung-Ching [Shin Kong Wu-Ho Su Memorial Hospital, Division of Cardiology, Taipei (China); Chen, Yen-Kung [Shin Kong Wu-Ho Su Memorial Hospital, Department of Nuclear Medicine, Taipei (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); Wu, Tao-Cheng [National Yang-Ming University, Cardiovascular Research Center, Taipei (China)

    2017-01-15

    The aim of this study was to evaluate the accuracy of myocardial blood flow (MBF) quantitation of {sup 99m}Tc-Sestamibi (MIBI) single photon emission computed tomography (SPECT) compared with {sup 13}N-Ammonia (NH3) position emission tomography (PET) on the same cohorts. Recent advances of SPECT technologies have been applied to develop MBF quantitation as a promising tool to diagnose coronary artery disease (CAD) for areas where PET MBF quantitation is not available. However, whether the SPECT approach can achieve the same level of accuracy as the PET approach for clinical use still needs further investigations. Twelve healthy volunteers (HVT) and 16 clinical patients with CAD received both MIBI SPECT and NH3 PET flow scans. Dynamic SPECT images acquired with high temporary resolution were fully corrected for physical factors and processed to quantify K1 using the standard compartmental modeling. Human MIBI tracer extraction fraction (EF) was determined by comparing MIBI K1 and NH3 flow on the HVT group and then used to convert flow values from K1 for all subjects. MIBI and NH3 flow values were systematically compared to validate the SPECT approach. The human MIBI EF was determined as [1.0-0.816*exp(-0.267/MBF)]. Global and regional MBF and myocardial flow reserve (MFR) of MIBI SPECT and NH3 PET were highly correlated for all subjects (global R{sup 2}: MBF = 0.92, MFR = 0.78; regional R{sup 2}: MBF ≥ 0.88, MFR ≥ 0.71). No significant differences for rest flow, stress flow, and MFR between these two approaches were observed (All p ≥ 0.088). Bland-Altman plots overall revealed small bias between MIBI SPECT and NH3 PET (global: ΔMBF = -0.03Lml/min/g, ΔMFR = 0.07; regional: ΔMBF = -0.07 - 0.06, ΔMFR = -0.02 - 0.22). Quantitation with SPECT technologies can be accurate to measure myocardial blood flow as PET quantitation while comprehensive imaging factors of SPECT to derive the variability between these two approaches were fully addressed and corrected

  20. Gated blood-pool SPECT automated versus manual left ventricular function calculations

    NARCIS (Netherlands)

    Slart, RHJA; Poot, L; Piers, DA; van Veldhuisen, DJ; Nichols, K; Jager, PL

    2004-01-01

    Planar gated blood-pool imaging (GBPI) is a standard method for non-invasive assessment of left ventricular (LV) function. Gated blood-pool single photon emission computed tomographic (GBPS) data acquisition can be accomplished in the same time as GBPI, with the benefit of enabling visualization of

  1. Simulation of realistic abnormal SPECT brain perfusion images: application in semi-quantitative analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ward, T [Department of Medical Physics and Bioengineering, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom); Fleming, J S [Department of Medical Physics and Bioengineering, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom); Hoffmann, S M A [Department of Medical Physics and Bioengineering, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom); Kemp, P M [Department of Nuclear Medicine, Southampton University Hospitals Trust, Southampton, Hampshire, SO16 6YD (United Kingdom)

    2005-11-21

    Simulation is useful in the validation of functional image analysis methods, particularly when considering the number of analysis techniques currently available lacking thorough validation. Problems exist with current simulation methods due to long run times or unrealistic results making it problematic to generate complete datasets. A method is presented for simulating known abnormalities within normal brain SPECT images using a measured point spread function (PSF), and incorporating a stereotactic atlas of the brain for anatomical positioning. This allows for the simulation of realistic images through the use of prior information regarding disease progression. SPECT images of cerebral perfusion have been generated consisting of a control database and a group of simulated abnormal subjects that are to be used in a UK audit of analysis methods. The abnormality is defined in the stereotactic space, then transformed to the individual subject space, convolved with a measured PSF and removed from the normal subject image. The dataset was analysed using SPM99 (Wellcome Department of Imaging Neuroscience, University College, London) and the MarsBaR volume of interest (VOI) analysis toolbox. The results were evaluated by comparison with the known ground truth. The analysis showed improvement when using a smoothing kernel equal to system resolution over the slightly larger kernel used routinely. Significant correlation was found between effective volume of a simulated abnormality and the detected size using SPM99. Improvements in VOI analysis sensitivity were found when using the region median over the region mean. The method and dataset provide an efficient methodology for use in the comparison and cross validation of semi-quantitative analysis methods in brain SPECT, and allow the optimization of analysis parameters.

  2. Simulation of realistic abnormal SPECT brain perfusion images: application in semi-quantitative analysis

    Science.gov (United States)

    Ward, T.; Fleming, J. S.; Hoffmann, S. M. A.; Kemp, P. M.

    2005-11-01

    Simulation is useful in the validation of functional image analysis methods, particularly when considering the number of analysis techniques currently available lacking thorough validation. Problems exist with current simulation methods due to long run times or unrealistic results making it problematic to generate complete datasets. A method is presented for simulating known abnormalities within normal brain SPECT images using a measured point spread function (PSF), and incorporating a stereotactic atlas of the brain for anatomical positioning. This allows for the simulation of realistic images through the use of prior information regarding disease progression. SPECT images of cerebral perfusion have been generated consisting of a control database and a group of simulated abnormal subjects that are to be used in a UK audit of analysis methods. The abnormality is defined in the stereotactic space, then transformed to the individual subject space, convolved with a measured PSF and removed from the normal subject image. The dataset was analysed using SPM99 (Wellcome Department of Imaging Neuroscience, University College, London) and the MarsBaR volume of interest (VOI) analysis toolbox. The results were evaluated by comparison with the known ground truth. The analysis showed improvement when using a smoothing kernel equal to system resolution over the slightly larger kernel used routinely. Significant correlation was found between effective volume of a simulated abnormality and the detected size using SPM99. Improvements in VOI analysis sensitivity were found when using the region median over the region mean. The method and dataset provide an efficient methodology for use in the comparison and cross validation of semi-quantitative analysis methods in brain SPECT, and allow the optimization of analysis parameters.

  3. 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

  4. [Quantitative evaluation of 123I-FP-CIT SPECT: validation of a semiautomated method].

    Science.gov (United States)

    Lorenzo Bosquet, C; Cuberas Borrós, G; Miquel Rodríguez, F; Caresia, P; Aguadé Bruix, S; Castell Conesa, J

    2005-01-01

    To assess the utility of a quantification of the 123I-FP-CIT uptake by the definition of some reference values, normal range values and interobserver variation. Fifty patients with a 123I-FP-CIT SPECT: 25 patients had a pathological SPECT with the diagnosis of Parkinson's disease and the remaining had a qualitative normal SPET, with the diagnosis of 14 drug-induced Parkinsonism and 11 with psychogenic Parkinsonism. In the transversal slices, the best central slice that showed the nuclei of the base best was selected and standard ROIs (Region Of Interest) were applied. Specific (caudate and putamen) versus non specific (occipital) and laterality ratios were calculated. A normal statistical analysis for independent quantitative samples was used (mean, standard deviation and range) as well as variation coefficient and correlation coefficient of two observers and the 10th and 90th percentile. The variation coefficient interobserver was 3.24-5.61 and the correlation coefficient was 0.89-0.99. Cut-off values between both populations were established at 2.10 in the right putamen and at 2.05 in the left. Cut-off values definition in caudate were not assessable due to overlapping of ratios of both populations. This quantification method is highly reproducible. It makes it possible to obtain reference values and to define normal range.

  5. An observer study methodology for evaluating detection of motion abnormalities in gated myocardial perfusion SPECT.

    Science.gov (United States)

    Lalush, David S; Jatko, Megan K; Segars, W Paul

    2005-03-01

    To address the task of detecting nonischemic motion abnormalities from animated displays of gated myocardial perfusion single photon emission computed tomography data, we performed an observer study to evaluate the difference in detection performance between gating to 8 and 16 frames. Images were created from the NCAT mathematical phantom with a realistic heart simulating hypokinetic motion in the left lateral wall. Realistic noise-free projection data were simulated for both normal and defective hearts to obtain 16 frames for the cardiac cycle. Poisson noise was then simulated for each frame to create 50 realizations of each heart, All datasets were processed in two ways: reconstructed as a 16-frame set, and collapsed to 8 frames and reconstructed. Ten observers viewed the cardiac images animated with a realistic real-time frame rate. Observers trained on 100 images and tested on 100 images, rating their confidence on the presence of a motion defect on a continuous scale. None of the observers showed a significant difference in performance between the two gating methods. The 95% confidence interval on the difference in areas under the ROC curve (Az8 - Az16) was -0.029-0.085. Our test did not find a significant difference in detection performance between 8-frame gating and 16-frame gating. We conclude that, for the task of detecting abnormal motion, increasing the number of gated frames from 8 to 16 offers no apparent advantage.

  6. Improved SPECT quantitation using fully three-dimensional iterative spatially variant scatter response compensation.

    Science.gov (United States)

    Beekman, F J; Kamphuis, C; Viergever, M A

    1996-01-01

    The quality and quantitative accuracy of iteratively reconstructed SPECT images improves when better point spread function (PSF) models of the gamma camera are used during reconstruction. Here, inclusion in the PSF model of photon crosstalk between different slices caused by limited gamma camera resolution and scatter is examined. A three-dimensional (3-D) projector back-projector (proback) has been developed which models both the distance dependent detector point spread function and the object shape-dependent scatter point spread function of single photon emission computed tomography (SPECT). A table occupying only a few megabytes of memory is sufficient to represent this scatter model. The contents of this table are obtained by evaluating an analytical expression for object shape-dependent scatter. The proposed approach avoids the huge memory requirements of storing the full transition matrix needed for 3-D reconstruction including object shape-dependent scatter. In addition, the method avoids the need for lengthy Monte Carlo simulations to generate such a matrix. In order to assess the quantitative accuracy of the method, reconstructions of a water filled cylinder containing regions of different activity levels and of simulated 3-D brain projection data have been evaluated for technetium-99m. It is shown that fully 3-D reconstruction including complete detector response and object shape-dependent scatter modeling clearly outperforms simpler methods that lack a complete detector response and/or a complete scatter response model. Fully 3-D scatter correction yields the best quantitation of volumes of interest and the best contrast-to-noise curves.

  7. Quantitative assessment of rest and acetazolamide CBF using quantitative SPECT reconstruction and sequential administration of (123)I-iodoamphetamine: comparison among data acquired at three institutions.

    Science.gov (United States)

    Yamauchi, Miho; Imabayashi, Etsuko; Matsuda, Hiroshi; Nakagawara, Jyoji; Takahashi, Masaaki; Shimosegawa, Eku; Hatazawa, Jun; Suzuki, Michiyasu; Iwanaga, Hideyuki; Fukuda, Kenji; Iihara, Koji; Iida, Hidehiro

    2014-11-01

    A recently developed technique which reconstructs quantitative images from original projection data acquired using existing single-photon emission computed tomography (SPECT) devices enabled quantitative assessment of cerebral blood flow (CBF) at rest and after acetazolamide challenge. This study was intended to generate a normal database and to investigate its inter-institutional consistency. The three institutions carried out a series of SPECT scanning on 32 healthy volunteers, following a recently proposed method that involved dual administration of (123)I-iodoamphetamine during a single SPECT scan. Intra-institute and inter-institutional variations of regional CBF values were evaluated both at rest and after acetazolamide challenge. Functional images were pooled for both rest and acetazolamide CBF, and inter-institutional difference was evaluated among these images using two independent software programs. Quantitative assessment of CBF images at rest and after acetazolamide was successfully achieved with the given protocol in all institutions. Intra-institutional variation of CBF values at rest and after acetazolamide was consistent with previously reported values. Quantitative CBF values showed no significant difference among institutions in all regions, except for a posterior cerebral artery region after acetazolamide challenge in one institution which employed SPECT device with lowest spatial resolution. Pooled CBF images at rest and after acetazolamide generated using two software programs showed no institutional differences after equalization of the spatial resolution. SPECT can provide reproducible images from projection data acquired using different SPECT devices. A common database acquired at different institutions may be shared among institutions, if images are reconstructed using a quantitative reconstruction program, and acquired by following a standardized protocol.

  8. Prognostic value of Tc-99m tetrofosmin myocardial perfusion gated SPECT in patients with diabetes mellitus and suspected coronary artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcia Maria Sales dos; Pantoja, Mauricio da Rocha; Cwajg, Eduardo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); CINTILAB, Rio de Janeiro, RJ (Brazil); E-mail: mmsales@oi.com.br

    2008-01-15

    Background: The cardiovascular disease is the main cause of death among diabetic patients, which makes it crucial to identify the individuals at higher risk of cardiovascular events. Objective: To evaluate the prognostic value of scintigraphy with gated single photon emission computed tomography (SPECT) in patients with diabetes mellitus (DM) and suspected coronary artery disease. Methods: Retrospective study with 232 diabetic patients submitted to scintigraphy with gated SPECT. Perfusion Gated SPECT (scores and number of altered segments) as well as ventricular function parameters (ejection fraction, left ventricle volume and contractility) were evaluated. Cardiac death, acute ischemic coronary syndrome, revascularization procedures or encephalic vascular accident were considered future cardiovascular events. The uni- and multivariate analyses were carried out by the multiple logistic regression model (p< 0.05). Results: At the univariate analysis, age (p=0.02), chest angina (p=0.01), insulin therapy (p=0.02), myocardial perfusion abnormalities (p<0.0001), the number of segments involved (p=0.0001), the perfusion scores (p=0.0001), the ejection fraction (p=0.004), the final systolic volume (p=0.03) and the finding of segmental alteration at the LV contractility (p<0.0001) were associated with future events at the univariate analysis. At the multivariate analysis, the male sex (p=0.007), age (p=0.03), angina (p=0.001), insulin therapy (p=0.007) and the SDS {>=} 3 (p=0.0001), and the number of altered segments {>=} 3 (p=0.0001) were predictors of cardiovascular events. Conclusion: The myocardial scintigraphy with gated SPECT adds independent information to the stratification of the risk of future cardiovascular events in patients with DM and suspected coronary artery disease. (author)

  9. Improving quantitative dosimetry in (177)Lu-DOTATATE SPECT by energy window-based scatter corrections

    DEFF Research Database (Denmark)

    de Nijs, Robin; Lagerburg, Vera; Klausen, Thomas L

    2014-01-01

    and the activity, which depends on the collimator type, the utilized energy windows and the applied scatter correction techniques. In this study, energy window subtraction-based scatter correction methods are compared experimentally and quantitatively. MATERIALS AND METHODS: (177)Lu SPECT images of a phantom...... with known activity concentration ratio between the uniform background and filled hollow spheres were acquired for three different collimators: low-energy high resolution (LEHR), low-energy general purpose (LEGP) and medium-energy general purpose (MEGP). Counts were collected in several energy windows......, and scatter correction was performed by applying different methods such as effective scatter source estimation (ESSE), triple-energy and dual-energy window, double-photopeak window and downscatter correction. The intensity ratio between the spheres and the background was measured and corrected for the partial...

  10. Quantitative (177)Lu SPECT imaging using advanced correction algorithms in non-reference geometry.

    Science.gov (United States)

    D'Arienzo, M; Cozzella, M L; Fazio, A; De Felice, P; Iaccarino, G; D'Andrea, M; Ungania, S; Cazzato, M; Schmidt, K; Kimiaei, S; Strigari, L

    2016-12-01

    Peptide receptor therapy with (177)Lu-labelled somatostatin analogues is a promising tool in the management of patients with inoperable or metastasized neuroendocrine tumours. The aim of this work was to perform accurate activity quantification of (177)Lu in complex anthropomorphic geometry using advanced correction algorithms. Acquisitions were performed on the higher (177)Lu photopeak (208keV) using a Philips IRIX gamma camera provided with medium-energy collimators. System calibration was performed using a 16mL Jaszczak sphere surrounded by non-radioactive water. Attenuation correction was performed using μ-maps derived from CT data, while scatter and septal penetration corrections were performed using the transmission-dependent convolution-subtraction method. SPECT acquisitions were finally corrected for dead time and partial volume effects. Image analysis was performed using the commercial QSPECT software. The quantitative SPECT approach was validated on an anthropomorphic phantom provided with a home-made insert simulating a hepatic lesion. Quantitative accuracy was studied using three tumour-to-background activity concentration ratios (6:1, 9:1, 14:1). For all acquisitions, the recovered total activity was within 12% of the calibrated activity both in the background region and in the tumour. Using a 6:1 tumour-to-background ratio the recovered total activity was within 2% in the tumour and within 5% in the background. Partial volume effects, if not properly accounted for, can lead to significant activity underestimations in clinical conditions. In conclusion, accurate activity quantification of (177)Lu can be obtained if activity measurements are performed with equipment traceable to primary standards, advanced correction algorithms are used and acquisitions are performed at the 208keV photopeak using medium-energy collimators.

  11. Optimization of Ecg Gating in Quantitative Femoral Angiography

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, S.; Berglund, I.; Erikson, U. [Univ. Hospital, Uppsala (Sweden). Dept. of Oncology, Radiology and Clinical Immunology; Johansson, J.; Walldius, G. [Karolinska Hospital, Stockholm (Sweden). King Gustav V Research Inst.

    2003-09-01

    Purpose: To determine which phase of the heart cycle would yield the highest reproducibility in measuring atherosclerosis-related variables such as arterial lumen volume and edge roughness. Material and Methods: 35 patients with hypercholesterolemia underwent select ive femoral angiography, repeated four times at 10-min intervals. The angiographies were performed with Ecg-gated exposures. In angiographies 1 and 2 the delay from R-wave maximum to each exposure was 0.1 s, in angiographies 3 and 4 the delay was 0.1, 0.3, 0.5 or 0.7 s or the exposures were performed 1/s without Ecg gating. Arterial lumen volume and edge roughness were measured in a 20-cm segment of the superficial femoral artery using a computer-based densitometric method. Measurement reproducibility was determined by comparing angiographies 1-2 and angiographies 3-4. Results: When measuring arterial lumen volume and edge roughness of a 20-cm segment of the femoral artery, reproducibility was not dependent on Ecg gating. In measuring single arterial diameters and cross-sectional areas, the reproducibility was better when exposures were made 0.1 s after the R-wave maximum than when using other settings of the Ecg gating device or without Ecg gating. Conclusion: The influence of pulsatile flow upon quantitative measurement in femoral angiograms seems to be the smallest possible in early systole, as can be demonstrated when measuring single diameters and cross-sectional areas. In variables based on integration over longer segments, measurement reproducibility seems to be independent of phase.

  12. 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

    Full Text Available 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, obtidos pela cintilografia de perfusão miocárdica tomográfica sincronizada pelo eletrocardiograma (Gated SPECT, com os mesmos parâmetros medidos pela ressonância magnética cardíaca em 20 pacientes submetidos à revascularização miocárdica. MÉTODOS: A correlação foi medida pelo coeficiente de correlação de Spearman (ρ, enquanto a concordância foi avaliada por meio da análise de Bland e Altman. RESULTADOS: Houve uma correlação boa entre o Gated SPECT e a ressonância magnética cardíaca nos pacientes após CRM em relação à fração de ejeção do ventrículo esquerdo (ρ = 0,85; p = 0,0001, uma correlação moderada para o volume sistólico final (ρ = 0,51; p = 0,02 e uma correlação insignificante para o volume diastólico final (ρ = 0,13; p = 0,5. Os limites de concordância para FEVE, VSF e VDF foram: de -20% a 12%; de -38 a 54ml e de -96 a 100ml, respectivamente. CONCLUSÃO: A fração de ejeção do ventrículo esquerdo obtida pelo Gated SPECT correlaciona-se de modo confiável com a da ressonância magnética em pacientes submetidos à CRM. Os volumes ventriculares, entretanto, não apresentam uma correlação adequada.FUNDAMENTO: La evaluación de la función ventricular izquierda puede limitarse por el movimiento anómalo del septo interventricular, frecuentemente encontrado tras cirugía de revascularización miocárdica (CRM. La validación del Gated SPECT como herramienta para evaluación de la funci

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-15

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

  14. Applicability of a set of tomographic reconstruction algorithms for quantitative SPECT on irradiated nuclear fuel assemblies

    Science.gov (United States)

    Jacobsson Svärd, Staffan; Holcombe, Scott; Grape, Sophie

    2015-05-01

    A fuel assembly operated in a nuclear power plant typically contains 100-300 fuel rods, depending on fuel type, which become strongly radioactive during irradiation in the reactor core. For operational and security reasons, it is of interest to experimentally deduce rod-wise information from the fuel, preferably by means of non-destructive measurements. The tomographic SPECT technique offers such possibilities through its two-step application; (1) recording the gamma-ray flux distribution around the fuel assembly, and (2) reconstructing the assembly's internal source distribution, based on the recorded radiation field. In this paper, algorithms for performing the latter step and extracting quantitative relative rod-by-rod data are accounted for. As compared to application of SPECT in nuclear medicine, nuclear fuel assemblies present a much more heterogeneous distribution of internal attenuation to gamma radiation than the human body, typically with rods containing pellets of heavy uranium dioxide surrounded by cladding of a zirconium alloy placed in water or air. This inhomogeneity severely complicates the tomographic quantification of the rod-wise relative source content, and the deduction of conclusive data requires detailed modelling of the attenuation to be introduced in the reconstructions. However, as shown in this paper, simplified models may still produce valuable information about the fuel. Here, a set of reconstruction algorithms for SPECT on nuclear fuel assemblies are described and discussed in terms of their quantitative performance for two applications; verification of fuel assemblies' completeness in nuclear safeguards, and rod-wise fuel characterization. It is argued that a request not to base the former assessment on any a priori information brings constraints to which reconstruction methods that may be used in that case, whereas the use of a priori information on geometry and material content enables highly accurate quantitative assessment, which

  15. Computed-tomography-guided anatomic standardization for quantitative assessment of dopamine transporter SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kota [National Center of Neurology and Psychiatry, Department of Radiology, Tokyo (Japan); National Center of Neurology and Psychiatry, Integrative Brain Imaging Center, Tokyo (Japan); Imabayashi, Etsuko; Matsuda, Hiroshi [National Center of Neurology and Psychiatry, Integrative Brain Imaging Center, Tokyo (Japan); Sumida, Kaoru; Sone, Daichi; Kimura, Yukio; Sato, Noriko [National Center of Neurology and Psychiatry, Department of Radiology, Tokyo (Japan); Mukai, Youhei; Murata, Miho [National Center of Neurology and Psychiatry, Department of Neurology, Tokyo (Japan)

    2017-03-15

    For the quantitative assessment of dopamine transporter (DAT) using [{sup 123}I]FP-CIT single-photon emission computed tomography (SPECT) (DaTscan), anatomic standardization is preferable for achieving objective and user-independent quantification of striatal binding using a volume-of-interest (VOI) template. However, low accumulation of DAT in Parkinson's disease (PD) would lead to a deformation error when using a DaTscan-specific template without any structural information. To avoid this deformation error, we applied computed tomography (CT) data obtained using SPECT/CT equipment to anatomic standardization. We retrospectively analyzed DaTscan images of 130 patients with parkinsonian syndromes (PS), including 80 PD and 50 non-PD patients. First we segmented gray matter from CT images using statistical parametric mapping 12 (SPM12). These gray-matter images were then anatomically standardized using the diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) algorithm. Next, DaTscan images were warped with the same parameters used in the CT anatomic standardization. The target striatal VOIs for decreased DAT in PD were generated from the SPM12 group comparison of 20 DaTscan images from each group. We applied these VOIs to DaTscan images of the remaining patients in both groups and calculated the specific binding ratios (SBRs) using nonspecific counts in a reference area. In terms of the differential diagnosis of PD and non-PD groups using SBR, we compared the present method with two other methods, DaTQUANT and DaTView, which have already been released as software programs for the quantitative assessment of DaTscan images. The SPM12 group comparison showed a significant DAT decrease in PD patients in the bilateral whole striatum. Of the three methods assessed, the present CT-guided method showed the greatest power for discriminating PD and non-PD groups, as it completely separated the two groups. CT-guided anatomic standardization using

  16. Improved dose-volume histogram estimates for radiopharmaceutical therapy by optimizing quantitative SPECT reconstruction parameters

    Science.gov (United States)

    Cheng, Lishui; Hobbs, Robert F.; Segars, Paul W.; Sgouros, George; Frey, Eric C.

    2013-06-01

    In radiopharmaceutical therapy, an understanding of the dose distribution in normal and target tissues is important for optimizing treatment. Three-dimensional (3D) dosimetry takes into account patient anatomy and the nonuniform uptake of radiopharmaceuticals in tissues. Dose-volume histograms (DVHs) provide a useful summary representation of the 3D dose distribution and have been widely used for external beam treatment planning. Reliable 3D dosimetry requires an accurate 3D radioactivity distribution as the input. However, activity distribution estimates from SPECT are corrupted by noise and partial volume effects (PVEs). In this work, we systematically investigated OS-EM based quantitative SPECT (QSPECT) image reconstruction in terms of its effect on DVHs estimates. A modified 3D NURBS-based Cardiac-Torso (NCAT) phantom that incorporated a non-uniform kidney model and clinically realistic organ activities and biokinetics was used. Projections were generated using a Monte Carlo (MC) simulation; noise effects were studied using 50 noise realizations with clinical count levels. Activity images were reconstructed using QSPECT with compensation for attenuation, scatter and collimator-detector response (CDR). Dose rate distributions were estimated by convolution of the activity image with a voxel S kernel. Cumulative DVHs were calculated from the phantom and QSPECT images and compared both qualitatively and quantitatively. We found that noise, PVEs, and ringing artifacts due to CDR compensation all degraded histogram estimates. Low-pass filtering and early termination of the iterative process were needed to reduce the effects of noise and ringing artifacts on DVHs, but resulted in increased degradations due to PVEs. Large objects with few features, such as the liver, had more accurate histogram estimates and required fewer iterations and more smoothing for optimal results. Smaller objects with fine details, such as the kidneys, required more iterations and less

  17. Validation of Cross-calibration Schemes for Quantitative Bone SPECT/CT Using Different Sources under Various Geometric Conditions.

    Science.gov (United States)

    Miyaji, Noriaki; Miwa, Kenta; Motegi, Kazuki; Umeda, Takuro; Wagatsuma, Kei; Fukai, Shohei; Takiguchi, Tomohiro; Terauchi, Takashi; Koizumi, Mitsuru

    Several cross-calibration schemes have been proposed to produce quantitative values in bone SPECT imaging. Differences in the radionuclide sources and geometric conditions can decrease the accuracy of cross-calibration factor (CCF). The present study aimed to validate the effects of calibration schemes using different sources under various geometric conditions. Temporal variations as well as variations in acquisition counts and the shapes of (57)Co standard and (99m)Tc point sources and a (99m)Tc disk source were determined. The effects of the geometric conditions of the source-to-camera distance (SCD) and lateral distance on the CCF were investigated by moving the camera or source away from the origin. The system planar sensitivity of NEMA incorporated into a Symbia Intevo SPECT/CT device (Siemens®) was defined as reference values. The temporal variation in CCF using the (57)Co source was relatively stable within the range of 0.7% to 2.3%, whereas the (99m)Tc source ranged from 2.7% to 7.3%. In terms of source shape, the (57)Co standard point source was the most stable. Both SCD and lateral distance decreased as a function of distance from the origin. Errors in the geometric condition were higher for the (57)Co standard point source than the (99m)Tc disk source. Different calibration schemes influenced the reliability of quantitative values. The (57)Co standard point source was stable over a long period, and this helped to maintain the quality of quantitative SPECT/CT imaging data. The CCF accuracy of the (99m)Tc source decreased depending on the preparative method. The method of calibration for quantitative SPECT should be immediately standardized to eliminate uncertainty.

  18. Quantitative simultaneous 111In∕99mTc SPECT-CT of osteomyelitis.

    Science.gov (United States)

    Cervo, Morgan; Gerbaudo, Victor H; Park, Mi-Ae; Moore, Stephen C

    2013-08-01

    A well-established approach for diagnostic imaging of osteomyelitis (OM), a bone infection, is simultaneous SPECT-CT of 99mTc sulfur colloid (SC) and 111In white blood cells (WBC). This method provides essentially perfect spatial registration of the tracers within anatomic sites of interest. Currently, diagnosis is based purely on a visual assessment-where relative discordance between 99mTc and 111In uptake in bone, i.e., high 111In and low 99mTc, suggests OM. To achieve more quantitative images, noise, scatter, and crosstalk between radionuclides must be addressed through reconstruction. Here the authors compare their Monte Carlo-based joint OSEM (MC-JOSEM) algorithm, which reconstructs both radionuclides simultaneously, to a more conventional triple-energy window-based reconstruction (TEW-OSEM), and to iterative reconstruction with no compensation for scatter (NC-OSEM). The authors created numerical phantoms of the foot and torso. Multiple bone-infection sites were modeled using high-count Monte Carlo simulation. Counts per voxel were then scaled to values appropriate for 111In WBC and 99mTc SC imaging. Ten independent noisy projection image sets were generated by drawing random Poisson deviates from these very low-noise images. Data were reconstructed using the two iterative scatter-compensation methods, TEW-OSEM and MC-JOSEM, as well as the uncorrected method (NC-OSEM). Mean counts in volumes of interest (VOIs) were used to evaluate the bias and precision of each method. Data were also acquired using a phantom, approximately the size of an adult ankle, consisting of regions representing infected and normal bone marrow, within a bone-like attenuator and surrounding soft tissue; each compartment contained a mixture of 111In and 99mTc. Low-noise data were acquired during multiple short scans over 29 h on a Siemens Symbia T6 SPECT-CT with medium-energy collimators. Pure 99mTc and 111In projection datasets were derived by fitting the acquired projections to the sum

  19. A Computer-Aided Analysis Method of SPECT Brain Images for Quantitative Treatment Monitoring: Performance Evaluations and Clinical Applications

    Science.gov (United States)

    Wei, Wentao; Huang, Qiu; Wan, Jieqing; Huang, Gang

    2017-01-01

    The objective and quantitative analysis of longitudinal single photon emission computed tomography (SPECT) images are significant for the treatment monitoring of brain disorders. Therefore, a computer aided analysis (CAA) method is introduced to extract a change-rate map (CRM) as a parametric image for quantifying the changes of regional cerebral blood flow (rCBF) in longitudinal SPECT brain images. The performances of the CAA-CRM approach in treatment monitoring are evaluated by the computer simulations and clinical applications. The results of computer simulations show that the derived CRMs have high similarities with their ground truths when the lesion size is larger than system spatial resolution and the change rate is higher than 20%. In clinical applications, the CAA-CRM approach is used to assess the treatment of 50 patients with brain ischemia. The results demonstrate that CAA-CRM approach has a 93.4% accuracy of recovered region's localization. Moreover, the quantitative indexes of recovered regions derived from CRM are all significantly different among the groups and highly correlated with the experienced clinical diagnosis. In conclusion, the proposed CAA-CRM approach provides a convenient solution to generate a parametric image and derive the quantitative indexes from the longitudinal SPECT brain images for treatment monitoring. PMID:28251150

  20. Left ventricular diastolic dyssynchrony assessed with phase analysis of gated myocardial perfusion SPECT: a comparison with tissue Doppler imaging

    Energy Technology Data Exchange (ETDEWEB)

    Boogers, Mark J.; Veltman, Caroline E. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands); Chen, Ji; Garcia, Ernest V. [Emory University School of Medicine, Department of Radiology, Atlanta, GA (United States); Bommel, Rutger J. van; Mooyaart, Eline A.Q.; Wall, Ernst E. van der; Schalij, Martin J.; Bax, Jeroen J.; Delgado, Victoria [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Younis, Imad Al; Hiel, Bernies van der; Dibbets-Schneider, Petra [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands)

    2011-11-15

    The aim of the current study was to evaluate the feasibility of phase analysis on gated myocardial perfusion SPECT (GMPS) for the assessment of left ventricular (LV) diastolic dyssynchrony in a head-to-head comparison with tissue Doppler imaging (TDI). The population consisted of patients with end-stage heart failure of New York Heart Association functional class III or IV with a reduced LV ejection fraction of {<=}35%. LV diastolic dyssynchrony was calculated using TDI as the maximal time delay between early peak diastolic velocities of two opposing left ventricle walls (diastolic mechanical delay). Significant LV diastolic dyssynchrony was defined as a diastolic mechanical delay of >55 ms on TDI. Furthermore, phase analysis on GMPS was performed to evaluate LV diastolic dyssynchrony; diastolic phase standard deviation (SD) and histogram bandwidth (HBW) were used as markers of LV diastolic dyssynchrony. A total of 150 patients (114 men, mean age 66.0 {+-} 10.4 years) with end-stage heart failure were enrolled. Both diastolic phase SD (r = 0.81, p < 0.01) and diastolic HBW (r = 0.75, p < 0.01) showed good correlations with LV diastolic dyssynchrony on TDI. Additionally, patients with LV diastolic dyssynchrony on TDI (>55 ms) showed significantly larger diastolic phase SD (68.1 {+-} 13.4 vs. 40.7 {+-} 14.0 , p < 0.01) and diastolic HBW (230.6 {+-} 54.3 vs. 129.0 {+-} 55.6 , p < 0.01) as compared to patients without LV diastolic dyssynchrony on TDI ({<=}55 ms). Finally, phase analysis on GMPS showed a good intra- and interobserver reproducibility for the determination of diastolic phase SD (ICC 0.97 and 0.88) and diastolic HBW (ICC 0.98 and 0.93). Phase analysis on GMPS showed good correlations with TDI for the assessment of LV diastolic dyssynchrony. (orig.)

  1. Utility of Quantitative 99mTc-MAA SPECT/CT for 90yttrium-Labelled Microsphere Treatment Planning: Calculating Vascularized Hepatic Volume and Dosimetric Approach

    Directory of Open Access Journals (Sweden)

    Etienne Garin

    2011-01-01

    Full Text Available Objectives. The aim of this study was to assess the effectiveness of SPECT/CT for volume measurements and to report a case illustrating the major impact of SPECT/CT in calculating the vascularized liver volume and dosimetry prior to injecting radiolabelled yttrium-90 microspheres (Therasphere. Materials and Methods. This was a phantom study, involving volume measurements carried out by two operators using SPECT and SPECT/CT images. The percentage of error for each method was calculated, and interobserver reproducibility was evaluated. A treatment using Therasphere was planned in a patient with three hepatic arteries, and the quantitative analysis of SPECT/CT for this patient is provided. Results. SPECT/CT volume measurements proved to be accurate (mean error <6% for volumes ≥16 cm3 and reproductive (interobserver agreement = 0.9. In the case report, 99mTc-MAA SPECT/CT identified a large liver volume, not previously identified with angiography, which was shown to be vascularized after selective MAA injection into an arterial branch, resulting in a large modification in the activity of Therasphere used. Conclusions. MAA SPECT/CT is accurate for vascularized liver volume measurements, providing a valuable contribution to the therapeutic planning of patients with complex hepatic vascularization.

  2. Parametric Cerebrovascular Reserve Images Using Acetazolamide {sup 99m}Tc-HMPAO SPECT: A Feasibility Study of Quantitative Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hongyoon; Yoo, Min Young; Cheon, Gi Jeong; Kang, Keon Wook; Chung, Junekey; Lee, Dong Soo [Seoul National Univ., Seoul (Korea, Republic of)

    2013-09-15

    Basal/acetazolamide stress {sup 99m}Tc-HMPAO single-photon emission computed tomography (SPECT) has been widely used for evaluation of hemodynamics; however, qualitative and subjective visual assessment of cerebrovascular reserve (CVR) has been performed in clinical settings. The aim of this study was to generate parametric CVR images and evaluate its feasibility of quantification. Basal/acetazolamide stress {sup 99m}Tc-HMPAO SPECT data from 17 patients who underwent bypass surgery or percutaneous transluminal angioplasty were used. Spatial normalization was performed and parametric CVR images were generated using relative CVR (rCVR) of each voxel proportional to CVR of the whole brain. Binary parametric maps to show area of relatively reduced CVR were generated also using threshold of rCVR < 90 %. We calculated rCVR of internal carotid artery (ICA) using the parametric CVR images and probabilistic maps for ICA territory. Pre- and postprocedural parametric CVR images were obtained and quantitative rCVRs were compared. The rCVRs were evaluated according to visual grades for regional decreased CVR. Postprocedural rCVR obtained from parametric CVR images increased significantly from preprocedural rCVR. The rCVR was significantly correlated with visual grades of reduced CVR for each side of ICA territories. We generated parametric CVR images for basal/acetazolamide stress {sup 99m}Tc-HMPAO SPECT. As a quantitative measurement, rCVR obtained from the parametric image was feasibly assessed hemodynamic abnormalities with preserved anatomical information.

  3. Asymmetrically thickened posterior wall is associated with decline of ejection fraction after stress on adenosine stress/rest thallium-201 gated myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bom Sahn; Lee, Won Woo; Lee, Dong Soo; Chung, June Key; Lee, Myung Chul; Kim, Sang Eun [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    2004-07-01

    LV parameters (LVEF. ESVI and EDVI) on adenosine stress/rest thallium-201 gated myocardial SPECT (gSPECT) are various from stress to rest. We investigated the reason why they were various in patients without coronary artery disease. Seventy-one patients(M:F=32:39, age 58.1{+-}9.7yrs), who underwent gSPECT and coronary angiography (CAG) due to chest pain or preoperative evaluation were included. CAG results were normal or insignificant. Exclusion criteria were atrial fibrillation, thyroid disease, primary cardiomyopathy, myocardial bridge, LBBB, MI, and valvular heart disease. Patients were calssified into 3 groups by EF difference ({delta}EF=rest-stress EF) on gSPECT : group1 ({delta}EF{>=}10), group2 (0 {<=}{delta}EF<10), and group3 ({delta}EF<0). LV parameters on gSPECT and thicknesses of IVS (interventricular septum) and LVPW (left ventricular posterior wall) on echocardiography were compared among the 3 groups. Myocardial perfusion status were normal or mild reversible/persistent perfusion defect in 76.1% (54/71). LVEFs at stress were not different among all 3 groups : 59.3{+-}8.54% in group 1 (61.3{+-}10.22% in group 2 and 64.8{+-}7.58% in group 3 (p>0.05). But LVEF at rest was smaller in group 3 (58.7{+-}8.38%) than the other groups (72.5{+-}8.77% in group1 and 66.7{+-}10.6% in group2) (p<0.01). EDVIs and ESVI at stress were larger than those at rest in all groups (p<0.05) except ESVI in group 3 (16.2{+-}6.21ml at stress and 17.5{+-}6.41ml at rest, p<0.01), and that was attributed to EF<0 in group 3. In echocardiographical analysis, group 3 had significantly increased wall thickness of LVPW (10.7{+-}1.2mm versus 9.4{+-}1.6mm, p=0.01) and decreased wall thickness ratio of IVS/LVPW (0.963{+-}0.102 versus 1.048{+-}0.104, p=0.035) than group 1. In patients without coronary artery disease, LVEF, EDVI and ESVI on gSPECT were various and decline of LVEF from stress to rest was caused by unnormalized ESVI . Asymmetrically thickened LVPW may play a crucial role and

  4. Quantitative image reconstruction for dual-isotope parathyroid SPECT/CT: phantom experiments and sample patient studies

    Science.gov (United States)

    Shcherbinin, S.; Chamoiseau, S.; Celler, A.

    2012-08-01

    We investigated the quantitative accuracy of the model-based dual-isotope single-photon emission computed tomography (DI-SPECT) reconstructions that use Klein-Nishina expressions to estimate the scattered photon contributions to the projection data. Our objective was to examine the ability of the method to recover the absolute activities pertaining to both radiotracers: Tc-99m and I-123. We validated our method through a series of phantom experiments performed using a clinical hybrid SPECT/CT camera (Infinia Hawkeye, GE Healthcare). Different activity ratios and different attenuating media were used in these experiments to create cross-talk effects of varying severity, which can occur in clinical studies. Accurate model-based corrections for scatter and cross-talk with CT attenuation maps allowed for the recovery of the absolute activities from DI-SPECT/CT scans with errors that ranged 0-10% for both radiotracers. The unfavorable activity ratios increased the computational burden but practically did not affect the resulting accuracy. The visual analysis of parathyroid patient data demonstrated that our model-based processing improved adenoma/background contrast and enhanced localization of small or faint adenomas.

  5. Avaliação da perfusão e função miocárdicas em vítimas de escorpionismo utilizando o Gated-SPECT Evaluación de la perfusión y función miocárdicas en víctimas de escorpionismo utilizando el Gated-SPECT Assessment of myocardial perfusion and function in victims of scorpion envenomation using Gated-SPECT

    Directory of Open Access Journals (Sweden)

    Alexandre Baldini de Figueiredo

    2010-04-01

    are the major causes of death of patients with scorpion envenomation, whose pathophysiological mechanism remains controversial. OBJECTIVE: To investigate the correlation between myocardial perfusion abnormalities and left ventricular contractile function in victims of scorpion envenomation. METHODS: Fifteen patients underwent ECG-gated myocardial perfusion scintigraphy (gated SPECT within 72 hours of, and 15 days after scorpion envenomation. Images were analyzed by means of a semi-quantitative visual perfusion score (0 = normal, 4 = absent and motion score (0 = normal, 4 = akinesia, using the 17-segment model. Summed perfusion (SPS and summed motion (SMS scores were calculated for each patient. Ejection fraction (LVEF was calculated by a commercially available software. RESULTS: At baseline, 12 out of the 15 patients presented abnormal myocardial perfusion and contractility. Mean values of SPS, SMS and LVEF were 12.5 ± 7.3, 17.0 ± 12.8, and 44.6 ± 16.0%, respectively. A positive correlation between SPS and SMS (r = 0.68; p = 0.005 and negative correlation between SPS and LVEF (r = -0.75; p = 0.0021 were found. The follow-up studies showed recovery of global contractility (LVEF of 68.9 ± 9.5, p = 0.0002, segmental contractility (SMS of 2.6 ± 3.1, p = 0.0009 and perfusion (SPS of 3.7 ± 3.3, p = 0.0003. Improvement of LVEF correlated positively with improvement of SPS (r = 0.72; p = 0.0035. CONCLUSIONS: Myocardial perfusion abnormalities are common in scorpion envenomation and correlate topographically with the contractile dysfunction. Recovery of contractility correlates with reversibility of perfusion defects. These findings suggest the participation of myocardial perfusion abnormalities in the pathophysiology of this form of acute ventricular failure. (Arq Bras Cardiol 2010;94(4: 418-425

  6. Fatores biológicos e superestimação da fração de ejeção do ventrículo esquerdo no gated SPECT Biological factors and overestimation of left ventricular ejection fraction by gated SPECT

    Directory of Open Access Journals (Sweden)

    Marco Antônio Condé de Oliveira

    2008-05-01

    Full Text Available FUNDAMENTO: Alguns pacientes apresentam fração de ejeção do ventrículo esquerdo (FEVE superestimada na cintilografia miocárdica com sincronização eletrocardiográfica (gated SPECT. OBJETIVO: Estabelecer a relação entre fatores biológicos e FEVE superestimada. MÉTODOS: Selecionamos 3.838 pacientes que realizaram gated SPECT entre 20/5/2000 e 16/9/2005, com imagens normais de perfusão e FEVE >50%. Analisamos as variáveis: sexo (29,4% feminino e 70,6% masculino, idade (de 20 a 94 anos - média: 56 anos, peso (de 33,5 a 150 kg - média: 79,6 kg, altura (de 138 a 220 cm - média: 171 cm e IMC (de 13,9 a 54 - média: 27,2. Em um subgrupo de 1.002 pacientes que realizaram ecocardiograma, incluímos as variáveis diâmetros diastólico (de 36 a 68 mm - média 47,5 mm e sistólico (de 22 a 41 mm - média 29,8 mm. Dividimos os pacientes em dois grupos: FEVE normal (80%. A Razão de Chances (RC para apresentar FEVE superestimada foi calculada para cada variável por regressão logística. RESULTADOS: Encontramos as seguintes Razões de Chances (p 0,2. No subgrupo de 1.002 pacientes, encontramos influência estatisticamente significativa na obtenção da FEVE superestimada para as variáveis diâmetro sistólico, sexo e altura. CONCLUSÃO: Apesar de o diâmetro sistólico influenciar na obtenção da FEVE superestimada, as variáveis sexo e altura apresentam influência independente na superestimação da FEVE pelo gated SPECT.BACKGROUND: Some patients present an overestimated left ventricular ejection fraction (LVEF on electrocardiogram-gated myocardial scintigraphy (gated SPECT. OBJECTIVE: To establish the relationship between biological factors and overestimated LVEF. METHODS: We selected 3838 patients who underwent gated SPECT between May 20, 2000 and September 16, 2005 with normal perfusion images and LVEF >50%. The following variables were analyzed: gender (29.4% females and 70.6% males, age (from 20 to 94 years - mean: 56 years, weight

  7. Combined visual and semi-quantitative assessment of (123)I-FP-CIT SPECT for the diagnosis of dopaminergic neurodegenerative diseases.

    Science.gov (United States)

    Ueda, Jun; Yoshimura, Hajime; Shimizu, Keiji; Hino, Megumu; Kohara, Nobuo

    2017-07-01

    Visual and semi-quantitative assessments of (123)I-FP-CIT single-photon emission computed tomography (SPECT) are useful for the diagnosis of dopaminergic neurodegenerative diseases (dNDD), including Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy, multiple system atrophy, and corticobasal degeneration. However, the diagnostic value of combined visual and semi-quantitative assessment in dNDD remains unclear. Among 239 consecutive patients with a newly diagnosed possible parkinsonian syndrome who underwent (123)I-FP-CIT SPECT in our medical center, 114 patients with a disease duration less than 7 years were diagnosed as dNDD with the established criteria or as non-dNDD according to clinical judgment. We retrospectively examined their clinical characteristics and visual and semi-quantitative assessments of (123)I-FP-CIT SPECT. The striatal binding ratio (SBR) was used as a semi-quantitative measure of (123)I-FP-CIT SPECT. We calculated the sensitivity and specificity of visual assessment alone, semi-quantitative assessment alone, and combined visual and semi-quantitative assessment for the diagnosis of dNDD. SBR was correlated with visual assessment. Some dNDD patients with a normal visual assessment had an abnormal SBR, and vice versa. There was no statistically significant difference between sensitivity of the diagnosis with visual assessment alone and semi-quantitative assessment alone (91.2 vs. 86.8%, respectively, p = 0.29). Combined visual and semi-quantitative assessment demonstrated superior sensitivity (96.7%) to visual assessment (p = 0.03) or semi-quantitative assessment (p = 0.003) alone with equal specificity. Visual and semi-quantitative assessments of (123)I-FP-CIT SPECT are helpful for the diagnosis of dNDD, and combined visual and semi-quantitative assessment shows superior sensitivity with equal specificity.

  8. Absolute quantitation of myocardial blood flow with {sup 201}Tl and dynamic SPECT in canine: optimisation and validation of kinetic modelling

    Energy Technology Data Exchange (ETDEWEB)

    Iida, Hidehiro; Kim, Kyeong-Min; Nakazawa, Mayumi; Sohlberg, Antti; Zeniya, Tsutomu; Hayashi, Takuya; Watabe, Hiroshi [National Cardiovascular Center Research Institute, Department of Investigative Radiology, Suita City, Osaka (Japan); Eberl, Stefan [National Cardiovascular Center Research Institute, Department of Investigative Radiology, Suita City, Osaka (Japan); Royal Prince Alfred Hospital, PET and Nuclear Medicine Department, Camperdown, NSW (Australia); Tamura, Yoshikazu [Akita Kumiai General Hospital, Department of Cardiology, Akita City (Japan); Ono, Yukihiko [Akita Research Institute of Brain, Akita City (Japan)

    2008-05-15

    {sup 201}Tl has been extensively used for myocardial perfusion and viability assessment. Unlike {sup 99m}Tc-labelled agents, such as {sup 99m}Tc-sestamibi and {sup 99m}Tc-tetrofosmine, the regional concentration of {sup 201}Tl varies with time. This study is intended to validate a kinetic modelling approach for in vivo quantitative estimation of regional myocardial blood flow (MBF) and volume of distribution of {sup 201}Tl using dynamic SPECT. Dynamic SPECT was carried out on 20 normal canines after the intravenous administration of {sup 201}Tl using a commercial SPECT system. Seven animals were studied at rest, nine during adenosine infusion, and four after beta-blocker administration. Quantitative images were reconstructed with a previously validated technique, employing OS-EM with attenuation-correction, and transmission-dependent convolution subtraction scatter correction. Measured regional time-activity curves in myocardial segments were fitted to two- and three-compartment models. Regional MBF was defined as the influx rate constant (K{sub 1}) with corrections for the partial volume effect, haematocrit and limited first-pass extraction fraction, and was compared with that determined from radio-labelled microspheres experiments. Regional time-activity curves responded well to pharmacological stress. Quantitative MBF values were higher with adenosine and decreased after beta-blocker compared to a resting condition. MBFs obtained with SPECT (MBF{sub SPECT}) correlated well with the MBF values obtained by the radio-labelled microspheres (MBF{sub MS}) (MBF{sub SPECT} = -0.067 + 1.042 x MBF{sub MS}, p < 0.001). The three-compartment model provided better fit than the two-compartment model, but the difference in MBF values between the two methods was small and could be accounted for with a simple linear regression. Absolute quantitation of regional MBF, for a wide physiological flow range, appears to be feasible using {sup 201}Tl and dynamic SPECT. (orig.)

  9. Comparison of (99m)Tc-MDP SPECT qualitative vs quantitative results in patients with suspected condylar hyperplasia.

    Science.gov (United States)

    López Buitrago, D F; Ruiz Botero, J; Corral, C M; Carmona, A R; Sabogal, A

    To compare qualitative vs quantitative results of Single Photon Emission Computerised Tomography (SPECT), calculated from percentage of (99m)Tc-MDP (methylene diphosphonate) uptake, in condyles of patients with a presumptive clinical diagnosis of condylar hyperplasia. A retrospective, descriptive study was conducted on the (99m)Tc-MDP SPECT bone scintigraphy reports from 51 patients, with clinical impression of facial asymmetry related to condylar hyperplasia referred by their specialist in orthodontics or maxillofacial surgery, to a nuclear medicine department in order to take this type of test. Quantitative data from (99m)Tc-MDP condylar uptake of each were obtained and compared with qualitative image interpretation reported by a nuclear medicine expert. The concordances between the 51 qualitative and quantitative reports results was established. The total sample included 32 women (63%) and 19 men (37%). The patient age range was 13-45 years (21±8 years). According to qualitative reports, 19 patients were positive for right side condylar hyperplasia, 12 for left side condylar hyperplasia, with 8 bilateral, and 12 negative. The quantitative reports diagnosed 16 positives for right side condylar hyperplasia, 10 for left side condylar hyperplasia, and 25 negatives. Nuclear medicine images are an important diagnostic tool, but the qualitative interpretation of the images is not as reliable as the quantitative calculation. The agreement between the two types of report is low (39.2%, Kappa=0.13; P>.2). The main limitation of quantitative reports is that they do not register bilateral condylar hyperplasia cases. Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.

  10. Qualitative and quantitative comparison of gated blood pool single photon emission computed tomography using low-energy high-resolution and SMARTZOOM collimation.

    Science.gov (United States)

    Erwin, William D; Jessop, Aaron C; Mar, Martha V; Macapinlac, Homer A; Mawlawi, Osama R

    2017-01-01

    The aim of this study was to assess the feasibility of IQ-SPECT gated blood pool (MUGA) under conditions of decreased scan time (ST). Ten patients underwent routine 26-min, two-view planar, followed by LEHR and IQ-SPECT MUGA, on a Siemens dual-head Symbia scanner. Six 'back and forth' 4-min SPECT scans were summed into 4-, 8-, 12-, 16-, 20-, and 24-min equivalent scans, and reconstructed iteratively (IQ-SPECT and LEHR) and with FBP (LEHR). Uniformity, contrast, and wall motion were scored on a five-point scale. Linear regressions of left ventricular (LV) ejection fraction (EF) were performed between FBP, Flash 3D, and IQ-SPECT versus planar and Flash 3D and IQ-SPECT versus FBP. Agreement tables between Flash 3D and IQ-SPECT versus FBP LV EF were generated using a normal versus cardiotoxicity threshold of 50%. IQ-SPECT had the best scores for all STs, and 4, 8, and 16 min IQ-SPECT were judged to be similar to 24-min LEHR FBP, Flash 3D, and planar, respectively. The average LV EF correlation coefficients were 0.69, 0.71, and 0.63 between IQ-SPECT, Flash 3D, and FBP versus planar, respectively; 0.70 between IQ-SPECT and FBP; and 0.88 between Flash 3D and FBP, and all were statistically significant (P<0.05), except for 16-min FBP LEHR versus planar. Agreement tables showed diagnostic equivalence of IQ-SPECT, Flash 3D, and FBP. These preliminary results suggest that IQ-SPECT is equivalent to LEHR Flash 3D and FBP for MUGA SPECT, and better at reduced ST. A larger patient population study is necessary for a more definitive assessment.

  11. Four-dimensional MAP-RBI-EM image reconstruction method with a 4D motion prior for 4D gated myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taek-Soo; Tsui, Benjamin M.W. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Radiology; Gullberg, Grant T. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2011-07-01

    We evaluated and proposed here a 4D maximum a posteriori rescaled-block iterative (MAP-RBI)-EM image reconstruction method with a motion prior to improve the accuracy of 4D gated myocardial perfusion (GMP) SPECT images. We hypothesized that a 4D motion prior which resembles the global motion of the true 4D motion of the heart will improve the accuracy of the reconstructed images with regional myocardial motion defect. Normal heart model in the 4D XCAT (eXtended CArdiac-Torso) phantom is used as the prior in the 4D MAP-RBI-EM algorithm where a Gaussian-shaped distribution is used as the derivative of potential function (DPF) that determines the smoothing strength and range of the prior in the algorithm. The mean and width of the DPF equal to the expected difference between the reconstructed image and the motion prior, and smoothing range, respectively. To evaluate the algorithm, we used simulated projection data from a typical clinical {sup 99m}Tc Sestamibi GMP SPECT study using the 4D XCAT phantom. The noise-free projection data were generated using an analytical projector that included the effects of attenuation, collimator-detector response and scatter (ADS) and Poisson noise was added to generated noisy projection data. The projection datasets were reconstructed using the modified 4D MAP-RBI-EM with various iterations, prior weights, and sigma values as well as with ADS correction. The results showed that the 4D reconstructed image estimates looked more like the motion prior with sharper edges as the weight of prior increased. It also demonstrated that edge preservation of the myocardium in the GMP SPECT images could be controlled by a proper motion prior. The Gaussian-shaped DPF allowed stronger and weaker smoothing force for smaller and larger difference of neighboring voxel values, respectively, depending on its parameter values. We concluded the 4D MAP-RBI-EM algorithm with the general motion prior can be used to provide 4D GMP SPECT images with improved

  12. Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc- HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Juh, Ra Hyeong; Suh, Tae Suk; Kwark, Chul Eun; Choe, Bo Young; Lee, Hyoung Koo; Chung, Yong An; Kim, Sung Hoon; Chung, Soo Kyo [College of Medicine, The Catholic Univ. of Seoul, Seoul (Korea, Republic of)

    2002-06-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of '9{sup 9m}Tc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and {sup 99m}Tc-HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map(SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

  13. Quantitative evaluation of regional cerebral blood flow by visual stimulation in {sup 99m}Tc-HMPAO brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Juh, R. H.; Suh, T. S.; Chung, Y. A. [The Catholic Univ., of Korea, Seoul (Korea, Republic of)

    2002-07-01

    The purpose of this study is to investigate the effects of visual activation and quantitative analysis of regional cerebral blood flow. Visual activation was known to increase regional cerebral blood flow in the visual cortex in occipital lobe. We evaluated that change in the distribution of 99mTc-HMPAO (Hexamethyl propylene amine oxime) to reflect in regional cerebral blood flow. The six volunteers were injected with 925 MBq (mean ages: 26.75 years, n=6, 3men, 3women) underwent MRI and 99mTc- HMPAO SPECT during a rest state with closed eyes and visual stimulated with 8 Hz LED. We delineate the region of interest and calculated the mean count per voxel in each of the fifteen slices to quantitative analysis. The ROI to whole brain ratio and regional index was calculated pixel to pixel subtraction visual non-activation image from visual activation image and constructed brain map using a statistical parameter map (SPM99). The mean regional cerebral blood flow was increased due to visual stimulation. The increase rate of the mean regional cerebral blood flow which of the activation region in primary visual cortex of occipital lobe was 32.50{+-}5.67%. The significant activation sites using a statistical parameter of brain constructed a rendering image and image fusion with SPECT and MRI. Visual activation was revealed significant increase through quantitative analysis in visual cortex. Activation region was certified in Talairach coordinate and primary visual cortex (Ba17),visual association area (Ba18,19) of Brodmann.

  14. Proprieties of quantitative evaluation of defect size by myocardial SPECT. Evaluation using myocardial phantom

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Jiro; Nakatsuka, Teruo; Fujioka, Tadao; Kashima, Kenji; Matsumura, Yasushi; Yamamoto, Kazuhiro

    1987-09-01

    The accuracy to quantify the size and the extent of Thallium-201 (Tl) uptake of defect zone by Tl single photon emission computed tomogram (SPECT) was evaluated, using myocardial phantom. Long-axis SPECT image was devided into 6 slices from apex to base, and radians were projected from the center to define 32 myocardial secters, 11.25 degrees each. Then the maximum count in each secter was plotted on each radian (maximum count circumferential profile analysis:mcCPA), and was normalized to the maximum count for the whole heart (%Tl-uptake). In this way, circumferential profile curve was obtained, and normal value in each secter of myocardial phantom with defects was analysed and the ratio of segments, %Tl-uptake of which was below the normal value, was defined as % defect volume (%DV). The difference between the value of %Tl-uptake of defect zone and the normal value was difined as defect severity, and the average of defect severity was defined as mean defect severity (mDS). We prepared myocardial phantoms with a variety of area of defect, and with a variety of thickness of defect, and acquired these SPECT images. %DV and mDS were calculated from those images and compared with real area and thickess of defect. In the phantom with given thickness of defect, %DV was closely correlated to area of defect (r > 0.976), but also correlated to thickness of defect. In the phantom with given area of defect, mDS was closely correlated to thickness of defect (r = 0.988), and also correlated to area of defect. In conclusion, %DV and mDS were good indices of the defect size and the extent of Tl-uptake respectively, but it is necessary to consider their influence on each other.

  15. Task-based evaluation of a 4D MAP-RBI-EM image reconstruction method for gated myocardial perfusion SPECT using a human observer study

    Science.gov (United States)

    Lee, Taek-Soo; Higuchi, Takahiro; Lautamäki, Riikka; Bengel, Frank M.; Tsui, Benjamin M. W.

    2015-09-01

    We evaluated the performance of a new 4D image reconstruction method for improved 4D gated myocardial perfusion (MP) SPECT using a task-based human observer study. We used a realistic 4D NURBS-based Cardiac-Torso (NCAT) phantom that models cardiac beating motion. Half of the population was normal; the other half had a regional hypokinetic wall motion abnormality. Noise-free and noisy projection data with 16 gates/cardiac cycle were generated using an analytical projector that included the effects of attenuation, collimator-detector response, and scatter (ADS), and were reconstructed using the 3D FBP without and 3D OS-EM with ADS corrections followed by different cut-off frequencies of a 4D linear post-filter. A 4D iterative maximum a posteriori rescaled-block (MAP-RBI)-EM image reconstruction method with ADS corrections was also used to reconstruct the projection data using various values of the weighting factor for its prior. The trade-offs between bias and noise were represented by the normalized mean squared error (NMSE) and averaged normalized standard deviation (NSDav), respectively. They were used to select reasonable ranges of the reconstructed images for use in a human observer study. The observers were trained with the simulated cine images and were instructed to rate their confidence on the absence or presence of a motion defect on a continuous scale. We then applied receiver operating characteristic (ROC) analysis and used the area under the ROC curve (AUC) index. The results showed that significant differences in detection performance among the different NMSE-NSDav combinations were found and the optimal trade-off from optimized reconstruction parameters corresponded to a maximum AUC value. The 4D MAP-RBI-EM with ADS correction, which had the best trade-off among the tested reconstruction methods, also had the highest AUC value, resulting in significantly better human observer detection performance when detecting regional myocardial wall motion

  16. High diagnostic accuracy of low-dose gated-SPECT with solid-state ultrafast detectors: preliminary clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Gimelli, Alessia; Genovesi, Dario; Giorgetti, Assuero; Marzullo, Paolo [CNR, Fondazione Toscana Gabriele Monasterio, Pisa (Italy); Bottai, Matteo [University of South Carolina, Division of Biostatistics, Columbia, SC (United States); Karolinska Institutet, Division of Biostatistics, Stockholm (Sweden); Di Martino, Fabio [AOUP, UO Fisica Sanitaria, Pisa (Italy)

    2012-01-15

    Appropriate use of SPECT imaging is regulated by evidence-based guidelines and appropriateness criteria in an effort to limit the burden of radiation administered to patients. We aimed at establishing whether the use of a low dose for stress-rest single-day nuclear myocardial perfusion imaging on an ultrafast (UF) cardiac gamma camera using cadmium-zinc-telluride solid-state detectors could be used routinely with the same accuracy obtained with standard doses and conventional cameras. To this purpose, 137 consecutive patients (mean age 61 {+-} 8 years) with known or suspected coronary artery disease (CAD) were enrolled. They underwent single-day low-dose stress-rest myocardial perfusion imaging using UF SPECT and invasive coronary angiography. Patients underwent the first scan with a 7-min acquisition time 10 min after the end of the stress protocol (dose range 185 to 222 MBq of {sup 99m}Tc-tetrofosmin). The rest scan (dose range 370 to 444 MBq of {sup 99m}Tc-tetrofosmin) was acquired with a 6-min acquisition time. The mean summed stress scores (SSS) and mean summed rest scores (SRS) were obtained semiquantitatively. Coronary angiograms showed significant epicardial CAD in 83% of patients. Mean SSS and SRS were 10 {+-} 5 and 3 {+-} 3, respectively. Overall the area under the ROC curve for the SSS values was 0.904, while the areas under the ROC curves for each vascular territory were 0.982 for the left anterior descending artery, 0.931 for the left circumflex artery and 0.889 for the right coronary artery. This pilot study demonstrated the feasibility of a low-dose single-day stress-rest fasting protocol performed using UF SPECT, with good sensitivity and specificity in detecting CAD at low patient exposure, opening new perspectives in the use of myocardial perfusion in ischaemic patients. (orig.)

  17. Defect of {sup 18}F-FDG Uptake Observed in Infarcted Myocardium Showing Reverse Redistribution on Rest / 24-Hour Delayed {sup 201}Tl Myocardial SPECT after Acute Myocardial Infarction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Young; Paeng, Jin Chul; Oh, So Won; Kim, Ji Yeong; Chung, Woo Young [Seoul national University College of Medicine, Seoul (Korea, Republic of)

    2008-12-15

    Reverse redistribution is frequently observed after revascularization in acute myocardial infarction, and usually regarded as a predictor of viable myocardium on stress/rest and 2- to 4-hour redistribution {sup 201}Tl SPECT. However, there is not enough report of reverse redistribution in case of 24-hour delayed SPECT, which is commonly used for viability assessment. In this report, a case of reverse redistribution on rest and 24-hour delayed {sup 201}Tl SPECT is reported with use of automatic segmental quantitative analysis. The myocardium of reverse redistribution was dysfunctional on gated SPECT, and diagnosed as non-viable on {sup 18}F-FDG PET.

  18. Detection of myocardial viability by means of Single Proton Emission Computed Tomography (Perfused SPECT) dual {sup 201} Tl (rest of 15 minutes, 24 late hours and 24 hours reinjection) and gated-SPECT {sup 99m} Tc-SESTAMIBI in effort or stimulation of the coronary reserves; Deteccion de viabilidad miocardica mediante tomografia por emision de foton unico (SPECT perfusorio) dual {sup 201} Talio (Reposo de 15 minutos, 24 horas tardio y 24 horas reinyeccion) y gated-SPECT {sup 99m} Tc-SESTAMIBI en esfuerzo o estimulo de reserva coronaria

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza V, R

    2004-07-01

    The objective of this work was to determine if the images of SPECT {sup 201} TI in rest of 15 minutes, 24 late hours and Gated-SPECT {sup 99m} Tc-SESTAMIBI in effort or stimulation of coronary reservation correlate with the study of 24 hours post reinjection of {sup 201}TI to determine the presence of having knitted viable myocardium. Material and methods: 29 patients were studied with coronary arterial illness (EAC) to who are carried out SPECT {sup 201} TI in rest with images of 15 minutes, 24 late hours and 24 hours reinjection, by means of the administration of {sup 201}TI to dose of 130 MBq and reinjection with 37 MBq. and Gated-SPECT {sup 99m}Tc-SESTAMIBI in effort or stimulation of coronary reservation, later to the administration of 1110 MBq. Results: 29 patients were included according to inclusion approaches and exclusion, of those which 22 (75.86%) they correspond at the masculine sex and 7 (24.13%) to the feminine one, with an average of 62.1 year-old age, 2320 segments myocardial were analysed so much it is phase post-effort as rest; they were diagnosed a total of 264 segments with heart attack, of which viability myocardium was observed in 174 segments. The statistical tests are analysis of frequencies. The non parametric test of Wilcoxon and Mann-Whitney. Conclusions: the viability myocardial at the 24 late hours and 24 hours reinjection was similar; significant difference exists between the study of 15 minutes and 24 hours reinjection, ischemic illness was also demonstrated in territories different to the heart attack area in the studies of 15 minutes, late 24 hours and 24 hours reinjection. (Author)

  19. Quantitative Determination on Ionic-Liquid-Gating Control of Interfacial Magnetism.

    Science.gov (United States)

    Zhao, Shishun; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Feng, Mengmeng; Yang, Qu; Yan, Yuan; Ren, Wei; Ye, Zuo-Guang; Liu, Yaohua; Liu, Ming

    2017-03-03

    Ionic-liquid gating on a functional thin film with a low voltage has drawn a lot of attention due to rich chemical, electronic, and magnetic phenomena at the interface. Here, a key challenge in quantitative determination of voltage-controlled magnetic anisotropy (VCMA) in Au/[DEME](+) [TFSI](-) /Co field-effect transistor heterostructures is addressed. The magnetic anisotropy change as response to the gating voltage is precisely detected by in situ electron spin resonance measurements. A reversible change of magnetic anisotropy up to 219 Oe is achieved with a low gating voltage of 1.5 V at room temperature, corresponding to a record high VCMA coefficient of ≈146 Oe V(-1) . Two gating effects, the electrostatic doping and electrochemical reaction, are distinguished at various gating voltage regions, as confirmed by X-ray photoelectron spectroscopy and atomic force microscopy experiments. This work shows a unique ionic-liquid-gating system for strong interfacial magnetoelectric coupling with many practical advantages, paving the way toward ion-liquid-gating spintronic/electronic devices.

  20. 4D-SPECT/CT in orthopaedics: a new method of combined quantitative volumetric 3D analysis of SPECT/CT tracer uptake and component position measurements in patients after total knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Rasch, Helmut; Falkowski, Anna L.; Forrer, Flavio [Kantonsspital Baselland, Institute for Radiology and Nuclear Medicine, Bruderholz (Switzerland); Henckel, Johann [Imperial College London, London (United Kingdom); Hirschmann, Michael T. [Kantonsspital Baselland, Department of Orthopaedic Surgery and Traumatology, Bruderholz (Switzerland)

    2013-09-15

    The purpose was to evaluate the intra- and inter-observer reliability of combined quantitative 3D-volumetric single-photon emission computed tomography (SPECT)/CT analysis including size, intensity and localisation of tracer uptake regions and total knee arthroplasty (TKA) position. Tc-99m-HDP-SPECT/CT of 100 knees after TKA were prospectively analysed. The anatomical areas represented by a previously validated localisation scheme were 3D-volumetrically analysed. The maximum intensity was recorded for each anatomical area. Ratios between the respective value and the mid-shaft of the femur as the reference were calculated. Femoral and tibial TKA position (varus-valgus, flexion-extension, internal rotation- external rotation) were determined on 3D-CT. Two consultant radiologists/nuclear medicine physicians interpreted the SPECT/CTs twice with a 2-week interval. The inter- and intra-observer reliability was determined (ICCs). Kappa values were calculated for the area with the highest tracer uptake between the observers. The measurements of tracer uptake intensity showed excellent inter- and intra-observer reliabilities for all regions (tibia, femur and patella). Only the tibial shaft area showed ICCs <0.89. The kappa values were almost perfect (0.856, p < 0.001; 95 % CI 0.778, 0.922). For measurements of the TKA position, there was strong agreement within and between the readings of the two observers; the ICCs for the orientation of TKA components for inter- and intra-observer reliability were nearly perfect (ICCs >0.84). This combined 3D-volumetric standardised method of analysing the location, size and the intensity of SPECT/CT tracer uptake regions (''hotspots'') and the determination of the TKA position was highly reliable and represents a novel promising approach to biomechanics. (orig.)

  1. Effectiveness of quantitative MAA SPECT/CT for the definition of vascularized hepatic volume and dosimetric approach: phantom validation and clinical preliminary results in patients with complex hepatic vascularization treated with yttrium-90-labeled microspheres.

    Science.gov (United States)

    Garin, Etienne; Lenoir, Laurence; Rolland, Yan; Laffont, Sophie; Pracht, Marc; Mesbah, Habiba; Porée, Philippe; Ardisson, Valérie; Bourguet, Patrick; Clement, Bruno; Boucher, Eveline

    2011-12-01

    The goal of this study was to assess the use of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) analysis for vascularized volume measurements in the use of the yttrium-90-radiolabeled microspheres (TheraSphere). A phantom study was conducted for the validation of SPECT/CT volume measurement. SPECT/CT quantitative analysis was used for the measurement of the volume of distribution of the albumin macroaggregates (MAA; i.e., the vascularized volume) in the liver and the tumor, and the total activity contained in the liver and the tumor in four consecutive patients presenting with a complex liver vascularization referred for a treatment with TheraSphere. SPECT/CT volume measurement proved to be accurate (mean error data, instead of angiography and CT data, results in modifying the activity injected for three treatments of eight. Moreover, quantitative analysis of SPECT/CT allows us to calculate the absorbed dose in the tumor and in the healthy liver, leading to doubling of the injected activity for one treatment of eight. MAA SPECT/CT is accurate for volume measurements. It provides a valuable contribution to the therapeutic planning of patients presenting with complex hepatic vascularization, in particular for calculating the vascularized liver volume, the activity to be injected and the absorbed doses. Studies should be conducted to assess the role of quantitative MAA/SPECT CT in therapeutic planning.

  2. Left ventricular dyssynchrony assessed by two three-dimensional imaging modalities: phase analysis of gated myocardial perfusion SPECT and tri-plane tissue Doppler imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ajmone Marsan, Nina [Leiden University Medical Center, Department of Cardiology, Albinusdreef 2, ZA, Leiden (Netherlands); Policlinico S. Matteo, Department of Cardiology, Pavia (Italy); Henneman, Maureen M.; Ypenburg, Claudia; Bleeker, Gabe B.; Bax, Jeroen J. [Leiden University Medical Center, Department of Cardiology, Albinusdreef 2, ZA, Leiden (Netherlands); Chen, Ji; Garcia, Ernest V. [Emory University School of Medicine, Department of Radiology, Atlanta, Georgia (United States); Dibbets, Petra; Stokkel, Marcel P. [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands); Ghio, Stefano; Tavazzi, Luigi [Policlinico S. Matteo, Department of Cardiology, Pavia (Italy); Wall, Ernst E. van der [Leiden University Medical Center, Department of Cardiology, Albinusdreef 2, ZA, Leiden (Netherlands); The Interuniversity Cardiology Institute of the Netherlands, Utrecht (Netherlands)

    2008-01-15

    To compare left ventricular (LV) dyssynchrony assessment by phase analysis from gated myocardial perfusion SPECT (GMPS) with LV dyssynchrony assessment by tri-plane tissue Doppler imaging (TDI). Baseline LV dyssynchrony assessed with standard deviation (SD) of time-to-peak systolic velocity of 12 LV segments (Ts-SD) with TDI has proven to be a powerful predictor of response to CRT. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle. Forty heart failure patients, referred for evaluation of potential eligibility for CRT, underwent both 3D echocardiography, with tri-plane TDI, and resting GMPS. From tri-plane TDI, Ts-SD was used as a validated parameter of LV dyssynchrony and compared with different indices (histogram bandwidth, phase SD, histogram skewness and kurtosis) derived from phase analysis of GMPS. Histogram bandwidth and phase SD showed good correlation with Ts-SD (r=0.77 and r=0.74, p<0.0001, respectively). Patients with substantial LV dyssynchrony assessed with tri-plane TDI (Ts-SD {>=}33 ms) had also significantly higher values of histogram bandwidth and phase SD. The results of this study support the use of phase analysis by GMPS to evaluate LV dyssynchrony. Histogram bandwidth and phase SD showed the best correlation with Ts-SD assessed with tri-plane TDI and appeared the most optimal variables for assessment of LV dyssynchrony with GMPS. (orig.)

  3. The significance of post-stress decrease in left ventricular ejection fraction in patients undergoing regadenoson stress gated SPECT myocardial perfusion imaging.

    Science.gov (United States)

    Gomez, Javier; Golzar, Yasmeen; Fughhi, Ibtihaj; Olusanya, Adebayo; Doukky, Rami

    2017-02-08

    The significance of post-stress decrease in left ventricular ejection fraction (LVEF) with regadenoson stress gated SPECT (GSPECT) myocardial perfusion imaging (MPI) has not been studied. Consecutive patients who underwent rest/regadenoson stress GSPECT-MPI followed by coronary angiography within 6 months were analyzed. Change in LVEF by GSPECT-MPI was calculated as stress LVEF minus rest LVEF; a significant decrease was tested at 5% and 10% thresholds. In a diagnostic cohort of 793 subjects, LVEF change was not predictive of severe/extensive coronary artery disease (area under the curve, 0.50; 95% confidence interval, 0.44-0.57; P = 0.946). There was no significant difference in the rates of severe/extensive coronary artery disease in patients with or without a decrease in LVEF, irrespective of MPI findings. In an outcome cohort of the 929 subjects followed for 30 ± 16 months, post-regadenoson stress decrease in LVEF was not associated with increased risk of the composite endpoint of cardiac death or myocardial infarction or in the risk of coronary revascularization. In patients selected to undergo coronary angiography following regadenoson stress GSPECT-MPI, a decrease in LVEF after regadenoson stress is not predictive of severe/extensive CAD or adverse clinical outcomes, irrespective of MPI findings.

  4. Prognostic implications of post-stress ejection fraction decrease detected by gated SPECT in the absence of stress-induced perfusion abnormalities

    Energy Technology Data Exchange (ETDEWEB)

    Dona, Manjola; Massi, Lucia; Settimo, Leonardo; Bartolini, Matteo; Gianni, Gianluca; Pupi, Alberto; Sciagra, Roberto [University of Florence, Nuclear Medicine Unit, Department of Clinical Physiopathology, Florence (Italy)

    2011-03-15

    The prognostic meaning of a post-stress ejection fraction (EF) decrease detected by perfusion gated SPECT is still unclear. We therefore followed up patients with post-stress EF decrease in the absence of stress-induced perfusion abnormalities. We prospectively enrolled 57 consecutive patients with post-stress EF drop {>=} 5 EF units and summed difference score (SDS) {<=} 1. They were followed up for more than 1 year and their outcome was compared with a group of sex- and age-matched controls with the same SDS but without EF decrease. During follow-up there were 13 events (1 cardiac death, 1 non-fatal myocardial infarction, 1 congestive heart failure and 10 late revascularizations). In the control group we registered six events. There was a significant difference (p < 0.0001) between the event-free survival curves of the two groups. The event rate of patients with post-stress EF decrease {>=} 5 EF units is relatively high and is significantly worse than that of a control group of patients with similarly normal SDS but without EF changes. Therefore, a post-stress EF decrease without stress-induced perfusion abnormalities should be cautiously interpreted. (orig.)

  5. Quantitative Tc-99m myocardial perfusion SPECT with 180[degree] acquisition

    Energy Technology Data Exchange (ETDEWEB)

    Ye, J.

    1992-01-01

    Myocardial perfusion single photon emission computed tomography (SPECT) images using 180[degrees] acquisition are degraded by the effects of scatter, nonuniform attenuation and system geometric resolution variation with source depth. Using a 180[degrees] scan orbit which is closer to the heart may provide higher image resolution, signal-to-noise ratio and defect-to-normal contrast than using a 360[degrees] orbit, however, significant object shape distortion has been observed in the 180[degrees] reconstructed images. A method has been developed that combines filtered back-projection (FBP) with iterative attenuation and three-dimensional (3-D) resolution compensation for Tc-99m myocardial perfusion imaging, data. The non-uniform attenuation coefficient distribution is obtained by a quick transmission scan using a flood source and segmentation of the reconstructed transmission image to define areas of significantly different attenuation. A priori attenuation coefficients are assigned to the areas to form the attenuation distribution map. The 3-D correction is accomplished by including both the non-uniform attenuation and depth-dependent resolution variation in the reprojection procedure of an iterative correction algorithm. The method was evaluated with both simulated and experimental data using clinical protocols with a cardiac phantom. A significant improvement in image resolution was observed with line source images was reduced from approximately 10 mm to 7.l5 mm after 7 iterations of the 3-D correction. The contrast of two perfusion defects to the surrounding normally perfused regions was significantly improved with the correction. Significant improvement in uniformity at different positions in the 100% perfused areas in the myocardium was also observed. The normalized root squared error (NRSE) of one transaxial image from the original source distribution in the simulation study was reduced from 0.8 to 0.2 after 5 iterations of the 3-D correction.

  6. Quantitative Assessment of Radioisotope Uptake in Condyles by SPECT Bone Scintigraphy

    Directory of Open Access Journals (Sweden)

    Z. Dalili

    2006-03-01

    Full Text Available Statement of problem: Condylar hyperplasia of the mandible is a self limiting abnormality which can cause facial asymmetry, temporomandibular joint (TMJdysfunction and esthetic problems. Treatment planning is based on the results of isotope scanning, clinical findings and patient age. Single photon emission tomography(SPECT is considered to be a sensitive method in the calculation of condylar uptake differences.Purpose: The aim of this study was to determine the growth activity occurring in the mandibular condyles, and to devise an index of side-to-side differences in condylar activity in different individuals.Material and Methods: 38 patients, with an age range of 13 to 34 years, undergoing skeletal scintigraphy for a variety of conditions, were chosen for this study. 25 mci TC-99 was injected to all subjects in order to assess the difference between right (Rt andleft (Lt condylar uptake percentage and to calculate the Lt to Rt condylar uptake ratio.The normal index was determined.Results: The maximum amount of difference between the uptake of Rt and Lt condyles was 6.2 percent (Lt side and Rt side were 53.1 % and 46.9 %, respectively in the male patients and 5.7 percent in the female patients (Lt side and Rt side were 52.85 % and 47.15 %, respectively. The condylar activity difference and ratio of Lt to Rt condylar uptakes did not show a significant difference between the male and female groups.Conclusion: The difference between the growth activity of RT and LT normal TMJs was less than 6.2 percent.

  7. Evaluation of crossed cerebellar diaschisis in 30 patients with major cerebral artery occlusion by means of quantitative I-123 IMP SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Miyazawa, Nobuhiko; Toyama, Keiji; Arbab, A.S.; Arai, Takao; Nukui, Hideaki [Yamanashi Medical Univ., Tamaho (Japan); Koizumi, Kiyoshi

    2001-12-01

    Quantitative crossed cerebellar diaschisis (CCD) and the correlation with a reduction in supratentorial regional cerebral blood flow (rCBF) and cerebrovascular reserve capacity (CVR) were investigated in clinically stable patients with major cerebral artery occlusion by the iodine-123-N-isopropyl-p-iodoamphetamine (I-123 IMP) single photon emission computed tomography (SPECT) method. Thirty patients with major cerebral artery occlusion underwent SPECT by the I-123 IMP autoradiographic method. Regional CBF was measured in the cerebral hemisphere, frontal and parietal lobes, temporo-parietal lobe, and cerebellum both at rest and after administration of acetazolamide. Eighteen of 30 patients (60%) had CCD. CCD was significantly related to magnetic resonance imaging evidence of infarction. Quantitative CCD was 17% and the CVR in the cerebellum was preserved in patients with CCD. There was a significant difference in CBF and CVR between the affected and normal sides in all regions of interest in the patients without CCD [CBF (ml/100 g/min): hemisphere (H), normal side (N): 31.4{+-}6.8, affected side (A): 27.5{+-}7.4; p<0.05. CVR: H, N: 0.56{+-}0.38, A: 0.42{+-}0.18; p<0.01]. CCD is common in patients with major cerebral artery occlusion, and quantitative I-123 IMP SPECT is helpful in detecting CCD in clinically stable patients with occlusion of major cerebral arteries. (author)

  8. Comparison of two different segmentation methods on planar lung perfusion scan with reference to quantitative value on SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Min Seok; Kang, Yeon Koo; Ha, Seung Gyun [Dept. of Nuclear Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); and others

    2017-06-15

    Until now, there was no single standardized regional segmentation method of planar lung perfusion scan. We compared planar scan based two segmentation methods, which are frequently used in the Society of Nuclear Medicine, with reference to the lung perfusion single photon emission computed tomography (SPECT)/computed tomography (CT) derived values in lung cancer patients. Fifty-five lung cancer patients (male:female, 37:18; age, 67.8 ± 10.7 years) were evaluated. The patients underwent planar scan and SPECT/CT after injection of technetium-99 m macroaggregated albumin (Tc-99 m-MAA). The % uptake and predicted postoperative percentage forced expiratory volume in 1 s (ppoFEV1%) derived from both posterior oblique (PO) and anterior posterior (AP) methods were compared with SPECT/CT derived parameters. Concordance analysis, paired comparison, reproducibility analysis and spearman correlation analysis were conducted. The % uptake derived from PO method showed higher concordance with SPECT/CT derived % uptake in every lobe compared to AP method. Both methods showed significantly different lobar distribution of % uptake compared to SPECT/CT. For the target region, ppoFEV1% measured from PO method showed higher concordance with SPECT/CT, but lower reproducibility compared to AP method. Preliminary data revealed that every method significantly correlated with actual postoperative FEV1%, with SPECT/CT showing the best correlation. The PO method derived values showed better concordance with SPECT/CT compared to the AP method. Both PO and AP methods showed significantly different lobar distribution compared to SPECT/CT. In clinical practice such difference according to different methods and lobes should be considered for more accurate postoperative lung function prediction.

  9. A quantitative assessment of heart phantom motion and its effect on myocardial perfusion SPECT images

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to study the image characteristics of motion artifacts and todetermine the relations of motion artifacts with varied motion types, and the inag-ing timings, frames, distances and directions during SPECT acquisition, a myocardialphantom filled with pertechnetate solution was used to simulate the patient motion.In nonreturning pattern, the simulation motion was timed at the 0°, -45° and -90°positions during the rotation of the detector over a 180° arc from +45° right antcrioroblique to -135° left posterior oblique. Simulation motion was performed by movingthe phantom +5mm, ±-10mm and +20mm along X- (from left to right), Y- (fromhead to caudal) and Z-axis (from back to ventral) respectively. In returning patternthe acquired 30 projections were divided into three equal parts. The simulation motionwas timed at the middle 1-7 projections of each part and performed by moving thephantom +5, ±10, ±15, ±20, ±25, ±30 and ±50 mm along X-, Y- and Z-axis respec-tively. Each image was compared with normal image and assessed by three experiencedobservers without knowledge of the phantom motion. Logistic regression analysis wasused to determine the relationship of motion artifacts with the affecting factors. Nosignificant artifacts can be found when the phantom was moved slightly, no matterwhich motion pattern, direction and timing were taken. The characteristics of motionartifacts showed a radioactive marker dot in inferior wall firstly when the phantomwas moved along X-axis. Septal and lateral wall became "hot" symmetrically whenthe phantom was moved along Y-axis. And nodular hot could be found in anteriorwall when the phantom was moved along Z-axis. At last the "lumpy" and "defect"areas existed alternately and formed a triangle respectively. The presence of motionartifacts was related to motion directions, distance and affected frames, but was in-dependent of motion timing. The characteristics of motion artifacts could be foundwhen the phantom was moved

  10. Simplifying volumes-of-interest (VOIs) definition in quantitative SPECT: Beyond manual definition of 3D whole-organ VOIs.

    Science.gov (United States)

    Vicente, Esther M; Lodge, Martin A; Rowe, Steven P; Wahl, Richard L; Frey, Eric C

    2017-05-01

    We investigated the feasibility of using simpler methods than manual whole-organ volume-of-interest (VOI) definition to estimate the organ activity concentration in single photon emission computed tomography (SPECT) in cases where the activity in the organ can be assumed to be uniformly distributed on the scale of the voxel size. In particular, we investigated an anatomic region-of-interest (ROI) defined in a single transaxial slice, and a single sphere placed inside the organ boundaries. The evaluation was carried out using Monte Carlo simulations based on patient indium (111) In pentetreotide SPECT and computed tomography (CT) images. We modeled constant activity concentrations in each organ, validating this assumption by comparing the distribution of voxel values inside the organ VOIs of the simulated data with the patient data. We simulated projection data corresponding to 100, 50, and 25% of the clinical count level to study the effects of noise level due to shortened acquisition time. Images were reconstructed using a previously validated quantitative SPECT reconstruction method. The evaluation was performed in terms of the accuracy and precision of the activity concentration estimates. The results demonstrated that the non-uniform image intensity observed in the reconstructed images in the organs with normal uptake was consistent with uniform activity concentration in the organs on the scale of the voxel size; observed non-uniformities in image intensity were due to a combination of partial-volume effects at the boundaries of the organ, artifacts in the reconstructed image due to collimator-detector response compensation, and noise. Using an ROI defined in a single transaxial slice produced similar biases compared to the three-dimensional (3D) whole-organ VOIs, provided that the transaxial slice was near the central plane of the organ and that the pixels from the organ boundaries were not included in the ROI. Although this slice method was sensitive to noise

  11. Stress-induced myocardial ischemia is associated with early post-stress left ventricular mechanical dyssynchrony as assessed by phase analysis of {sup 201}Tl gated SPECT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chien-Cheng; Shen, Thau-Yun [Show Chwan Memorial Hospital, Department of Cardiology, Changhua (China); Chang, Ming-Che [Changhua Christian Hospital, Department of Nuclear Medicine, Changhua (China); Hung, Guang-Uei [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Wan-Chen [Chang Bing Show Chwan Memorial Hospital, Department of Nuclear Medicine, Changhua (China); Kao, Chia-Hung [China Medical University, Department of Biomedical Imaging and Radiological Science, Taichung (China); Chen, Ji [Emory University School of Medicine, Department of Radiology and Imaging Sciences, Atlanta, GA (United States)

    2012-12-15

    In {sup 201}Tl SPECT myocardial perfusion imaging (MPI) data are acquired shortly after the stress injection to assess early post-stress left ventricle (LV) function. The purpose of this study was to use {sup 201}Tl SPECT MPI to investigate whether stress-induced myocardial ischemia is associated with LV mechanical dyssynchrony. Enrolled in the study were 75 patients who were referred for dipyridamole stress and rest {sup 201}Tl gated SPECT MPI. The early post-stress scan was started 5 min after injection, and followed by the rest scan 4 h later. The patients were divided into three groups: ischemia group (N = 25, summed stress score, SSS, {>=}5, summed rest score, SRS, <5), infarct group (N = 16, SSS {>=}5, SRS {>=}5) and normal group (N = 34, SSS <5, SRS <5). LV dyssynchrony parameters were calculated by phase analysis, and compared between the stress and rest images. In the ischemia group, LV dyssynchrony was significantly larger during stress than during rest. On the contrary, LV dyssynchrony during stress was significantly smaller than during rest in the normal and infarct groups. LV dyssynchrony during rest was significantly larger in the infarct group than in the normal and ischemia groups. There were no significant differences in LV dyssynchrony during rest between the normal and ischemia groups. Stress-induced myocardial ischemia caused dyssynchronous contraction in the ischemic region, leading to a deterioration in LV synchrony. Normal myocardium had more synchronous contraction during stress. The different dyssynchrony pattern between ischemic and normal myocardium early post-stress may aid the diagnosis of coronary artery disease using {sup 201}Tl gated SPECT MPI. (orig.)

  12. Left ventricular dyssynchrony assessed by two three-dimensional imaging modalities: phase analysis of gated myocardial perfusion SPECT and tri-plane tissue Doppler imaging

    Science.gov (United States)

    Ajmone Marsan, Nina; Henneman, Maureen M.; Chen, Ji; Ypenburg, Claudia; Dibbets, Petra; Ghio, Stefano; Bleeker, Gabe B.; Stokkel, Marcel P.; van der Wall, Ernst E.; Tavazzi, Luigi; Garcia, Ernest V.

    2007-01-01

    Purpose To compare left ventricular (LV) dyssynchrony assessment by phase analysis from gated myocardial perfusion SPECT (GMPS) with LV dyssynchrony assessment by tri-plane tissue Doppler imaging (TDI). Baseline LV dyssynchrony assessed with standard deviation (SD) of time-to-peak systolic velocity of 12 LV segments (Ts-SD) with TDI has proven to be a powerful predictor of response to CRT. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle. Methods Forty heart failure patients, referred for evaluation of potential eligibility for CRT, underwent both 3D echocardiography, with tri-plane TDI, and resting GMPS. From tri-plane TDI, Ts-SD was used as a validated parameter of LV dyssynchrony and compared with different indices (histogram bandwidth, phase SD, histogram skewness and kurtosis) derived from phase analysis of GMPS. Results Histogram bandwidth and phase SD showed good correlation with Ts-SD (r=0.77 and r=0.74, p<0.0001, respectively). Patients with substantial LV dyssynchrony assessed with tri-plane TDI (Ts-SD ≥33 ms) had also significantly higher values of histogram bandwidth and phase SD. Conclusions The results of this study support the use of phase analysis by GMPS to evaluate LV dyssynchrony. Histogram bandwidth and phase SD showed the best correlation with Ts-SD assessed with tri-plane TDI and appeared the most optimal variables for assessment of LV dyssynchrony with GMPS. PMID:17874098

  13. 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.

  14. Gamma camera calibration and validation for quantitative SPECT imaging with (177)Lu.

    Science.gov (United States)

    D'Arienzo, M; Cazzato, M; Cozzella, M L; Cox, M; D'Andrea, M; Fazio, A; Fenwick, A; Iaccarino, G; Johansson, L; Strigari, L; Ungania, S; De Felice, P

    2016-06-01

    Over the last years (177)Lu has received considerable attention from the clinical nuclear medicine community thanks to its wide range of applications in molecular radiotherapy, especially in peptide-receptor radionuclide therapy (PRRT). In addition to short-range beta particles, (177)Lu emits low energy gamma radiation of 113keV and 208keV that allows gamma camera quantitative imaging. Despite quantitative cancer imaging in molecular radiotherapy having been proven to be a key instrument for the assessment of therapeutic response, at present no general clinically accepted quantitative imaging protocol exists and absolute quantification studies are usually based on individual initiatives. The aim of this work was to develop and evaluate an approach to gamma camera calibration for absolute quantification in tomographic imaging with (177)Lu. We assessed the gamma camera calibration factors for a Philips IRIX and Philips AXIS gamma camera system using various reference geometries, both in air and in water. Images were corrected for the major effects that contribute to image degradation, i.e. attenuation, scatter and dead- time. We validated our method in non-reference geometry using an anthropomorphic torso phantom provided with the liver cavity uniformly filled with (177)LuCl3. Our results showed that calibration factors depend on the particular reference condition. In general, acquisitions performed with the IRIX gamma camera provided good results at 208keV, with agreement within 5% for all geometries. The use of a Jaszczak 16mL hollow sphere in water provided calibration factors capable of recovering the activity in anthropomorphic geometry within 1% for the 208keV peak, for both gamma cameras. The point source provided the poorest results, most likely because scatter and attenuation correction are not incorporated in the calibration factor. However, for both gamma cameras all geometries provided calibration factors capable of recovering the activity in

  15. Semi-quantitative model of the gating of KcsA ion channel. 2. Dynamic self-organization model of the gating

    Directory of Open Access Journals (Sweden)

    Boiteux C.

    2009-12-01

    Full Text Available The aim of this series of papers is to develop the semi-quantitative theory of the gating of KcsA channel. Methods. For this purpose available structural and electrophysiological data and the results of molecular dynamics simulations were used in the context of the concept of dynamical self-organization. In the second paper we describe the principles of dynamic self-organization and develop the theory of KcsA channel gating based on this concept. Conclusions. Present work is the first successful attempt of combining the structure and dynamics of real protein and the general concept of dynamic self-organization

  16. Quantitative assessment of left-sided valvular regurgitation by multi-gated equilibrium scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kosuda, Shigeru; Kunieda, Etsuo; Takagi, Yaeko (Keio Univ., Tokyo (Japan). School of Medicine)

    1983-04-01

    In order to evaluate quantitatively left-sided valvular regurgitation by multi-gated equilibrium scintigraphy, regurgitant fraction (RF) was defined as following, RF = (LVCO - RVCO)/RVCO = SVR - 1. LVCO; left ventricular count output. RVCO; right ventricular count output. SVR; stroke volume ratio. RF values in 70 subjects were calculated after multigated equilibrium scintigraphies were performed. In 85% of 54 subjects without regurgitation, RF was less than 0.5 (MEAN +- S.D. 0.29 +- 0.28). In all of 16 patients with mitral and/or aortic regurgitation, RF was more than 0.5 (MEAN +- S.D. 1.68 +- 0.99) (P<0.001). Furthermore, the value of RF indicated the severity of regurgitation based on Sellers' criteria determined by contrast angiography. After successful valve replacement, post-operative RF reduced and were within normal values. We conclude that RF by multi-gated equilibrium scintigraphy permits noninvasive, quantitative assessment of left-sided valvular regurgitation, and RF is highly reproducible and useful for post-operative assessment in patients with valvular regurgitation.

  17. Respiratory-gated PET/CT versus delayed images for the quantitative evaluation of lower pulmonary and hepatic lesions.

    Science.gov (United States)

    Tahari, Abdel K; Lodge, Martin A; Wahl, Richard L

    2014-01-01

    Respiratory motion degrades fluorodeoxyglucose positron emission tomography (FDG PET) images of the lower chest and upper abdomen, as the blur introduced by breathing motion increases the apparent size of the moving tumour lesions and decreases their apparent uptake, reducing the sensitivity of PET in detection of small lesions. We assessed the role of delayed and respiratory-gated PET acquisition in the quantitative evaluation of lung and liver lesions. A retrospective analysis of 64 lesions was performed. After initial non-gated whole-body PET/CT, respiratory gating was performed with 15 min in list mode. Non-gated delayed images were obtained by summing all list mode data. SUV(max) adjusted for lean body mass (SUL(max)) was measured in the initial whole-body scan, the delayed non-gated scans and the individual gated bins for each lesion. The axial z-position of SUL(max) for each lesion in five respiratory-gated bins was determined. The mean SUL of the non-pathological liver parenchyma was also recorded for each patient. Tumour lesion SUL(max) increased by an average of 34% in the delayed non-gated scan as compared with the whole-body initial scan and further by an additional 17.2% in respiratory-gated images. The maximum lesion displacement was 6.2 ± 5.0 mm. Delayed imaging alone substantially increases the magnitude of the SUL of liver and lung lesions as compared with standard whole-body images and may allow for a more accurate definition of the lesion's volume and localisation and improve tracer quantitation in malignant lesions in the lungs or upper abdomen. While respiratory gating provides more optimal imaging with greatest increase in SUL(max), the benefit is small, and delayed imaging appears sufficient in most cases. © 2014 The Royal Australian and New Zealand College of Radiologists.

  18. Combined use of 64-slice computed tomography angiography and gated myocardial perfusion SPECT for the detection of functionally relevant coronary artery stenoses. First results in a clinical setting concerning patients with stable angina

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, M.; Hack, N.; Tiling, R. [Klinikum Grosshadern (Germany). Dept. of Nuclear Medicine; Jakobs, T.; Nikolaou, K.; Becker, C. [Klinikum Grosshadern (Germany). Dept. of Clinical Radiology; Ziegler, F. von; Knez, A. [Klinikum Grosshadern (Germany). Dept. of Cardiology; Koenig, A.; Klauss, V. [Medizinische Poliklinik-Innenstadt, Univ. of Munich (Germany). Dept. of Cardiology

    2007-07-01

    Aim: In patients with stable angina pectoris both morphological and functional information about the coronary artery tree should be present before revascularization therapy is performed. High accuracy was shown for spiral computed tomography (MDCT) angiography acquired with a 64-slice CT scanner compared to invasive coronary angiography (ICA) in detecting ''obstructive'' coronary artery disease (CAD). Gated myocardial SPECT (MPI) is an established method for the noninvasive assessment of functional significance of coronary stenoses. Aim of the study was to evaluate the combination of 64-slice CT angiography plus MPI in comparison to ICA plus MPI in the detection of hemodynamically relevant coronary artery stenoses in a clinical setting. Patients, methods: 30 patients (63 {+-} 10.8 years, 23 men) with stable angina (21 with suspected, 9 with known CAD) were investigated. MPI, 64-slice CT angiography and ICA were performed, reversible and fixed perfusion defects were allocated to determining lesions separately for MDCT angiography and ICA. The combination of MDCT angiography plus MPI was compared to the results of ICA plus MPI. Results: Sensitivity, specificity, negative and positive predictive value for the combination of MDCT angiography plus MPI was 85%, 97%, 98% and 79%, respectively, on a vessel-based and 93%, 87%, 93% and 88%, respectively, on a patient-based level. 19 coronary arteries with stenoses =50% in both ICA and MDCT angiography showed no ischemia in MPI. Conclusion: The combination of 64-slice CT angiography and gated myocardial SPECT enabled a comprehensive non-invasive view of the anatomical and functional status of the coronary artery tree. (orig.)

  19. Comparison of diagnostic sensitivity and quantitative indices between {sup 68}Ga-DOTATOC PET and {sup 111}In-pentetreotide SPECT/CT in neuroendocrine tumors: A preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Ki; Paeng, Jin Chul; Shin, Chan Soo; Lee, Soo Jin; Jang, Jin Young; Cheon, Gi Jeong; Lee, Dong Soo; Chung, June Key; Kang, Keon Wook [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2015-12-15

    In-pentetreotide has been used for neuroendocrine tumors expressing somatostatin receptors. Recently, {sup 68}Ga-DOTATOC PET has been used with the advantage of high image quality. In this study, we compared quantitative indices between {sup 111}In-pentetreotide SPECT/CT and {sup 68}Ga-DOTATOC PET/CT. Thirteen patients diagnosed with neuroendocrine tumors were prospectively recruited. Patients underwent {sup 111}In-pentetreotide scans with SPECT/CT and {sup 68}Ga-DOTATOC PET/CT before treatment. The number and location of lesions were analyzed on both imaging techniques to compare lesion detectability. Additionally, the maximal uptake count of each lesion and mean uptake count of the lungs were measured on both imagings, and target-to-normal lung ratios (TNR) were calculated as quantitative indices. Among 13 patients, 10 exhibited lesions with increased uptake on {sup 111}In-pentetreotide SPECT/CT and/or {sup 68}Ga-DOTATOC PET/CT. Scans with SPECT/CT detected 19 lesions, all of which were also detected on PET/CT. Moreover, 16 additional lesions were detected on PET/CT (6 in the liver, 9 in the pancreas and 1 in the spleen). PET/CT exhibited a significantly higher sensitivity than SPECT/CT (100 % vs. 54 %, P < 0.001). TNR was significantly higher on PET/CT than on SPECT/CT (99.9 ± 84.3 vs. 71.1 ± 114.9, P < 0.001) in spite of a significant correlation (r = 0.692, P = 0.01). Ga-DOTATOC PET/CT has a higher diagnostic sensitivity than {sup 111}In-pentetreotide scans with SPECT/CT. The TNR on PET/CT is higher than that of SPECT/CT, which also suggests the higher sensitivity of PET/CT. {sup 111}In-pentetreotide SPECT/CT should be used carefully if it is stead of {sup 68}Ga-DOTATOC PET/CT.

  20. Assessment of cerebral hemodynamics before and after revascularization in patients with occlusive cerebrovascular disease by means of quantitative IMP-SPECT with double-injection protocol

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Makoto; Nishizawa, Sadahiko; Toyoda, Hiroshi; Shimono, Taro; Miyamoto, Susumu; Hashimoto, Nobuo; Konishi, Junji [Kyoto Univ. (Japan). Graduate School of Medicine

    2001-06-01

    The purpose of this study was to validate a double-injection (DI) method with N-isopropyl-[{sup 123}I]p-iodoamphetamine (IMP) to measure regional cerebral blood flow (rCBF) twice in a single session of dynamic SPECT and to elucidate a possible role of this method to identify patients with occlusive disease of major cerebral arteries, who might benefit from cerebral revascularization procedures (CR). Fourteen patients with occlusion or severe stenosis of the internal carotid or middle cerebral artery were studied before and after CR to assess hemodynamic changes after revascularization treatment. We quantitatively measured rCBF before and after acetazolamide (ACZ) challenge along with cerebrovascular reserve capacity (CVR) with two injections of IMP in a single session of dynamic SPECT scans (DI method). The reliability and reproducibility of the DI method were validated by means of a simulation study and in eight patients who were examined without ACZ challenge to measure baseline rCBF twice. The analysis of simulated noisy data with realistic noise levels showed that the errors of the estimates for the first and the second rCBF and for the increase in rCBF were 2.6%, 8.1% and 10.4%, respectively. In the 8 patients examined by the DI method to measure baseline rCBF twice, the mean and the SD of percentage differences between the two consecutive measurements in rCBF were -1.3% and 5.5%, respectively. Eight out of 14 patients with occlusive disease had at least one region with a CVR less than 10%. They showed a significant increase in resting rCBF after CR, not only in the ipsilateral hemisphere (from 26.1{+-}6.4 to 33.4{+-}4.7) but also in the contralateral one (from 28.3{+-}7.0 to 34.7{+-}4.7) with a recovery of the ipsilateral CVR from 9.3{+-}17.2 to 41.2{+-}20.1%. The remaining six patients with good-moderate CVR did not show an increase in rCBF after CR (from 28.0{+-}2.7 to 28.3{+-}3.4). The three of them with a moderate CVR (10-25%) before CR showed

  1. Left ventricle function in patients with ischemic cardiopathy: determination of the expulsion fraction of the left ventricle with gated-SPECT. Experience in the CMN 20 de Noviembre ISSSTE; Funcion ventricular izquierda en pacientes con cardiopatia isquemica: determinacion de la fraccion de expulsion del ventriculo izquierdo con gated-SPECT. Experiencia en el CMN 20 de Noviembre ISSSTE

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, L.; Puente, A.; Hernandez, T.; Jimenez, L. [Departamento de Medicina Nuclear y Cardiologia, Hospital CMN 20 de Noviembre, ISSSTE, 03000 Mexico D.F. (Mexico)

    2007-07-01

    The objective of this work is to correlate the expulsion fraction of the left ventricle (FEVI) obtained by means of g-SPECT and other diagnostic methods: ECO 2D and ventriculography for heart catheterization (CTT). (Author)

  2. Validation of semi-quantitative methods for DAT SPECT: influence of anatomical variability and partial volume effect

    Science.gov (United States)

    Gallego, J.; Niñerola-Baizán, A.; Cot, A.; Aguiar, P.; Crespo, C.; Falcón, C.; Lomeña, F.; Sempau, J.; Pavía, J.; Ros, D.

    2015-08-01

    The aim of this work was to evaluate the influence of anatomical variability between subjects and of the partial volume effect (PVE) on the standardized Specific Uptake Ratio (SUR) in [123I]FP-bib SPECT studies. To this end, magnetic resonance (MR) images of 23 subjects with differences in the striatal volume of up to 44% were segmented and used to generate a database of 138 Monte Carlo simulated SPECT studies. Data included normal uptakes and pathological cases. Studies were reconstructed by filtered back projection (FBP) and the ordered-subset expectation-maximization algorithm. Quantification was carried out by applying a reference method based on regions of interest (ROIs) derived from the MR images and ROIs derived from the Automated Anatomical Labelling map. Our results showed that, regardless of anatomical variability, the relationship between calculated and true SUR values for caudate and putamen could be described by a multiple linear model which took into account the spill-over phenomenon caused by PVE ({{R}2}≥slant 0.963 for caudate and ≥0.980 for putamen) and also by a simple linear model (R2 ≥ 0.952 for caudate and ≥0.973 for putamen). Calculated values were standardized by inverting both linear systems. Differences between standardized and true values showed that, although the multiple linear model was the best approach in terms of variability ({χ2}  ≥ 11.79 for caudate and  ≤7.36 for putamen), standardization based on a simple linear model was also suitable ({χ2}  ≥ 12.44 for caudate and  ≤12.57 for putamen).

  3. Quantitation of dopamine transporter blockade by methylphenidate: first in vivo investigation using [{sup 123}I]FP-CIT and a dedicated small animal SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaus, Susanne; Wirrwar, Andreas; Antke, Christina; Arkian, Shahram; Mueller, Hans-Wilhelm; Larisch, Rolf [Heinrich-Heine University, Clinic of Nuclear Medicine, Duesseldorf (Germany); Schramm, Nils [Research Center Juelich, Central Laboratory for Electronics, Juelich (Germany)

    2005-03-01

    The aim of this study was to investigate the feasibility of assessing dopamine transporter binding after treatment with methylphenidate in the rat using a recently developed high-resolution small animal single-photon emission computed tomograph (TierSPECT) and [{sup 123}I]FP-CIT. [{sup 123}I]FP-CIT was administered intravenously 1 h after intraperitoneal injection of methylphenidate (10 mg/kg) or vehicle. Animals underwent scanning 2 h after radioligand administration. The striatum was identified by superimposition of [{sup 123}I]FP-CIT scans with bone metabolism and perfusion scans obtained with {sup 99m}Tc-DPD and {sup 99m}Tc-tetrofosmin, respectively. As these tracers do not pass the blood-brain barrier, their distribution permits the identification of extracerebral anatomical landmarks such as the orbitae and the harderian glands. The cerebellum was identified by superimposing [{sup 123}I]FP-CIT scans with images of brain perfusion obtained with {sup 99m}Tc-HMPAO. Methylphenidate-treated animals and vehicle-treated animals yielded striatal equilibrium ratios (V''{sub 3}) of 0.24{+-}0.26 (mean {+-} SD) and 1.09{+-}0.42, respectively (ttest, two-tailed, p<0.0001). Cortical V''{sub 3} values amounted to 0.05{+-}0.28 (methylphenidate) and 0.3{+-}0.39 (saline, p=0.176). This first in vivo study of rat dopamine transporter binding after pre-treatment with methylphenidate showed a mean reduction of 78% in striatal [{sup 123}I]FP-CIT accumulation. The results can be interpreted in terms of a pharmacological blockade in the rat striatum and show that in vivo quantitation of dopamine transporter binding is feasible with [{sup 123}I]FP-CIT and the TierSPECT. This may be of future relevance for in vivo investigations on rat models of attention deficit/hyperactivity disorder. Furthermore, our findings suggest that investigations in other animal models, e.g. of Parkinson's and Huntington's disease, may be feasible using SPECT radioligands and

  4. Feasibility and diagnostic accuracy of Ecg-gated SPECT myocardial perfusion imaging by a two-hour protocol: The Myofast study;Faisabilite et precision diagnostique d'un protocole de scintigraphie myocardique synchronisee a l'ECG en deux heures: l'etude Myofast

    Energy Technology Data Exchange (ETDEWEB)

    Dunet, V.; Costo, S.; Sabatier, R.; Grollier, G.; Bouvard, G.; Agostini, D. [CHU Cote-de-Nacre, Service de medecine nucleaire, 14 - Caen (France)

    2010-04-15

    Aim of the study: To assess the feasibility of early stress and rest myocardial perfusion and function study using a fast {sup 99m}Tc-tetrofosmin gated-SPECT protocol in patients with known coronary artery disease. Materials and methods: Forty-three patients (pts) (37 M, 6 F, mean age 63.8 +- 9.8 years) underwent a {sup 99m}Tc-Tetrofosmin gated-SPECT (Axis Picker-Philips) myocardial study and a coronary angiography (C.A.) within 3 months. Images were acquired (LEHR, eight bins, 40 sec per image) after injection of {sup 99m}Tc-tetrofosmin (200 to 380 MBq) early (15 min) post-stress (36 dipyridamole, two dobutamine and five ergo-metric stress), and at rest after {sup 99m}Tc-tetrofosmin reinjection (600 to 1150 MBq), in a total time not exceeding 2 hours. Processing was performed with Q.G.S. software using the 17-segment model. Pathological study was defined as a summed difference score (SDS) greater than or equal to 4 4, a fixed defect with summed rest score greater than or equal to 4 and/or L.V. dysfunction defined as myocardial stunning (variation between stress and rest L.V.E.F. greater than or equal to 4 5%), stress L.V.E.F. less than or equal to 45% or rest L.V.E.F. less than or equal to 40%. Results were compared with C.A., and stenosis greater than or equal to 4 50% was considered as significant. Results: For 100% the quality of SPECT imaging was good or excellent. For six patients gating was impossible because of arrhythmia. The overall sensitivity, specificity and accuracy were 95%, 50%, and 91%, respectively. The concordance between gated SPECT and C.A. was moderate (kappa = 0.45, S.E. = 0.15). Interestingly, early-gated acquisition permitted to underline left ventricular dysfunction in 11 cases (30%), of whom eight had poly vascular disease. Stunning was detected in six of 37 cases (16%), of whom six had poly vascular disease. Conclusion: A one-day two-hour {sup 99m}Tc-tetrofosmin gated-SPECT protocol to assess left ventricular perfusion and function is

  5. Does percutaneous nephrolithotomy and its outcomes have an impact on renal function? Quantitative analysis using SPECT-CT DMSA.

    Science.gov (United States)

    Pérez-Fentes, Daniel; Cortés, Julia; Gude, Francisco; García, Camilo; Ruibal, Alvaro; Aguiar, Pablo

    2014-10-01

    To assess the functional effects of percutaneous nephrolithotomy (PCNL) and its outcomes in the operated kidney, we prospectively studied 30 consecutive cases undergoing PCNL. Kidney function was evaluated preoperatively and 3 months after surgery with serum creatinine, glomerular filtration rate (GFR), and with (99m)Tc-DMSA SPECT-CT scans to determine the differential renal function (DRF). PCNL effects in the operated kidney DRF were considered globally (DRFPLANAR, DRFSPECT) and in the region of percutaneous access (DRFACCESS). PCNL functional impact was also assessed depending on its outcomes, namely success (stone-free status) and the development of perioperative complications. PCNL has rendered 73 % of the cases completely stone free with a 33 % complication rate. After PCNL, serum creatinine and GFR did not change significantly, whereas DRFPLANAR and DRFSPECT dropped 1.2 % (p = 0.014) and 1.0 % (p = 0.041), respectively. The highest decrease was observed in DRFACCESS (1.8 %, p = 0.012). Stone-free status after PCNL did not show any impact on kidney function. Conversely, cases that suffered from a complication showed impairment in serum creatinine (0.1 mg/dL, p = 0.028), in GFR (11.1 mL/min, p = 0.036) as well as in DRFPLANAR (2.7 %, p = 0.018), DRFSPECT (2.2 %, p = 0.023) and DRFACCESS (2.7 %, p = 0.049). We conclude that PCNL has a minimal impact on global kidney function, which is mainly located in the region of percutaneous access. The advent of perioperative complications increased PCNL functional damage, whereas the stone-free status did not show any meaningful effect.

  6. Detectability of motions in AAA with ECG-gated CTA: A quantitative study

    NARCIS (Netherlands)

    Klein, Almar; Oostveen, Luuk J.; Greuter, Marcel J.W.; Hoogeveen, Yvonne; Schultze Kool, Leo J.; Slump, Cornelis H.; Renema, W. Klaas Jan

    2009-01-01

    Purpose: ECG-gated CT enables the visualization of motions caused by the beating of the heart. Although ECG gating is frequently used in cardiac CT imaging, this technique is also very promising for evaluating vessel wall motion of the aortic artery and the motions of (stent grafts inside) abdominal

  7. Detectability of motions in AAA with ECG-gated CTA: a quantitative study.

    NARCIS (Netherlands)

    Klein, A.; Oostveen, L.J.; Greuter, M.J.; Hoogeveen, Y.L.; Kool, L.J.; Slump, C.H.; Renema, W.K.J.

    2009-01-01

    PURPOSE: ECG-gated CT enables the visualization of motions caused by the beating of the heart. Although ECG gating is frequently used in cardiac CT imaging, this technique is also very promising for evaluating vessel wall motion of the aortic artery and the motions of (stent grafts inside) abdominal

  8. Detectability of motions in AAA with ECG-gated CTA : A quantitative study

    NARCIS (Netherlands)

    Klein, Almar; Oostveen, Luuk J.; Greuter, Marcel J. W.; Hoogeveen, Yvonne; Kool, Leo J. Schultze; Slump, Cornelis H.; Renema, W. Klaas Jan

    2009-01-01

    Purpose: ECG-gated CT enables the visualization of motions caused by the beating of the heart. Although ECG gating is frequently used in cardiac CT imaging, this technique is also very promising for evaluating vessel wall motion of the aortic artery and the motions of (stent grafts inside) abdominal

  9. Evaluation of right ventricular function by NuSMUGA software : gated blood-pool SPECT vs. first-pass radionuclide angiography

    NARCIS (Netherlands)

    Slart, RHJA; Poot, L; Piers, DA; van Veldhuisen, DJ; Jager, PL

    2003-01-01

    Background: In comparison with planar imaging gated blood-pool single photon emission computed tomography (GBPS) has the advantage of separating left and right ventricle. The purpose of this investigation was to evaluate the right ventricular ejection fraction (RVEF) calculations by GBPS software ('

  10. A quantitative analysis of the benefits of cardiac gating in practical diffusion tensor imaging of the brain.

    Science.gov (United States)

    Habib, Josef; Auer, Dorothee P; Morgan, Paul S

    2010-04-01

    Increasing demand for quantitative diffusion MRI in biomedical research necessitates a reevaluation of potential sources of artifact. While cardiac pulsation-induced effects have been reported previously, their quantitative characterization under standard acquisition protocols remains outstanding. To determine whether practical data quality improvements merit the use of cardiac gating, the maximum effects induced in apparent diffusion coefficient, fractional anisotropy, and mean diffusivity measurements were quantitatively estimated via measurements and bootstrapping simulations. In apparent diffusion coefficient time courses, cardiac pulsation effects were measured to occupy approximately 6% of the heartbeat duration, with considerable intersession differences in effect magnitude. Bootstrapping revealed overestimations in fractional anisotropy up to 0.26, and mean diffusivity up to 0.19 x 10(-3) mm(2) sec(-1) without gating compared to 0.072 (fractional anisotropy) and 0.043 x 10(-3) mm(2) sec(-1) (mean diffusivity) in the same gated simulation. However, while cardiac pulsation may thus impair the quantification of fractional anisotropy and mean diffusivity in some individuals, our data suggested negligible effects in group studies.

  11. 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...

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

    Institute of Scientific and Technical Information of China (English)

    许守林; 冯雪凤; 施鸣

    2013-01-01

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

  13. Retrospective image-based gating of intracoronary optical coherence tomography: Implications for quantitative analysis

    NARCIS (Netherlands)

    K. Sihan (Kenji); C.P. Botha (Charl); F.H. Post (Frits); S. de Winter (Sebastiaan); N. Gonzalo (Nieves); E.S. Regar (Eveline); P.W.J.C. Serruys (Patrick); R. Hamers (Ronald); N. Bruining (Nico)

    2011-01-01

    textabstractAims: Images acquired of coronary vessels during a pullback of time-domain optical coherence tomography (OCT) are influenced by the dynamics of the heart. This study explores the feasibility of applying an in-house developed retrospective image-based gating method for OCT and the influen

  14. Assessment of automatic quantification of myocardial perfusion and left ventricular function derived from ECG gated myocardial SPECT with {sup 99m}Tc-tetrofosmin in ischemic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Mitsunori; Habara, Hirokazu; Tatsuno, Hironari; Fukuda, Hiroshi; Hamada, Noriko; Kazatani, Yukio [Ehime Prefectural Central Hospital (Japan)

    1999-09-01

    Non-invasive assessment of ischemic heart disease (IHD) requires information of both myocardial perfusion and left ventricular (LV) function. Recently, automatic quantification of ECG-gated myocardial scintigraphy with {sup 99m}Tc-tetrofosmin (QGS) can provide both of them. QGS, coronary angiograms (CAG) and left venticulograms (LVG) were performed in 83 patients with severe IHD in same period. Significant stenosis of coronary artery in CAG were assessed by QGS. The sensitivity, specificity and accuracy of significant stenosis by QGS was excellent (85%, 93% and 88%). The LV end-distolic and end-systolic volumes (EDV and ESV), LV ejection fraction (EF) and regional LV wall motion determined by QGS were compared to LVG. There was a good correlation between the values obtained from QGS and LVG (EDV: r=0.86, ESV: r=0.94, EF: r=0.84, p<0.0001), but QGS tended to underestimate EDV and EF. High complete agreement of regional LV wall motion was gained with 427 (74.0%) out of total 581 segments. In conclusion, QGS data was considered to be useful for assessment of determine significant stenosis and LV function in severe IHD. (author)

  15. [Studies of biologic activation associated with molecular receptor increase and tumor response in ChL6/L6 protocol patients; Studies in phantoms; Quantitative SPECT; Preclinical studies; and Clinical studies]. DOE annual report, 1994--95

    Energy Technology Data Exchange (ETDEWEB)

    DeNardo, S.J.

    1995-12-31

    The authors describe results which have not yet been published from their associated studies listed in the title. For the first, they discuss Lym-1 single chain genetically engineered molecules, analysis of molecular genetic coded messages to enhance tumor response, and human dosimetry and therapeutic human use radiopharmaceuticals. Studies in phantoms includes a discussion of planar image quantitation, counts coincidence correction, organ studies, tumor studies, and {sup 90}Y quantitation with Bremsstrahlung imaging. The study on SPECT discusses attenuation correction and scatter correction. Preclinical studies investigated uptake of {sup 90}Y-BrE-3 in mice using autoradiography. Clinical studies discuss image quantitation verses counts from biopsy samples, S factors for radiation dose calculation, {sup 67}Cu imaging studies for lymphoma cancer, and {sup 111}In MoAb imaging studies for breast cancer to predict {sup 90}Y MoAb therapy.

  16. [Studies of biologic activation associated with molecular receptor increase and tumor response in ChL6/L6 protocol patients; Studies in phantoms; Quantitative SPECT; Preclinical studies; and Clinical studies]. DOE annual report, 1994--95

    Energy Technology Data Exchange (ETDEWEB)

    DeNardo, S.J.

    1995-12-31

    The authors describe results which have not yet been published from their associated studies listed in the title. For the first, they discuss Lym-1 single chain genetically engineered molecules, analysis of molecular genetic coded messages to enhance tumor response, and human dosimetry and therapeutic human use radiopharmaceuticals. Studies in phantoms includes a discussion of planar image quantitation, counts coincidence correction, organ studies, tumor studies, and {sup 90}Y quantitation with Bremsstrahlung imaging. The study on SPECT discusses attenuation correction and scatter correction. Preclinical studies investigated uptake of {sup 90}Y-BrE-3 in mice using autoradiography. Clinical studies discuss image quantitation verses counts from biopsy samples, S factors for radiation dose calculation, {sup 67}Cu imaging studies for lymphoma cancer, and {sup 111}In MoAb imaging studies for breast cancer to predict {sup 90}Y MoAb therapy.

  17. Quantitative Immuno-SPECT Monitoring of Pretargeted Radioimmunotherapy with a Bispecific Antibody in an Intraperitoneal Nude Mouse Model of Human Colon Cancer

    NARCIS (Netherlands)

    Schoffelen, R.; Graaf, W.T. van der; Sharkey, R.M.; Franssen, G.M.; McBride, W.J.; Chang, C.H.; Bos, D.L.; Goldenberg, D.M.; Oyen, W.J.G.; Boerman, O.C.

    2012-01-01

    The prospects for using pretargeted immuno-SPECT to monitor the response to pretargeted radioimmunotherapy were examined. In this study, a bispecific anticarcinoembryonic antigen (CEACAM5; CD66e) x antihapten monoclonal antibody, TF2, was used in combination with a small (1.5 kD) peptide, IMP288, la

  18. Clinical values of left ventricular mechanical dyssynchrony assessment by gated myocardial perfusion SPECT in patients with acute myocardial infarction and multivessel disease

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang-Geon; Park, Ki Seong; Kim, Jahae; Kim, Jong Sang; Song, Ho-Chun [Chonnam National University Hospital, Department of Nuclear Medicine, Gwang-ju (Korea, Republic of); Jabin, Zeenat; Kang, Sae-Ryung; Kwon, Seong Young; Jeong, Geum-Cheol; Song, Minchul; Min, Jung-Joon; Bom, Hee-Seung [Chonnam National University Hwasun Hospital, Department of Nuclear Medicine, Hwasun-gun, Jeonnam (Korea, Republic of); Cho, Jae Yeong; Kim, Hyun Kuk [Chonnam National University Hospital, Department of Cardiology, Gwang-ju (Korea, Republic of)

    2017-02-15

    The aim of this study was to evaluate the prognostic value of additional evaluation of left ventricular mechanical dyssynchrony (LVMD) by gated myocardial perfusion single-photon emission computed tomography (GMPS) in patients with acute myocardial infarction (MI) and multivessel disease. One hundred and nine acute MI patients with >50 % stenosis in at least one non-culprit artery who underwent GMPS within 2 weeks were enrolled. All patients underwent successful revascularization of the culprit arteries. Those with previous MI, atrial fibrillation, or frequent ventricular premature complexes, cardiac devices, significant patient motion, or procedure-related events were excluded. Phase standard deviation (PSD) and phase histogram bandwidth (PBW) were measured for assessment of LVMD. Patients were followed up for a median of 26 months after index MI, for composite major adverse cardiac events (MACE), which consisted with all-cause death, unplanned hospitalization due to heart failure and severe ventricular arrhythmias (sustained ventricular tachycardia or ventricular fibrillation). Independent predictors of MACE were evaluated. MACE occurred in 22 patients (20 %). Stress PSD (53.3 ± 17.3 vs. 35.3 ± 18.9 ; p <0.001), stress PBW (147.6 ± 54.6 vs. 96.8 ± 59.2 ; p = 0.001) and resting PBW (126.8 ± 37.5 vs. 96.6 ± 48.9 ; p = 0.001) were significantly higher in patients with MACE compared to those without. Multivariate analysis revealed that stress PSD ≥45.5 and stress PBW ≥126.0 were predictive of MACE, as well as suboptimal non-culprit artery revascularization (SNR) and renin-angiotensin system (RAS) blockade medication. Higher stress PSD and stress PBW were associated with poorer prognosis both in patients with and without SNR, and those with RAS blockade medication, but not in those without RAS blockade medication. LVMD measured by GMPS showed added prognostic value in acute MI with multivessel disease. GMPS could serve as a comprehensive evaluation imaging

  19. A study of partial volume effect on SPECT imaging using myocardial phantom. With HCM (ASH) model myocardial phantom

    Energy Technology Data Exchange (ETDEWEB)

    Onoguchi, Masahisa [Kanazawa Univ. (Japan). School of Medicine

    1997-05-01

    In order to evaluate simultaneously both myocardial perfusion and regional wall motion using ECG-gated myocardial SPECT imaging, correction for the partial volume effect (PVE) should be performed. For the quantitative analysis of myocardial SPECT imaging in patients with hypertrophic cardiomyopathy (HCM), we formed a new phantom simulating HCM with various septal wall thicknesses and estimated PVE using the recovery coefficient (RC). The value of RC in all phantoms increased with increasing thickness of the septal wall reaching a plateau at 25 mm for the cylindrical phantom and 25 mm for the Ep-phantom. Compared with the RC value, the PMMA-phantom had little influence on PVE. Therefore, our results suggested that the count in the septal wall could be underestimated if PVE was corrected by the value obtained for the cylindrical phantom. In conclusion, our new phantom simulating HCM was useful in assessing PVE in the hypertrophic septal wall. (author)

  20. 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).

  1. Quantitative assessment of the infarct size with the unfolded map method of sup 201 Tl myocardial SPECT in patient with acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, Masahiro (Sapporo Medical Coll. (Japan))

    1992-03-01

    The unfolded map method of {sup 201}Tl single photon emission computed tomography (SPECT) was evaluated as to the ability to quantify and the clinical reliability in estimation of infarct size. The following results were obtained from basic experiments using a thoracic phantom. The defect area estimated by the unfolded map method was well correlated with the real defect area, in spite of overestimation of the defect area, when the defect area was determined by an isocount method (below 80% of maximum count) (y=1.941 + 2.292x, r=0.971). The defect volume estimated by short-axis images of {sup 201}Tl SPECT was closely correlated with real defect volume in spite of overestimation of defect volume (y=0.762 + 2.156x, r=0.982). When the defect area was estimated by division of the defect volume by the mean myocardial compartment thickness, it was closely correlated with real defect area (y=0.946 + 1.232x, r=0.990). When the volume was calculated from the summation of voxels in the regions districted by isocount threshold level at each section of the {sup 99m}Tc SPECT, the optimal isocount threshold level (percentage to maximum count) was 55%. Then, the clinical reliability of the unfolded map method as infarct sizing was evaluated in 26 patients with acute myocardial infarction by comparing it with enzymatic method, Bull's eye method, and {sup 99m}Tc pyrophosphate (PYP) SPECT method. In 14 first attack patients without right ventricular infarction, infarct area (IA) of the unfolded map method correlated most closely with the accumulated creatine kinase MB isoenzyme release (CK-MBr) (r=0.897), compared with the extent score (ES) (r=0.853) and the severity score (SS) (r=0.871) of Bull's eye method and the infarct volume (IV) (r=0.595) of {sup 99m}Tc PYP SPECT. In conclusion, although the unfolded map method of {sup 201}Tl SPECT has the tendency for overestimating infarct size, it is accurate and clinically reliable in estimating infarct size. (author).

  2. 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.)

  3. Tunable PIE and synchronized gating detections by FastFLIM for quantitative microscopy measurements of fast dynamics of single molecules

    Science.gov (United States)

    Sun, Yuansheng; Coskun, Ulas; Ferreon, Allan Chris; Barbieri, Beniamino; Liao, Shih-Chu Jeff

    2016-03-01

    The crosstalk between two fluorescent species causes problems in fluorescence microscopy imaging, especially for quantitative measurements such as co-localization, Förster resonance energy transfer (FRET), fluorescence cross correlation spectroscopy (FCCS). In laser scanning confocal microscopy, the lasers can be switched on and off by acousto-optic tunable filters (AOTF) in the microsecond scale for alternative line scanning in order to avoid the crosstalk while minimizing the time delay between two lasers on the same pixel location. In contrast, the pulsed interleaved excitation (PIE) technique synchronizes two pulsed lasers of different wavelengths in the nanosecond scale to enable measuring superfast dynamics of two fluorescent species simultaneously and yet quantitatively without the crosstalk contamination. This feature is critical for many cell biology applications, e.g. accurate determination of stoichiometry in FRET measurements for studying protein-protein interactions or cell signal events, detection of weaker bindings in FCCS by eliminating the false cross correlation due to the crosstalk. The PIE has been used with the time correlated single photon counting (TCSPC) electronics. Here, we describe a novel PIE development using the digital frequency domain (DFD) technique -- FastFLIM, which provides tunable PIE setups and synchronized gating detections, tailored and optimized to specific applications. A few PIE setups by FastFLIM and measurement examples are described. Combined with the sensitivity of Alba and Q2 systems, the PIE allowed us to quantitatively measure the fast dynamics of single molecules.

  4. Measurement of pulmonary parenchymal attenuation: use of spirometric gating with quantitative CT.

    Science.gov (United States)

    Kalender, W A; Rienmüller, R; Seissler, W; Behr, J; Welke, M; Fichte, H

    1990-04-01

    A new approach to reproducible measurement of lung attenuation and structure by means of respiratory-gated computed tomography (CT) was developed. The patient breathes through a microcomputer-controlled pocket spirometer during the complete CT examination, starting with a measurement of the vital capacity. At a user-selected respiratory level, the CT scan is triggered and air flow is inhibited mechanically. To exclude operator-related reproducibility errors, evaluation is based on semiautomated algorithms that isolate lung parenchyma by fast contour tracing. In a study on one volunteer, measurement of lung attenuation changed by a factor of about 2.6 (-895 to -730 HU) as a function of inspirational status. Reproducibility on the order of 5% or better can be achieved only with tight spirometric control of respiration.

  5. Electrokinetic gated injection-based microfluidic system for quantitative analysis of hydrogen peroxide in individual HepG2 cells.

    Science.gov (United States)

    Zhang, Xinyuan; Li, Qingling; Chen, Zhenzhen; Li, Hongmin; Xu, Kehua; Zhang, Lisheng; Tang, Bo

    2011-03-21

    A microfluidic system to determine hydrogen peroxide (H(2)O(2)) in individual HepG2 cells based on the electrokinetic gated injection was developed for the first time. A home-synthesized fluorescent probe, bis(p-methylbenzenesulfonate)dichlorofluorescein (FS), was employed to label intracellular H(2)O(2) in the intact cells. On a simple cross microchip, multiple single-cell operations, including single cell injection, cytolysis, electrophoresis separation and detection of H(2)O(2), were automatically carried out within 60 s using the electrokinetic gated injection and laser-induced fluorescence detection (LIFD). The performance of the method was evaluated under the optimal conditions. The linear calibration curve was over a range of 4.39-610 amol (R(2)=0.9994). The detection limit was 0.55 amol or 9.0×10(-10) M (S/N=3). The relative standard deviations (RSDs, n=6) of migration time and peak area were 1.4% and 4.8%, respectively. With the use of this method, the average content of H(2)O(2) in single HepG2 cells was found to be 16.09±9.84 amol (n=15). Separation efficiencies in excess of 17,000 theoretical plates for the cells were achieved. These results demonstrated that the efficient integration and automation of these single-cell operations enabled the sensitive, reproducible, and quantitative examination of intracellular H(2)O(2) at single-cell level. Owing to the advantages of simple microchip structure, controllable single-cell manipulation and ease in building, this platform provides a universal way to automatically determine other intracellular constituents within single cells.

  6. Regional cerebral blood flow in children with autism spectrum disorders: a quantitative 99mTc-ECD brain SPECT study with statistical parametric mapping evaluation

    Institute of Scientific and Technical Information of China (English)

    YANG Wen-han; JING Jin; XIU Li-juan; CHENG Mu-hua; WANG Xin; BAO Peng; WANG Qing-xiong

    2011-01-01

    Background Autism spectrum disorders (ASD), which include autism, asperger syndrome (AS) and pervasive developmental disorder-not otherwise specified (PDD-NOS), are devastating neurodevelopmental disorders of childhood resulting in deficits in social interaction, repetitive patterns of behaviors, and restricted interests and activities. Single photon emission computed tomography (SPECT) is a common technique used to measure regional cerebral blood flow (rCBF). Several studies have measured rCBF in children with ASD using SPECT, however, findings are discordant. In addition, the majority of subjects used in these studies were autistic. In this study, we aimed to investigate changes in rCBF in children with ASD using SPECT.Methods A Technetium-99m-ethyl cysteinate dimmer (99mTc-ECD) brain SPECT study was performed on an ASD group consisting of 23 children (3 girls and 20 boys; mean age (7.2±3.0) years) who were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-Ⅳ) criteria and an age-matched control group with 8children (1 girl and 7 boys, mean age (5.5±2.4) years). Image data were evaluated with Statistical Parametric Mapping,5th version (SPM5). A Student's t test for unpaired data was used to compare rCBF and asymmetry in the autism and corresponding control group. The covariance analysis, taking age as covariance, was performed between the ASD and control group.Results There was a significant reduction in rCBF in the bilateral frontal lobe (frontal poles, arcula frontal gyrus) and the bilateral basal ganglia in the autism group, and a reduction in the bilateral frontal, temporal, parietal, legumina nucleus and cerebellum in the AS group compared to the control. In addition, asymmetry of hemispheric hypoperfusion in the ASD group was observed. Inner-group comparison analysis revealed that rCBF decreased significantly in the bilateral frontal lobe (42.7%), basal nucleus (24.9%) and temporal lobe (22.8%) in the autism

  7. Dual-energy micro-CT imaging of pulmonary airway obstruction: correlation with micro-SPECT

    Science.gov (United States)

    Badea, C. T.; Befera, N.; Clark, D.; Qi, Y.; Johnson, G. A.

    2014-03-01

    To match recent clinical dual energy (DE) CT studies focusing on the lung, similar developments for DE micro-CT of the rodent lung are required. Our group has been actively engaged in designing pulmonary gating techniques for micro- CT, and has also introduced the first DE micro-CT imaging method of the rodent lung. The aim of this study was to assess the feasibility of DE micro-CT imaging for the evaluation of airway obstruction in mice, and to compare the method with micro single photon emission computed tomography (micro-SPECT) using technetium-99m labeled macroaggregated albumin (99mTc-MAA). The results suggest that the induced pulmonary airway obstruction causes either atelectasis, or air-trapping similar to asthma or chronic bronchitis. Atelectasis could only be detected at early time points in DE micro-CT images, and is associated with a large increase in blood fraction and decrease in air fraction. Air trapping had an opposite effect with larger air fraction and decreased blood fraction shown by DE micro-CT. The decrease in perfusion to the hypoventilated lung (hypoxic vasoconstriction) is also seen in micro-SPECT. The proposed DE micro-CT technique for imaging localized airway obstruction performed well in our evaluation, and provides a higher resolution compared to micro-SPECT. Both DE micro-CT and micro-SPECT provide critical, quantitative lung biomarkers for image-based anatomical and functional information in the small animal. The methods are readily linked to clinical methods allowing direct comparison of preclinical and clinical results.

  8. 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.)

  9. High-resolution brain SPECT imaging in attention deficit hyperactivity disorder children without comorbidity: quantitative analysis using statistical parametric mapping(SPM)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myoung Hoon; Yoon, Seok Nam; Oh, Eun Young [Ajou University School of Medicine, Suwon (Korea, Republic of); Chung, Young Ki; Hwang, Isaac; Lee, Jae Sung [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2002-07-01

    We examined the abnormalities of regional cerebral blood flow(rCBF) in children with attention deficit hyperactivity disorder(ADHD) without comorbidity using statistical parametric mapping(SPM) method. We used the patients with not compatible to DSM-IV diagnostic criteria of ADHD and normal rCBF pattern in visual analysis as normal control children. Tc-99m ECD brain SPECT was performed on 75 patients (M:F=64:11, 10.0{+-}2.5y) with the DSM-IV diagnostic criteria of ADHD and 13 normal control children (M:F=9:4, 10.3{+-}4.1y). Using SPM method, we compared patient group's SPECT images with those of 13 control subjects and measured the extent of the area with significant hypoperfusion(p<0.01) in predefined 34 cerebral regions. Only on area of left temporal lobe showed significant hypoperfusion in ADHD patients without comorbidity (n=75) compared with control subjects(n=13). (n=75, p<0.01, extent threshold=16). rCBF of left temporal area was decreased in ADHD group without comorbidity, such as tic, compared with control group.

  10. Effects of CT-based attenuation correction of rat microSPECT images on relative myocardial perfusion and quantitative tracer uptake

    Energy Technology Data Exchange (ETDEWEB)

    Strydhorst, Jared H., E-mail: jared.strydhorst@gmail.com; Ruddy, Terrence D.; Wells, R. Glenn [Cardiac Imaging, University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7 (Canada)

    2015-04-15

    Purpose: Our goal in this work was to investigate the impact of CT-based attenuation correction on measurements of rat myocardial perfusion with {sup 99m}Tc and {sup 201}Tl single photon emission computed tomography (SPECT). Methods: Eight male Sprague-Dawley rats were injected with {sup 99m}Tc-tetrofosmin and scanned in a small animal pinhole SPECT/CT scanner. Scans were repeated weekly over a period of 5 weeks. Eight additional rats were injected with {sup 201}Tl and also scanned following a similar protocol. The images were reconstructed with and without attenuation correction, and the relative perfusion was analyzed with the commercial cardiac analysis software. The absolute uptake of {sup 99m}Tc in the heart was also quantified with and without attenuation correction. Results: For {sup 99m}Tc imaging, relative segmental perfusion changed by up to +2.1%/−1.8% as a result of attenuation correction. Relative changes of +3.6%/−1.0% were observed for the {sup 201}Tl images. Interscan and inter-rat reproducibilities of relative segmental perfusion were 2.7% and 3.9%, respectively, for the uncorrected {sup 99m}Tc scans, and 3.6% and 4.3%, respectively, for the {sup 201}Tl scans, and were not significantly affected by attenuation correction for either tracer. Attenuation correction also significantly increased the measured absolute uptake of tetrofosmin and significantly altered the relationship between the rat weight and tracer uptake. Conclusions: Our results show that attenuation correction has a small but statistically significant impact on the relative perfusion measurements in some segments of the heart and does not adversely affect reproducibility. Attenuation correction had a small but statistically significant impact on measured absolute tracer uptake.

  11. Accelerated GPU based SPECT Monte Carlo simulations

    Science.gov (United States)

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

    2016-06-01

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

  12. Accelerated GPU based SPECT Monte Carlo simulations.

    Science.gov (United States)

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

    2016-06-07

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  14. 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.)

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

    Directory of Open Access Journals (Sweden)

    Baškot Branislav

    2009-01-01

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

  16. Origin of mobility enhancement by chemical treatment of gate-dielectric surface in organic thin-film transistors: Quantitative analyses of various limiting factors in pentacene thin films

    Science.gov (United States)

    Matsubara, R.; Sakai, Y.; Nomura, T.; Sakai, M.; Kudo, K.; Majima, Y.; Knipp, D.; Nakamura, M.

    2015-11-01

    For the better performance of organic thin-film transistors (TFTs), gate-insulator surface treatments are often applied. However, the origin of mobility increase has not been well understood because mobility-limiting factors have not been compared quantitatively. In this work, we clarify the influence of gate-insulator surface treatments in pentacene thin-film transistors on the limiting factors of mobility, i.e., size of crystal-growth domain, crystallite size, HOMO-band-edge fluctuation, and carrier transport barrier at domain boundary. We quantitatively investigated these factors for pentacene TFTs with bare, hexamethyldisilazane-treated, and polyimide-coated SiO2 layers as gate dielectrics. By applying these surface treatments, size of crystal-growth domain increases but both crystallite size and HOMO-band-edge fluctuation remain unchanged. Analyzing the experimental results, we also show that the barrier height at the boundary between crystal-growth domains is not sensitive to the treatments. The results imply that the essential increase in mobility by these surface treatments is only due to the increase in size of crystal-growth domain or the decrease in the number of energy barriers at domain boundaries in the TFT channel.

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

    Directory of Open Access Journals (Sweden)

    Sinem Ozyurt

    2015-07-01

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

  18. Applications of cerebral SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-15

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

  19. Central benzodiazepine receptor imaging and quantitation with single photon emission computerised tomography

    DEFF Research Database (Denmark)

    Okocha, C I; Kapczinski, F; Lassen, N

    1995-01-01

    This review discusses the current use of single photon emission computerised tomography (SPECT) for central benzodiazepine receptor imaging and quantitation. The general principles underlying SPECT imaging and receptor quantitation methods such as the kinetic, pseudo-equilibrium and steady...

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

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1995-12-01

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

  1. Cerebral perfusion SPECT in transient ischemic attack

    Energy Technology Data Exchange (ETDEWEB)

    You, D.-L. E-mail: dlyou@mail.kfcc.org.tw; Shieh, F.-Y.; Tzen, K.-Y.; Tsai, M.-F.; Kao, P.-F

    2000-04-01

    Purpose: The purpose of our study is to evaluate the efficacy of cerebral perfusion single photon emission computerized tomography (SPECT) in patients with transient ischemic attack (TIA). Methods: Thirty-seven patients with TIA were collected for study. All patients had transient focal neurological symptoms or signs with complete recovery within 24 h after onset. The patients underwent cerebral perfusion SPECT between 6 h and 11 days after onset, with 10 cases performed within 24 h (group A), nine cases performed between 1 and 3 days (group B), 11 cases performed between 3 and 5 days (group C), and seven cases performed after more than 5 days (group D). A semi-quantitative method was used for analyzing the SPECT data, and the difference ratios between lesion side and contralateral normal side were calculated on each pair of regions of interest. Results: In total, 78.4% (29/37) of patients had reduced perfusion in the cerebral cortical regions or deep nuclei, and the regions with reduced perfusion corresponded with clinical presentations of the patients. The abnormal rate with reduced perfusion was 90.0% in group A, 77.8% in group B, 72.7% in group C and 71.4% in group D. Cross cerebellar diaschisis (CCD) was present in seven patients, and all of the primary cerebral perfusion defects of these patients were located at the territory of left or right middle cerebral artery. Conclusion: Cerebral perfusion SPECT is a potential tool to detect cerebral perfusion defects and CCD in patients with TIA. Although the perfusion defect may persist more than 5 days after onset, we suggest cerebral perfusion SPECT should be performed as soon as possible.

  2. Monte Carlo scatter correction for SPECT

    Science.gov (United States)

    Liu, Zemei

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

  3. Effect of physiological heart rate variability on quantitative T2 measurement with ECG-gated Fast Spin Echo (FSE) sequence and its retrospective correction.

    Science.gov (United States)

    de Roquefeuil, Marion; Vuissoz, Pierre-André; Escanyé, Jean-Marie; Felblinger, Jacques

    2013-11-01

    Quantitative T2 measurement is applied in cardiac Magnetic Resonance Imaging (MRI) for the diagnosis and follow-up of myocardial pathologies. Standard Electrocardiogram (ECG)-gated fast spin echo pulse sequences can be used clinically for T2 assessment, with multiple breath-holds. However, heart rate is subject to physiological variability, which causes repetition time variations and affects the recovery of longitudinal magnetization between TR periods. The bias caused by heart rate variability on quantitative T2 measurements is evaluated for fast spin echo pulse sequence. Its retrospective correction based on an effective TR is proposed. Heart rate variations during breath-holds are provided by the ECG recordings from healthy volunteers. T2 measurements were performed on a phantom with known T2 values, by synchronizing the sequence with the recorded ECG. Cardiac T2 measurements were performed twice on six volunteers. The impact of T1 on T2 is also studied. Maximum error in T2 is 26% for phantoms and 18% for myocardial measurement. It is reduced by the proposed compensation method to 20% for phantoms and 10% for in vivo measurements. Only approximate knowledge of T1 is needed for T2 correction. Heart rate variability may cause a bias in T2 measurement with ECG-gated FSE. It needs to be taken into account to avoid a misleading diagnosis from the measurements. © 2013.

  4. Evaluation of SPECT imaging using myocardial phantoms in Akita prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Kiyohiko [Akita Univ. (Japan). Hospital; Watarai, Jiro; Miura, Mamoru

    1998-09-01

    Evaluation of SPECT imaging using myocardial phantom in Akita Prefecture. The Society of Nuclear Medicine for Circulation disease in Akita was established in July, 1997. To improve myocardial spect imaging in Akita Prefecture, we first visually evaluated two acrlic defect (2 cm{phi} x 1 cm thickness aqcliel and 1 cm{phi} x 1 cm thickness) images of long axis and short axis of myocardial phantoms, using 14 SPECT Cameras. These defect images of myocardial phantom were evaluated by four cardiologists and twelve radiologists between August and December, 1996. Secondly, we measured the FWHM of four line sources (anterior, lateral, inferior, and septum positions in the short axis of myocardial phantom) using quantitative analysis by myocardial phantom between April and July, 1997. The results were reported at the 4th and 5th meeting of the Society of Nuclear Medicine for Circulation Disease in Akita. In conclusion, about 70% of myocardial spect images were of good or normal quality, whereas about 30% of the images were evaluated as of bad quality. To improve the myocardial spect images, we recognized that the basic performance of the SPECT cameras need be investigated. (author)

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-15

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

  7. 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

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

    Science.gov (United States)

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

    2003-12-01

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

  9. 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.)

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  11. GATE V6: a major enhancement of the GATE simulation platform enabling modelling of CT and radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jan, S; Becheva, E [DSV/I2BM/SHFJ, Commissariat a l' Energie Atomique, Orsay (France); Benoit, D; Rehfeld, N; Stute, S; Buvat, I [IMNC-UMR 8165 CNRS-Paris 7 and Paris 11 Universities, 15 rue Georges Clemenceau, 91406 Orsay Cedex (France); Carlier, T [INSERM U892-Cancer Research Center, University of Nantes, Nantes (France); Cassol, F; Morel, C [Centre de physique des particules de Marseille, CNRS-IN2P3 and Universite de la Mediterranee, Aix-Marseille II, 163, avenue de Luminy, 13288 Marseille Cedex 09 (France); Descourt, P; Visvikis, D [INSERM, U650, Laboratoire du Traitement de l' Information Medicale (LaTIM), CHU Morvan, Brest (France); Frisson, T; Grevillot, L; Guigues, L; Sarrut, D; Zahra, N [Universite de Lyon, CREATIS, CNRS UMR5220, Inserm U630, INSA-Lyon, Universite Lyon 1, Centre Leon Berard (France); Maigne, L; Perrot, Y [Laboratoire de Physique Corpusculaire, 24 Avenue des Landais, 63177 Aubiere Cedex (France); Schaart, D R [Delft University of Technology, Radiation Detection and Medical Imaging, Mekelweg 15, 2629 JB Delft (Netherlands); Pietrzyk, U, E-mail: buvat@imnc.in2p3.fr [Reseach Center Juelich, Institute of Neurosciences and Medicine and Department of Physics, University of Wuppertal (Germany)

    2011-02-21

    GATE (Geant4 Application for Emission Tomography) is a Monte Carlo simulation platform developed by the OpenGATE collaboration since 2001 and first publicly released in 2004. Dedicated to the modelling of planar scintigraphy, single photon emission computed tomography (SPECT) and positron emission tomography (PET) acquisitions, this platform is widely used to assist PET and SPECT research. A recent extension of this platform, released by the OpenGATE collaboration as GATE V6, now also enables modelling of x-ray computed tomography and radiation therapy experiments. This paper presents an overview of the main additions and improvements implemented in GATE since the publication of the initial GATE paper (Jan et al 2004 Phys. Med. Biol. 49 4543-61). This includes new models available in GATE to simulate optical and hadronic processes, novelties in modelling tracer, organ or detector motion, new options for speeding up GATE simulations, examples illustrating the use of GATE V6 in radiotherapy applications and CT simulations, and preliminary results regarding the validation of GATE V6 for radiation therapy applications. Upon completion of extensive validation studies, GATE is expected to become a valuable tool for simulations involving both radiotherapy and imaging.

  12. 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

  13. A Comparison between Quantitative Gated Myocardial Perfusion Scintigraphy and Strain Echocardiography as Indicators of Ventricular Functions in Patients with Anterior Myocardial Infarction

    Science.gov (United States)

    Karacavus, Seyhan; Celik, Ahmet; Tutus, Ahmet; Kula, Mustafa; Oguzhan, Abdurrahman; Ozdogru, Ibrahim; Kalay, Nihat

    2014-01-01

    The purpose of this study is to compare the strain echocardiographic and scintigraphic parameters for evaluating of the left ventricular (LV) functions in patients with anterior myocardial infarction (MI). Fifty-four patients (male/female: 36/18; mean age 62 ± 13 years) with anterior MI were prospectively enrolled. All patients were performed gated myocardial perfusion scintigraphy gated single-photon emission computed tomography (GSPECT) and echocardiography (EC). GSPECT data were processed and analyzed using 4D-MSPECT (4DM, Invia Medical Imaging Solutions, Ann Arbor, MI, USA). The echocardiographic strain (S) and strain rate (SR) values were calculated. The results obtained by these techniques were compared each other. A total of 918 segments of LV wall were evaluated. In all patients, 385 segments were automatically scored as normokinetic, 206 as hypokinetic, 122 as akinetic, 205 as dyskinetic and 300 as normal thickening, 348 as decrease thickening and 270 as no thickening. The means of S and SR values in thickening and motion score groups according to GSPECT were statistically different from each other (P < 0.001). There was a negative significant correlation between LV wall thickening sum score and S and SR and between LV wall motion sum score and S and SR (P < 0.001). There was a good correlation between GSPECT and echocardiographic LV-ejection fraction (r = 0.7, P < 0.001). GSPECT and strain EC are similar in quantitative grading of the severity of regional and global myocardial dysfunction in patients with anterior MI and these techniques provide valuable diagnostic information. PMID:25538490

  14. Scatter and attenuation correction in Technetium-99m brain SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Jun [Keio Univ., Tokyo (Japan). School of Medicine

    1997-11-01

    The imaging in the nuclear medicine is inferior to other modalities in the spatial resolution, but it can quantitatively evaluate the biological function. The attempt to measure the absolute or the relative values of local functions quantitatively based on the SPECT of the brain or the heart, has become popular recently. It is not only necessary to introduce an appropriate analytical model for each radioisotope tracer for the correct quantification, but also to be equipped with the photographing system to measure correctly the accumulation of the tracer. The main cause to decrease the precision of the photographing system is the scatter and the absorption (attenuation) of photon. In the present study we attempted to enhance the quantification of the brain SPECT by the usable and practical correction method for the scatter and the attenuation in the daily clinical business. We used the triple-energy-window (TEW) method as the scatter correction and the attenuation calculation map obtained from the transmission scanning (TCT) by the external source as the attenuation correction. We examined the brain SPECT in combination with these two correction methods. We could not measure correctly the amount of the tracer accumulation by only one correction method, and obtain the excellent quantitative SPECT images in combination with both correction methods. We could get excellently stable data by collecting the emission and the transmission data simultaneously as well as separately, and the excellent images by the arithmetical treatment of data between the scatter beam and the detector correction when we used {sup 99m}Tc as the source which is economically cheap, and adopted the combination of the tracers labeled by the same kind of radioisotopes. Altogether we expect that our method is very practical and will contribute to enhance the accuracy in quantitative analysis of clinical brain SPECT imaging. (K.H.)

  15. Quantitative analysis of arterial flow properties for detection of non-calcified plaques in ECG-gated coronary CT angiography

    Science.gov (United States)

    Wei, Jun; Zhou, Chuan; Chan, Heang-Ping; Chughtai, Aamer; Agarwal, Prachi; Kuriakose, Jean; Hadjiiski, Lubomir; Patel, Smita; Kazerooni, Ella

    2015-03-01

    We are developing a computer-aided detection system to assist radiologists in detection of non-calcified plaques (NCPs) in coronary CT angiograms (cCTA). In this study, we performed quantitative analysis of arterial flow properties in each vessel branch and extracted flow information to differentiate the presence and absence of stenosis in a vessel segment. Under rest conditions, blood flow in a single vessel branch was assumed to follow Poiseuille's law. For a uniform pressure distribution, two quantitative flow features, the normalized arterial compliance per unit length (Cu) and the normalized volumetric flow (Q) along the vessel centerline, were calculated based on the parabolic Poiseuille solution. The flow features were evaluated for a two-class classification task to differentiate NCP candidates obtained by prescreening as true NCPs and false positives (FPs) in cCTA. For evaluation, a data set of 83 cCTA scans was retrospectively collected from 83 patient files with IRB approval. A total of 118 NCPs were identified by experienced cardiothoracic radiologists. The correlation between the two flow features was 0.32. The discriminatory ability of the flow features evaluated as the area under the ROC curve (AUC) was 0.65 for Cu and 0.63 for Q in comparison with AUCs of 0.56-0.69 from our previous luminal features. With stepwise LDA feature selection, volumetric flow (Q) was selected in addition to three other luminal features. With FROC analysis, the test results indicated a reduction of the FP rates to 3.14, 1.98, and 1.32 FPs/scan at sensitivities of 90%, 80%, and 70%, respectively. The study indicated that quantitative blood flow analysis has the potential to provide useful features for the detection of NCPs in cCTA.

  16. A new method to evaluate ischemic heart disease. Combined use of rest thallium-201 myocardial SPECT and Tc-99m exercise tetrofosmin first pass and myocardial SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong-ih; Goto, Hideki; Kobayashi, Katsuhiro; Sawada, Yoshihiro; Miyake, Yoshitaka; Fujiwara, Go [Nishiyodo Hospital, Osaka (Japan); Okada, Tomoya; Nishimura, Tsunehiko

    1999-06-01

    We developed a new diagnostic method for simultaneously evaluating myocardial ischemia, myocardial viability and ventricular function in less than 90 minutes by combined use of rest thallium-201 (Tl) SPECT and exercise Tc-99m tetrofosmin (TF) first pass and SPECT. The subjects were 9 healthy controls, 19 angina pectoris patients, and 19 old myocardial infarction patients, in all of whom coronary angiography had been performed. Rest Tl myocardial SPECT was performed first, and was followed by exercise TF myocardial SPECT. We also performed first pass radionuclide angiography by TF during maximum exercise on a bicycle ergometer to assess the left ventricular ejection fraction (LVEF). The total examination time was less than 90 minutes. SPECT diagnosis was performed by semi-quantitative analysis. LVEF below 55% was regarded as abnormal. In the patients with angina pectoris, analysis according to the coronary artery showed that the diagnostic accuracy of SPECT was 85.0% for ischemia in the region of the left anterior descending branch (LAD), 87.5% for the left circumflex branch (LCX) and 77.8% for the right coronary artery (RCA). The accuracy of diagnosis for angina pectoris was 82.1%, as determined by SPECT alone, and rose to 89,3% when the LVEF levels were also taken into consideration. In the patients with old myocardial infarction, the diagnostic accuracy of SPECT was 84.2% for the LAD, 92.3% for the LCX and 85.0% for the RCA. Analysis by patients showed that the accuracy of diagnosis for myocardial infarction was 85.7%, as determined by SPECT alone. The diagnostic accuracy, however, rose to 89.3% when the LVEF levels also were taken into consideration. In conclusion, it was demonstrated that this combined diagnostic method was highly reliable for evaluating ischemic heart disease within a short time. (author)

  17. 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.

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

    OpenAIRE

    K Uday Bhanu; Niranjan Khandelwal; Sameer Vyas; Paramjeet Singh; Anuj Prabhakar; B R Mittal; Ashish Bhalla

    2017-01-01

    Aim: Acute organophosphate (OP) pesticide poisoning causes substantial morbidity and mortality worldwide. Many imaging modalities, such as computerized tomography (CT), magnetic resonance imaging (MRI), and single photon emission computed tomography (SPECT) of the brain, have been used for quantitative assessment of the acute brain insult caused by acute OP poisoning. Perfusion defects on SPECT in acutely poisoned patients with OPs have been described, however, MR perfusion abnormalities have...

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  20. Quantitative assessment of changes in carotid plaques during cilostazol administration using three-dimensional ultrasonography and non-gated magnetic resonance plaque imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Mao; Ohba, Hideki; Mori, Kiyofumi; Narumi, Shinsuke; Katsura, Noriyuki; Ohura, Kazumasa; Terayama, Yasuo [Iwate Medical University, Department of Neurology and Gerontology, Morioka (Japan); Sasaki, Makoto; Kudo, Kohsuke [Iwate Medical University, Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Morioka (Japan)

    2012-09-15

    Cilostazol, an antiplatelet agent, is reported to induce the regression of atherosclerotic changes. However, its effects on carotid plaques are unknown. Hence, we quantitatively investigated the changes that occur within carotid plaques during cilostazol administration using three-dimensional (3D) ultrasonography (US) and non-gated magnetic resonance (MR) plaque imaging. We prospectively examined 16 consecutive patients with carotid stenosis. 3D-US and T1-weighted MR plaque imaging were performed at baseline and 6 months after initiating cilostazol therapy (200 mg/day). We measured the volume and grayscale median (GSM) of the plaques from 3D-US data. We also calculated the contrast ratio (CR) of the carotid plaque against the adjacent muscle and areas of the intraplaque components: fibrous tissue, lipid, and hemorrhage components. The plaque volume on US decreased significantly (median at baseline and 6 months, 0.23 and 0.21 cm{sup 3}, respectively; p = 0.03). In the group exhibiting a plaque volume reduction of more than 10%, GSM on US increased significantly (24.8 and 71.5, respectively; p = 0.04) and CR on MRI decreased significantly (1.13 and 1.04, respectively; p = 0.02). In this group, in addition, the percent area of the fibrous component on MRI increased significantly (68.6% and 79.4%, respectively; p = 0.02), while those of the lipid and hemorrhagic components decreased (24.9% and 20.5%, respectively; p = 0.12) (1.0% and 0.0%, respectively; p = 0.04). There were no substantial changes in intraplaque characteristics in either US or MRI in the other group. 3D-US and MR plaque imaging can quantitatively detect changes in the size and composition of carotid plaques during cilostazol therapy. (orig.)

  1. 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.)

  2. CT-Based Attenuation Correction in I-123-Ioflupane SPECT

    Science.gov (United States)

    Lange, Catharina; Seese, Anita; Schwarzenböck, Sarah; Steinhoff, Karen; Umland-Seidler, Bert; Krause, Bernd J.; Brenner, Winfried; Sabri, Osama

    2014-01-01

    Purpose Attenuation correction (AC) based on low-dose computed tomography (CT) could be more accurate in brain single-photon emission computed tomography (SPECT) than the widely used Chang method, and, therefore, has the potential to improve both semi-quantitative analysis and visual image interpretation. The present study evaluated CT-based AC for dopamine transporter SPECT with I-123-ioflupane. Materials and methods Sixty-two consecutive patients in whom I-123-ioflupane SPECT including low-dose CT had been performed were recruited retrospectively at 3 centres. For each patient, 3 different SPECT images were reconstructed: without AC, with Chang AC and with CT-based AC. Distribution volume ratio (DVR) images were obtained by scaling voxel intensities using the whole brain without striata as reference. For assessing the impact of AC on semi-quantitative analysis, specific-to-background ratios (SBR) in caudate and putamen were obtained by fully automated SPM8-based region of interest (ROI) analysis and tested for their diagnostic power using receiver-operator-characteristic (ROC) analysis. For assessing the impact of AC on visual image reading, screenshots of stereotactically normalized DVR images presented in randomized order were interpreted independently by two raters at each centre. Results CT-based AC resulted in intermediate SBRs about half way between no AC and Chang. Maximum area under the ROC curve was achieved by the putamen SBR, with negligible impact of AC (0.924, 0.935 and 0.938 for no, CT-based and Chang AC). Diagnostic accuracy of visual interpretation also did not depend on AC. Conclusions The impact of CT-based versus Chang AC on the interpretation of I-123-ioflupane SPECT is negligible. Therefore, CT-based AC cannot be recommended for routine use in clinical patient care, not least because of the additional radiation exposure. PMID:25268228

  3. CT-based attenuation correction in I-123-ioflupane SPECT.

    Directory of Open Access Journals (Sweden)

    Catharina Lange

    Full Text Available PURPOSE: Attenuation correction (AC based on low-dose computed tomography (CT could be more accurate in brain single-photon emission computed tomography (SPECT than the widely used Chang method, and, therefore, has the potential to improve both semi-quantitative analysis and visual image interpretation. The present study evaluated CT-based AC for dopamine transporter SPECT with I-123-ioflupane. MATERIALS AND METHODS: Sixty-two consecutive patients in whom I-123-ioflupane SPECT including low-dose CT had been performed were recruited retrospectively at 3 centres. For each patient, 3 different SPECT images were reconstructed: without AC, with Chang AC and with CT-based AC. Distribution volume ratio (DVR images were obtained by scaling voxel intensities using the whole brain without striata as reference. For assessing the impact of AC on semi-quantitative analysis, specific-to-background ratios (SBR in caudate and putamen were obtained by fully automated SPM8-based region of interest (ROI analysis and tested for their diagnostic power using receiver-operator-characteristic (ROC analysis. For assessing the impact of AC on visual image reading, screenshots of stereotactically normalized DVR images presented in randomized order were interpreted independently by two raters at each centre. RESULTS: CT-based AC resulted in intermediate SBRs about half way between no AC and Chang. Maximum area under the ROC curve was achieved by the putamen SBR, with negligible impact of AC (0.924, 0.935 and 0.938 for no, CT-based and Chang AC. Diagnostic accuracy of visual interpretation also did not depend on AC. CONCLUSIONS: The impact of CT-based versus Chang AC on the interpretation of I-123-ioflupane SPECT is negligible. Therefore, CT-based AC cannot be recommended for routine use in clinical patient care, not least because of the additional radiation exposure.

  4. Molecular imaging of angiogenesis with SPECT.

    NARCIS (Netherlands)

    Dijkgraaf, I.; Boerman, O.C.

    2010-01-01

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

  5. Progress in BazookaSPECT.

    Science.gov (United States)

    Miller, Brian W; Barber, H Bradford; Furenlid, Lars R; Moore, Stephen K; Barrett, Harrison H

    2009-01-01

    Recent progress on a high-resolution, photon-counting gamma-ray and x-ray imager called BazookaSPECT is presented. BazookaSPECT is an example of a new class of scintillation detectors based on integrating detectors such as CCD(charge-coupled device) or CMOS(complementary metal-oxide semiconductor) sensors. BazookaSPECT is unique in that it makes use of a scintillator in close proximity to a microchannel plate-based image intensifier for up-front optical amplification of scintillation light. We discuss progress made in bringing about compact BazookaSPECT modules and in real-time processing of event data using graphics processing units (GPUs). These advances are being implemented in the design of a high-resolution rodent brain imager called FastSPECT III. A key benefit of up-front optical gain is that any CCD/CMOS sensor can now be utilized for photon counting. We discuss the benefits and feasibility of using CMOS sensors as photon-counting detectors for digital radiography, with application in mammography and computed tomography (CT). We present as an appendix a formal method for comparing various photon-counting integrating detectors using objective statistical criteria.

  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. Cerebral SPECT under VEEG monitoring combined with semi-quantitative analysis in localization of epileptogenic zone%视频脑电结合半定量分析的脑血流灌注显像定位致痫灶

    Institute of Scientific and Technical Information of China (English)

    郝科技; 王茜; 刘献增; 邱李恒; 高旭光; 李原

    2014-01-01

    目的 评价一种在视频脑电监测(VEEG)下结合半定量分析的脑血流灌注SPECT显像法用于癫痫致痫灶定位诊断的价值.方法 对81例难治性癫痫患者的临床资料进行回顾性分析.脑血流灌注SPECT在VEEG监测下进行,显像前以睡眠剥夺、逐步减少或停服抗癫痫药的方式争取诱发癫痫发作.影像判读采用视觉判断与半定量分析结合的方法.结果 19例同时获得发作期和发作间期显像,62例仅获得发作间期显像.SPECT、VEEG和MRI对病灶的检出率分别为95%、98%和42%,SPECT与VEEG检出率之间差异无统计学意义(P>0.05),但二者均显著高于MRI(x 2=52.913,P<0.001;x2 =59.247,P<0.001).SPECT与VEEG、SPECT与MRI和MRI与VEEG对病灶的定位符合率分别为69%、25%和27%,SPECT与VEEG之间的符合率显著高于SPECT与MRI(x2=26.905,P<0.001)及MRI与VEEG之间的符合率(x2=26.905,P<0.001).SPECT、VEEG和MRI的定位准确性分别为83%、74%和52%;术后随访结果示,疗效达Ⅰ~Ⅱ级患者中,有11例(n=14)其术前SPECT与VEEG定位结果一致.结论 脑SPECT显像法对致痫灶定位具有较高的价值,提倡作为常规检查法用于难治性癫痫的定位诊断.%Objective To investigate the value of the cerebral blood flow SPECT used for localization of epileptogenic zone in patients with intractable epilepsy,which was performed under the videoelectroencephalogram (VEEG) monitoring combined with the semi-quantitative analysis.Methods Ccrcbral blood flow SPECT was performed under VEEG monitoring and seizures were captured either by sleep-deprived or by reducing dose or by withholding of antiepileptic drugs (AEDs).Neurogam analysis was used in the procedure of image interpretation.Results 19 inter-ictal combined with ictal images and 62 only inter-ictal images were obtained in this study.The detection rates of the pathological focus for SPECT,VEEG and MRI were 95%、98% and 42%,respectively.There was no

  8. 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.

  9. Echocardiography versus (201)Tl semi-quantitative gated single photon emission tomography for the evaluation of cardiac disease associated with late stage Duchenne muscular dystrophy.

    Science.gov (United States)

    Fujita, Atsushi; Arahata, Hajime; Sugawara, Miwa; Watanabe, Akihiro; Kawano, Yuji; Sasagasako, Naokazu; Fujii, Naoki

    2016-01-01

    In Duchenne muscular dystrophy (DMD) patients cardiac abnormalities are often detected. In adult DMD patients cardiac disease (CD) is a cause of death which increases by age and is related to respiratory dysfunction. Studies have demonstrated that CD in early DMD can be detected by echocardiography (EC) or semi-quantitative gated single photon emission tomography ((201)Tl SQGS), and the accuracy of these two tests is similar. As the disease advances, evaluation of CD by EC becomes difficult due to thoracic deformity and scoliosis. We compared (201)Tl SQGS and EC in the evaluation of cardiac function in late stage DMD, based on the ejection fraction (EF) value calculated by both tests. Twenty-three males with late stage DMD, 12 to 35 years of age (22.2±7.5), were studied by (201)Tl SQGS and EC. The mean EF value by (201)Tl SQGS was 60.8%±14.1%, which differed from that obtained by EC (52.7%±9.8%, P=0.003). Eleven patients less than 20 years old did not demonstrate a significant difference between the two tests (P=0.06), however, 12 patients over 20 years of age had significantly different results between tests (P=0.002). Although our patients were few we indicated that in DMD patients, aged older than 20 years, at an advanced stage of the disease, the EF values calculated by EC were lower than those by (201)Tl SQGS possibly due to thoracic deformity.

  10. Acute myocardial infarction: estimation of at-risk and salvaged myocardium at myocardial perfusion SPECT 1 month after infarction.

    Science.gov (United States)

    Romero-Farina, Guillermo; Aguadé-Bruix, Santiago; Candell-Riera, Jaume; Pizzi, M Nazarena; Pineda, Victor; Figueras, Jaume; Cuberas, Gemma; de León, Gustavo; Castell-Conesa, Joan; García-Dorado, David

    2013-11-01

    To estimate at-risk and salvaged myocardium by using gated single photon emission computed tomography (SPECT) myocardial perfusion imaging after acute myocardial infarction (AMI). The study was approved by the hospital's Ethical Committee on Clinical Trials (trial register number, PR(HG)36/2000), and all patients gave informed consent. Forty patients (mean age, 61.78 years; eight women) with a first AMI underwent two gated SPECT examinations--one before percutaneous coronary intervention (PCI) and one 4-5 weeks after PCI. Myocardium at risk was estimated by assessing the perfusion defect at the first gated SPECT examination, and salvaged myocardium was estimated by assessing the risk area minus necrosis at the second examination. Myocardium at risk was estimated by determining the discordance between the areas of left ventricular (LV) wall motion and perfusion at the second examination. Concordance between tests was analyzed by means of linear regression analysis, the Pearson correlation, the intraclass correlation coefficient, and Bland-Altman analysis. An improvement in perfusion, wall motion, wall thickening, and LV ejection fraction (P Myocardial perfusion gated SPECT performed 1 month after early PCI in a first AMI provides potentially useful information on at-risk and salvaged myocardium. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122324/-/DC1. RSNA, 2013

  11. Partition Model-Based 99mTc-MAA SPECT/CT Predictive Dosimetry Compared with 90Y TOF PET/CT Posttreatment Dosimetry in Radioembolization of Hepatocellular Carcinoma: A Quantitative Agreement Comparison.

    Science.gov (United States)

    Gnesin, Silvano; Canetti, Laurent; Adib, Salim; Cherbuin, Nicolas; Silva Monteiro, Marina; Bize, Pierre; Denys, Alban; Prior, John O; Baechler, Sebastien; Boubaker, Ariane

    2016-11-01

    (90)Y-microsphere selective internal radiation therapy (SIRT) is a valuable treatment in unresectable hepatocellular carcinoma (HCC). Partition-model predictive dosimetry relies on differential tumor-to-nontumor perfusion evaluated on pretreatment (99m)Tc-macroaggregated albumin (MAA) SPECT/CT. The aim of this study was to evaluate agreement between the predictive dosimetry of (99m)Tc-MAA SPECT/CT and posttreatment dosimetry based on (90)Y time-of-flight (TOF) PET/CT. We compared the (99m)Tc-MAA SPECT/CT results for 27 treatment sessions (25 HCC patients, 41 tumors) with (90)Y SIRT (7 glass spheres, 20 resin spheres) and the posttreatment (90)Y TOF PET/CT results. Three-dimensional voxelized dose maps were computed from the (99m)Tc-MAA SPECT/CT and (90)Y TOF PET/CT data. Mean absorbed dose ([Formula: see text]) was evaluated to compute the predicted-to-actual dose ratio ([Formula: see text]) in tumor volumes (TVs) and nontumor volumes (NTVs) for glass and resin spheres. The Lin concordance ([Formula: see text]) was used to measure accuracy ([Formula: see text]) and precision (ρ). Administered activity ranged from 0.8 to 1.9 GBq for glass spheres and from 0.6 to 3.4 GBq for resin spheres, and the respective TVs ranged from 2 to 125 mL and from 6 to 1,828 mL. The mean dose [Formula: see text] was 240 Gy for glass and 122 Gy for resin in TVs and 72 Gy for glass and 47 Gy for resin in NTVs. [Formula: see text] was 1.46 ± 0.58 (0.65-2.53) for glass and 1.16 ± 0.41 (0.54-2.54) for resin, and the respective values for [Formula: see text] were 0.88 ± 0.15 (0.56-1.00) and 0.86 ± 0.2 (0.58-1.35). DR variability was substantially lower in NTVs than in TVs. The Lin concordance between [Formula: see text] and [Formula: see text] (resin) was significantly better for tumors larger than 150 mL than for tumors 150 mL or smaller ([Formula: see text] = 0.93 and [Formula: see text] = 0.95 vs. [Formula: see text] = 0.57 and [Formula: see text] = 0.93; P < 0.05). In (90)Y

  12. Advances in SPECT imaging with respect to radionuclide therapy.

    Science.gov (United States)

    D'Asseler, Y

    2009-06-01

    Radionuclide therapy is gradually becoming more important as a therapy option in various diseases. Nuclear medicine imaging plays an important role in this, before, during and after the therapy. Single photon emission computed tomography (SPECT) imaging can be used to predict therapy response, calculate doses delivered to the tumour and the surrounding organ, check radiopharmaceutical distribution and follow-up this distribution in time. On a technological level, radionuclide imaging in a therapy setting shows some particularities and issues to be resolved. Accurate quantification is important but is hampered by attenuation, scatter from different energy peaks and from bremsstrahlung photons, septal penetration, partial volume effects etc. Some of these issues are discussed in this paper. A technique specific for therapy imaging is bremsstrahlung imaging, which can be used if the therapeutical agent is a pure beta emitter. Quantitative bremsstrahlung imaging is particularly challenging due to the complicated nature of the energy spectrum of these photons. Some work towards quantitative bremsstrahlung imaging is discussed here. Finally, some recent technical advances relevant to this field are pointed out. On the software side, Monte Carlo simulations seem to have a great potential for accurate quantitative SPECT reconstruction and subsequent patient specific image based dose calculations. Concerning hardware, the availability of SPECT-CT technology may have a large impact in imaging in radionuclide therapy. Novel detector technologies such as solid-state detectors may also prove to have significant advantages in this field.

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

    Science.gov (United States)

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

    2008-03-01

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

  14. 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.

  15. SPECT og PET i neurobiologien

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  16. 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

  17. 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...

  18. Targeted multi-pinhole SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  19. Respiratory-gated time-of-flight PET/CT during whole-body scan for lung lesions: feasibility in a routine clinical setting and quantitative analysis.

    Science.gov (United States)

    Suzawa, Naohisa; Ichikawa, Yasutaka; Ishida, Masaki; Tomita, Yoya; Nakayama, Ryohei; Sakuma, Hajime

    2016-12-01

    To demonstrate the feasibility of respiratory gating during whole-body scan for lung lesions in routine (18)F-FDG PET/CT examinations using a time-of-flight (TOF)-capable scanner to determine the effect of respiratory gating on reduction of both misregistration (between CT and PET) and image blurring, and on improvement of the maximum standardized uptake value (SUVmax). Patients with lung lesions who received FDG PET/CT were prospectively studied. Misregistration, volume of PET (Vp), and SUVmax were compared between ungated and gated images. The difference in respiratory gating effects was compared between lesions located in the upper or middle lobes (UML) and the lower lobe (LL). The correlation between three parameters (% change in misregistration, % change in Vp, and lesion size) and % change in SUVmax was analyzed. The study population consisted of 60 patients (37 males, 23 females; age 68 ± 12 years) with lung lesions (2.5 ± 1.7 cm). Fifty-eight out of sixty respiratory gating studies were successfully completed with a total scan time of 20.9 ± 1.9 min. Eight patients' data were not suitable for analysis, while the remaining 50 patients' data were analyzed. Respiratory gating reduced both misregistration by 21.4 % (p UML lesions. The correlation with % change in SUVmax was stronger in % change in Vp (r = 0.57) than % change in misregistration (r = 0.35). There was no statistically significant correlation between lesion size and % change in SUVmax (r = -0.20). Respiratory gating during whole-body scan in routine TOF PET/CT examinations is feasible and can reduce both misregistration and PET image blurring, and improve the SUVmax of lung lesions located primarily in the LL.

  20. Evolution of the GATE project: new results and developments

    Energy Technology Data Exchange (ETDEWEB)

    Santin, G. [ESA-ESTEC, Keplerlaan 1, 2200 AG Noordwijk (Netherlands); Staelens, S. [ELIS Department, Ghent University, B-9000 Ghent (Belgium); Taschereau, R. [CRUMP Institute for Molecular Imaging, University of California Los Angeles, 700 Westwood Plaza A438, Los Angeles, CA 90095-1770 (United States); Descourt, P. [U650 INSERM, LaTIM, Brest (France); Schmidtlein, C.R. [Memorial Sloan-Kettering Cancer Center, New York, New York, US (United States); Simon, L. [Department of Radiation Oncology, Institut Curie, Paris (France); Visvikis, D. [U650 INSERM, LaTIM, Brest (France); Jan, S. [Service Hospitalier Frederic Joliot (SHFJ), CEA-Orsay, Orsay (France); Buvat, I. [U678 INSERM, CHU Pitie-Salpetriere, Paris (France)

    2007-10-15

    We present the status of the Geant4 Application for Emission Tomography (GATE) project, a Monte Carlo simulator for Single Photon Emission Computed Tomography (SPECT) and Positron annihilation Emission Tomography (PET). Its main features are reminded, including modelling of time dependent phenomena and versatile, user-friendly scripting interface. The focus of this manuscript will be on new developments introduced in the past 4 years. New results have been achieved in the fields of validation on real medical and research PET and SPECT systems, voxel geometries, digitisation, distributed computing and dosimetry.

  1. 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

  2. Improvement of tomographic reconstruction in bone SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  3. Multi-centre evaluation of accuracy and reproducibility of planar and SPECT image quantification. An IAEA phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Brian E. [National Institute of Standards and Technology, Gaithersburg, MD (United States); Grosev, Darko [Univ. Hospital Centre Zagreb (Croatia); Buvat, Irene [Service Hospitalier Frederic Joliot, Paris (France); and others

    2017-08-01

    Accurate quantitation of activity provides the basis for internal dosimetry of targeted radionuclide therapies. This study investigated quantitative imaging capabilities at sites with a variety of experience and equipment and assessed levels of errors in activity quantitation in Single-Photon Emission Computed Tomography (SPECT) and planar imaging. Participants from 9 countries took part in a comparison in which planar, SPECT and SPECT with X ray computed tomography (SPECT-CT) imaging were used to quantify activities of four epoxy-filled cylinders containing {sup 133}Ba, which was chosen as a surrogate for {sup 131}I. The sources, with nominal volumes of 2, 4, 6 and 23 mL, were calibrated for {sup 133}Ba activity by the National Institute of Standards and Technology, but the activity was initially unknown to the participants. Imaging was performed in a cylindrical phantom filled with water. Two trials were carried out in which the participants first estimated the activities using their local standard protocols, and then repeated the measurements using a standardized acquisition and analysis protocol. Finally, processing of the imaging data from the second trial was repeated by a single centre using a fixed protocol. In the first trial, the activities were underestimated by about 15% with planar imaging. SPECT with Chang's first order attenuation correction (Chang-AC) and SPECT-CT overestimated the activity by about 10%. The second trial showed moderate improvements in accuracy and variability. Planar imaging was subject to methodological errors, e.g., in the use of a transmission scan for attenuation correction. The use of Chang-AC was subject to variability from the definition of phantom contours. The project demonstrated the need for training and standardized protocols to achieve good levels of quantitative accuracy and precision in a multicentre setting. Absolute quantification of simple objects with no background was possible with the strictest protocol to

  4. Influence of Respiratory Gating, Image Filtering, and Animal Positioning on High-Resolution Electrocardiography-Gated Murine Cardiac Single-Photon Emission Computed Tomography

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2015-01-01

    Full Text Available 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 injected with 99m technetium (99mTc-tetrofosmin, and each was scanned in supine and prone positions in a U-SPECT-II scanner with respiratory and electrocardiographic (ECG gating. ECG-gated SPECT images were created without applying respiratory motion correction or with two different respiratory motion correction strategies. The images were filtered with a range of three-dimensional gaussian kernels, after which end-diastolic volumes (EDVs, end-systolic volumes (ESVs, and left ventricular ejection fractions were calculated. No significant differences in the measured cardiac parameters were detected when any strategy to reduce or correct for respiratory motion was applied, whereas big differences (> 5% in EDV and ESV were found with regard to different positioning of animals. A linear relationship (p < .001 was found between the EDV or ESV and the kernel size of the gaussian filter. In short, respiratory gating did not significantly affect the cardiac parameters of mice obtained with ultra-high-resolution SPECT, whereas the position of the animals and the image filters should be the same in a comparative study with multiple scans to avoid systematic differences in measured cardiac parameters.

  5. 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.).

  6. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-06-15

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

  8. 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.)

  9. Novel SPECT Technologies and Approaches in Cardiac Imaging

    Directory of Open Access Journals (Sweden)

    Piotr Slomka

    2016-12-01

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

  10. 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

  11. 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.

  12. 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.)

  13. 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...

  14. Myocardial CT perfusion imaging and SPECT for the diagnosis of coronary artery disease

    DEFF Research Database (Denmark)

    George, Richard T; Mehra, Vishal C; Chen, Marcus Y

    2014-01-01

    ). Sensitivity and specificity were calculated with use of prespecified cutoffs. The reference standard was a stenosis of at least 50% at coronary angiography as determined with quantitative methods. RESULTS: CAD was diagnosed in 229 of the 381 patients (60%). The per-patient sensitivity and specificity......PURPOSE: To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography...... or pharmacologic stress SPECT before and within 60 days of coronary angiography. Images from CT perfusion imaging, SPECT, and coronary angiography were interpreted at blinded, independent core laboratories. The primary diagnostic parameter was the area under the receiver operating characteristic curve (Az...

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

    Science.gov (United States)

    Cao, Liji; Peter, Jörg

    2010-05-01

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

  16. Neuroradiological findings in primary progressive aphasia: CT, MRI and cerebral perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Sinnatamby, R. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Antoun, N.A. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Freer, C.E.L. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Miles, K.A. [Dept. of Nuclear Medicine, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Hodges, J.R. [Dept. of Neurology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom)

    1996-04-01

    Primary progressive aphasia (PPA) is defined as progressive decline in language for 2 or more years with preservation of activities of daily living and general cognitive functions. Whereas the clinical features of this syndrome have been well documented, the neuroradiological findings have not been studied systematically. We studied 13 patients with PPA retrospectively: 10 underwent CT, 12 MRI and 12 cerebral perfusion studies using {sup 99m}Tc-HMPAO SPECT. CT and MR images were scored for focal atrophy by two independent assessors. Initial qualitative assessment of SPECT images was confirmed by quantitative analysis. CY was normal in 5 patients. Focal atrophy, affecting predominantly the left temporal lobe, was seen in 4 of 10 patients on CT, and 10 of 12 on MRI. Atrophy was localised primarily to the superior and middle temporal gyri on MRI. All 12 patients who underwent SPECT had unilateral temporal lobe perfusion defects, in 2 patients of whom MRI was normal. CT is relatively insensitive to focal abnormalities in PPA; MRI and SPECT are the imaging modalities of choice. MRI allows accurate, specific localisation of atrophy with the temporal neocortex. SPECT may reveal a functional decrease in cerebral perfusion prior to establishment of structural change. (orig.)

  17. Non-ECG-gated CT pulmonary angiography and the prediction of right ventricular dysfunction in patients suspected of pulmonary embolism

    DEFF Research Database (Denmark)

    Gutte, Henrik; Mortensen, Jann; Mørk, Mette Louise;

    2016-01-01

    PURPOSE: Right ventricular dysfunction (RVD) is an important prognostic factor of 30-day mortality in patients with acute pulmonary embolism (PE). The aim of our study was to evaluate whether non-electrocardiogram (ECG)-gated cardiovascular parameters attained during computed tomography pulmonary...... angiography (CTPA) could predict RVD in patients suspected of PE using ECG-gated cardiac CT angiography as reference. METHODS: Consecutive patients suspected of PE were referred to a ventilation/perfusion single-photon emission tomography (V/Q-SPECT) as first-line imaging procedure. Patients had a V....../Q-SPECT/CT, a CTPA and an ECG-gated cardiac CT angiography performed the same day. RESULTS: A total of 71 patients were available for analysis. Seventeen patients (24%) had RVD. The non-ECG-gated dimensions of left and right ventricle and the major vessels were correlated with ECG-gated cardiac dimensions. The size...

  18. Molecular imaging of angiogenesis with SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-08-15

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

  19. Quantitative right and left ventricular functional analysis during gated whole-chest MDCT: A feasibility study comparing automatic segmentation to semi-manual contouring

    Energy Technology Data Exchange (ETDEWEB)

    Coche, Emmanuel, E-mail: Emmanuel.coche@uclouvain.b [Department of Medical Imaging, Universite Catholique de Louvain, Cliniques Universitaires St-Luc (UCL), Avenue Hippocrate, 10, 1200 Brussels (Belgium); Walker, Matthew J. [Philips Healthcare, CT Clinical Science, Cleveland, OH (United States); Zech, Francis [Department of Internal Medicine, Universite Catholique de Louvain, Cliniques Universitaires St-Luc, Brussels (Belgium); Crombrugghe, Rodolphe de [Department of Medical Imaging, Universite Catholique de Louvain, Cliniques Universitaires St-Luc (UCL), Avenue Hippocrate, 10, 1200 Brussels (Belgium); Vlassenbroek, Alain [Philips Healthcare, Brussels (Belgium)

    2010-06-15

    Purpose: To evaluate the feasibility of an automatic, whole-heart segmentation algorithm for measuring global heart function from gated, whole-chest MDCT images. Material and methods: 15 patients with suspicion of PE underwent whole-chest contrast-enhanced MDCT with retrospective ECG synchronization. Two observers computed right and left ventricular functional indices using a semi-manual and an automatic whole-heart segmentation algorithm. The two techniques were compared using Bland-Altman analysis and paired Student's t-test. Measurement reproducibility was calculated using intraclass correlation coefficient. Results: Ventricular analysis with automatic segmentation was successful in 13/15 (86%) and in 15/15 (100%) patients for the right ventricle and left ventricle, respectively. Reproducibility of measurements for both ventricles was perfect (ICC: 1.00) and very good for automatic and semi-manual measurements, respectively. Ventricular volumes and functional indices except right ventricular ejection fraction obtained from the automatic method were significantly higher for the RV compared to the semi-manual methods. Conclusions: The automatic, whole-heart segmentation algorithm enabled highly reproducible global heart function to be rapidly obtained in patients undergoing gated whole-chest MDCT for assessment of acute chest pain with suspicion of pulmonary embolism.

  20. 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)

  1. Impaired coronary flow reserve is the most important marker of viable myocardium in the myocardial segment-based analysis of dual-isotope gated myocardial perfusion single-photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Woo [Dept. of Nuclear Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); So, Young [Dept. of Nuclear Medicine, Konkuk University School of Medicine, Seoul (Korea, Republic of); Kim, Ki Bong; Lee, Dong Soo [Seoul National University Hospital, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-04-15

    The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), {sup 201}Tl perfusion status at rest, {sup 201}Tl 24 hours redistribution and systolic wall thickening of {sup 99m}Tc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery. A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG. The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p < 0.001) in 22 patients who had a pre-CABG LVEF lower than 50%. Among 590 myocardial segments in the re-vascularized area, 115 showed abnormal wall motion before CABG and 73.9% (85 of 115) had wall motion improvement after CABG. In the univariate analysis (n = 115 segments), stress/rest reversibility (p < 0.001) and {sup 201}Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001). Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.

  2. Ictal SPECT in Sturge-Weber syndrome

    OpenAIRE

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

    2008-01-01

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

  3. Automatic composition of MRI and SPECT images

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Hiromi [Research Inst. of Brain and Blood Vessels, Akita (Japan)

    1999-12-01

    The new method to automatically compose MRI image and SPECT image was devised to support the SPECT image which was inferior in the morphological information. This method is a kind of the coordinate transformation to obtain maximal agreement between images using cross correlation of MRI image and SPECT image as the evaluation function to show the degree of the agreement. For the calculation of the cross correlation, MRI T1 weighted image and the morphological information of SPECT image treated by the spatial quadratic differentiation (Laplacian) were used. This method does not require to fix the control point in the tomographic imaging, and can be also applied to PET other than SPECT. This is also useful to follow up the chronological change of a patient by composition among SPECT images and among PET images. Since this method is focused on the internal structure of brain, it is also useful for cases such as cerebral infarction which brain structure has little change. But this method is still under the trial and the examination of the accuracy remained. (K.H.)

  4. 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.)

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

    Directory of Open Access Journals (Sweden)

    K Uday Bhanu

    2017-01-01

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

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

    Science.gov (United States)

    Bhanu, K Uday; Khandelwal, Niranjan; Vyas, Sameer; Singh, Paramjeet; Prabhakar, Anuj; Mittal, B R; Bhalla, Ashish

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-01

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

  8. 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

  9. 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.

  10. 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

  11. SPECT/CT workflow and imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

  12. 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.)

  13. Dopamine transporter density of the basal ganglia assessed with I-123 IPT SPECT in methamphetamine abusers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo Ryung; Ahn, Byeong Cheol [Kyungpook National University Medical School, Daegu (Korea, Republic of); Kewm, Do Hun [National Bugok Mental Hospital, Changryung (Korea, Republic of)] (and others)

    2005-10-15

    Functional imaging of dopamine transporter (DAT) defines integrity of the dopaminergic system, and DAT is the target site of drugs of abuse such as cocaine and methamphetamine. Functional imaging the DAT may be a sensitive and selective indicator of neurotoxic change by the drug. The aim of the present study is to evaluate the clinical implications of qualitative/quantitative analyses of dopamine transporter imaging in methamphetamine abusers. Six detoxified methamphetamine abusers (abuser group) and 4 volunteers (control group) were enrolled in this study. Brain MRI was performed in all of abuser group. Abuser group underwent psychiatric and depression assessment using brief psychiatric rating scale (BPRS) and Hamilton depression rating scale (HAMD), respectively. All of the subjects underwent I-123 IPT SPECT (IPT SPECT). IPT SPECT image was analysed with visual qualitative method and quantitative method using basal ganglia dopamine transporter (DAT) specific/non-specific binding ratio (SBR). Comparison of DAT SBR between abuser and control groups was performed. We also performed correlation tests between psychiatric and depression assessment results and DAT SBR in abuser group. All of abuser group showed normal MRI finding, but had residual psychiatric and depressive symptoms, and psychiatric and depressive symptom scores were exactly correlated (r=1.0, {rho} =0.005) each other. Five of them showed abnormal finding on qualitative visual I-123 IPT SPECT. Abuser group had lower basal ganglia DAT SBR than that of control (2.38 {+-} 0.20 vs 3.04 {+-} 0.27, {rho} =0.000). Psychiatric and depressive symptoms were negatively well correlated with basal ganglia DAT SBR (r=-0.908, {rho} =0.012, r=-0.924, {rho} =0.009) This results suggest that dopamine transporter imaging using I-123 IPT SPECT may be used to evaluate dopaminergic system of the basal ganglia and the clinical status in methamphetamine abusers.

  14. Brain SPECT imaging in Sydenham's chorea

    Directory of Open Access Journals (Sweden)

    Barsottini O.G.P.

    2002-01-01

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

  15. Attenuation Correction in SPECT during Image Reconstruction using an Inverse Monte Carlo Method: A Simulation Study

    OpenAIRE

    Shahla Ahmadi; Hossein Rajabi; Farshid Babapoor; Faraz Kalantari

    2011-01-01

    Introduction: The main goal of SPECT imaging is to determine activity distribution inside the organs of the body. However, due to photon attenuation, it is almost impossible to do a quantitative study. In this paper, we suggest a mathematical relationship between activity distribution and its corresponding projections using a transfer matrix. Monte Carlo simulation was used to find a precise transfer matrix including the effects of photon attenuation.  Material and Methods: List mode output o...

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

    OpenAIRE

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

    2015-01-01

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

  17. SPECT/CT and tumour imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

  18. N-isopropyl-p-( sup 123 I)iodoamphetamine SPECT in MELAS syndrome: Comparison with CT and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, M.; Ishikawa, N.; Yoshizawa, T.; Takeda, T.; Akisada, M. (Univ. of Tsukuba (Japan))

    1991-01-01

    Regional cerebral perfusion was studied in three patients with the mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome, using single photon emission computed tomography (SPECT) with N-isopropyl-p-(123I)iodoamphetamine (IMP). Accumulation of the tracer was relatively decreased in the parietooccipital regions and also in the frontotemporal regions after stroke-like episodes. However, quantitative regional cerebral blood flow (rCBF) measurement showed that rCBF was relatively well preserved even at these sites, and a hyperemic state was observed at the sites of normal accumulation. IMP SPECT may be useful in the diagnosis and assessment of the progress of the MELAS syndrome.

  19. Quantum Gates and Circuits

    CERN Document Server

    Di Vincenzo, D P

    1997-01-01

    A historical review is given of the emergence of the idea of the quantum logic gate from the theory of reversible Boolean gates. I highlight the quantum XOR or controlled NOT as the fundamental two-bit gate for quantum computation. This gate plays a central role in networks for quantum error correction.

  20. Phantom Validation of Tc-99m Absolute Quantification in a SPECT/CT Commercial Device

    Directory of Open Access Journals (Sweden)

    Silvano Gnesin

    2016-01-01

    Full Text Available Aim. Similar to PET, absolute quantitative imaging is becoming available in commercial SPECT/CT devices. This study’s goal was to assess quantitative accuracy of activity recovery as a function of image reconstruction parameters and count statistics in a variety of phantoms. Materials and Methods. We performed quantitative Tc99m-SPECT/CT acquisitions (Siemens Symbia Intevo, Erlangen, Germany of a uniform cylindrical, NEMA/IEC, and an anthropomorphic abdominal phantom. Background activity concentrations tested ranged: 2–80 kBq/mL. SPECT acquisitions used 120 projections (20 s/projection. Reconstructions were performed with the proprietary iterative conjugate gradient algorithm. NEMA phantom reconstructions were obtained as a function of the iteration number (range: 4–48. Recovery coefficients, hot contrast, relative lung error (NEMA phantom, and image noise were assessed. Results. In all cases, absolute activity and activity concentration were measured within 10% of the expected value. Recovery coefficients and hot contrast in hot inserts did not vary appreciably with count statistics. RC converged at 16 iterations for insert size > 22 mm. Relative lung errors were comparable to PET levels indicating the efficient integration of attenuation and scatter corrections with adequate detector modeling. Conclusions. The tested device provided accurate activity recovery within 10% of correct values; these performances are comparable to current generation PET/CT systems.

  1. Motor activation SPECT for the neurosurgical diseases. Clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, Hiroshi; Kawaguchi, Shoichiro; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime [Nara Medical Univ., Kashihara (Japan)

    1999-08-01

    We evaluated and analyzed the motor activation single photon emission computed tomography (M-SPECT) findings on patients with ischemic cerebrovascular diseases (CVD). The M-SPECT studies were carried out on 91 patients with ischemic cerebrovascular diseases. The M-SPECT study was performed using the finger opposition task in each case. The SPECT images were superimposed on the magnetic resonance images (MRIs) for each case using Image Fusion Software. The result of the M-SPECT was expressed as positive or negative. The cases with a marked increase of blood flow in the sensorio-motor cortex after the finger opposition task were categorized as positive, and those cases showing no marked increase of blood flow were categorized as negative. Among the 91 cases examined, 53 (58%) were categorized as positive in the M-SPECT study. Among the negative M-SPECT cases treated with revascularization surgery, there were some cases showing positive M-SPECT results postoperatively. The cases without any revascularization surgery did not change the M-SPECT findings in each during the follow-up period. The M-SPECT procedure for examining intracranial lesions could provide the cortical localization of the motor function. The M-SPECT procedure in the ischemic CVDs contributes to knowledge about the choices of treatment and the evaluation of the treatment result. (author)

  2. Application of SPECT to psychiatry

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-01

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

  3. Semi-quantitative analysis of post-transarterial radioembolization {sup 90}Y Microsphere position emission tomography combined with computed tomography (PET/CT) images in advance liver malignancy: Comparison with {sup 99m}Tc macroaggregated albumin (MAA) single photon emission computed tomography (SPECT)

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Seung Hong; Kim, Sung Eun; Cho, Jae Hyuk; Park, Ju Kyung; Kim, Yun Hwan; Choe, Jae Gol [Korea University Anam Hospital, Seoul (Korea, Republic of); Eo, Jae Seon; Park, So Yeon; Lee, Eun Sub [Dept. of Nuclear Medicine, Korea University Guro Hospital, Seoul (Korea, Republic of)

    2016-03-15

    The purpose of this study is to evaluate the correlation between pretreatment planning technetium-99m ({sup 99}mTc) macroaggregated albumin (MAA) SPECT images and posttreatment transarterial radioembolization (TARE) yttirum-90 ({sup 90}Y) PET/CT images by comparing the ratios of tumor-to-normal liver counts. Fifty-two patients with advanced hepatic malignancy who underwent {sup 90}Y microsphere radioembolization from January 2010 to December 2012 were retrospectively reviewed. Patients had undergone {sup 99}mTc MAA intraarterial injection SPECT for a pretreatment evaluation of microsphere distribution and therapy planning. After the administration of {sup 90}Y microspheres, the patients underwent posttreatment {sup 90}Y PET/CT within 24 h. For semiquantitative analysis, the tumor-to-normal uptake ratios in {sup 90}Y PET/CT (TNR-yp) and {sup 99}mTc MAA SPECT (TNR-ms) as well as the tumor volumes measured in angiographic CT were obtained and analyzed. The relationship of TNR-yp and TNR-ms was evaluated by Spearman's rank correlation and Wilcoxon's matched pairs test. In a total of 79 lesions of 52 patients, the distribution of microspheres was well demonstrated in both the SPECT and PET/CT images. A good correlation was observed of between TNR-ms and TNR-yp (rho value = 0.648, p < 0.001). The TNR-yp (median 2.78, interquartile range 2.43) tend to show significantly higher values than TNR-ms (median 2.49, interquartile range of 1.55) (p = 0.012). The TNR-yp showed weak correlation with tumor volume (rho = 0.230, p = 0.041). The 99mTc MAA SPECT showed a good correlation with {sup 90}Y PET/CT in TNR values, suggesting that {sup 99}mTc MAA can be used as an adequate pretreatment evaluation method. However, the {sup 99}mTc MAA SPECT image consistently shows lower TNR values compared to 90Y PET/CT, which means the possibility of underestimation of tumorous uptake in the partition dosimetry model using {sup 99}mTc MAA SPECT. Considering that

  4. A Modified Post Processing Correction Matrix For SPECT

    Science.gov (United States)

    Macey, D. J.; DeNardo, G. L.; DeNardo, S. J.; Seibert, J. A.

    1986-01-01

    A post reconstruction method of attenuation compensation for Single Photon Emission Computed Tomography (SPECT) has been investigated that offers a new approach to the problem of quantitation. A modified correction matrix is generated for attenuation compensation in which the Linear Attenuation Coefficient (LAC) for each pixel is assigned a value depending on the radial distance of the pixel from the true section boundary. Attenuation compensation of transverse section images of small and large volume sources of Tc-99m in phantoms using this modified matrix indicated that a known quantity of radionuclide could be determined to better than 10%. The scatter fraction was estimated as the difference in the corrected section images using a multiplicative matrix generated with a constant LAC for each pixel and the modified matrix proposed in this report.

  5. Registration of renal SPECT and 2.5D US images.

    Science.gov (United States)

    Galdames, Francisco J; Perez, Claudio A; Estévez, Pablo A; Held, Claudio M; Jaillet, Fabrice; Lobo, Gabriel; Donoso, Gilda; Coll, Claudia

    2011-06-01

    Image registration is the process of transforming different image data sets of an object into the same coordinate system. This is a relevant task in the field of medical imaging; one of its objectives is to combine information from different imaging modalities. The main goal of this study is the registration of renal SPECT (Single Photon Emission Computerized Tomography) images and a sparse set of ultrasound slices (2.5D US), combining functional and anatomical information. Registration is performed after kidney segmentation in both image types. The SPECT segmentation is achieved using a deformable model based on a simplex mesh. The 2.5D US image segmentation is carried out in each of the 2D slices employing a deformable contour and Gabor filters to capture multi-scale image features. Moreover, a renal medulla detection method was developed to improve the US segmentation. A nonlinear optimization algorithm is used for the registration. In this process, movements caused by patient breathing during US image acquisition are also corrected. Only a few reports describe registration between SPECT images and a sparse set of US slices of the kidney, and they usually employ an optical localizer, unlike our method, that performs movement correction using information only from the SPECT and US images. Moreover, it does not require simultaneous acquisition of both image types. The registration method and both segmentations were evaluated separately. The SPECT segmentation was evaluated qualitatively by medical experts, obtaining a score of 5 over a scale from 1 to 5, where 5 represents a perfect segmentation. The 2.5D US segmentation was evaluated quantitatively, by comparing our method with an expert manual segmentation, and obtaining an average error of 3.3mm. The registration was evaluated quantitatively and qualitatively. Quantitatively the distance between the manual segmentation of the US images and the model extracted from the SPECT image was measured, obtaining an

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-10-01

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

  7. [Development of a Novel Body Phantom with Bone Equivalent Density for Evaluation of Bone SPECT].

    Science.gov (United States)

    Ichikawa, Hajime; Miwa, Kenta; Matsutomo, Norikazu; Watanabe, Yoichi; Kato, Toyohiro; Shimada, Hideki

    2015-12-01

    We developed a custom-designed phantom for bone single photon emission computed tomography (SPECT)-specific radioactivity distribution and linear attenuation coefficient. The aim of this study was to evaluate the accuracy of the phantom. The lumbar phantom consisted of the trunk of a body phantom (background) containing a cylinder (vertebral body), a sphere (tumor), and a T-shaped container (processus). The vertebral body, tumor, and processus phantoms contained a K(2)HPO(4) solution of bone equivalent density and 50, 300 and 50 kBq/mL of (99m)Tc, respectively. The body phantom contained 8 kBq/mL of (99m)Tc solution. SPECT images were acquired using low-energy high-resolution collimation, a 128 × 128 matrix and 120 projections over 360° with a dwell time of 15 sec/view × 4 times. Thereafter, CT images were acquired at 130 kV and 70 ref mAs using adaptive dose modulation. The SPECT data were reconstructed with ordered subset expectation maximization with three-dimensional, scatter, and CT-based attenuation correction. Count ratio, linear attenuation coefficient (LAC), and full-width at half-maximum (FWHM) were measured. Count ratios between the background, the vertebral body, and the tumor in SPECT images were 463.8: 2888.0: 15150.3 (1: 6.23: 32.7). The LAC of the background and vertebral body in the CT-derived attenuation map were 0.155 cm⁻¹ and 0.284 cm⁻¹, respectively, and the FWHM measured from the processus was 15.27 mm. The precise counts and LAC indicated that the phantom was accurate and could serve as a tool for evaluating acquisition, reconstruction parameters, and quantitation in bone SPECT images.

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

    Science.gov (United States)

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

    2009-05-07

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

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

    Science.gov (United States)

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

    2009-05-01

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

  10. {sup 201}Thallium SPECT, accuracy in astrocytoma diagnosis and treatment evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Kaellen, K

    1999-10-01

    The aims of the studies included in this thesis were: - to investigate the reliability of {sup 201}Thallium single photon emission computed tomography. Tl SPECT for preoperative diagnosis and histological staging of malignant astrocytomas in comparison with CT; - to develop a method for quantification of cerebral thallium uptake, and to evaluate the quantitative measurement in comparison with CT, for astrocytoma treatment follow-up purposes; - to compare quantitative Tl SPECT and proton magnetic resonance spectroscopy (H-MRS) with conventional MR imagingfor astrocytoma monitoring, and to evaluate associations between change of morphological tumour characteristics during treatment and changes of cerebral thallium uptake and metabolic ratios. Results and conclusions: - High TI-index, calculated as a ratio comparing tumour uptake to uptake in the contralateral hemisphere, is an indicator of highly malignant astrocytoma. Differentiation between the high-grade astrocytomas, the low-grade astrocytomas, and infectious lesions is only partial, with an overlap of Tl-indexes between these groups. High-grade astrocytomas that do not show contrast enhancement on CT, and astrocytomas with central necrosis and moderate ring-enhancement, tend to be underestimated when evaluated by Tl-index calculation. Tl SPECT is not a reliable method for non-invasive tumour staging among the group of highly malignant astrocytomas. - Quantification of cerebral TI-uptake, defining the volume of viable tumour tissue, is a new method for astrocytoma chemotherapy monitoring. Results suggest that the method provides prognostic information, and information of treatment efficacy, at an earlier stage than CT. - We did not find a higher accuracy of quantitative Tl SPECT than of MR for monitoring purposes and our results indicated that treatment induced MR changes were interrelated with TI-uptake variations. - Multi-voxel H-MRS was difficult to apply for astrocytoma treatment monitoring, due to the

  11. 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''.

  12. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

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

  13. Singular Value Decomposition of Pinhole SPECT Systems.

    Science.gov (United States)

    Palit, Robin; Kupinski, Matthew A; Barrett, Harrison H; Clarkson, Eric W; Aarsvold, John N; Volokh, Lana; Grobshtein, Yariv

    2009-03-12

    A single photon emission computed tomography (SPECT) imaging system can be modeled by a linear operator H that maps from object space to detector pixels in image space. The singular vectors and singular-value spectra of H provide useful tools for assessing system performance. The number of voxels used to discretize object space and the number of collection angles and pixels used to measure image space make the matrix dimensions H large. As a result, H must be stored sparsely which renders several conventional singular value decomposition (SVD) methods impractical. We used an iterative power methods SVD algorithm (Lanczos) designed to operate on very large sparsely stored matrices to calculate the singular vectors and singular-value spectra for two small animal pinhole SPECT imaging systems: FastSPECT II and M(3)R. The FastSPECT II system consisted of two rings of eight scintillation cameras each. The resulting dimensions of H were 68921 voxels by 97344 detector pixels. The M(3)R system is a four camera system that was reconfigured to measure image space using a single scintillation camera. The resulting dimensions of H were 50864 voxels by 6241 detector pixels. In this paper we present results of the SVD of each system and discuss calculation of the measurement and null space for each system.

  14. SPECT and PET in Eating Disorders

    NARCIS (Netherlands)

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

    2014-01-01

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

  15. PET and SPECT imaging in veterinary medicine.

    Science.gov (United States)

    LeBlanc, Amy K; Peremans, Kathelijne

    2014-01-01

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

  16. SPECT and PET in Eating Disorders

    NARCIS (Netherlands)

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

    2014-01-01

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

  17. SPECT using asymmetric pinholes with truncated projections

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-07

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

  18. 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.

  19. Comparison and planar and SPECT ventilation/perfusion lung scanning

    Energy Technology Data Exchange (ETDEWEB)

    Eberl, S.; Uren, R.; Bautovich, G.; Dugal, T.; Forster, J. [Royal Prince Alfred Hospital, Camperdown, NSW (Australia). Department of PET and Nuclear Medicine

    1998-06-01

    Full text: Ventilation/perfusion (V/Q) lung scanning, using multiple planar views, is an accepted technique for diagnosing pulmonary embolism (PE). Under PIOPED criteria, there are a substantial number of indeterminate results due to confounding factors such as CAL, unusual anatomy or superimposed activity in the planar image. Our aim was to investigate if SPECT could improve the diagnostic accuracy of V/Q scanning in the diagnosis of PE. Both planar and SPECT images were acquired on a dual or a triple head gamma camera following inhalation of {sup 99m}Tc-Technegas and after injection of {sup 99m}Tc-MAA. Total acquisition time for SPECT studies was 7.5 min for ventilation and 5 min for perfusion. SPECT studies were reconstructed with an accelerated iterative reconstruction (OSEM) and ventilation slices and perfusion slices were registered with an automated image registration package. Total processing time was 5 min. We have now performed more than 600 planar and SPECT studies. A subset of 50 sequential patients and 10 cases with pulmonary angiography were scored blinded by experienced nuclear medicine physicians. Scores ranged from 0 (no PE) to 5 (definite PE). A score of 3 indicated indeterminate for PE. In the 60 patients analysed, planar and SPECT scores were equal in 27 patients, SPECT was more definite in 16 and less definite in 7 patients. In 8 patients, SPECT indicated PE and planar imaging low probability of PE. In 1 patient planar imaging was scored as PE and SPECT as low probability. Indeterminate rate was reduced from 8 to 1 with SPECT. In the 10 patients with angiography, SPECT studies agreed with angiography findings in 8 patients, while planar studies agreed with angiography findings in 5 patients. Our preliminary data suggest that SPECT V/Q lung scanning can: i) provide a significant improvement over planar imaging for the diagnosis of PE, and ii) our short acquisition time for V/Q SPECT is clinically practicable

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-15

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

  1. In vivo quantification by SPECT of [{sup 123}I] ADAM bound to serotonin transporters in the brains of rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Ye, X.-X. [Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Hwang, J.-J. [Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Hsieh, J.-F. [Department of Nuclear Medicine, Chi-Mei Foundation Medical Center, Yungkang City 710, Taiwan (China); Chen, J.-C. [Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China)]. E-mail: jcchen@ym.edu.tw; Chou, Y.-T. [Institute of Physiology, National Yang-Ming University, Taipei 112, Taiwan (China); Tu, K.-Y. [Department of Nuclear Medicine, Mackey Memorial Hospital, Taipei, Taiwan 104 (China); Wey, S.-P. [Department of Medical Imaging and Radiological Sciences, Chang-Gung University, Taoyuan, Taiwan 333 (China); Ting Gann [Institute of Nuclear Energy Research, Tao- Yuan 335, Taiwan (China)

    2004-11-01

    Background: A novel radioiodine ligand [{sup 123}I] ADAM (2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine) has been suggested as a promising serotonin transporter (SERT) imaging agent for the central nervous system. In this study, the biodistribution of SERTs in the rabbit brain was investigated using [{sup 123}I] ADAM and mapping images of the same animal produced by both single-photon emission computed tomography (SPECT) and microautoradiography. A semiquantification method was adopted to deduce the optimum time for SPECT imaging, whereas the input for a simple fully quantitative tracer kinetic model was provided from arterial blood sampling data. Methods: SPECT imaging was performed on female rabbits postinjection of 185 MBq [{sup 123}I] ADAM. The time-activity curve obtained from the SPECT images was used to quantify the SERTs, for which the binding potential was calculated from the kinetic modeling of [{sup 123}I] ADAM. The kinetic data were analyzed by the nonlinear least squares method. The effects of the selective serotonin reuptake inhibitors fluoxetine and p-chloroamphetamine (PCA) on rabbits were also evaluated. After scanning, the same animal was sacrificed and the brain was removed for microautoradiography. Regions-of-interest were analyzed using both SPECT and microautoradiography images. The SPECT images were coregistered manually with the corresponding microautoradiography images for comparative study. Results: During the time interval 90-100 min postinjection, the peak specific binding levels in different brain regions were compared and the brain stem was shown to have the highest activity. The target-to-background ratio was 1.89{+-}0.02. Similar studies with fluoxetine and PCA showed a background level for SERT occupation. Microautoradiography demonstrated a higher level of anatomical details of the [{sup 123}I] ADAM distribution than that obtained by SPECT imaging of the rabbit brain. Conclusion: SPECT imaging of the rabbit brain with

  2. New gate opening hours

    CERN Multimedia

    GS Department

    2009-01-01

    Please note the new opening hours of the gates as well as the intersites tunnel from the 19 May 2009: GATE A 7h - 19h GATE B 24h/24 GATE C 7h - 9h\t17h - 19h GATE D 8h - 12h\t13h - 16h GATE E 7h - 9h\t17h - 19h Prévessin 24h/24 The intersites tunnel will be opened from 7h30 to 18h non stop. GS-SEM Group Infrastructure and General Services Department

  3. Automatic Vertebral Column Extraction by Whole-Body Bone SPECT Scan

    Directory of Open Access Journals (Sweden)

    Sheng-Fang Huang

    2013-01-01

    Full Text Available Bone extraction and division can enhance the accuracy of diagnoses based on whole-body bone SPECT data. This study developed a method for using conventional SPECT for automatic recognition of the vertebral column. A novel feature of the proposed approach is a novel “bone graph" image description method that represents the connectivity between these image regions to facilitate manipulation of morphological relationships in the skeleton before surgery. By tracking the paths shown on the bone graph, skeletal structures can be identified by performing morphological operations. The performance of the method was evaluated quantitatively and qualitatively by two experienced nuclear medicine physicians. Datasets for whole-body bone SPECT scans in 46 lung cancer patients with bone metastasis were obtained with Tc-99m MDP. The algorithm successfully segmented vertebrae in the thoracolumbar spine. The quantitative assessment shows that the segmentation method achieved an average TP, FP, and FN rates of 95.1%, 9.1%, and 4.9%. The qualitative evaluation shows an average acceptance rate of 83%, where the data for the acceptable and unacceptable groups had a Cronbach’s alpha value of 0.718, which indicated reasonable internal consistency and reliability.

  4. Application of texture analysis to DAT SPECT imaging: Relationship to clinical assessments

    Directory of Open Access Journals (Sweden)

    Arman Rahmim

    2016-01-01

    Full Text Available Dopamine transporter (DAT SPECT imaging is increasingly utilized for diagnostic purposes in suspected Parkinsonian syndromes. We performed a cross-sectional study to investigate whether assessment of texture in DAT SPECT radiotracer uptake enables enhanced correlations with severity of motor and cognitive symptoms in Parkinson's disease (PD, with the long-term goal of enabling clinical utility of DAT SPECT imaging, beyond standard diagnostic tasks, to tracking of progression in PD. Quantitative analysis in routine DAT SPECT imaging, if performed at all, has been restricted to assessment of mean regional uptake. We applied a framework wherein textural features were extracted from the images. Notably, the framework did not require registration to a common template, and worked in the subject-native space. Image analysis included registration of SPECT images onto corresponding MRI images, automatic region-of-interest (ROI extraction on the MRI images, followed by computation of Haralick texture features. We analyzed 141 subjects from the Parkinson's Progressive Marker Initiative (PPMI database, including 85 PD and 56 healthy controls (HC (baseline scans with accompanying 3 T MRI images. We performed univariate and multivariate regression analyses between the quantitative metrics and different clinical measures, namely (i the UPDRS (part III - motor score, disease duration as measured from (ii time of diagnosis (DD-diag. and (iii time of appearance of symptoms (DD-sympt., as well as (iv the Montreal Cognitive Assessment (MoCA score. For conventional mean uptake analysis in the putamen, we showed significant correlations with clinical measures only when both HC and PD were included (Pearson correlation r = −0.74, p-value < 0.001. However, this was not significant when applied to PD subjects only (r = −0.19, p-value = 0.084, and no such correlations were observed in the caudate. By contrast, for the PD subjects, significant correlations

  5. Focal epilepsies: HM-PAO SPECT compared with CT, MR, and EEG.

    Science.gov (United States)

    Cordes, M; Christe, W; Henkes, H; Delavier, U; Eichstädt, H; Schörner, W; Langer, R; Felix, R

    1990-01-01

    Regional cerebral blood flow (rCBF) was evaluated quantitatively by 99mTc hexamethyl propyleneamine oxime and single photon emission CT (SPECT) during the interictal phase in 52 patients with focal epilepsy. The results were compared with those obtained by electroencephalography (EEG), CT, and magnetic resonance (MR) imaging. Twenty-four of the 52 patients had one area of local hypoperfusion whereas 7 patients showed an area of local hyperperfusion. In 20 of the 52 patients, both reduced and elevated rCBF values were found. One patient had a normal perfusion pattern. The SPECT findings correlated well with the foci shown by EEG, both with regard to the sides affected and the locations of the regions of altered perfusion. The MR images showed focal lesions in only approximately one-half of the patients examined, and CT in even fewer.

  6. Fully automated contour detection algorithm the preliminary step for scatter and attenuation compensation in SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Younes, R.B.; Mas, J.; Bidet, R.

    1988-12-01

    Contour detection is an important step in information extraction from nuclear medicine images. In order to perform accurate quantitative studies in single photon emission computed tomography (SPECT) a new procedure is described which can rapidly derive the best fit contour of an attenuated medium. Some authors evaluate the influence of the detected contour on the reconstructed images with various attenuation correction techniques. Most of the methods are strongly affected by inaccurately detected contours. This approach uses the Compton window to redetermine the convex contour: It seems to be simpler and more practical in clinical SPECT studies. The main advantages of this procedure are the high speed of computation, the accuracy of the contour found and the programme's automation. Results obtained using computer simulated and real phantoms or clinical studies demonstrate the reliability of the present algorithm.

  7. Pre and post betahistine therapy 99m Tc - HMPAO brain spect studies in patients with vertigo.

    Directory of Open Access Journals (Sweden)

    Krishna B

    2000-07-01

    Full Text Available Vertebro basilar insufficiency (VBI is a well known cause of vertigo. Brain Single Photon Emission Computed Tomography (SPECT is an important diagnostic tool to detect and to quantitate the perfusion abnormalities in different areas of the brain. Effect of an antivertigo drug Betahistine on improving the hypoperfusion in different areas of the brain in vertigo patients was studied using brain SPECT. Betahistine at a dose of 16 mg three times daily was shown to improve perfusion in the hypoperfused areas of the brain resulting in relief from symptoms of vertigo. The cerebellar region, which is the most important area involved in vertigo patients with vascular pathology, showed almost complete normalisation of perfusion following Betahistine therapy.

  8. Gate-enclosed NMOS transistors

    Institute of Scientific and Technical Information of China (English)

    Fan Xue; Li Ping; Li Wei; Zhang Bin; Xie Xiaodong; Wang Gang; Hu Bin; Zhai Yahong

    2011-01-01

    In order to quantitatively compare the design cost and performance of various gate styles,NMOS transistors with two-edged,annular and ring gate layouts were designed and fabricated by a commercial 0.35 μm CMOS process.By comparing the minimum W/L ratios and transistor areas,it was found that either the annular layout or its ring counterpart incurs a higher area penalty that depends on the W/L ratio of the transistor to be designed.Furthermore,by comparing the output and transfer characteristics of the transistors and analyzing the popular existing methods for extracting the effective W/L ratio,it was shown that the mid-line approximation for annular NMOS could incur an error of more than 10%.It was also demonstrated that the foundry-provided extraction tool needs significant adaptation when being applied to the enclosed-gate transistors,since it is targeted only toward the two-edged transistor.A simple approach for rough extraction of the W/L ratio for the ring-gate NMOS was presented and its effectiveness was confirmed by the experimental results with an error up to 8%.

  9. Clinical results of neurotransmission SPECT in extra-pyramidal diseases; Resultats cliniques de la TEMP de la neurotransmission en pathologie extra-pyramidale

    Energy Technology Data Exchange (ETDEWEB)

    Baulieu, J.L.; Prunier, C.; Tranquart, F.; Guilloteau, D. [Centre Hospitalier Universitaire Bretonneau, Service de Medecine Nucleaire in vitro, INSERM U316, 37 - Tours (France)

    1999-12-01

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

  10. Fully automatic multi-atlas segmentation of CTA for partial volume correction in cardiac SPECT/CT

    Science.gov (United States)

    Liu, Qingyi; Mohy-ud-Din, Hassan; Boutagy, Nabil E.; Jiang, Mingyan; Ren, Silin; Stendahl, John C.; Sinusas, Albert J.; Liu, Chi

    2017-05-01

    Anatomical-based partial volume correction (PVC) has been shown to improve image quality and quantitative accuracy in cardiac SPECT/CT. However, this method requires manual segmentation of various organs from contrast-enhanced computed tomography angiography (CTA) data. In order to achieve fully automatic CTA segmentation for clinical translation, we investigated the most common multi-atlas segmentation methods. We also modified the multi-atlas segmentation method by introducing a novel label fusion algorithm for multiple organ segmentation to eliminate overlap and gap voxels. To evaluate our proposed automatic segmentation, eight canine 99mTc-labeled red blood cell SPECT/CT datasets that incorporated PVC were analyzed, using the leave-one-out approach. The Dice similarity coefficient of each organ was computed. Compared to the conventional label fusion method, our proposed label fusion method effectively eliminated gaps and overlaps and improved the CTA segmentation accuracy. The anatomical-based PVC of cardiac SPECT images with automatic multi-atlas segmentation provided consistent image quality and quantitative estimation of intramyocardial blood volume, as compared to those derived using manual segmentation. In conclusion, our proposed automatic multi-atlas segmentation method of CTAs is feasible, practical, and facilitates anatomical-based PVC of cardiac SPECT/CT images.

  11. Impact of intracoronary injection of mononuclear bone marrow cells in acute myocardial infarction on left ventricular perfusion and function: a 6-month follow-up gated {sup 99m}Tc-MIBI single-photon emission computed tomography study

    Energy Technology Data Exchange (ETDEWEB)

    Lipiec, Piotr [Medical University of Lodz, 2nd Department of Cardiology, Lodz (Poland); Medical University of Lodz, 2nd Department of Cardiology, Bieganski Hospital, Lodz (Poland); Krzeminska-Pakula, Maria; Plewka, Michal; Kasprzak, Jaroslaw D. [Medical University of Lodz, 2nd Department of Cardiology, Lodz (Poland); Kusmierek, Jacek; Plachcinska, Anna; Szuminski, Remigiusz [Medical University of Lodz, Department of Nuclear Medicine, Lodz (Poland); Robak, Tadeusz; Korycka, Anna [Medical University of Lodz, Department of Hematology, Lodz (Poland)

    2009-04-15

    We investigated the impact of intracoronary injection of autologous mononuclear bone marrow cells (BMC) in patients with acute ST elevation myocardial infarction (STEMI) on left ventricular volumes, global and regional systolic function and myocardial perfusion. The study included 39 patients with first anterior STEMI treated successfully with primary percutaneous coronary intervention. They were randomly assigned to the treatment group or the control group in a 2:1 ratio. The patients underwent baseline gated single-photon emission computed tomography (G-SPECT) 3-10 days after STEMI with quantitative and qualitative analysis of left ventricular perfusion and systolic function. On the following day, patients from the BMC treatment group were subjected to bone marrow aspiration, mononuclear BMC isolation and intracoronary injection. No placebo procedure was performed in the control group. G-SPECT was repeated 6 months after STEMI. Baseline and follow-up G-SPECT studies were available for 36 patients. At 6 months in the BMC group we observed a significantly enhanced improvement in the mean extent of the perfusion defect, the left ventricular perfusion score index, the infarct area perfusion score and the infarct area wall motion score index compared to the control group (p=0.01-0.04). However, the changes in left ventricular volume, ejection fraction and the left ventricular wall motion score index as well as the relative changes in the infarct area wall motion score index did not differ significantly between the groups. Intracoronary injection of autologous mononuclear BMC in patients with STEMI improves myocardial perfusion at 6 months. The benefit in infarct area systolic function is less pronounced and there is no apparent improvement of global left ventricular systolic function. (orig.)

  12. Self-gated fat-suppressed cardiac cine MRI.

    Science.gov (United States)

    Ingle, R Reeve; Santos, Juan M; Overall, William R; McConnell, Michael V; Hu, Bob S; Nishimura, Dwight G

    2015-05-01

    To develop a self-gated alternating repetition time balanced steady-state free precession (ATR-SSFP) pulse sequence for fat-suppressed cardiac cine imaging. Cardiac gating is computed retrospectively using acquired magnetic resonance self-gating data, enabling cine imaging without the need for electrocardiogram (ECG) gating. Modification of the slice-select rephasing gradients of an ATR-SSFP sequence enables the acquisition of a one-dimensional self-gating readout during the unused short repetition time (TR). Self-gating readouts are acquired during every TR of segmented, breath-held cardiac scans. A template-matching algorithm is designed to compute cardiac trigger points from the self-gating signals, and these trigger points are used for retrospective cine reconstruction. The proposed approach is compared with ECG-gated ATR-SSFP and balanced steady-state free precession in 10 volunteers and five patients. The difference of ECG and self-gating trigger times has a variability of 13 ± 11 ms (mean ± SD). Qualitative reviewer scoring and ranking indicate no statistically significant differences (P > 0.05) between self-gated and ECG-gated ATR-SSFP images. Quantitative blood-myocardial border sharpness is not significantly different among self-gated ATR-SSFP ( 0.61±0.15 mm -1), ECG-gated ATR-SSFP ( 0.61±0.15 mm -1), or conventional ECG-gated balanced steady-state free precession cine MRI ( 0.59±0.15 mm -1). The proposed self-gated ATR-SSFP sequence enables fat-suppressed cardiac cine imaging at 1.5 T without the need for ECG gating and without decreasing the imaging efficiency of ATR-SSFP. © 2014 Wiley Periodicals, Inc.

  13. Multipinhole SPECT helical scan parameters and imaging volume

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Rutao, E-mail: rutaoyao@buffalo.edu; Deng, Xiao [Department of Nuclear Medicine, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Wei, Qingyang; Dai, Tiantian; Ma, Tianyu [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Lecomte, Roger [Department of Nuclear Medicine and Radiobiology, Sherbrooke Molecular Imaging Center, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4 (Canada)

    2015-11-15

    Purpose: The authors developed SPECT imaging capability on an animal PET scanner using a multiple-pinhole collimator and step-and-shoot helical data acquisition protocols. The objective of this work was to determine the preferred helical scan parameters, i.e., the angular and axial step sizes, and the imaging volume, that provide optimal imaging performance. Methods: The authors studied nine helical scan protocols formed by permuting three rotational and three axial step sizes. These step sizes were chosen around the reference values analytically calculated from the estimated spatial resolution of the SPECT system and the Nyquist sampling theorem. The nine helical protocols were evaluated by two figures-of-merit: the sampling completeness percentage (SCP) and the root-mean-square (RMS) resolution. SCP was an analytically calculated numerical index based on projection sampling. RMS resolution was derived from the reconstructed images of a sphere-grid phantom. Results: The RMS resolution results show that (1) the start and end pinhole planes of the helical scheme determine the axial extent of the effective field of view (EFOV), and (2) the diameter of the transverse EFOV is adequately calculated from the geometry of the pinhole opening, since the peripheral region beyond EFOV would introduce projection multiplexing and consequent effects. The RMS resolution results of the nine helical scan schemes show optimal resolution is achieved when the axial step size is the half, and the angular step size is about twice the corresponding values derived from the Nyquist theorem. The SCP results agree in general with that of RMS resolution but are less critical in assessing the effects of helical parameters and EFOV. Conclusions: The authors quantitatively validated the effective FOV of multiple pinhole helical scan protocols and proposed a simple method to calculate optimal helical scan parameters.

  14. Pharmacokinetics of SPECT radiopharmaceuticals for imaging hypoxic tissues.

    Science.gov (United States)

    Wiebe, L I; Stypinski, D

    1996-09-01

    Although hypoxia has been known for decades to play an important role in the outcome of radiotherapy in oncology, and inspite of the contribution of hypoxia to a myriad of pathologies that involve vascular disease, the selective imaging of hypoxic tissue has attained prominence only within the past decade. Contemporary research in the hypoxia imaging field is based largely on radiosensitizer research of the 1960's and 1970's. Early sensitizer research identified a family of nitro-organic compounds, the N-1 substituted 2-nitroimidazoles as candidate drugs. The early champion, and still the reference standard for therapeutic radiosensitization of hypoxic tumor cells is misonidazole (MISO). Its peripheral neurotoxicity led to failure in clinical studies, but its biological, biophysical and biochemical properties have been investigated in detail and serve as a basis for further design, not only of sensitizers, but of diagnostic radiopharmaceuticals for imaging tissue hypoxia. Pharmacokinetic characterization of radiopharmaceuticals, specifically radiopharmaceuticals for imaging tissue hypoxia, has not been a central theme in their development. The advent of PET, through which quantitative determinations first became possible, opened the field for both descriptive and analytical radiopharmacokinetic studies. In SPECT, however, this approach is still undergoing refinement. This paper addresses some of the underlying issues in radiopharmaceutical pharmacokinetics. There is a paucity of published radiopharmacokinetic data for SPECT hypoxia imaging agents. Consequently, the pharmacokinetic issues for MISO are presented as a basis for development of pharmacokinetics for the chemically-related imaging agents. Properties of an hypoxia marker are described from a pharmacokinetic viewpoint, a theoretical model for descriptive pharmacokinetics is introduced and finally, recent pharmacokinetic studies from our laboratory are described.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-17

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

  16. 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.

  17. Use of the GATE Monte Carlo package for dosimetry applications

    Energy Technology Data Exchange (ETDEWEB)

    Visvikis, D. [INSERM U650, LaTIM, University Hospital Medical School, F 29609 Brest (France)]. E-mail: Visvikis.Dimitris@univ-brest.fr; Bardies, M. [INSERM U601, CHU Nantes, F 44093 Nantes (France); Chiavassa, S. [INSERM U601, CHU Nantes, F 44093 Nantes (France); Danford, C. [Department of Medical Physics, MSKCC, New York (United States); Kirov, A. [Department of Medical Physics, MSKCC, New York (United States); Lamare, F. [INSERM U650, LaTIM, University Hospital Medical School, F 29609 Brest (France); Maigne, L. [Departement de Curietherapie-Radiotherapie, Centre Jean Perrin, F 63000 Clemont-Ferrand (France); Staelens, S. [UGent-ELIS, St-Pietersnieuwstraat, 41, B 9000 Gent (Belgium); Taschereau, R. [CRUMP Institute for Molecular Imaging, UCLA, Los Angeles (United States)

    2006-12-20

    One of the roles for Monte Carlo (MC) simulation studies is in the area of dosimetry. A number of different codes dedicated to dosimetry applications are available and widely used today, such as MCNP, EGSnrc and PTRAN. However, such codes do not easily facilitate the description of complicated 3D sources or emission tomography systems and associated data flow, which may be useful in different dosimetry application domains. Such problems can be overcome by the use of specific MC codes such as GATE (GEANT4 Application to Tomographic Emission), which is based on Geant4 libraries, providing a scripting interface with a number of advantages for the simulation of SPECT and PET systems. Despite this potential, its major disadvantage is in terms of efficiency involving long execution times for applications such as dosimetry. The strong points and disadvantages of GATE in comparison to other dosimetry specific codes are discussed and illustrated in terms of accuracy, efficiency and flexibility. A number of features, such as the use of voxelised and moving sources, as well as developments such as advanced visualization tools and the development of dose estimation maps allowing GATE to be used for dosimetry applications are presented. In addition, different examples from dosimetry applications with GATE are given. Finally, future directions with respect to the use of GATE for dosimetry applications are outlined.

  18. SPECT Molecular Imaging in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2012-01-01

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

  19. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo;

    2010-01-01

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

  20. Silicon Detectors for PET and SPECT

    Science.gov (United States)

    Cochran, Eric R.

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

  1. SPECT/CT in pediatric patient management

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-03-15

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

  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. ENVISION, developing SPECT imaging for particle therapy

    CERN Multimedia

    2013-01-01

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

  5. SPECT and PET Imaging of Meningiomas

    Directory of Open Access Journals (Sweden)

    Varvara Valotassiou

    2012-01-01

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

  6. 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.

  7. SPECT detectors: the Anger Camera and beyond.

    Science.gov (United States)

    Peterson, Todd E; Furenlid, Lars R

    2011-09-07

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-05-07

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-15

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

  10. Assessment of vascularization within hydroxyapatite ocular implant by bone scintigraphy: compartive analysis of planar and SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Seok Tae; Sohn, Myung Hee; Park, Soon Ah [College of Medicine, Chonbuk National Univ., Chonju (Korea, Republic of)

    1999-08-01

    Complete fibrovascular ingrowth within the hydroxyapatite ocular implant is necessary for peg drilling which is performed to prevent infection and to provide motility to the ocular prosthesis. We compared planar bone scintigraphy and SPECT for the evaluation of the vascularization within hydroxyapatite ocular implants. Seventeen patients (M:F=12:5, mean age: 50.4{+-}17.5 years) who had received a coralline hydroxyapatite ocular implant after enucleation surgery were enrolled. Patients underwent Tc-99m MDP planar bone and SPECT imaging by dual head gamma camera after their implant surgery (interval: 197{+-}81 days). Uptake on planar and SPECT images was graded visually as less than (grade 1), equal to (grade 2), and greater than (grade 3) nasal bridge activity. Quantitative ratio of implanted to non-implanted intraorbital activity was also measured. Vascularization within hydroxyapatite implants was confirmed by slit lamp examination and ocular movement. All but three patients were considered to be vascularized within hydroxyapatite implants. In visual analysis of planar image and SPECT, grade 1 was noted in 9/18 (50%) and 6/18 (33%), respectively. Grade 2 pattern 7/18 (39%) and 4/18 (22%), and grade 3 pattern was 2/18 (11%) and 8/18 (44%) respectively. When grade 2 or 3 was considered to be positive for vascularization, the sensitivity of planar and SPECT imaging were 60% (9/15) and 80% (12/15), respectively. In 3 patients with incomplete vascularization, both planar and SPECT showed grade 1 uptake. The orbital activity ratios on planar imaging were not significantly different between complete and incomplete vascularization (1.96{+-}9.87 vs 1.17{+-}0.08 , p>0.05), however, it was significantly higher on SPECT in patients with complete vascularization (8.44{+-}5.45 vs 2.20{+-}0.87, p<0.05). In the assessment of fibrovascular ingrowth within ocular implants by Tc-99m MDP bone scintigraphy, SPECT image appears to be more effective than planar scintigraphy.

  11. The study of low level laser irradiation therapy on brain infarction with SPECT

    Institute of Scientific and Technical Information of China (English)

    Xiao Xuechang; Jia Shaowei; Zleng Xiyuan

    2000-01-01

    Objective: Effect of rCBF and brain function on ILIB treating brain infarction will be investigated by SPECT brain perfusion imaging. Method: 3 1 patients with brain infarction, 17 patients were treated by ILIB on standard pharmaceutial treatment. SPECT brain perfusion imaging was performed before and after ILIB therapy with comparison of oneself. They were quantified with BFCR% model effect during ILIB in 14 patients were observed. Result: ILIB 30 rnme SPECT showed the improvement of rCBF and cerebral function in 14 patients with brain infarction, and in 17 patients locus were prominence than mirror regions att er ILIB therapy, both are higher singnitficant difference ( t=4.4052, P<0.0001 ), but mirror regions were not singnificant difference before and after ILIB (t=1.6995, P>0.05). BFCR% quantitative results of locus were higher mirror regions, and higher singnificant difference (t=4.5278 p<0.0001 )。 Conclusion: ILIB can improve the rCBF and cerebral function of patients with brain infarction, and provoke function of brain cells. Some new evidence was provided for ILIB treatment of cerebral ischemia

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  13. {sup 99m}Tc-HMPAO SPECT study during balloon occlusion test

    Energy Technology Data Exchange (ETDEWEB)

    Iwabuchi, Satoshi [Toho Univ., Tokyo (Japan). School of Medicine; Ogata, Noboru; Goto, Katsuya; Takechi, Akihiko

    1995-03-01

    The authors have evaluated the cerebral blood flow (CBF) using single photon emission computed tomography (SPECT) during balloon occlusion of the internal carotid artery (ICA) as a preembolization test for permanent carotid ligation. Seventeen patients were studied. These included 8 cases with aneurysm, 5 cases with direct carotid cavernous fistula (DCCF), 2 cases with arteriovenous fistula (AVF), 1 case with carotid basal plexus fistula and 1 case of parasellar tumor. The SPECT study during the balloon occlusion test was performed using technetium-99m hexamethyl-propyleneamine oxime ({sup 99m}Tc-HMPAO) intravenous injection method. The results showed that the SPECT study during the balloon occlusion test was a secure and useful examination, but it was necessary to be aware of the following: (1) As there were some cases whose blood pressure was unstable after the permanent carotid ligation, it was necessary to inject {sup 99m}Tc-HMPAO under induced hypotension. (2) In cases with DCCF, the steal phenomenon through the fistula is enhanced under proximal ICA occlusion. Therefore administration of {sup 99m}Tc-HMPAO should be done under complete occlusion of the fistula together with ICA. (3) For patients with preexisting reduction of regional CBF, a quantitative analysis was required. (author).

  14. Evaluation of attenuation and scatter correction requirements in small animal PET and SPECT imaging

    Science.gov (United States)

    Konik, Arda Bekir

    Positron emission tomography (PET) and single photon emission tomography (SPECT) are two nuclear emission-imaging modalities that rely on the detection of high-energy photons emitted from radiotracers administered to the subject. The majority of these photons are attenuated (absorbed or scattered) in the body, resulting in count losses or deviations from true detection, which in turn degrades the accuracy of images. In clinical emission tomography, sophisticated correction methods are often required employing additional x-ray CT or radionuclide transmission scans. Having proven their potential in both clinical and research areas, both PET and SPECT are being adapted for small animal imaging. However, despite the growing interest in small animal emission tomography, little scientific information exists about the accuracy of these correction methods on smaller size objects, and what level of correction is required. The purpose of this work is to determine the role of attenuation and scatter corrections as a function of object size through simulations. The simulations were performed using Interactive Data Language (IDL) and a Monte Carlo based package, Geant4 application for emission tomography (GATE). In IDL simulations, PET and SPECT data acquisition were modeled in the presence of attenuation. A mathematical emission and attenuation phantom approximating a thorax slice and slices from real PET/CT data were scaled to 5 different sizes (i.e., human, dog, rabbit, rat and mouse). The simulated emission data collected from these objects were reconstructed. The reconstructed images, with and without attenuation correction, were compared to the ideal (i.e., non-attenuated) reconstruction. Next, using GATE, scatter fraction values (the ratio of the scatter counts to the total counts) of PET and SPECT scanners were measured for various sizes of NEMA (cylindrical phantoms representing small animals and human), MOBY (realistic mouse/rat model) and XCAT (realistic human model

  15. Automated Analysis of {sup 123}I-beta-CIT SPECT Images with Statistical Probabilistic Anatomical Mapping

    Energy Technology Data Exchange (ETDEWEB)

    Eo, Jae Seon; Lee, Hoyoung; Lee, Jae Sung; Kim, Yu Kyung; Jeon, Bumseok; Lee, Dong Soo [Seoul National Univ., Seoul (Korea, Republic of)

    2014-03-15

    Population-based statistical probabilistic anatomical maps have been used to generate probabilistic volumes of interest for analyzing perfusion and metabolic brain imaging. We investigated the feasibility of automated analysis for dopamine transporter images using this technique and evaluated striatal binding potentials in Parkinson's disease and Wilson's disease. We analyzed 2β-Carbomethoxy-3β-(4-{sup 123}I-iodophenyl)tropane ({sup 123}I-beta-CIT) SPECT images acquired from 26 people with Parkinson's disease (M:F=11:15,mean age=49±12 years), 9 people with Wilson's disease (M: F=6:3, mean age=26±11 years) and 17 normal controls (M:F=5:12, mean age=39±16 years). A SPECT template was created using striatal statistical probabilistic map images. All images were spatially normalized onto the template, and probability-weighted regional counts in striatal structures were estimated. The binding potential was calculated using the ratio of specific and nonspecific binding activities at equilibrium. Voxel-based comparisons between groups were also performed using statistical parametric mapping. Qualitative assessment showed that spatial normalizations of the SPECT images were successful for all images. The striatal binding potentials of participants with Parkinson's disease and Wilson's disease were significantly lower than those of normal controls. Statistical parametric mapping analysis found statistically significant differences only in striatal regions in both disease groups compared to controls. We successfully evaluated the regional {sup 123}I-beta-CIT distribution using the SPECT template and probabilistic map data automatically. This procedure allows an objective and quantitative comparison of the binding potential, which in this case showed a significantly decreased binding potential in the striata of patients with Parkinson's disease or Wilson's disease.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

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

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

    NARCIS (Netherlands)

    Xiao, J.

    2009-01-01

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

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

    NARCIS (Netherlands)

    Have, F. van der

    2007-01-01

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

  19. 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

  20. Quantitative electroencephalography in frontotemporal dementia with methylphenidate response: a case study.

    Science.gov (United States)

    Goforth, Harold W; Konopka, Lukasz; Primeau, Margaret; Ruth, Amity; O'Donnell, Kathleen; Patel, Roopal; Poprawski, Teresa; Shirazi, Parvez; Rao, Murali

    2004-04-01

    Frontotemporal dementia is an underdiagnosed illness with predominant behavioral and executive manifestations. Historically, diagnosis has been based on a combination of clinical history, neuropsychological testing, and brain imaging. No effective treatment currently exists for this disorder. A case is presented using quantitative EEG with methylphenidate challenge correlated with SPECT. The patient underwent neuropsychological testing, a SPECT brain study, and a quantitative EEG, which was repeated after methylphenidate administration. SPECT was significant for hypoperfusion to the bilateral frontotemporal regions, with left-sided hypoperfusion greater than homologous right as demonstrated by LORETA analysis. QEEG correlated with SPECT, and demonstrated profound left greater than right bi-frontotemporal slowing, which normalized partially after methylphenidate administration. The patient has remained on methylphenidate as an outpatient, and has had significant behavioral improvement. Quantitative EEG may provide both diagnostic and therapeutic data with regard to frontotemporal dementia. Further studies of methylphenidate in this population are needed to confirm these data.

  1. Comparison of I-123 MIBG planar imaging and SPECT for the detection of decreased heart uptake in Parkinson disease.

    Science.gov (United States)

    Oh, Jin-Kyoung; Choi, Eun-Kyoung; Song, In-Uk; Kim, Joong-Seok; Chung, Yong-An

    2015-10-01

    Decreased myocardial uptake of I-123 metaiodobenzylguanidine (MIBG) is an important finding for diagnosis of Parkinson's disease (PD). This study compared I-123 MIBG SPECT and planar imaging with regard to their diagnostic yield for PD. 52 clinically diagnosed PD patients who also had decreased striatal uptake on FP-CIT PET/CT were enrolled. 16 normal controls were also included. All underwent cardiac MIBG planar scintigraphy and SPECT separately. Myocardial I-123 MIBG uptake was interpreted on planar and SPECT/CT images separately by visual and quantitative analysis. The final diagnosis was made by consensus between two readers. Kappa analyses were performed to determine inter-observer agreement for both methods. Sensitivity, specificity, and accuracy were compared with McNemar's test. The sensitivity, specificity, and accuracy were 84.6, 100, and 88.2% for planar images and 96.2, 100 and 97.1% for SPECT, respectively, with a significant difference between the two imaging methods (p diagnostic performance for PD than planar images. Increased lung uptake may cause false-negative results on planar imaging.

  2. Single photon emission computed tomography (SPECT) in epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, R.F. [Univ. of Texas Southwestern Medical School, Dallas (United States)

    1991-12-31

    Epilepsy is a common neurologic disorder which has just begun to be studied with single photon emission computerized tomography (SPECT). Epilepsy usually is studied with electroencephalographic (EEG) techniques that demonstrate the physiologic changes that occur during seizures, and with neuroimaging techniques that show the brain structures where seizures originate. Neither method alone has been adequate to describe the pathophysiology of the patient with epilepsy. EEG techniques lack anatomic sensitivity, and there are no structural abnormalities shown by neuroimaging which are specific for epilepsy. Functional imaging (FI) has developed as a physiologic tool with anatomic sensitivity, and SPECT has been promoted as a FI technique because of its potentially wide availability. However, SPECT is early in its development and its clinical utility for epilepsy still has to be demonstrated. To understand this role of SPECT, consideration must be given to the pathophysiology of epilepsy, brain physiology, types of seizure, epileptic syndromes, and the SPECT technique itself. 44 refs., 2 tabs.

  3. Bayesian learning for cardiac SPECT image interpretation.

    Science.gov (United States)

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

    2002-01-01

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

  4. Investigation of Metastatic Breast Tumor Heterogeneity and Progression Using Dual Optical/SPECT Imaging

    Science.gov (United States)

    2005-05-01

    tumors in the lungs or other internal organs. Figures 3c and 3d show images obtained first in air and then in gel, with the fiber displaced 10 mm from the...the mouse lungs and viscera, and characterize the advantages of this method for quantitative imaging. We have also demonstrated micro-SPECT imaging of...resolution, high-throughput screening. 3. Prototype Recently, a prototype system using CR image plates for co-registered 1-125 planar scintigraphy and x

  5. SPECT imaging evaluation in movement disorders: far beyond visual assessment

    Energy Technology Data Exchange (ETDEWEB)

    Badiavas, Kosmas [General Hospital, Medical Physics Department, Thessaloniki (Greece); Molyvda, Elisavet; Psarrakos, Kyriakos [Medical Physics Dept., General Hospital, Thessaloniki (Greece); Iakovou, Ioannis; Karatzas, Nikolaos [Medical Physical Dept., Aristotle Univ., Thessaloniki (Greece); Tsolaki, Magdalini [3. Neurology Clinic, Aristotle Univ., Thessaloniki (Greece)

    2011-04-15

    Single photon emission computed tomography (SPECT) imaging with {sup 123}I-FP-CIT is of great value in differentiating patients suffering from Parkinson's disease (PD) from those suffering from essential tremor (ET). Moreover, SPECT with {sup 123}I-IBZM can differentiate PD from Parkinson's ''plus'' syndromes. Diagnosis is still mainly based on experienced observers' visual assessment of the resulting images while many quantitative methods have been developed in order to assist diagnosis since the early days of neuroimaging. The aim of this work is to attempt to categorize, briefly present and comment on a number of semi-quantification methods used in nuclear medicine neuroimaging. Various arithmetic indices have been introduced with region of interest (ROI) manual drawing methods giving their place to automated procedures, while advancing computer technology has allowed automated image registration, fusion and segmentation to bring quantification closer to the final diagnosis based on the whole of the patient's examinations results, clinical condition and response to therapy. The search for absolute quantification has passed through neuroreceptor quantification models, which are invasive methods that involve tracer kinetic modelling and arterial blood sampling, a practice that is not commonly used in a clinical environment. On the other hand, semi-quantification methods relying on computers and dedicated software try to elicit numerical information out of SPECT images. The application of semi-quantification methods aims at separating the different patient categories solving the main problem of finding the uptake in the structures of interest. The semi-quantification methods which were studied fall roughly into three categories, which are described as classic methods, advanced automated methods and pixel-based statistical analysis methods. All these methods can be further divided into various subcategories. The plethora of

  6. Pulmonary Ventilation Imaging Based on 4-Dimensional Computed Tomography: Comparison With Pulmonary Function Tests and SPECT Ventilation Images

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Tokihiro, E-mail: toyamamoto@ucdavis.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Department of Radiation Oncology, University of California Davis School of Medicine, Sacramento, California (United States); Kabus, Sven; Lorenz, Cristian [Department of Digital Imaging, Philips Research Europe, Hamburg (Germany); Mittra, Erik [Departments of Radiology, Stanford University School of Medicine, Stanford, California (United States); Hong, Julian C.; Chung, Melody; Eclov, Neville; To, Jacqueline; Diehn, Maximilian; Loo, Billy W. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, Sydney, New South Wales (Australia)

    2014-10-01

    Purpose: 4-dimensional computed tomography (4D-CT)-based pulmonary ventilation imaging is an emerging functional imaging modality. The purpose of this study was to investigate the physiological significance of 4D-CT ventilation imaging by comparison with pulmonary function test (PFT) measurements and single-photon emission CT (SPECT) ventilation images, which are the clinical references for global and regional lung function, respectively. Methods and Materials: In an institutional review board–approved prospective clinical trial, 4D-CT imaging and PFT and/or SPECT ventilation imaging were performed in thoracic cancer patients. Regional ventilation (V{sub 4DCT}) was calculated by deformable image registration of 4D-CT images and quantitative analysis for regional volume change. V{sub 4DCT} defect parameters were compared with the PFT measurements (forced expiratory volume in 1 second (FEV{sub 1}; % predicted) and FEV{sub 1}/forced vital capacity (FVC; %). V{sub 4DCT} was also compared with SPECT ventilation (V{sub SPECT}) to (1) test whether V{sub 4DCT} in V{sub SPECT} defect regions is significantly lower than in nondefect regions by using the 2-tailed t test; (2) to quantify the spatial overlap between V{sub 4DCT} and V{sub SPECT} defect regions with Dice similarity coefficient (DSC); and (3) to test ventral-to-dorsal gradients by using the 2-tailed t test. Results: Of 21 patients enrolled in the study, 18 patients for whom 4D-CT and either PFT or SPECT were acquired were included in the analysis. V{sub 4DCT} defect parameters were found to have significant, moderate correlations with PFT measurements. For example, V{sub 4DCT}{sup HU} defect volume increased significantly with decreasing FEV{sub 1}/FVC (R=−0.65, P<.01). V{sub 4DCT} in V{sub SPECT} defect regions was significantly lower than in nondefect regions (mean V{sub 4DCT}{sup HU} 0.049 vs 0.076, P<.01). The average DSCs for the spatial overlap with SPECT ventilation defect regions were only moderate (V

  7. Attenuation correction in SPECT images using attenuation map estimation with its emission data

    Science.gov (United States)

    Tavakoli, Meysam; Naji, Maryam; Abdollahi, Ali; Kalantari, Faraz

    2017-03-01

    Photon attenuation during SPECT imaging significantly degrades the diagnostic outcome and the quantitative accuracy of final reconstructed images. It is well known that attenuation correction can be done by using iterative reconstruction methods if we access to attenuation map. Two methods have been used to calculate the attenuation map: transmission-based and transmissionless techniques. In this phantom study, we evaluated the importance of attenuation correction by quantitative evaluation of errors associated with each method. For transmissionless approach, the attenuation map was estimated from the emission data only. An EM algorithm with attenuation model was developed and used for attenuation correction during image reconstruction. Finally, a comparison was done between reconstructed images using our OSEM code and analytical FBP method before and after attenuation correction. The results of measurements showed that: our programs are capable to reconstruct SPECT images and correct the attenuation effects. Moreover, to evaluate reconstructed image quality before and after attenuation correction we applied a novel approach using Image Quality Index. Attenuation correction increases the quality and quantitative accuracy in both methods. This increase is independent of activity in quantity factor and decreases with activity in quality factor. In EM algorithm, it is necessary to use regularization to obtain true distribution of attenuation coefficients.

  8. Comparative value of brain perfusion SPECT and [{sup 123}I]MIBG myocardial scintigraphy in distinguishing between dementia with Lewy bodies and Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Hanyu, Haruo; Shimizu, Soichiro; Hirao, Kentaro; Kanetaka, Hidekazu; Iwamoto, Toshihiko [Tokyo Medical University, Department of Geriatric Medicine, Tokyo (Japan); Chikamori, Taishiro; Usui, Yasuhiro; Yamashina, Akira [Tokyo Medical University, 2. Department of Internal Medicine, Tokyo (Japan); Koizumi, Kiyoshi; Abe, Kimihiko [Tokyo Medical University, Department of Radiology, Tokyo (Japan)

    2006-03-15

    Both decreased occipital perfusion on brain single-photon emission computed tomography (SPECT) and reduction in cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) uptake are characteristic features of dementia with Lewy bodies (DLB), and potentially support the clinical diagnosis of DLB. The aim of this study was to compare the diagnostic value of these two methods for differentiation of DLB from Alzheimer's disease (AD). The study population comprised 19 patients with probable DLB and 39 patients with probable AD who underwent both SPECT with N-isopropyl-p-[{sup 123}I]iodoamphetamine and MIBG myocardial scintigraphy. Objective and quantitative measurement of perfusion in the medial occipital lobe, including the cuneus and lingual gyrus, was performed by the use of three-dimensional stereotactic surface projections. Medial occipital perfusion was significantly decreased in the DLB group compared with the AD group. The mean heart/mediastinum ratios of MIBG uptake were significantly lower in the DLB group than in the AD group. Although SPECT failed to demonstrate significant hypoperfusion in the medial occipital lobe in five patients with DLB, marked reduction of MIBG uptake was found in all patients with DLB. Receiver operating characteristic analysis revealed that MIBG myocardial scintigraphy enabled more accurate discrimination between DLB and AD than was possible with perfusion SPECT. MIBG myocardial scintigraphy may improve the sensitivity in the detection of DLB. In particular, this method may provide a powerful differential diagnostic tool when it is difficult to distinguish cases of DLB from AD using brain perfusion SPECT. (orig.)

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

    Science.gov (United States)

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

    2007-03-01

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

  10. Can DCE-MRI explain the heterogeneity in radiopeptide uptake imaged by SPECT in a pancreatic neuroendocrine tumor model?

    Directory of Open Access Journals (Sweden)

    Karin Bol

    Full Text Available Although efficient delivery and distribution of treatment agents over the whole tumor is essential for successful tumor treatment, the distribution of most of these agents cannot be visualized. However, with single-photon emission computed tomography (SPECT, both delivery and uptake of radiolabeled peptides can be visualized in a neuroendocrine tumor model overexpressing somatostatin receptors. A heterogeneous peptide uptake is often observed in these tumors. We hypothesized that peptide distribution in the tumor is spatially related to tumor perfusion, vessel density and permeability, as imaged and quantified by DCE-MRI in a neuroendocrine tumor model. Four subcutaneous CA20948 tumor-bearing Lewis rats were injected with the somatostatin-analog (111In-DTPA-Octreotide (50 MBq. SPECT-CT and MRI scans were acquired and MRI was spatially registered to SPECT-CT. DCE-MRI was analyzed using semi-quantitative and quantitative methods. Correlation between SPECT and DCE-MRI was investigated with 1 Spearman's rank correlation coefficient; 2 SPECT uptake values grouped into deciles with corresponding median DCE-MRI parametric values and vice versa; and 3 linear regression analysis for median parameter values in combined datasets. In all tumors, areas with low peptide uptake correlated with low perfusion/density/ /permeability for all DCE-MRI-derived parameters. Combining all datasets, highest linear regression was found between peptide uptake and semi-quantitative parameters (R(2>0.7. The average correlation coefficient between SPECT and DCE-MRI-derived parameters ranged from 0.52-0.56 (p<0.05 for parameters primarily associated with exchange between blood and extracellular extravascular space. For these parameters a linear relation with peptide uptake was observed. In conclusion, the 'exchange-related' DCE-MRI-derived parameters seemed to predict peptide uptake better than the 'contrast amount- related' parameters. Consequently, fast and efficient

  11. Dopamine transporter density of the basal ganglia in children with attention deficit hyperactivity disorder assessed with I-123 IPT SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Won Gee; Kim, Tae Hoon; Ryu, Young Hoon; Yun, Mi Jin; Lee, Jong Doo; Cheon, Keun Ah [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of); Chi, Dae Yoon [College of Medicine, Inha Univ., Incheon (Korea, Republic of); Kim, Jong Ho; Choi, Tae Hyun [School of Medicine, Gachon Univ., Gachon (Korea, Republic of)

    2003-08-01

    Attention deficit hyperactivity disorder (ADHD) has been known as psychiatric disorder in childhood associated with dopamine dysregulation. In present study, we investigated changes in dopamine transporter (DAT) density of the basal ganglias using I-123 N-(3-iodopropen-2-yl) -2-carbomethoxy-3beta-(4-chlorphenyl) tropane (I-123 IPT) SPECT in children with ADHD before and after methylphenidate treatment. Nine drug-naive children with ADHD and seven normal children were included in the study. We performed brain SPECT two hours after the intravenous administration of I-123 IPT and made both quantitative and qualitative analyses using the obtained SPECT data, which were reconstructed for the assessment of specific/nonspecific DAT binding ratios in the basal ganglia. All children with ADHD reperformed (123I)IPT SPECT after treatment with methylphenidate (0.7mg/kg/d) during about 8 weeks. SPECT data reconstructed for the assessment of specific/nonspecific DAT binding ratio of the basal ganglia were compared between before and after treatment methyphenidate. We investigated correlation between the change of ADHD symptom severity assessed with ADHD rating scale-IV and specific/nonspecific DAT binding ratio of basal ganglia. Children with ADHD had a significantly greater specific/nonspecific DAT binding ratio of the basal ganglia comparing to normal children (Right : z = 2.057, p = 0.041 ; Left : z = 2.096, p = 0.032). Under treatment with methylphenidate in all children with ADHD, specific/nonspecific DAT binding ratio of both ganglia decreased significantly greater than before treatment with methylphenidate (Right : t = 3.239, p = 0.018 ; Left : t = 3.133, p 0.020). However, no significant correlation between the change of ADHD symptom severity scores and specific/nonspecific DAT binding ratio of the basal ganglia were found. These findings support the complex dysregulation of the dopaminergic neurotransmitter system in children with ADHD.

  12. 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

  13. Advances in SPECT and PET Hardware.

    Science.gov (United States)

    Slomka, Piotr J; Pan, Tinsu; Berman, Daniel S; Germano, Guido

    2015-01-01

    There have been significant recent advances in single photon emission computed tomography (SPECT) and positron emission tomography (PET) hardware. Novel collimator designs, such as multi-pinhole and locally focusing collimators arranged in geometries that are optimized for cardiac imaging have been implemented to reduce imaging time and radiation dose. These new collimators have been coupled with solid state photon detectors to further improve image quality and reduce scanner size. The new SPECT scanners demonstrate up to a 7-fold increase in photon sensitivity and up to 2 times improvement in image resolution. Although PET scanners are used primarily for oncological imaging, cardiac imaging can benefit from the improved PET sensitivity of 3D systems without inter-plane septa and implementation of the time-of-flight reconstruction. Additionally, resolution recovery techniques are now implemented by all major PET vendors. These new methods improve image contrast, image resolution, and reduce image noise. Simultaneous PET/magnetic resonance (MR) hybrid systems have been developed. Solid state detectors with avalanche photodiodes or digital silicon photomultipliers have also been utilized in PET. These new detectors allow improved image resolution, higher count rate, as well as a reduced sensitivity to electromagnetic MR fields. Copyright © 2015. Published by Elsevier Inc.

  14. Radiation dose study in nuclear medicine using GATE

    Science.gov (United States)

    Aguwa, Kasarachi

    Dose as a result of radiation exposure is the notion generally used to disclose the imparted energy in a volume of tissue to a potential biological effect. The basic unit defined by the international system of units (SI system) is the radiation absorbed dose, which is expressed as the mean imparted energy in a mass element of the tissue known as "gray" (Gy) or J/kg. The procedure for ascertaining the absorbed dose is complicated since it involves the radiation transport of numerous types of charged particles and coupled photon interactions. The most precise method is to perform a full 3D Monte Carlo simulation of the radiation transport. There are various Monte Carlo toolkits that have tool compartments for dose calculations and measurements. The dose studies in this thesis were performed using the GEANT4 Application for Emission Tomography (GATE) software (Jan et al., 2011) GATE simulation toolkit has been used extensively in the medical imaging community, due to the fact that it uses the full capabilities of GEANT4. It also utilizes an easy to-learn GATE macro language, which is more accessible than learning the GEANT4/C++ programming language. This work combines GATE with digital phantoms generated using the NCAT (NURBS-based cardiac-torso phantom) toolkit (Segars et al., 2004) to allow efficient and effective estimation of 3D radiation dose maps. The GATE simulation tool has developed into a beneficial tool for Monte Carlo simulations involving both radiotherapy and imaging experiments. This work will present an overview of absorbed dose of common radionuclides used in nuclear medicine and serve as a guide to a user who is setting up a GATE simulation for a PET and SPECT study.

  15. Segmentation and visual analysis of whole-body mouse skeleton microSPECT.

    Science.gov (United States)

    Khmelinskii, Artem; Groen, Harald C; Baiker, Martin; de Jong, Marion; Lelieveldt, Boudewijn P F

    2012-01-01

    Whole-body SPECT small animal imaging is used to study cancer, and plays an important role in the development of new drugs. Comparing and exploring whole-body datasets can be a difficult and time-consuming task due to the inherent heterogeneity of the data (high volume/throughput, multi-modality, postural and positioning variability). The goal of this study was to provide a method to align and compare side-by-side multiple whole-body skeleton SPECT datasets in a common reference, thus eliminating acquisition variability that exists between the subjects in cross-sectional and multi-modal studies. Six whole-body SPECT/CT datasets of BALB/c mice injected with bone targeting tracers (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) and (99m)Tc-hydroxymethane diphosphonate ((99m)Tc-HDP) were used to evaluate the proposed method. An articulated version of the MOBY whole-body mouse atlas was used as a common reference. Its individual bones were registered one-by-one to the skeleton extracted from the acquired SPECT data following an anatomical hierarchical tree. Sequential registration was used while constraining the local degrees of freedom (DoFs) of each bone in accordance to the type of joint and its range of motion. The Articulated Planar Reformation (APR) algorithm was applied to the segmented data for side-by-side change visualization and comparison of data. To quantitatively evaluate the proposed algorithm, bone segmentations of extracted skeletons from the correspondent CT datasets were used. Euclidean point to surface distances between each dataset and the MOBY atlas were calculated. The obtained results indicate that after registration, the mean Euclidean distance decreased from 11.5±12.1 to 2.6±2.1 voxels. The proposed approach yielded satisfactory segmentation results with minimal user intervention. It proved to be robust for "incomplete" data (large chunks of skeleton missing) and for an intuitive exploration and comparison of multi-modal SPECT/CT cross

  16. Segmentation and visual analysis of whole-body mouse skeleton microSPECT.

    Directory of Open Access Journals (Sweden)

    Artem Khmelinskii

    Full Text Available Whole-body SPECT small animal imaging is used to study cancer, and plays an important role in the development of new drugs. Comparing and exploring whole-body datasets can be a difficult and time-consuming task due to the inherent heterogeneity of the data (high volume/throughput, multi-modality, postural and positioning variability. The goal of this study was to provide a method to align and compare side-by-side multiple whole-body skeleton SPECT datasets in a common reference, thus eliminating acquisition variability that exists between the subjects in cross-sectional and multi-modal studies. Six whole-body SPECT/CT datasets of BALB/c mice injected with bone targeting tracers (99mTc-methylene diphosphonate ((99mTc-MDP and (99mTc-hydroxymethane diphosphonate ((99mTc-HDP were used to evaluate the proposed method. An articulated version of the MOBY whole-body mouse atlas was used as a common reference. Its individual bones were registered one-by-one to the skeleton extracted from the acquired SPECT data following an anatomical hierarchical tree. Sequential registration was used while constraining the local degrees of freedom (DoFs of each bone in accordance to the type of joint and its range of motion. The Articulated Planar Reformation (APR algorithm was applied to the segmented data for side-by-side change visualization and comparison of data. To quantitatively evaluate the proposed algorithm, bone segmentations of extracted skeletons from the correspondent CT datasets were used. Euclidean point to surface distances between each dataset and the MOBY atlas were calculated. The obtained results indicate that after registration, the mean Euclidean distance decreased from 11.5±12.1 to 2.6±2.1 voxels. The proposed approach yielded satisfactory segmentation results with minimal user intervention. It proved to be robust for "incomplete" data (large chunks of skeleton missing and for an intuitive exploration and comparison of multi-modal SPECT

  17. A SVD-based method to assess the uniqueness and accuracy of SPECT geometrical calibration.

    Science.gov (United States)

    Ma, Tianyu; Yao, Rutao; Shao, Yiping; Zhou, Rong

    2009-12-01

    Geometrical calibration is critical to obtaining high resolution and artifact-free reconstructed image for SPECT and CT systems. Most published calibration methods use analytical approach to determine the uniqueness condition for a specific calibration problem, and the calibration accuracy is often evaluated through empirical studies. In this work, we present a general method to assess the characteristics of both the uniqueness and the quantitative accuracy of the calibration. The method uses a singular value decomposition (SVD) based approach to analyze the Jacobian matrix from a least-square cost function for the calibration. With this method, the uniqueness of the calibration can be identified by assessing the nonsingularity of the Jacobian matrix, and the estimation accuracy of the calibration parameters can be quantified by analyzing the SVD components. A direct application of this method is that the efficacy of a calibration configuration can be quantitatively evaluated by choosing a figure-of-merit, e.g., the minimum required number of projection samplings to achieve desired calibration accuracy. The proposed method was validated with a slit-slat SPECT system through numerical simulation studies and experimental measurements with point sources and an ultra-micro hot-rod phantom. The predicted calibration accuracy from the numerical studies was confirmed by the experimental point source calibrations at approximately 0.1 mm for both the center of rotation (COR) estimation of a rotation stage and the slit aperture position (SAP) estimation of a slit-slat collimator by an optimized system calibration protocol. The reconstructed images of a hot rod phantom showed satisfactory spatial resolution with a proper calibration and showed visible resolution degradation with artificially introduced 0.3 mm COR estimation error. The proposed method can be applied to other SPECT and CT imaging systems to analyze calibration method assessment and calibration protocol

  18. Effect of the reverse redistribution pattern on the left ventricular ejection fraction in the Tc- 99m MIBI SPECT myocardial perfusion scintigraphy

    Directory of Open Access Journals (Sweden)

    Bekir Taşdemir

    2015-09-01

    Full Text Available Objective: The causes and prognostic significance of the reverse redistribution pattern (RRP is not clear yet. In this study, we aimed to evaluate the RRP effect on the left ventricular ejection fraction (EF. Methods: Imaging of the patients whose technetium-99m sestamibi myocardial perfusion scintigraphy was carried out and reported as normal were retrospectively examined. One-day protocol and/or pharmacologic stress testing applied patients were excluded. 21 patients with RRP met the inclusion criteria. All of these patients were included in the study as RRP group. Randomly selected 21 patients with non-RRP were included in the study as control group. Transient ischemic dilation (TID scores and EF values were automatically calculated with the Quantitative Gated SPECT (QGS program. Results: While a statistically significant difference was not found between the RRP and control groups in terms of age, sex, hypertension, family history, hyperlipidemia, and diabetes (p>0.05, there was a statistically significant difference in terms of smoking (p=0.019. TID scores in the RRP group were significantly lower compared to the control group (p<0.001. In addition, a statistically significant decrease was determined in the EF values in the rest images compared to the stress images in the RRP group (p=0.002. Furthermore, this decrease was significantly higher than in the control group (p= 0.034. Conclusion: The results related to the TID scores and EF values are suggesting the existence of an ischemic cause in the background of the RRP. Additionally, the relationship found between smoking and RRP may be associated with the tachycardia and / or coronary spasm-inducing effect of smoking. J Clin Exp Invest 2015; 6 (3: 286-290

  19. Assessment of a Monte-Carlo simulation of SPECT recordings from a new-generation heart-centric semiconductor camera: from point sources to human images

    Science.gov (United States)

    Imbert, Laetitia; Galbrun, Ernest; Odille, Freddy; Poussier, Sylvain; Noel, Alain; Wolf, Didier; Karcher, Gilles; Marie, Pierre-Yves

    2015-02-01

    Geant4 application for tomographic emission (GATE), a Monte-Carlo simulation platform, has previously been used for optimizing tomoscintigraphic images recorded with scintillation Anger cameras but not with the new-generation heart-centric cadmium-zinc-telluride (CZT) cameras. Using the GATE platform, this study aimed at simulating the SPECT recordings from one of these new CZT cameras and to assess this simulation by direct comparison between simulated and actual recorded data, ranging from point sources to human images. Geometry and movement of detectors, as well as their respective energy responses, were modeled for the CZT ‘D.SPECT’ camera in the GATE platform. Both simulated and actual recorded data were obtained from: (1) point and linear sources of 99mTc for compared assessments of detection sensitivity and spatial resolution, (2) a cardiac insert filled with a 99mTc solution for compared assessments of contrast-to-noise ratio and sharpness of myocardial borders and (3) in a patient with myocardial infarction using segmented cardiac magnetic resonance imaging images. Most of the data from the simulated images exhibited high concordance with the results of actual images with relative differences of only: (1) 0.5% for detection sensitivity, (2) 6.7% for spatial resolution, (3) 2.6% for contrast-to-noise ratio and 5.0% for sharpness index on the cardiac insert placed in a diffusing environment. There was also good concordance between actual and simulated gated-SPECT patient images for the delineation of the myocardial infarction area, although the quality of the simulated images was clearly superior with increases around 50% for both contrast-to-noise ratio and sharpness index. SPECT recordings from a new heart-centric CZT camera can be simulated with the GATE software with high concordance relative to the actual physical properties of this camera. These simulations may be conducted up to the stage of human SPECT-images even if further refinement is needed

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

    Science.gov (United States)

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

    2001-05-01

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

  1. TH-E-BRF-02: 4D-CT Ventilation Image-Based IMRT Plans Are Dosimetrically Comparable to SPECT Ventilation Image-Based Plans

    Energy Technology Data Exchange (ETDEWEB)

    Kida, S [UC Davis School of Medicine, Sacramento, CA (United States); University of Tokyo Hospital, Bunkyo, Tokyo (Japan); Bal, M [Philips Healthcare (Netherlands); Kabus, S [Philips Research, Hamburg (Germany); Loo, B [Stanford University, Stanford, CA (United States); Keall, P [University of Sydney, Camperdown (Australia); Yamamoto, T [UC Davis School of Medicine, Sacramento, CA (United States); Stanford University, Stanford, CA (United States)

    2014-06-15

    Purpose: An emerging lung ventilation imaging method based on 4D-CT can be used in radiotherapy to selectively avoid irradiating highly-functional lung regions, which may reduce pulmonary toxicity. Efforts to validate 4DCT ventilation imaging have been focused on comparison with other imaging modalities including SPECT and xenon CT. The purpose of this study was to compare 4D-CT ventilation image-based functional IMRT plans with SPECT ventilation image-based plans as reference. Methods: 4D-CT and SPECT ventilation scans were acquired for five thoracic cancer patients in an IRB-approved prospective clinical trial. The ventilation images were created by quantitative analysis of regional volume changes (a surrogate for ventilation) using deformable image registration of the 4D-CT images. A pair of 4D-CT ventilation and SPECT ventilation image-based IMRT plans was created for each patient. Regional ventilation information was incorporated into lung dose-volume objectives for IMRT optimization by assigning different weights on a voxel-by-voxel basis. The objectives and constraints of the other structures in the plan were kept identical. The differences in the dose-volume metrics have been evaluated and tested by a paired t-test. SPECT ventilation was used to calculate the lung functional dose-volume metrics (i.e., mean dose, V20 and effective dose) for both 4D-CT ventilation image-based and SPECT ventilation image-based plans. Results: Overall there were no statistically significant differences in any dose-volume metrics between the 4D-CT and SPECT ventilation imagebased plans. For example, the average functional mean lung dose of the 4D-CT plans was 26.1±9.15 (Gy), which was comparable to 25.2±8.60 (Gy) of the SPECT plans (p = 0.89). For other critical organs and PTV, nonsignificant differences were found as well. Conclusion: This study has demonstrated that 4D-CT ventilation image-based functional IMRT plans are dosimetrically comparable to SPECT ventilation image

  2. Allowable Generalized Quantum Gates

    Institute of Scientific and Technical Information of China (English)

    LONG Gui-Lu; LIU Yang; WANG Chuan

    2009-01-01

    In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form Σ(d-1)(i=0)piUi, and the Pi's are complex numbers with module less or equal to I and constrained by |Σipi|≤1.

  3. SUV measurement of normal vertebrae using SPECT/CT with Tc-99m methylene diphosphonate

    Science.gov (United States)

    Kaneta, Tomohiro; Ogawa, Matsuyoshi; Daisaki, Hiromitsu; Nawata, Shintaro; Yoshida, Keisuke; Inoue, Tomio

    2016-01-01

    The purpose of this study is to perform quantitative measurement based on the standardized uptake value (SUV) of the uptake of Tc-99m methylene diphosphonate (MDP) in the normal vertebrae using a single photon emission tomography (SPECT)/computed tomography (CT) scanner. A retrospective study of patients with cancer or joint disorders was performed. We acquired data for a group of 29 patients (8 women and 21 men; mean age, 68.2 ± 6.7 years; age range, 44-87 years) undergoing bone SPECT/CT scans with Tc-99m MDP between September and October 2015. Various SUVs were calculated based on body-weight, lean-body-weight (lbw), Japanese lean-body-weight (jlbw) and Japanese bone-mineral-content (jbmc). SUVs of normal vertebrae showed a wide range of values. Among these, the maximum body-weight based SUV showed the lowest coefficient of variation. The SUVs also showed relatively small intra-subject variability. In addition, all SUVs showed moderate and significant correlation with height. Moreover, lbw-, jlbw-, and jbmc-based SUVs of men were significantly higher than those of women. In conclusions, SUVs of normal vertebrae showed a relatively large inter-individual variability and small intra-individual variability. As a quantitative imaging biomarker, SUVs might require standardization with adequate reference data for the same subject to minimize variability. PMID:27766184

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-15

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

  5. 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.

  6. Application of PET/SPECT imaging in vascular disease

    NARCIS (Netherlands)

    van der Vaart, M. G.; Meerwaidt, R.; Slart, R. H. J. A.; van Dam, G. M.; Tio, R. A.; Zeebregts, C. J.

    2008-01-01

    Background. Nuclear medicine imaging differs from other imaging modalities by showing physiological processes instead of anatomical details. Objective. To describe the current applications of positron emission tomography (PET) and single photon emission computed tomography (SPECT) as a diagnostic to

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

    Science.gov (United States)

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

    2014-12-01

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

  8. The value of SPECT/CT in carpal boss

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-15

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

  9. A review on the clinical uses of SPECT/CT

    Energy Technology Data Exchange (ETDEWEB)

    Mariani, Giuliano; Bruselli, Laura [University of Pisa Medical School, Regional Center of Nuclear Medicine, Pisa (Italy); Kuwert, Torsten [Friedrich-Alexander-University, Clinic of Nuclear Medicine, Erlangen-Nuremberg (Germany); Kim, Edmund E. [MD Anderson Cancer Center, Nuclear Medicine Service, Houston, TX (United States); Flotats, Albert [Universitat Autonoma de Barcelona, Hospital de Sant Pau, Nuclear Medicine Department, Barcelona (Spain); Israel, Ora [Rambam Health Care Campus, Department of Nuclear Medicine, Haifa (Israel); Dondi, Maurizio [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Watanabe, Naoyuki [International Atomic Energy Agency, Nuclear Medicine Section, Division of Human Health, Vienna (Austria); Gunma Prefectural College of Health Sciences, Department of Radiological Technology, Gunma (Japan)

    2010-10-15

    In the era when positron emission tomography (PET) seems to constitute the most advanced application of nuclear medicine imaging, still the conventional procedure of single photon emission computed tomography (SPECT) is far from being obsolete, especially if combined with computed tomography (CT). In fact, this dual modality imaging technique (SPECT/CT) lends itself to a wide variety of useful diagnostic applications whose clinical impact is in most instances already well established, while the evidence is growing for newer applications. The increasing availability of new hybrid SPECT/CT devices with advanced technology offers the opportunity to shorten acquisition time and to provide accurate attenuation correction and fusion imaging. In this review we analyse and discuss the capabilities of SPECT/CT for improving sensitivity and specificity in the imaging of both oncological and non-oncological diseases. The main advantages of SPECT/CT are represented by better attenuation correction, increased specificity, and accurate depiction of the localization of disease and of possible involvement of adjacent tissues. Endocrine and neuroendocrine tumours are accurately localized and characterized by SPECT/CT, as also are solitary pulmonary nodules and lung cancers, brain tumours, lymphoma, prostate cancer, malignant and benign bone lesions, and infection. Furthermore, hybrid SPECT/CT imaging is especially suited to support the increasing applications of minimally invasive surgery, as well as to precisely define the diagnostic and prognostic profile of cardiovascular patients. Finally, the applications of SPECT/CT to other clinical disorders or malignant tumours is currently under extensive investigation, with encouraging results in terms of diagnostic accuracy. (orig.)

  10. Comparison of heterogeneity quantification algorithms for brain SPECT perfusion images

    OpenAIRE

    Modzelewski, Romain; Janvresse, Elise; De La Rue, Thierry; Vera, Pierre

    2012-01-01

    Background Several algorithms from the literature were compared with the original random walk (RW) algorithm for brain perfusion heterogeneity quantification purposes. Algorithms are compared on a set of 210 brain single photon emission computed tomography (SPECT) simulations and 40 patient exams. Methods Five algorithms were tested on numerical phantoms. The numerical anthropomorphic Zubal head phantom was used to generate 42 (6 × 7) different brain SPECT simulations. Seven diffuse cortical ...

  11. 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.

  12. Simulating technetium-99m cerebral perfusion studies with a three-dimensional Hoffman brain phantom. Collimator and filter selection in SPECT neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee-Joung; Yang, Seoung-Oh; Moon, Dae-Hyuk; Lee, Hee-Kyung [Asan Medical Center, Seoul (Korea, Republic of); Karp, J.S.; Mozley, P.D.; Kung, H.F.; Alavi, A.

    1996-02-01

    The choice of a collimator and the selection of a filter can affect the quality of clinical SPECT images of the brain. The compromises that 4 different collimators make between spatial resolution and sensitivity were studied by imaging a three-dimensional Hoffman brain phantom. The planar data were acquired with each collimator on a three-headed SPECT system and were reconstructed with both a standard Butterworth filter and a Wiener pre-filter. The reconstructed images were then evaluated by specialists in nuclear medicine and were also quantitatively analyzed with specific regions of interest (ROI) in the brain. All observers preferred the Wiener filter reconstructed images regardless of the collimator used to acquire the planar images. With this filter, the ultrahigh-resolution fan-beam collimator was the most subjectively preferable and quantitatively produced the highest contrast ratios. The findings support suggestions that higher resolution collimators are preferable to higher sensitivity collimators, and indicate that fan-beam collimators are preferable to parallel-hole collimators for clinical SPECT studies of cerebral perfusion. The results also suggest that the Wiener filter enhances the quality of SPECT brain images regardless of which collimator is used to acquire the data. (author).

  13. ACR testing of a dedicated head SPECT unit.

    Science.gov (United States)

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

    2014-07-08

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

  14. Tc-99m Ciprofloxacin SPECT of Pulmonary Tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of); Yoon, Min Ki [Good Samaritan Hospital, Pohang (Korea, Republic of); Choe, Won Sick [Kangbuk Samsung Hospital, Seoul (Korea, Republic of)

    2010-06-15

    Tc-99m ciprofloxacin is available for imaging infection. However, there has been no study on employing single photon emission computed tomography (SPECT) with using Tc-99m ciprofloxacin to image active pulmonary tuberculosis. Therefore, we conducted this study to assess the efficacy of Tc-99m ciprofloxacin SPECT for imaging active pulmonary tuberculosis. Twenty-one participants were enrolled in this prospective study. They were divided into two groups according to the clinical and radiological assessment. Group one (Gr. 1) consisted of five normal volunteers and six patients with inactive pulmonary tuberculosis. Group two (Gr. 2) consisted of ten patients with active pulmonary tuberculosis. SPECT was performed 3 h after injecting 555 MBq (15 mCi) of Tc-99m ciprofloxacin. The findings of Tc-99m ciprofloxacin SPECT were interpreted by a nuclear medicine specialist and then the results were analyzed according to the patients' clinical and radiological classifications. The results of Tc-99m ciprofloxacin SPECT were as follows: eight true-positive cases, ten true-negative cases, one false-positive case and two false-negative cases. The sensitivity and specificity was 80.0% and 90.0%, respectively. The positive predictive value was 88.9% and the negative predictive value was 83.3%. Conclusions Tc-99m ciprofloxacin SPECT is feasible for imaging active pulmonary tuberculosis. It is a useful nuclear-imaging method for discriminating between the active and inactive tuberculosis states in patients with a past medical history of pulmonary tuberculosis.

  15. 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.

  16. Slide Gate Bricks

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Peng Xigao

    2010-01-01

    @@ 1 Scope This standard specifies the classification,shape,dimension,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,and quality certificate of slide gate bricks.

  17. Use of coronary calcium score scans from stand-alone multislice computed tomography for attenuation correction of myocardial perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Schepis, Tiziano; Gaemperli, Oliver; Koepfli, Pascal [University Hospital Zurich, Clinic of Nuclear Medicine, Nuclear Cardiology, Zurich (Switzerland); University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland); Rueegg, Christine; Burger, Cyrill [University Hospital Zurich, Clinic of Nuclear Medicine, Nuclear Cardiology, Zurich (Switzerland); Leschka, Sebastian; Desbiolles, Lotus; Husmann, Lars; Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic Radiology, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Clinic of Nuclear Medicine, Nuclear Cardiology, Zurich (Switzerland); University of Zurich, Centre for Integrative Human Physiology, Zurich (Switzerland); University Hospital Zurich, Cardiovascular Center, Zurich (Switzerland)

    2007-01-15

    To evaluate the use of CT attenuation maps, generated from coronary calcium scoring (CCS) scans at in- and expiration with a 64-slice CT scanner, for attenuation correction (AC) of myocardial perfusion SPECT images. Thirty-two consecutive patients underwent{sup 99m}Tc-tetrofosmin gated adenosine stress/rest SPECT scan on an Infinia Hawkeye SPECT-CT device (GE Medical Systems) followed by CCS and CT angiography on a 64-slice CT. AC of the iteratively reconstructed images was performed with AC maps obtained: (a) from the ''Hawkeye'' low-resolution X-ray CT facility attached to the Infinia camera (IRAC); (b) from the CCS scan acquired on a 64-slice CT scanner during maximal inspiration (AC{sub INSP}) and (c) during normal expiration (AC{sub EXP}). Automatically determined uptake values of stress scans (QPS, Cedars Medical Sinai) from AC{sub INSP} and AC{sub EXP} were compared with IRAC. Agatston score (AS) values using AC{sub INSP}versus AC{sub EXP} were also compared. AC{sub INSP} and AC{sub EXP} resulted in identical findings versus IRAC by visual analysis. A good correlation for uptake values between IRAC and AC{sub INSP} was found (apex, r=0.92; anterior, r=0.85; septal, r=0.91; lateral, r=0.86; inferior, r=0.90; all p<0.0001). The correlation was even closer between IRAC and AC{sub EXP} (apex, r=0.97; anterior, r=0.91; septal, r=0.94; lateral, r=0.92; inferior, r=0.97; all p<0.0001). The mean AS during inspiration (319{+-}737) and expiration(317{+-}778) was comparable (p=NS). Attenuation maps from CCS allow accurate AC of SPECT MPI images. AC{sub EXP} proved superior to AC{sub INSP}, suggesting that in hybrid scans CCS may be performed during normal expiration to allow its additional use for AC of SPECT MPI. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-06-01

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

  19. Advanced insulated gate bipolar transistor gate drive

    Science.gov (United States)

    Short, James Evans; West, Shawn Michael; Fabean, Robert J.

    2009-08-04

    A gate drive for an insulated gate bipolar transistor (IGBT) includes a control and protection module coupled to a collector terminal of the IGBT, an optical communications module coupled to the control and protection module, a power supply module coupled to the control and protection module and an output power stage module with inputs coupled to the power supply module and the control and protection module, and outputs coupled to a gate terminal and an emitter terminal of the IGBT. The optical communications module is configured to send control signals to the control and protection module. The power supply module is configured to distribute inputted power to the control and protection module. The control and protection module outputs on/off, soft turn-off and/or soft turn-on signals to the output power stage module, which, in turn, supplies a current based on the signal(s) from the control and protection module for charging or discharging an input capacitance of the IGBT.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-15

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

  1. Importance of SPECT/CT for knee and hip joint prostheses; Stellenwert der SPECT/CT bei Knie- und Hueftgelenkprothesen

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, K.; Steurer-Dober, I.; Huellner, M.W.; Veit-Haibach, P.; Allgayer, B. [Luzerner Kantonsspital (Switzerland). Institut fuer Nuklearmedizin und Roentgendiagnostik

    2012-07-15

    Complications, such as loosening or infections are common problems after hip or knee arthroplasty. If conventional X-rays are equivocal bone scintigraphy is the classical second-line imaging modality. Single photon emission computed tomography/computed tomography (SPECT/CT) offers metabolic and morphologic information in one imaging step and is becoming increasingly more available in larger hospitals. The SPECT/CT procedure is a promising method and is increasingly being used in daily routine to evaluate joint arthroplasty. The additional benefit compared with classical conventional bone scintigraphy has to be evaluated in further prospective studies. In our hospital SPECT/CT regularly gives important additional information regarding prosthetic joint complications. SPECT/CT is increasingly being used as the second step imaging standard modality if conventional X-rays are equivocal. (orig.) [German] Komplikationen wie Lockerung und Infekt stellen ein haeufiges Problem nach Hueft- und Kniegelenkprothesen dar. Wenn die konventionelle Roentgenaufnahme nicht zum Ziel fuehrt, ist die klassische konventionelle Skelettszintigraphie die am haeufigsten verwendete ''Second-line''-Bildgebung. Die ''single photon emission computed tomography''/CT (SPECT/CT) bietet metabolische und morphologische Informationen bzgl. Prothesenkomplikationen in einem Untersuchungsgang und ist zunehmend in groesseren Kliniken verfuegbar. Die SPECT/CT ist eine viel versprechende Methode und wird im klinischen Alltag bei der Evaluation von Gelenkprothesen zunehmend eingesetzt. Es sind noch mehr prospektive Studien noetig, um die Leistungsfaehigkeit und den Zusatznutzen gegenueber der klassischen Szintigraphie zu evaluieren. In unserer Klinik wird die Knochenszintigraphie bei der Abklaerung von Prothesenkomplikationen zumeist mit einer SPECT/CT kombiniert und liefert regelmaessig wichtige Zusatzinformationen. Die SPECT/CT entwickelt sich zunehmend zum Standard

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-15

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

  3. Impact of the Adaptive Statistical Iterative Reconstruction Technique on Radiation Dose and Image Quality in Bone SPECT/CT.

    Science.gov (United States)

    Sibille, Louis; Chambert, Benjamin; Alonso, Sandrine; Barrau, Corinne; D'Estanque, Emmanuel; Al Tabaa, Yassine; Collombier, Laurent; Demattei, Christophe; Kotzki, Pierre-Olivier; Boudousq, Vincent

    2016-07-01

    The purpose of this study was to compare a routine bone SPECT/CT protocol using CT reconstructed with filtered backprojection (FBP) with an optimized protocol using low-dose CT images reconstructed with adaptive statistical iterative reconstruction (ASiR). In this prospective study, enrolled patients underwent bone SPECT/CT, with 1 SPECT acquisition followed by 2 randomized CT acquisitions: FBP CT (FBP; noise index, 25) and ASiR CT (70% ASiR; noise index, 40). The image quality of both attenuation-corrected SPECT and CT images was visually (5-point Likert scale, 2 interpreters) and quantitatively (contrast ratio [CR] and signal-to-noise ratio [SNR]) estimated. The CT dose index volume, dose-length product, and effective dose were compared. Seventy-five patients were enrolled in the study. Quantitative attenuation-corrected SPECT evaluation showed no inferiority for contrast ratio and SNR issued from FBP CT or ASiR CT (respectively, 13.41 ± 7.83 vs. 13.45 ± 7.99 and 2.33 ± 0.83 vs. 2.32 ± 0.84). Qualitative image analysis showed no difference between attenuation-corrected SPECT images issued from FBP CT or ASiR CT for both interpreters (respectively, 3.5 ± 0.6 vs. 3.5 ± 0.6 and 3.6 ± 0.5 vs. 3.6 ± 0.5). Quantitative CT evaluation showed no inferiority for SNR between FBP and ASiR CT images (respectively, 0.93 ± 0.16 and 1.07 ± 0.17). Qualitative image analysis showed no quality difference between FBP and ASiR CT images for both interpreters (respectively, 3.8 ± 0.5 vs. 3.6 ± 0.5 and 4.0 ± 0.1 vs. 4.0 ± 0.2). Mean CT dose index volume, dose-length product, and effective dose for ASiR CT (3.0 ± 2.0 mGy, 148 ± 85 mGy⋅cm, and 2.2 ± 1.3 mSv) were significantly lower than for FBP CT (8.5 ± 3.7 mGy, 365 ± 160 mGy⋅cm, and 5.5 ± 2.4 mSv). The use of 70% ASiR blending in bone SPECT/CT can reduce the CT radiation dose by 60%, with no sacrifice in attenuation-corrected SPECT and CT image quality, compared with the conventional protocol using FBP CT

  4. Brain perfusion SPECT with Brodmann areas analysis in differentiating frontotemporal dementia subtypes.

    Science.gov (United States)

    Valotassiou, Varvara; Papatriantafyllou, John; Sifakis, Nikolaos; Tzavara, Chara; Tsougos, Ioannis; Psimadas, Dimitrios; Kapsalaki, Eftychia; Fezoulidis, Ioannis; Hadjigeorgiou, George; Georgoulias, Panagiotis

    2014-01-01

    Despite the known validity of clinical diagnostic criteria, significant overlap of clinical symptoms between Frontotemporal dementia (FTD) subtypes exists in several cases, resulting in great uncertainty of the diagnostic boundaries. We evaluated the perfusion between FTD subtypes using brain perfusion (99m)Tc-HMPAO SPECT with Brodmann areas (BA) mapping. NeuroGam software was applied on single photon emission computed tomographic (SPECT) studies for the semi-quantitative evaluation of perfusion in BA and the comparison with the software's normal database. We studied 91 consecutive FTD patients: 21 with behavioural variants (bvFTD), 39 with language variants (lvFTD) [12 with progressive non-fluent aphasia (PNFA), 27 with semantic dementia (SD)], and 31 patients with progressive supranuclear palsy (PSP)/corticobasal degeneration (CBD). Stepwise logistic regression analyses showed that the BA 28L and 32R could independently differentiate bvFTD from lvFTD, while the BA 8R and 25R could discriminate bvFTD from SD and PNFA, respectively. Additionally, BA 7R and 32R were found to discriminate bvFTD from CBD/PSP. The only BA that could differentiate SD from PNFA was 6L. BA 6R and 20L were found to independently differentiate CBD/PSP from lvFTD. Moreover, BA 20L and 22R could discriminate CBD/PSP from PNFA, while BA 6R, 20L and 45R were found to independently discriminate CBD/PSP from SD. Brain perfusion SPECT with BA mapping can be a useful additional tool in differentiating FTD variants by improving the definition of brain areas that are specifically implicated, resulting in a more accurate differential diagnosis in atypical or uncertain forms of FTD.

  5. Significance of postoperative crossed cerebellar hypoperfusion in patients with cerebral hyperperfusion following carotid endarterectomy: SPECT study

    Energy Technology Data Exchange (ETDEWEB)

    Ogasawara, Kuniaki; Kobayashi, Masakazu; Suga, Yasunori; Chida, Kohei; Saito, Hideo; Komoribayashi, Nobukazu; Otawara, Yasunari; Ogawa, Akira [Iwate Medical University, Department of Neurosurgery, Morioka (Japan); Iwate Medical University, Cyclotron Research Center, Morioka (Japan)

    2008-01-15

    Cerebral hyperperfusion after carotid endarterectomy (CEA) results in cerebral hyperperfusion syndrome and cognitive impairment. The goal of the present study was to clarify the clinical significance of postoperative crossed cerebellar hypoperfusion (CCH) in patients with cerebral hyperperfusion after CEA by assessing brain perfusion with single-photon emission computed tomography (SPECT). Brain perfusion was quantitatively measured using SPECT and the [{sup 123}I]N-isopropyl-p-iodoamphetamine-autoradiography method before and immediately after CEA and on the third postoperative day in 80 patients with ipsilateral internal carotid artery stenosis ({>=}70%). Postoperative CCH was determined by differences between asymmetry of perfusion in bilateral cerebellar hemispheres before and after CEA. Neuropsychological testing was also performed preoperatively and at the first postoperative month. Eleven patients developed cerebral hyperperfusion (cerebral blood flow increase of {>=}100% compared with preoperative values) on SPECT imaging performed immediately after CEA. In seven of these patients, CCH was observed on the third postoperative day. All three patients with hyperperfusion syndrome exhibited cerebral hyperperfusion and CCH on the third postoperative day and developed postoperative cognitive impairment. Of the eight patients with asymptomatic hyperperfusion, four exhibited CCH despite resolution of cerebral hyperperfusion on the third postoperative day, and three of these patients experienced postoperative cognitive impairment. In contrast, four patients without postoperative CCH did not experience postoperative cognitive impairment. The presence of postoperative CCH with concomitant cerebral hyperperfusion reflects the development of hyperperfusion syndrome. Further, the presence of postoperative CCH in patients with cerebral hyperperfusion following CEA suggests development of postoperative cognitive impairment, even when asymptomatic. (orig.)

  6. Diagnostic role of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for early and atypical bone metastases.

    Science.gov (United States)

    Chen, Xiao-Liang; Li, Qian; Cao, Lin; Jiang, Shi-Xi

    2014-01-01

    The bone metastasis appeared early before the bone imaging for most of the above patients. (99)Tc(m)-MDP ((99)Tc(m) marked methylene diphosphonate) bone imaging could diagnosis the bone metastasis with highly sensitivity, but with lower specificity. The aim of this study is to explore the diagnostic value of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for the early period atypical bone metastases. 15 to 30 mCi (99)Tc(m)-MDP was intravenously injected to the 34 malignant patients diagnosed as doubtful early bone metastases. SPECT, CT and SPECT/CT images were captured and analyzed consequently. For the patients diagnosed as early period atypical bone metastases by SPECT/CT, combining the SPECT/CT and MRI together as the SPECT/MRI integrated image. The obtained SPECT/MRI image was analyzed and compared with the pathogenic results of patients. The results indicated that 34 early period doubtful metastatic focus, including 34 SPECT positive focus, 17 focus without special changes by using CT method, 11 bone metastases focus by using SPECT/CT method, 23 doubtful bone metastases focus, 8 doubtful bone metastases focus, 14 doubtful bone metastases focus and 2 focus without clear image. Totally, SPECT/CT combined with SPECT/MRI method diagnosed 30 bone metastatic focus and 4 doubtfully metastatic focus. In conclusion, (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging shows a higher diagnostic value for the early period bone metastases, which also enhances the diagnostic accuracy rate.

  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. Radiotracers for SPECT imaging. Current scenario and future prospects

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  9. Ventricular dyssynchrony assessed by gated myocardial perfusion SPECT using a geometrical approach: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Veen, Berlinda J. van der; Younis, Imad Al [Leiden University Medical Centre, Department of Nuclear Medicine, Leiden (Netherlands); Ajmone-Marsan, Nina; Bax, Jeroen J. [Leiden University Medical Centre, Department of Cardiology, Leiden (Netherlands); Westenberg, Jos J.M.; Roos, Albert de [Leiden University Medical Centre, Department of Radiology, Leiden (Netherlands); Stokkel, Marcel P.M. [Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Netherlands Cancer Institute, Amsterdam (Netherlands)

    2012-03-15

    Left ventricular dyssynchrony may predict response to cardiac resynchronization therapy and may well predict adverse cardiac events. Recently, a geometrical approach for dyssynchrony analysis of myocardial perfusion scintigraphy (MPS) was introduced. In this study the feasibility of this geometrical method to detect dyssynchrony was assessed in a population with a normal MPS and in patients with documented ventricular dyssynchrony. For the normal population 80 patients (40 men and 40 women) with normal perfusion (summed stress score {<=}2 and summed rest score {<=}2) and function (left ventricular ejection fraction 55-80%) on MPS were selected; 24 heart failure patients with proven dyssynchrony on MRI were selected for comparison. All patients underwent a 2-day stress/rest MPS protocol. Perfusion, function and dyssynchrony parameters were obtained by the Corridor4DM software package (Version 6.1). For the normal population time to peak motion was 42.8 {+-} 5.1% RR cycle, SD of time to peak motion was 3.5 {+-} 1.4% RR cycle and bandwidth was 18.2 {+-} 6.0% RR cycle. No significant gender-related differences or differences between rest and post-stress acquisition were found for the dyssynchrony parameters. Discrepancies between the normal and abnormal populations were most profound for the mean wall motion (p value <0.001), SD of time to peak motion (p value <0.001) and bandwidth (p value <0.001). It is feasible to quantify ventricular dyssynchrony in MPS using the geometrical approach as implemented by Corridor4DM. (orig.)

  10. Predicting patient response to cardiac resynchronization therapy by gated SPECT myocardial perfusion imaging

    Institute of Scientific and Technical Information of China (English)

    Chen Ji; Yuan Gengbiao; Yan Qingbo; Wang Jinjun

    2011-01-01

    @@ Introduction Heart failure(HF)is widely prevalent(> 6 million cases)and rapidly growing(> 0.6 million new cases annually)in the United States.Although the prevalence of HF in China is less than that in the United States,the total number of HF patients in China exceeds 4 million.

  11. Dual Isotope SPECT Study With Epilepsy Patients Using Semiconductor SPECT System.

    Science.gov (United States)

    Shiga, Tohru; Suzuki, Atsuro; Sakurai, Kotarou; Kurita, Tsugiko; Takeuchi, Wataru; Toyonaga, Takuya; Hirata, Kenji; Kobashi, Keiji; Katoh, Chietsugu; Kubo, Naoki; Tamaki, Nagara

    2017-09-01

    We developed a prototype CdTe SPECT system with 4-pixel matched collimator for brain study. This system provides high-energy-resolution (6.6%), high-sensitivity (220 cps/MBq/head), and high-spatial-resolution images. The aim of this study was to evaluate dual-isotope study of CBF and central benzodiazepine receptor (BZR) images using Tc-ECD and I-IMZ with the new SPECT system in patients with epilepsy comparing with single-isotope study using the conventional scintillation gamma camera. This study included 13 patients with partial epilepsy. The BZR images were acquired at 3 hours after I-IMZ injection for 20 minutes. The images of IMZ were acquired with a conventional 3-head scintillation gamma camera. After BZR image acquisition with the conventional camera, Tc-ECD was injected, and CBF and BZR images were acquired simultaneously 5 minutes after ECD injection with the new SPECT system. The CBF images were also acquired with the conventional camera on separate days. The findings were visually analyzed, and 3D-SSP maximum Z scores of lesions were compared between the 2 studies. There were 47 abnormal lesions on BZR images and 60 abnormal lesions on CBF images in the single-isotope study with the conventional camera. Dual-isotope study with the new system showed concordant abnormal findings of 46 of 47 lesions on BZR and 54 of 60 lesions on CBF images with the single-isotope study with the conventional camera. There was high agreement between the 2 studies in both BZR and CBF findings (Cohen κ values = 0.96 for BZR and 0.78 for CBF). In semiquantitative analysis, maximum Z scores of dual-isotope study with the new system strongly correlated with those of single-isotope study with the conventional camera (BZR: r = 0.82, P < 0.05, CBF: r = 0.87, P < 0.05). Our new SPECT system permits dual-isotope study for pixel-by-pixel analysis of CBF and BZR information with the same pathophysiological condition in patients with epilepsy.

  12. A nanomechanical Fredkin gate.

    Science.gov (United States)

    Wenzler, Josef-Stefan; Dunn, Tyler; Toffoli, Tommaso; Mohanty, Pritiraj

    2014-01-08

    Irreversible logic operations inevitably discard information, setting fundamental limitations on the flexibility and the efficiency of modern computation. To circumvent the limit imposed by the von Neumann-Landauer (VNL) principle, an important objective is the development of reversible logic gates, as proposed by Fredkin, Toffoli, Wilczek, Feynman, and others. Here, we present a novel nanomechanical logic architecture for implementing a Fredkin gate, a universal logic gate from which any reversible computation can be built. In addition to verifying the truth table, we demonstrate operation of the device as an AND, OR, NOT, and FANOUT gate. Excluding losses due to resonator dissipation and transduction, which will require significant improvement in order to minimize the overall energy cost, our device requires an energy of order 10(4) kT per logic operation, similar in magnitude to state-of-the-art transistor-based technologies. Ultimately, reversible nanomechanical logic gates could play a crucial role in developing highly efficient reversible computers, with implications for efficient error correction and quantum computing.

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

    Science.gov (United States)

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

    2008-03-01

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

  14. Performance of coincidence imaging with long-lived positron emitters as an alternative to dedicated PET and SPECT

    Science.gov (United States)

    Sandström, Mattias; Tolmachev, Vladimir; Kairemo, Kalevi; Lundqvist, Hans; Lubberink, Mark

    2004-12-01

    An important application of quantitative imaging in nuclear medicine is the estimation of absorbed doses in radionuclide therapy. Depending on the radionuclide used for therapy, quantitative imaging of the kinetics of the therapeutic radiopharmaceutical could be done using planar imaging, SPECT or PET. Since many nuclear medicine departments have a gamma camera system that is also suitable for coincidence imaging, the performance of these systems with respect to quantitative imaging of PET isotopes that could be of use in radionuclide dosimetry is of interest. We investigated the performance of a gamma camera with coincidence imaging capabilities with 99mTc, 111In, 18F and 76Br and a dedicated PET system with 18F and 76Br, using a single standard set of phantom measurements. Here, 76Br was taken as a typical example of prompt gamma-emitting PET isotopes that are applicable in radionuclide therapy dosimetry such as 86Y and 124I. Image quality measurements show comparable image contrasts for 76Br coincidence imaging and 111In SPECT. Although the spatial resolution of coincidence imaging is better than single photon imaging, the contrast obtained with 76Br is not better than that with 99mTc or 111In because of the prompt gamma involved. Additional improvements are necessary to allow for quantitative coincidence imaging of long-lived, prompt gamma producing positron emitters.

  15. PET/SPECT/CT multimodal imaging in a transgenic mouse model of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Boisgard, R.; Alberini, J.L.; Jego, B.; Siquier, K.; Theze, B.; Guillermet, S.; Tavitian, B. [Service Hospitalier Frederic Joliot, Institut d' Imagerie BioMedicale, CEA, 91 - Orsay (France); Inserm, U803, 91 - Orsay (France)

    2008-02-15

    Background. - In the therapy monitoring of breast cancer, conventional imaging methods include ultrasound, mammography, CT and MRI, which are essentially based on tumor size modifications. However these modifications represent a late consequence of the biological response and fail to differentiate scar or necrotic tissue from residual viable tumoral tissue. Therefore, a current objective is to develop tools able to predict early response to treatment. Positron Emission Tomography (PET) and Single Photon Emission Computerized Tomography (SPECT) are imaging modalities able to provide extremely sensitive quantitative molecular data and are widely used in humans and animals. Results. - Mammary epithelial cells of female transgenic mice expressing the polyoma middle T onco-protein (Py M.T.), undergo four distinct stages of tumour progression, from pre malignant to malignant stages. Stages are identifiable in the mammary tissue and can lead to the development of distant metastases Longitudinal studies by dynamic whole body acquisitions by multimodal imaging including PET, SPECT and Computed Tomography (CT) allow following the tumoral evolution in Py M.T. mice in comparison with the histopathological analysis. At four weeks of age, mammary hyperplasia was identified by histopathology, but no abnormalities were found by palpation or detected by PET with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose. Such as in some human mammary cancers, the sodium iodide sym-porter (N.I.S.) in tumoral mammary epithelial cells is expressed in this mouse model. In order to investigate the expression of N.I.S. in the Py M.T. mice mammary tumours, [{sup 99m}Tc]TcO{sub 4} imaging was performed with a dedicated SPECT/CT system camera (B.I.O.S.P.A.C.E. Gamma Imager/CT). Local uptake of [{sup 99m}Tc]TcO{sub 4} was detected as early as four weeks of age. The efficacy of chemotherapy was evaluated in this mouse model using a conventional regimen (Doxorubicine, 100 mg/ kg) administered weekly from nine to

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

    NARCIS (Netherlands)

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

    2009-01-01

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

  17. The Gates at Pipe Spring National Monument, Arizona (gates)

    Data.gov (United States)

    National Park Service, Department of the Interior — This is an Arc/Info coverage consisting of 7 points representing gates at Pipe Spring National Monument, Arizona. The gates were collected by a Trimble GeoXT GPS...

  18. Amplifying genetic logic gates.

    Science.gov (United States)

    Bonnet, Jerome; Yin, Peter; Ortiz, Monica E; Subsoontorn, Pakpoom; Endy, Drew

    2013-05-03

    Organisms must process information encoded via developmental and environmental signals to survive and reproduce. Researchers have also engineered synthetic genetic logic to realize simpler, independent control of biological processes. We developed a three-terminal device architecture, termed the transcriptor, that uses bacteriophage serine integrases to control the flow of RNA polymerase along DNA. Integrase-mediated inversion or deletion of DNA encoding transcription terminators or a promoter modulates transcription rates. We realized permanent amplifying AND, NAND, OR, XOR, NOR, and XNOR gates actuated across common control signal ranges and sequential logic supporting autonomous cell-cell communication of DNA encoding distinct logic-gate states. The single-layer digital logic architecture developed here enables engineering of amplifying logic gates to control transcription rates within and across diverse organisms.

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Jaszczak, R.J.

    1993-08-20

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

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

    Science.gov (United States)

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

    2015-11-21

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

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

    Science.gov (United States)

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

    2017-03-01

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

  3. Enhancing the utility of prostascint SPECT scans for patient management.

    Science.gov (United States)

    Noz, Marilyn E; Chung, Grace; Lee, Benjamin Y; Maguire, Gerald Q; DeWyngaert, J Keith; Doshi, Jay V; Kramer, Elissa L; Murphy-Walcott, Antoinette D; Zeleznik, Michael P; Kwak, Noeun G

    2006-04-01

    This project investigated reducing the artifact content of In-ill ProstaScint SPECT scans for use in treatment planning and management. Forty-one patients who had undergone CT or MRI scans and simultaneous Tc-99m RBC/In-111 ProstaScint SPECT scans were included. SPECT volume sets, reconstructed using Ordered Set-Expectation Maximum (OS-EM) were compared against those reconstructed with standard Filtered Back projection (FBP). Bladder activity in Tc-99m scans was suppressed within an ellipsoidal volume. Tc-99m voxel values were subtracted from the corresponding In-111 after scaling based on peak activity within the descending aorta. The SPECT volume data sets were merged with the CT or MRI scans before and after processing. Volume merging, based both on visual assessment and statistical evaluation, was not affected. Thus iterative reconstruction together with bladder suppression and blood pool subtraction may improve the interpretation and utility of ProstaScint SPECT scans for patient management.

  4. Optimization of the filter parameters in (99m)Tc myocardial perfusion SPECT studies: the formulation of flowchart.

    Science.gov (United States)

    Shibutani, Takayuki; Onoguchi, Masahisa; Yamada, Tomoki; Kamida, Hiroki; Kunishita, Kohei; Hayashi, Yuuki; Nakajima, Tadashi; Kinuya, Seigo

    2016-06-01

    Myocardial perfusion single photon emission computed tomography (SPECT) is typically subject to a variation in image quality due to the use of different acquisition protocols, image reconstruction parameters and image display settings by each institution. One of the principal image reconstruction parameters is the Butterworth filter cut-off frequency, a parameter strongly affecting the quality of myocardial images. The objective of this study was to formulate a flowchart for the determination of the optimal parameters of the Butterworth filter for filtered back projection (FBP), ordered subset expectation maximization (OSEM) and collimator-detector response compensation OSEM (CDR-OSEM) methods using the evaluation system of the myocardial image based on technical grounds phantom. SPECT studies were acquired for seven simulated defects where the average counts of the normal myocardial components of 45° left anterior oblique projections were approximately 10-120 counts/pixel. These SPECT images were then reconstructed by FBP, OSEM and CDR-OSEM methods. Visual and quantitative assessment of short axis images were performed for the defect and normal parts. Finally, we formulated a flowchart indicating the optimal image processing procedure for SPECT images. Correlation between normal myocardial counts and the optimal cut-off frequency could be represented as a regression expression, which had high or medium coefficient of determination. We formulated the flowchart in order to optimize the image reconstruction parameters based on a comprehensive assessment, which enabled us to perform objectively processing. Furthermore, the usefulness of image reconstruction using the flowchart was demonstrated by a clinical case.

  5. Incorporating GSA-SPECT into CT-based dose-volume histograms for advanced hepatocellular carcinoma radiotherapy

    Institute of Scientific and Technical Information of China (English)

    Shintaro; Shirai; Morio; Sato; Yasutaka; Noda; Yoshitaka; Kumayama; Noritaka; Shimizu

    2014-01-01

    In single photon emission computed tomography-based three-dimensional radiotherapy(SPECT-B-3DCRT), im-ages of Tc-99 m galactosyl human serum albumin(GSA), which bind to receptors on functional liver cells, are merged with the computed tomography simulation im-ages. Functional liver is defined as the area of normal liver where GSA accumulation exceeds that of hepato-cellular carcinoma(HCC). In cirrhotic patients with a gigantic, proton-beam-untreatable HCC of ≥ 14 cm in diameter, the use of SPECT-B-3DCRT in combination with transcatheter arterial chemoembolization achieved a 2-year local tumor control rate of 78.6% and a 2-year survival rate of 33.3%. SPECT-B-3DCRT was applied to HCC to preserve as much functional liver as possible. Sixty-four patients with HCC, including 30 with Child B liver cirrhosis, received SPECT-B-3DCRT and none ex-perienced fatal radiation-induced liver disease(RILD). The Child-Pugh score deteriorated by 1 or 2 in > 20% of functional liver volume that was irradiated with ≥ 20 Gy. The deterioration in the Child-Pugh score decreased when the radiation plan was designed to irradiate ≤ 20% of the functional liver volume in patients givendoses of ≥ 20 Gy(FLV20Gy). Therefore, FLV20 Gy ≤ 20% may represent a safety index to prevent RILD during 3DCRT for HCC. To supplement FLV20 Gy as a qualitative index, we propose a quantitative indicator, F 20 Gy, which was calculated as F 20 Gy = 100% ×(the GSA count in the area irradiated with ≥ 20 Gy)/(the GSA count in the whole liver).

  6. A SPECT imager with synthetic collimation

    Science.gov (United States)

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

    2013-09-01

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

  7. Brain SPECT in neurology: A critical review; Hirn-SPECT in der Neurologie: Eine kritische Uebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Bartenstein, P. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik]|[Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Neurologie; Weiller, C. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik und Poliklinik]|[Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Neurologie

    1994-10-01

    SPECT of the brain with radiopharmaceuticals monitoring regional cerebral blood flow, receptor binding and metabolism offers a wide variety of potentially clinically useful applications. These can be found in neuro-oncology, epilepsy, cerebrovascular diseases, extrapyramidal disorders, dementia and the determination of brain death. The evaluation of the benefit of these methods in routine use requires a close cooperation between nuclear medicine physicians and neurologists, not only in the interpretation and analysis of the actual clinical studies, but also in the design and realization of clinically oriented research with large series of patients. (orig.) [Deutsch] Die SPECT-Untersuchung des Gehirnes bietet mit Radiopharmaka des regionalen zerebralen Blutflusses, Rezeptorliganden und Stoffwechselmarkern ein breites Spektrum diagnostischer Moeglichkeiten in der Neuro-Onkologie, die Epilepsiediagnostik, bei zerebrovaskulaeren Erkrankungen, extrapyramidalen Bewegungsstoerungen, dementiellen Syndromen und der Hirntodbestimmung. Zur Evaluierung klinisch sinnvoller Indikationen in der Routinediagnostik bedarf es einer engen Zusammenarbeit zwischen Nuklearmedizinern und Neurologen bei der Auswertung und Interpretation der Befunde, aber auch beim Design und der Durchfuehrung klinischer Studien mit ausreichend grossen Patientenzahlen. (orig.)

  8. Assessing the Reliability of Quantitative Imaging of Sm-153

    Science.gov (United States)

    Poh, Zijie; Dagan, Maáyan; Veldman, Jeanette; Trees, Brad

    2013-03-01

    Samarium-153 is used for palliation of and recently has been investigated for therapy for bone metastases. Patient specific dosing of Sm-153 is based on quantitative single-photon emission computed tomography (SPECT) and knowing the accuracy and precision of image-based estimates of the in vivo activity distribution. Physical phantom studies are useful for estimating these in simple objects, but do not model realistic activity distributions. We are using realistic Monte Carlo simulations combined with a realistic digital phantom modeling human anatomy to assess the accuracy and precision of Sm-153 SPECT. Preliminary data indicates that we can simulate projection images and reconstruct them with compensation for various physical image degrading factors, such as attenuation and scatter in the body as well as non-idealities in the imaging system, to provide realistic SPECT images.

  9. Stratification of cerebral hemodynamics of child moyamoya disease using CBF SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawara, Jyoji; Saito, Norihiro; Osato, Toshiaki; Kamiyama, Kenji; Takeda, Rihei; Nakamura, Hirohiko [Nakamura Memorial Hospital, Sapporo (Japan)

    2002-12-01

    In order to make sure the stratification of cerebral hemodynamics of child moyamoya disease, we evaluated {sup 123}I-IMP SPECT before and after surgical revascularization. The aim of this paper is to establish the semiquantitative parameters that can be applied to estimate severity of hemodynamic cerebral ischemia instead of quantitative parameters. Quantitative studies using IMP-autoradiography (ARG) method were performed on thirteen patients to measure resting regional cerebral blood flow (rCBF), and vascular reserve (rVR): (Diamox-activated rCBF/resting rCBF-1) x 100%. Semiquantitative parameters were calculated from the ratio of region of interest (ROI) counts in the anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory to the dominant cerebellum counts (ROI/Ce ratio) at resting and Diamox-activated conditions. From the quantitative study, both mean resting rCBF less than 40 ml/100 g/min and rVR less than 10% could indicate stage 2 hemodynamic cerebral ischemia. The prediction of stage 2 ischemia using semiquantitative parameters (resting ROI/Ce ratio less than 0.9 and Diamox-activated ROI/Ce ratio less than 0.85 in the MCA territory) was not statistically different comparison to the diagnosis using quantitative parameters (using Fisher exact test<0.0001, Sensitivity and specificity were 87.5% and 90.9%, respectively). The ROI/Ce ratio can be utilized as simple parameters instead of quantitative parameters. (author)

  10. Corrections in clinical Magnetic Resonance Spectroscopy and SPECT

    DEFF Research Database (Denmark)

    de Nijs, Robin

    to the known mean and median filtering. The data comes from non-anesthetized preterm infants, where motion during scanning is a common problem. Both the novel outlier identification and the independent component analysis (ICA) perform satisfactory and better than the common mean and median filtering. ICA...... a detrimental effect of the extra-uterine environment on brain development. Paper II describes a method to correct for downscatter in low count Iodine-123 SPECT with a broad energy window above the normal imaging window. Both spatial dependency and weight factors were measured. As expected, the implicitly...... of the striatum due to downscatter correction. This makes the difference between healthy subjects and patients more profound. Downscatter in Iodine-123 SPECT is not the only deteriorating mechanism. Normal scatter compromises the images quality as well. Since scatter correction of SPECT-images also can...

  11. Clinical Significance of Brain SPECT in Zipeprol Abusers

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-15

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

  12. Scanning Gate Spectroscopy on Nanoclusters

    OpenAIRE

    Gurevich, L.; Canali, L.; Kouwenhoven, L.P.

    1999-01-01

    A gated probe for scanning tunnelling microscopy (STM) has been developed. The probe extends normal STM operations by means of an additional electrode fabricated next to the tunnelling tip. The extra electrode does not make contact with the sample and can be used as a gate. We report on the recipe used for fabricating the tunnelling tip and the gate electrode on a silicon nitride cantilever. We demonstrate the functioning of the scanning gate probes by performing single-electron tunnelling sp...

  13. GATE Monte Carlo simulation in a cloud computing environment

    Science.gov (United States)

    Rowedder, Blake Austin

    The GEANT4-based GATE is a unique and powerful Monte Carlo (MC) platform, which provides a single code library allowing the simulation of specific medical physics applications, e.g. PET, SPECT, CT, radiotherapy, and hadron therapy. However, this rigorous yet flexible platform is used only sparingly in the clinic due to its lengthy calculation time. By accessing the powerful computational resources of a cloud computing environment, GATE's runtime can be significantly reduced to clinically feasible levels without the sizable investment of a local high performance cluster. This study investigated a reliable and efficient execution of GATE MC simulations using a commercial cloud computing services. Amazon's Elastic Compute Cloud was used to launch several nodes equipped with GATE. Job data was initially broken up on the local computer, then uploaded to the worker nodes on the cloud. The results were automatically downloaded and aggregated on the local computer for display and analysis. Five simulations were repeated for every cluster size between 1 and 20 nodes. Ultimately, increasing cluster size resulted in a decrease in calculation time that could be expressed with an inverse power model. Comparing the benchmark results to the published values and error margins indicated that the simulation results were not affected by the cluster size and thus that integrity of a calculation is preserved in a cloud computing environment. The runtime of a 53 minute long simulation was decreased to 3.11 minutes when run on a 20-node cluster. The ability to improve the speed of simulation suggests that fast MC simulations are viable for imaging and radiotherapy applications. With high power computing continuing to lower in price and accessibility, implementing Monte Carlo techniques with cloud computing for clinical applications will continue to become more attractive.

  14. Stanford, Duke, Rice,... and Gates?

    Science.gov (United States)

    Carey, Kevin

    2009-01-01

    This article presents an open letter to Bill Gates. In his letter, the author suggests that Bill Gates should build a brand-new university, a great 21st-century institution of higher learning. This university will be unlike anything the world has ever seen. He asks Bill Gates not to stop helping existing colleges create the higher-education system…

  15. Stanford, Duke, Rice,... and Gates?

    Science.gov (United States)

    Carey, Kevin

    2009-01-01

    This article presents an open letter to Bill Gates. In his letter, the author suggests that Bill Gates should build a brand-new university, a great 21st-century institution of higher learning. This university will be unlike anything the world has ever seen. He asks Bill Gates not to stop helping existing colleges create the higher-education system…

  16. The four-gate transistor

    Science.gov (United States)

    Mojarradi, M. M.; Cristoveanu, S.; Allibert, F.; France, G.; Blalock, B.; Durfrene, B.

    2002-01-01

    The four-gate transistor or G4-FET combines MOSFET and JFET principles in a single SOI device. Experimental results reveal that each gate can modulate the drain current. Numerical simulations are presented to clarify the mechanisms of operation. The new device shows enhanced functionality, due to the combinatorial action of the four gates, and opens rather revolutionary applications.

  17. SPECT-CT and PET-CT progress in the research of computer analysis method

    Directory of Open Access Journals (Sweden)

    Jingang Guo

    2015-04-01

    Full Text Available The development of multimodal imaging equipment is milestone in the development of imaging, after the PET-CT, American GE company launched a Discovery 670 NM/CT, CT and SPECT, the organic integration of the formation of SPECT-CT new molecular medical imaging equipment, with SPECT, CT and PET-CT is getting more and more widely attention and application, many of SPECT-CT and PET-CT image analysis computer method arises at the historic moment, getting increasing attention of the clinical and imaging science. The paper carried on the detailed description of the SPECT-CT and PET-CT computer analysis method.

  18. Determination of left ventricular mass through SPECT imaging

    Science.gov (United States)

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

    1998-08-01

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

  19. Blood oxygen level-dependent (BOLD) MRI: A novel technique for the assessment of myocardial ischemia as identified by nuclear imaging SPECT.

    Science.gov (United States)

    Egred, M; Waiter, G D; Redpath, T W; Semple, S K I; Al-Mohammad, A; Walton, S

    2007-12-01

    The different levels of deoxyhemoglobin in the ischemic myocardium, induced by stressors such as dipyridamole, can be detected by blood oxygen level-dependent (BOLD) MRI and may be used to diagnose myocardial ischemia. The aim of this study was to assess the signal change in the myocardium on BOLD MRI as well as wall thickening between rest and dipyridamole stress images in ischemic and non-ischemic myocardium as identified on SPECT imaging. Twelve patients with stress-induced myocardial ischemia on SPECT underwent rest and dipyridamole stress MRI using a double breath-hold, T2()-weighted, ECG-gated sequence to produce BOLD contrast images as well as cine-MRI for wall thickening assessment in 10 of the 12 patients. Signal change on BOLD MRI and wall thickening were compared between rest and stress images in ischemic and non-ischemic myocardial segments as identified on SPECT. In each patient, two MRI slices containing 16 segments per slice were analysed. In total, there were 384 segments for BOLD analysis and 320 for wall thickening. For BOLD signal 137 segments correlated to segments with reversible ischemia on SPECT and 247 to normal segments, while for wall thickening 112 segments correlated to segments with reversible ischemia and 208 to normal segments. The average BOLD MRI signal intensity change was -13.8 (+/-16.3)% in the ischemic segments compared to -10.3 (+/-14.7)% in the non-ischemic segments (p=0.05). The average wall thickening was 6.4 (+/-3.4) mm in the ischemic segments compared to 8.7 (+/-3.8) mm in the non-ischemic segments (p<0.0001). Stress-induced ischemic myocardium has a different signal change and wall thickening than non-ischemic myocardium and may be differentiated on BOLD MRI. Larger studies are needed to define a threshold for detection and to determine the sensitivity and specificity of this technique.

  20. Interference from high gall bladder uptake in Technetium-99m tetrofosmin myocardial perfusion SPECT imaging and improvement

    Energy Technology Data Exchange (ETDEWEB)

    Hisano, Harutaka; Urabe, Konomu; Hiroki, Akinori; Abe, Kazuyuki; Yoshikai, Tomonori [Saga Medical School (Japan). Hospital

    2000-08-01

    The purpose of this study was to estimate the influence of high gall bladder uptake in Technetium-99m myocardial SPECT imaging and to establish improvements of artifacts for better image quality and quantitativeness. In the phantom studies, artifactual defects were observed in the posterior, inferior, and anterior walls when the myocardium/gall bladder radioactive ratio increased (more than 1:1), and they were markedly demonstrated when the ratio increased further (more than 1:2). Marked artifactual defects were also observed when setting gall bladder activity in the myocardial reconstruction area. Although relative activity in myocardial SPECT images increased when the gall bladder was masked, counts in defect areas yielded by artifact did not increase, indicating that quantitativeness was not improved. Masking of gall bladder activity on the projection data was necessary for improvement of image quality and quantity. We examined countermeasures for promoting bile excretion and the ''right lateral bending position'' in the clinical studies. Radioactivity was decreased 60.2% in the gall bladder and 49.7% in the hepatic bile duct by excreting bile. These counts were increased 50.91% in the apex and 43.55% in the inferior wall by the right lateral bending position. We concluded that we could obtain more accurate image quality and quantitativeness by either promoting bile excretion or using the right lateral bending position. (author)

  1. Quantitative analysis of cardiac function: Comparison of electrocardiogram dual gated single photon emission tomography, planar radionuclide ventriculogram and contrast ventriculography in the determination of LV volume and ejection fraction

    Energy Technology Data Exchange (ETDEWEB)

    Ziada, G.; Abdel-Dayem, H.M.; Higazy, E.; Mohamed, M.M.; Bahar, R.; Hayat, N.; Yousof, A.M.

    1987-03-01

    A dual gated tomography (DGT) program for end systolic and end diastolic acquisition and subsequent processing for calculation of LVEF, end diastolic and end systolic volumes (EDV, ESV) has been evaluated in 20 healthy volunteers (25 years-40 years) and 45 patients (25 years-60 years): 20 with ischaemic heart disease and 25 with valvular heart disease (VHD). All had biplane multigated blood pool (MUGA) studies in the 40/sup 0/ LAO projection using in vivo /sup 99m/Tc-R BCs, immediately followed by DG. The results in the patients group were correlated with contrast ventriculography (CV). In the volunteer group, the normal values for LVEF, EDV and ESV measured with DGT were found to be 63%+10%, 91 ml + 6 ml and 30 ml + 6ml and r value for the LVEF=0.91 compared with MUGA. In the IHD group, r values compared with CV were 0.915 and 0.97 for the EDV and ESV and 0.934 for the LVEF. Compared with the MUGA, the r value for LVEF was 0.883. In the VHD group, r values were 0.98 for both the EDV and ESV and 0.948 for the LVEF (P<0.002) compared with CV and 0.789 for the LVEF compared with the MUGA. We feel that DGT is an accurate and reproducible technique for LV function measurements.

  2. 99mTc-ECD brain SPECT imaging in patients with acquired immunodeficiency syndromes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In order to investigate the changes of regional cerebral blood flow(rCBF) in patients with acquired immunodeficiency syndromes (AIDS), 99mTc-ECDbrain SPECT imaging was performed in 5 patients with AIDS and 16 sex and agematched normal controls, and the rCBF percentages compared to the cerebellum werecalculated using a semi-quantitative processing software. Hypoperfusions in the rightand left frontal, temporal, porietal lobe, basal ganglia and left thalamus were seen in1 patient with dementia. Hypoperfusions in the right and left frontal and temporallobe were seen in 4 asymptomatic patients. The rCBF in the right and left frontal.temporal, porietal lobe, basal ganglia and thalamus, front and pons were decreasedsignificantly in patients with AIDS than those of the control subjects (p <0.005). Itis concluded that there exists reduced cortico-subcortical rCBF in AIDS patients.``

  3. Dual-Energy SPECT and the Development of Peptide p5+14 for Imaging Amyloidosis

    Directory of Open Access Journals (Sweden)

    Jonathan S. Wall PhD

    2017-05-01

    Full Text Available Amyloidosis is associated with a number of rare diseases and is characterized by the deposition, in abdominothoracic organs and peripheral nerves, of extracellular protein fibrils, which leads to dysfunction and severe morbidity. Effective clinical evaluation and management of patients with systemic amyloidosis are hampered by the lack of a noninvasive, quantitative method for detecting whole-body amyloid load. We have used a battery of assays including dual-energy SPECT imaging and comparative effectiveness studies in support of translation of a synthetic polybasic peptide, p5+14, as a novel radiotracer for visualization of amyloidosis by molecular imaging. These data provide support for a phase 1 positron emission tomography/computed tomography imaging trial of this reagent, labeled with iodine-124, in patients with all forms of systemic amyloidosis.

  4. A comparative study of the quality of SPECT images obtained by {sup 123}I-IMP, {sup 99m}Tc-HMPAO and {sup 99m}Tc-ECD

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

    The purpose of this study was to comparatively evaluate the quality of SPECT images for the mapping of rCBF using three tracers, {sup 123}I-IMP, {sup 99m}Tc-HMPAO and {sup 99m}Tc-ECD. We performed three SPECT studies on seven patients with various cerebral diseases under the same conditions. An effect of Lassen`s correction on SPECT images obtained by HMPAO was also evaluated. The same irregular regions of interest were placed on the four transaxial SPECT images. To quantitatively evaluate the pattern of tracer uptake and image contrast, the uptake ratio, regional count/mean count of the cerebrum, and its coefficient variations (CV) were defined, respectively. The order of the value of CV was HMPAO with correction>IMP>ECD>HMPAO without correction. HMPAO with correction showed the best image contrast, but HMPAO without correction was the worst. Uptake ratios of ECD and HMPAO with correction were decreased in the brain stem and thalamus in comparison with those of IMP. Both uptake ratios of ECD and HMPAO without correction were increased in the occipital cortex. IMP provides high quality SPECT images. Images obtained by HMPAO should be modified by Lassen`s correction to increase image contrast. ECD or HMPAO should not be used to evaluate patients with spinocerebellar degeneration. (author)

  5. High permittivity gate dielectric materials

    CERN Document Server

    2013-01-01

    "The book comprehensively covers all the current and the emerging areas of the physics and the technology of high permittivity gate dielectric materials, including, topics such as MOSFET basics and characteristics, hafnium-based gate dielectric materials, Hf-based gate dielectric processing, metal gate electrodes, flat-band and threshold voltage tuning, channel mobility, high-k gate stack degradation and reliability, lanthanide-based high-k gate stack materials, ternary hafnia and lanthania based high-k gate stack films, crystalline high-k oxides, high mobility substrates, and parameter extraction. Each chapter begins with the basics necessary for understanding the topic, followed by a comprehensive review of the literature, and ultimately graduating to the current status of the technology and our scientific understanding and the future prospects."

  6. Evaluating image denoising methods in myocardial perfusion single photon emission computed tomography (SPECT) imaging

    Science.gov (United States)

    Skiadopoulos, S.; Karatrantou, A.; Korfiatis, P.; Costaridou, L.; Vassilakos, P.; Apostolopoulos, D.; Panayiotakis, G.

    2009-10-01

    The statistical nature of single photon emission computed tomography (SPECT) imaging, due to the Poisson noise effect, results in the degradation of image quality, especially in the case of lesions of low signal-to-noise ratio (SNR). A variety of well-established single-scale denoising methods applied on projection raw images have been incorporated in SPECT imaging applications, while multi-scale denoising methods with promising performance have been proposed. In this paper, a comparative evaluation study is performed between a multi-scale platelet denoising method and the well-established Butterworth filter applied as a pre- and post-processing step on images reconstructed without and/or with attenuation correction. Quantitative evaluation was carried out employing (i) a cardiac phantom containing two different size cold defects, utilized in two experiments conducted to simulate conditions without and with photon attenuation from myocardial surrounding tissue and (ii) a pilot-verified clinical dataset of 15 patients with ischemic defects. Image noise, defect contrast, SNR and defect contrast-to-noise ratio (CNR) metrics were computed for both phantom and patient defects. In addition, an observer preference study was carried out for the clinical dataset, based on rankings from two nuclear medicine clinicians. Without photon attenuation conditions, denoising by platelet and Butterworth post-processing methods outperformed Butterworth pre-processing for large size defects, while for small size defects, as well as with photon attenuation conditions, all methods have demonstrated similar denoising performance. Under both attenuation conditions, the platelet method showed improved performance with respect to defect contrast, SNR and defect CNR in the case of images reconstructed without attenuation correction, however not statistically significant (p > 0.05). Quantitative as well as preference results obtained from clinical data showed similar performance of the

  7. SPECT and PET in Late-Life Depression

    NARCIS (Netherlands)

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

    2014-01-01

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

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-06-01

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

  10. Role of SPECT/CT in diagnosis of hepatic hemangiomas

    Institute of Scientific and Technical Information of China (English)

    Jian-Guo Zheng; Zhi-Ming Yao; Chong-Ye Shu; Ying Zhang; Xia Zhang

    2005-01-01

    AIM: To investigate the role of SPECT/CT in the diagnosis of hepatic hemangiomas whose anatomical positions are not ideal, situated adjacent to the heart, the inferior cava,hepatic vessels or abdominal aorta, etc.METHODS: The hepatic perfusion, blood pool, and fusion imaging were carried out using SPECT/CT in 54 patients,who were suspected for hepatic hemangiomas. When the anatomical positions were not ideal, the diagnosis was difficult by SPECT only. So the information of computed tomography (CT) was applied to help in diagnosing. The results were recorded as hemangiomas or not.RESULTS: Of the 54 patients, 31 patients were diagnosed as suffering from hepatic hemangiomas. The anatomical positions of eight patients' hepatic hemangiomas (25.81%)were not ideal. Among these lesions of the eight patients,three patients' hepatic lesions were located near to the abdominal aorta, one to the heart, and four to the inferior cava. In addition, six abnormal radioactivity accumulation regions, adjacent to the heart and inferior cava, with the help of CT, were confirmed to be the imaging of inferior cava other than hepatic hemangiomas.CONCLUSION: When the anatomical positions of hepatic hemangiomas are not good enough for diagnosis, the fusion imaging of SPECT/CT is a simple and efficient method for differential diagnosis.

  11. Cerebral fat embolism studied with MRI and SPECT

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-03-01

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

  12. 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.

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-06-01

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

  16. Hemimegalencephaly: Clinical, EEG, neuroimaging, and IMP-SPECT correlation

    Energy Technology Data Exchange (ETDEWEB)

    Konkol, R.J.; Maister, B.H.; Wells, R.G.; Sty, J.R. (Medical College of Wisconsin, Milwaukee (USA))

    1990-11-01

    Iofetamine-single photon emission computed tomography (IMP-SPECT) was performed on 2 girls (5 1/2 and 6 years of age) with histories of intractable seizures, developmental delay, and unilateral hemiparesis secondary to hemimegalencephaly. Electroencephalography (EEG) revealed frequent focal discharges in 1 patient, while a nearly continuous burst suppression pattern over the malformed hemisphere was recorded in the other. IMP-SPECT demonstrated a good correlation with neuroimaging studies. In spite of the different EEG patterns, which had been proposed to predict contrasting clinical outcomes, both IMP-SPECT scans disclosed a similar decrease in tracer uptake in the malformed hemisphere. These results are consistent with the pattern of decreased tracer uptake found in other interictal studies of focal seizures without cerebral malformations. In view of recent recommendations for hemispherectomy in these patients, we suggest that the IMP-SPECT scan be used to compliment EEG as a method to define the extent of abnormality which may be more relevant to long-term prognosis than EEG alone.

  17. Accelerated Monte Carlo simulation for scatter correction in SPECT

    NARCIS (Netherlands)

    Jong, Hugo Wilhelmus Antonius Maria de

    2002-01-01

    Single Photon Emission Tomography (SPECT) is often used in the clinical practice to image the distribution of photon-emitting pharmaceuticals in the patient. From this distribution, functional information can be obtained (e.g. perfusion and metabolic processes). To assess the viability of myocardia

  18. Reduced contralateral hemispheric flow measured by SPECT in cerebellar lesions

    DEFF Research Database (Denmark)

    Sönmezoğlu, K; Sperling, B; Henriksen, T

    1993-01-01

    to the cerebellar lesion CBF showed variable alterations. A relative CBF decrease was seen in upper part of basal ganglia in all four cases, but it was not a constant phenomenon. A relative CBF increase in both early and late SPECT scans was seen at low levels of neostriatum in two cases. The remote CBF changes...

  19. Noise Gating Solar Images

    Science.gov (United States)

    DeForest, Craig; Seaton, Daniel B.; Darnell, John A.

    2017-08-01

    I present and demonstrate a new, general purpose post-processing technique, "3D noise gating", that can reduce image noise by an order of magnitude or more without effective loss of spatial or temporal resolution in typical solar applications.Nearly all scientific images are, ultimately, limited by noise. Noise can be direct Poisson "shot noise" from photon counting effects, or introduced by other means such as detector read noise. Noise is typically represented as a random variable (perhaps with location- or image-dependent characteristics) that is sampled once per pixel or once per resolution element of an image sequence. Noise limits many aspects of image analysis, including photometry, spatiotemporal resolution, feature identification, morphology extraction, and background modeling and separation.Identifying and separating noise from image signal is difficult. The common practice of blurring in space and/or time works because most image "signal" is concentrated in the low Fourier components of an image, while noise is evenly distributed. Blurring in space and/or time attenuates the high spatial and temporal frequencies, reducing noise at the expense of also attenuating image detail. Noise-gating exploits the same property -- "coherence" -- that we use to identify features in images, to separate image features from noise.Processing image sequences through 3-D noise gating results in spectacular (more than 10x) improvements in signal-to-noise ratio, while not blurring bright, resolved features in either space or time. This improves most types of image analysis, including feature identification, time sequence extraction, absolute and relative photometry (including differential emission measure analysis), feature tracking, computer vision, correlation tracking, background modeling, cross-scale analysis, visual display/presentation, and image compression.I will introduce noise gating, describe the method, and show examples from several instruments (including SDO

  20. Use of {sup 99m}Tc-MDP SPECT for assessment of mandibular growth: development of normal values

    Energy Technology Data Exchange (ETDEWEB)

    Fahey, Frederic H.; Treves, S. Ted [Children' s Hospital Boston, Division of Nuclear Medicine, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Abramson, Zachary R.; Nissenbaum, Mark [Harvard School of Dental Medicine, Boston, MA (United States); Massachusetts General Hospital, Department of Oral and Maxillofacial Surgery, Boston, MA (United States); Padwa, Bonnie L. [Harvard Medical School, Boston, MA (United States); Harvard School of Dental Medicine, Boston, MA (United States); Children' s Hospital Boston, Department of Plastic and Oral Surgery, Boston, MA (United States); Zimmerman, Robert E. [Brigham and Women' s Hospital, Division of Nuclear Medicine, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Zurakowski, David [Children' s Hospital Boston, Department of Orthopaedics, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Kaban, Leonard B. [Harvard Medical School, Boston, MA (United States); Harvard School of Dental Medicine, Boston, MA (United States); Massachusetts General Hospital, Department of Oral and Maxillofacial Surgery, Boston, MA (United States)

    2010-05-15

    Planar scintigraphy using {sup 99m}Tc-labeled methylene diphosphonate ({sup 99m}Tc-MDP) has been established as a method for evaluating mandibular growth and asymmetry. However, {sup 99m}Tc-MDP single photon emission computed tomography (SPECT) provides improved image contrast and quantitative capability potentially allowing the clinician to make a more accurate assessment of the stage of activity of normal and asymmetric mandibular growth. The purpose of this study was to utilize {sup 99m}Tc-MDP SPECT in normal subjects to develop a standardized approach to imaging the mandible that could subsequently be used to evaluate patients with potential for mandibular growth abnormalities. Thirty-two patients (22 females, 10 males, 8-25 years of age, mean of 14 years) having {sup 99m}Tc-MDP bone scans (7.4 MBq/kg, maximum of 518 MBq) for indications not involving the head were asked to have an additional SPECT that included the mandibular condyles. Internal (clivus) and external (source of known activity included within the field of view) standards were both investigated. Two- and three-dimensional (2-D and 3-D) regions of interest (ROI) were drawn over each condyle and the clivus in a single slice containing the maximum pixel value within the structure. A 3-D ROI was also drawn about the external standard. Maximum and average pixel values within the 2-D and 3-D ROIs were recorded. Correlation analysis indicated that essentially the same information was obtained whether the maximum or average pixel value within a 2-D or 3-D ROI was used. The right to left ratio provided a parameter that can be used to assess the magnitude of mandibular metabolic asymmetry. Use of an external standard provides the potential for quantifying condylar uptake for assessment of the activity of mandibular growth. Normal ranges for different age groups were determined for condylar uptake using both internal and external standards. {sup 99m}Tc-MDP SPECT provides a quantitative method for assessing

  1. A quantum Fredkin gate.

    Science.gov (United States)

    Patel, Raj B; Ho, Joseph; Ferreyrol, Franck; Ralph, Timothy C; Pryde, Geoff J

    2016-03-01

    Minimizing the resources required to build logic gates into useful processing circuits is key to realizing quantum computers. Although the salient features of a quantum computer have been shown in proof-of-principle experiments, difficulties in scaling quantum systems have made more complex operations intractable. This is exemplified in the classical Fredkin (controlled-SWAP) gate for which, desp