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Sample records for spect empirical validation

  1. Functional imaging studies of cognition using 99mTc-HMPAO SPECT: empirical validation using the n-back working memory paradigm

    Ludwig, Catherine; Ribaupierre, Anik de; Chicherio, Christian; Terraneo, Luc; Magistretti, Pierre; Slosman, Daniel

    2008-01-01

    Functional activation protocols are widely applied for the study of brain-cognition relations. Only few take advantage of the intrinsic characteristics of SPECT, particularly those allowing cognitive assessment outside of the camera, in settings close to the standard clinical or laboratory ones. The purpose of the study was to assess the feasibility of a split-dose activation protocol with 99m Tc-HMPAO using low irradiation dose. A two-scans protocol was applied to 12 healthy young volunteers using 270 MBq of 99m Tc-HMPAO per scan, with each image associated to a particular experimental condition of the verbal n-back working memory task (0-back, 2-back). Subtraction method was used to identify regional brain activity related to the task. Voxel-wise statistical analysis showed left lateralized activity associated with the 2-back task, compared to the 0-back task. Activated regions, mainly prefrontal and parietal, were similar to those observed in previous fMRI and 15 O-PET studies. The results support the use of 99m Tc-HMPAO SPECT for the investigation of brain-cognition relations and demonstrate the feasibility of optimal quality images despite low radiopharmaceutical doses. The findings also acknowledge the use of HMPAO as a radioligand to capture neuro-energetic modulations linked to cognitive activity. They encourage extending the application of the described activation protocol to clinical populations. (orig.)

  2. Functional imaging studies of cognition using {sup 99m}Tc-HMPAO SPECT: empirical validation using the n-back working memory paradigm

    Ludwig, Catherine; Ribaupierre, Anik de [University of Geneva, Center for Interdisciplinary Gerontology, Geneva (Switzerland); Chicherio, Christian [Max Planck Institute for Human Development, Center for Lifespan Psychology, Berlin (Germany); Terraneo, Luc [Geneva University Hospitals, Service of Nuclear Medicine, Geneva (Switzerland); Magistretti, Pierre [EPFL, Brain Mind Institute, Lausanne (Switzerland); Slosman, Daniel [Clinique Generale-Beaulieu, Nuclear Medicine Institute, Geneva (Switzerland)

    2008-04-15

    Functional activation protocols are widely applied for the study of brain-cognition relations. Only few take advantage of the intrinsic characteristics of SPECT, particularly those allowing cognitive assessment outside of the camera, in settings close to the standard clinical or laboratory ones. The purpose of the study was to assess the feasibility of a split-dose activation protocol with {sup 99m}Tc-HMPAO using low irradiation dose. A two-scans protocol was applied to 12 healthy young volunteers using 270 MBq of {sup 99m}Tc-HMPAO per scan, with each image associated to a particular experimental condition of the verbal n-back working memory task (0-back, 2-back). Subtraction method was used to identify regional brain activity related to the task. Voxel-wise statistical analysis showed left lateralized activity associated with the 2-back task, compared to the 0-back task. Activated regions, mainly prefrontal and parietal, were similar to those observed in previous fMRI and {sup 15}O-PET studies. The results support the use of {sup 99m}Tc-HMPAO SPECT for the investigation of brain-cognition relations and demonstrate the feasibility of optimal quality images despite low radiopharmaceutical doses. The findings also acknowledge the use of HMPAO as a radioligand to capture neuro-energetic modulations linked to cognitive activity. They encourage extending the application of the described activation protocol to clinical populations. (orig.)

  3. Validation of a method for radionuclide activity optimize in SPECT

    Perez Diaz, M.; Diaz Rizo, O.; Lopez Diaz, A.; Estevez Aparicio, E.; Roque Diaz, R.

    2007-01-01

    A discriminant method for optimizing the activity administered in NM studies is validated by comparison with ROC curves. the method is tested in 21 SPECT, performed with a Cardiac phantom. Three different cold lesions (L1, L2 and L3) were placed in the myocardium-wall for each SPECT. Three activities (84 MBq, 37 MBq or 18.5 MBq) of Tc-99m diluted in water were used as background. The linear discriminant analysis was used to select the parameters that characterize image quality (Background-to-Lesion (B/L) and Signal-to-Noise (S/N) ratios). Two clusters with different image quality (p=0.021) were obtained following the selected variables. the first one involved the studies performed with 37 MBq and 84 MBq, and the second one included the studies with 18.5 MBq. the ratios B/L, B/L2 and B/L3 are the parameters capable to construct the function, with 100% of cases correctly classified into the clusters. The value of 37 MBq is the lowest tested activity for which good results for the B/Li variables were obtained,without significant differences from the results with 84 MBq (p>0.05). The result is coincident with the applied ROC-analysis. A correlation between both method of r=890 was obtained. (Author) 26 refs

  4. Validation of a method for accurate and highly reproducible quantification of brain dopamine transporter SPECT studies

    Jensen, Peter S; Ziebell, Morten; Skouboe, Glenna

    2011-01-01

    In nuclear medicine brain imaging, it is important to delineate regions of interest (ROIs) so that the outcome is both accurate and reproducible. The purpose of this study was to validate a new time-saving algorithm (DATquan) for accurate and reproducible quantification of the striatal dopamine t...... transporter (DAT) with appropriate radioligands and SPECT and without the need for structural brain scanning....

  5. Empirical validation of directed functional connectivity.

    Mill, Ravi D; Bagic, Anto; Bostan, Andreea; Schneider, Walter; Cole, Michael W

    2017-02-01

    Mapping directions of influence in the human brain connectome represents the next phase in understanding its functional architecture. However, a host of methodological uncertainties have impeded the application of directed connectivity methods, which have primarily been validated via "ground truth" connectivity patterns embedded in simulated functional MRI (fMRI) and magneto-/electro-encephalography (MEG/EEG) datasets. Such simulations rely on many generative assumptions, and we hence utilized a different strategy involving empirical data in which a ground truth directed connectivity pattern could be anticipated with confidence. Specifically, we exploited the established "sensory reactivation" effect in episodic memory, in which retrieval of sensory information reactivates regions involved in perceiving that sensory modality. Subjects performed a paired associate task in separate fMRI and MEG sessions, in which a ground truth reversal in directed connectivity between auditory and visual sensory regions was instantiated across task conditions. This directed connectivity reversal was successfully recovered across different algorithms, including Granger causality and Bayes network (IMAGES) approaches, and across fMRI ("raw" and deconvolved) and source-modeled MEG. These results extend simulation studies of directed connectivity, and offer practical guidelines for the use of such methods in clarifying causal mechanisms of neural processing. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Rodriguez Marrero, J. P.; Diaz Garcia, A.; Gomez Facenda, A.

    2015-01-01

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

  7. Validation and the limits of SPECT for patients suffering from cerebrovascular accidents. Evaluations based on simultaneous PET and SPECT examinations

    Mizukawa, Norihiko; Yano, Ichiro; Tenjin, Hiroshi (Kyoto Prefectural Univ. of Medicine (Japan)) (and others)

    1989-02-01

    Contemporaneous single photon emission computed tomography (SPECT) and positron emission tomography (PET) were performed in 10 patients with cerebrovascular accidents (CVA), whose ages ranged from 11 to 67 years. I-123-isopropyl-iodoamphetamine (IMP) and/or Tc-99m hexamethylpropyleneamine oxime (HM-PAO) were used for SPECT. Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate for oxygen (CMRO{sub 2}) were measured by an O-15 labelled gas continuous-inhalation method. SPECT images were quite similar to CBF and CMRO{sub 2} during the chronic stage of CVA. Two patietns with vasospasm during the subacute stage had apparently low CBF and CMRO{sub 2} on PET, but did not have low perfusion on SPECT. Luxury perfusion areas were detected in 4 subacute stage patients and one chronic stage patient. A redistribution of IMP was detected in two patients with infarction during subacute stage. CMRO{sub 2} value in such an area was 2.0 ml/100 g/min. Low CBF and/or CMRO{sub 2} areas were well visualized by IMP rather than by HM-PAO SPECT. (N.K.).

  8. Empirical Validation of Listening Proficiency Guidelines

    Cox, Troy L.; Clifford, Ray

    2014-01-01

    Because listening has received little attention and the validation of ability scales describing multidimensional skills is always challenging, this study applied a multistage, criterion-referenced approach that used a framework of aligned audio passages and listening tasks to explore the validity of the ACTFL and related listening proficiency…

  9. Empirical Validation of Building Simulation Software

    Kalyanova, Olena; Heiselberg, Per

    The work described in this report is the result of a collaborative effort of members of the International Energy Agency (IEA), Task 34/43: Testing and validation of building energy simulation tools experts group.......The work described in this report is the result of a collaborative effort of members of the International Energy Agency (IEA), Task 34/43: Testing and validation of building energy simulation tools experts group....

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

    Iida, Hidehiro; Kim, Kyeong-Min; Nakazawa, Mayumi; Sohlberg, Antti; Zeniya, Tsutomu; Hayashi, Takuya; Watabe, Hiroshi; Eberl, Stefan; Tamura, Yoshikazu; Ono, Yukihiko

    2008-01-01

    201 Tl has been extensively used for myocardial perfusion and viability assessment. Unlike 99m Tc-labelled agents, such as 99m Tc-sestamibi and 99m Tc-tetrofosmine, the regional concentration of 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 201 Tl using dynamic SPECT. Dynamic SPECT was carried out on 20 normal canines after the intravenous administration of 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 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 SPECT ) correlated well with the MBF values obtained by the radio-labelled microspheres (MBF MS ) (MBF SPECT = -0.067 + 1.042 x MBF MS , p 201 Tl and dynamic SPECT. (orig.)

  11. Validation of co-registration of clinical lung ventilation and perfusion SPECT

    Marsh, S.H.; O'Keeffe, D.S.; Barnden, L.R.

    2010-01-01

    Full text: This talk will present results from a recent validation study of coregistration of computed tomography ventilation and perfusion (SPECT V/Q) images. The coregistration algorithm was incorporated in Qonsub, a program to coregister, normalise and subtract the SPECT (V/Q) images. Ventilation and perfusion image data were acquired from 23 patients undergoing a routine clinical SPECT V/Q study. The only change to normal patient management was the placement of three Tc 9 9 m filled fiducial markers adhered to the skin on the patient's torso. To quantify coregistration accuracy, image data were modified (within software) to remove the markers and Qonsub determined a parameter set of six values fully describing the six degree rigid transformation. The accuracy with which the six parameters coregister the images was then quantified by applying the same transformation parameters to the ventilation markers and determining how well they locate to the perfusion marker positions. Results show that for 65% of patients surveyed co-registration accuracy was to within I pixel, 30% were co-registered with an accuracy between 1 and 2 pixels and 5% were co-registered with an accuracy of between 2 and 3 pixels. Because patient placement between scans resulted in a misregistration of at most five pixels, a more rigorous test of the algorithm was required. Ethics approval had not been sought to intentionally misregister patient images, so the algorithm had to be further tested by synthetically misregistering the images. For these images Qonsub generally co-registered with the same accuracy as the original image. (author)

  12. Quantitative 177Lu-SPECT/CT imaging and validation of a commercial dosimetry software

    D'Ambrosio, L.; Aloj, L.; Morisco, A.; Aurilio, M.; Prisco, A.; Di Gennaro, F.; Lastoria, S.; Madesani, D.

    2015-01-01

    Full text of publication follows. Aim: 3D dosimetry is an appealing yet complex application of SPECT/CT in patients undergoing radionuclide therapy. In this study we have developed a quantitative imaging protocol and we have validated commercially available dosimetry software (Dosimetry Tool-kit Package, GE Heathcare) in patients undergoing 177 Lu-DOTATATE therapy. Materials and methods: dosimetry tool-kit uses multi SPECT/CT and/or WB planar datasets for quantifying changes in radiopharmaceutical uptake over time to determine residence times. This software includes tools for performing reconstruction of SPECT/CT data, registration of all scans to a common reference, segmentation of the different organs, creating time activity curves, curve fitting and calculation of residence times. All acquisitions were performed using a hybrid dual-head SPECT-CT camera (Discovery 670, GE Heathcare) equipped with medium energy collimator using a triple-energy window. SPECT images were reconstructed using an iterative reconstruction algorithm with attenuation, scatter and collimator depth-dependent three-dimensional resolution recovery correction. Camera sensitivity and dead time were evaluated. Accuracy of activity quantification was performed on a large homogeneous source with addition of attenuating/scattering medium. A NEMA/IEC body phantom was utilized to measure the recovery coefficient that the software does not take into account. The residence times for organs at risk were calculated in five patients. OLINDA-EXM software was used to calculate absorbed doses. Results: 177 Lu-sensitivity factor was 13 counts/MBq/s. Dead time was <3% with 1.11 GBq in the field of view. The measured activity was consistent with the decay-corrected calibrated activity for large volumes (>100 cc). The recovery coefficient varied from 0.71 (26.5 ml) to 0.16 (2.5 ml) in the absence of background activity and from 0.58 to 0.13 with a source to background activity concentration ratio 20:1. The

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

    Li, Suying; Zhang, Qiushi; Xie, Zhaoheng; Liu, Qi; Xu, Baixuan; Yang, Kun; Li, Changhui; Ren, Qiushi

    2015-01-01

    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

  14. Validation of brain tumour imaging with p-[123I]iodo-l-phenylalanine and SPECT

    Hellwig, Dirk; Sell, Nadja; Schaefer, Andrea; Kirsch, Carl-Martin; Samnick, Samuel; Ketter, Ralf; Moringlane, Jean R.; Romeike, Bernd F.M.

    2005-01-01

    The aims of this prospective study were to validate single-photon emission computed tomography (SPECT) with p-[ 123 I]iodo-l-phenylalanine (IPA) in brain tumours and to evaluate its potential for the characterisation of indeterminate brain lesions. In 45 patients with indeterminate brain lesions or suspected progression of glioma, amino acid uptake was studied using IPA-SPECT and compared with the final diagnosis established by biopsy or serial imaging. After image fusion of IPA-SPECT and magnetic resonance imaging, the presence of tumour was visually determined by two independent observers. IPA uptake was quantified as the ratio between maximum uptake in the suspicious lesion and mean uptake in unaffected brain. Primary brain tumours were present in 35 cases (12 low-grade and 23 high-grade gliomas). Non-neoplastic brain lesions were confirmed in seven cases (three dysplasias, three inflammatory lesions, one lesion after effective therapy). Visual analysis showed a high concordance between the two observers (kappa=0.90, p<0.001), with sensitivity and specificity of 86% and 100% for the discrimination of primary brain tumours and non-neoplastic lesions. At 30 min p.i., IPA uptake in primary brain tumours was higher than that in non-neoplastic lesions (1.70±0.36 vs 1.14±0.18, p<0.05). Brain metastases showed no increased uptake (1.13±0.22, n=3). The persistent retention of IPA in low-grade gliomas without disruption of the blood-brain barrier was visualised up to 24 h p.i. Low-grade and high-grade gliomas showed equivalent IPA uptake (1.72±0.37 vs 1.67±0.36 at 30 min, p=0.745). IPA shows long and specific retention in gliomas. IPA is a promising and safe radiopharmaceutical for the visualisation of gliomas and the characterisation of indeterminate brain lesions. (orig.)

  15. The conceptualization and empirical validation of website user satisfaction

    Moenaert, R.K.; Muylle, S.; Despontin, M.

    2004-01-01

    This article addresses the concern for effective web site design by means of the conceptualization and empirical validation of a web site user satisfaction construct. Based on IS success theory, hypermedia design theory, a qualitative exploratory pilot study, and a quantitative online critical

  16. Application of parameters space analysis tools for empirical model validation

    Paloma del Barrio, E. [LEPT-ENSAM UMR 8508, Talence (France); Guyon, G. [Electricite de France, Moret-sur-Loing (France)

    2004-01-01

    A new methodology for empirical model validation has been proposed in the framework of the Task 22 (Building Energy Analysis Tools) of the International Energy Agency. It involves two main steps: checking model validity and diagnosis. Both steps, as well as the underlying methods, have been presented in the first part of the paper. In this part, they are applied for testing modelling hypothesis in the framework of the thermal analysis of an actual building. Sensitivity analysis tools have been first used to identify the parts of the model that can be really tested on the available data. A preliminary diagnosis is then supplied by principal components analysis. Useful information for model behaviour improvement has been finally obtained by optimisation techniques. This example of application shows how model parameters space analysis is a powerful tool for empirical validation. In particular, diagnosis possibilities are largely increased in comparison with residuals analysis techniques. (author)

  17. Using face validity to recognize empirical community observations.

    Gaber, John; Gaber, Sharon L

    2010-05-01

    There is a growing interest among international planning scholars to explore community participation in the plan making process from a qualitative research approach. In this paper the research assessment tool "face validity" is discussed as one way to help planners decipher when the community is sharing empirically grounded observations that can advance the applicability of the plan making process. Face validity provides a common sense assessment of research conclusions. It allows the assessor to look at an entire research project and ask: "on the face of things, does this research make sense?" With planners listening to citizen comments with an ear for face validity observations, holds open the opportunity for government to empirically learn from the community to see if they "got it right." And if not, to chart out a course on how they can get it right. Copyright 2009 Elsevier Ltd. All rights reserved.

  18. The validation and the limits of SPECT for patients suffering from cerebrovascular accidents

    Mizukawa, Norihiko; Yano, Ichiro; Tenjin, Hiroshi

    1989-01-01

    Contemporaneous single photon emission computed tomography (SPECT) and positron emission tomography (PET) were performed in 10 patients with cerebrovascular accidents (CVA), whose ages ranged from 11 to 67 years. I-123-isopropyl-iodoamphetamine (IMP) and/or Tc-99m hexamethylpropyleneamine oxime (HM-PAO) were used for SPECT. Cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate for oxygen (CMRO 2 ) were measured by an O-15 labelled gas continuous-inhalation method. SPECT images were quite similar to CBF and CMRO 2 during the chronic stage of CVA. Two patietns with vasospasm during the subacute stage had apparently low CBF and CMRO 2 on PET, but did not have low perfusion on SPECT. Luxury perfusion areas were detected in 4 subacute stage patients and one chronic stage patient. A redistribution of IMP was detected in two patients with infarction during subacute stage. CMRO 2 value in such an area was 2.0 ml/100 g/min. Low CBF and/or CMRO 2 areas were well visualized by IMP rather than by HM-PAO SPECT. (N.K.)

  19. Validation of a Multimodality Flow Phantom and Its Application for Assessment of Dynamic SPECT and PET Technologies.

    Gabrani-Juma, Hanif; Clarkin, Owen J; Pourmoghaddas, Amir; Driscoll, Brandon; Wells, R Glenn; deKemp, Robert A; Klein, Ran

    2017-01-01

    Simple and robust techniques are lacking to assess performance of flow quantification using dynamic imaging. We therefore developed a method to qualify flow quantification technologies using a physical compartment exchange phantom and image analysis tool. We validate and demonstrate utility of this method using dynamic PET and SPECT. Dynamic image sequences were acquired on two PET/CT and a cardiac dedicated SPECT (with and without attenuation and scatter corrections) systems. A two-compartment exchange model was fit to image derived time-activity curves to quantify flow rates. Flowmeter measured flow rates (20-300 mL/min) were set prior to imaging and were used as reference truth to which image derived flow rates were compared. Both PET cameras had excellent agreement with truth ( [Formula: see text]). High-end PET had no significant bias (p > 0.05) while lower-end PET had minimal slope bias (wash-in and wash-out slopes were 1.02 and 1.01) but no significant reduction in precision relative to high-end PET ( 0.3). SPECT (without scatter and attenuation corrections) slope biases were noted (0.85 and 1.32) and attributed to camera saturation in early time frames. Analysis of wash-out rates from non-saturated, late time frames resulted in excellent agreement with truth ( [Formula: see text], slope = 0.97). Attenuation and scatter corrections did not significantly impact SPECT performance. The proposed phantom, software and quality assurance paradigm can be used to qualify imaging instrumentation and protocols for quantification of kinetic rate parameters using dynamic imaging.

  20. Nursing intellectual capital theory: operationalization and empirical validation of concepts.

    Covell, Christine L; Sidani, Souraya

    2013-08-01

    To present the operationalization of concepts in the nursing intellectual capital theory and the results of a methodological study aimed at empirically validating the concepts. The nursing intellectual capital theory proposes that the stocks of nursing knowledge in an organization are embedded in two concepts, nursing human capital and nursing structural capital. The theory also proposes that two concepts in the work environment, nurse staffing and employer support for nursing continuing professional development, influence nursing human capital. A cross-sectional design. A systematic three-step process was used to operationalize the concepts of the theory. In 2008, data were collected for 147 inpatient units from administrative departments and unit managers in 6 Canadian hospitals. Exploratory factor analyses were conducted to determine if the indicator variables accurately reflect their respective concepts. The proposed indicator variables collectively measured the nurse staffing concept. Three indicators were retained to construct nursing human capital: clinical expertise and experience concept. The nursing structural capital and employer support for nursing continuing professional development concepts were not validated empirically. The nurse staffing and the nursing human capital: clinical expertise and experience concepts will be brought forward for further model testing. Refinement for some of the indicator variables of the concepts is indicated. Additional research is required with different sources of data to confirm the findings. © 2012 Blackwell Publishing Ltd.

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

    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.)

  2. Technical Note: Development of a 3D printed subresolution sandwich phantom for validation of brain SPECT analysis

    Negus, Ian S.; Holmes, Robin B.; Thorne, Gareth C.; Saunders, Margaret; Jordan, Kirsty C.; Nash, David A.

    2016-01-01

    Purpose: To make an adaptable, head shaped radionuclide phantom to simulate molecular imaging of the brain using clinical acquisition and reconstruction protocols. This will allow the characterization and correction of scanner characteristics, and improve the accuracy of clinical image analysis, including the application of databases of normal subjects. Methods: A fused deposition modeling 3D printer was used to create a head shaped phantom made up of transaxial slabs, derived from a simulated MRI dataset. The attenuation of the printed polylactide (PLA), measured by means of the Hounsfield unit on CT scanning, was set to match that of the brain by adjusting the proportion of plastic filament and air (fill ratio). Transmission measurements were made to verify the attenuation of the printed slabs. The radionuclide distribution within the phantom was created by adding 99m Tc pertechnetate to the ink cartridge of a paper printer and printing images of gray and white matter anatomy, segmented from the same MRI data. The complete subresolution sandwich phantom was assembled from alternate 3D printed slabs and radioactive paper sheets, and then imaged on a dual headed gamma camera to simulate an HMPAO SPECT scan. Results: Reconstructions of phantom scans successfully used automated ellipse fitting to apply attenuation correction. This removed the variability inherent in manual application of attenuation correction and registration inherent in existing cylindrical phantom designs. The resulting images were assessed visually and by count profiles and found to be similar to those from an existing elliptical PMMA phantom. Conclusions: The authors have demonstrated the ability to create physically realistic HMPAO SPECT simulations using a novel head-shaped 3D printed subresolution sandwich method phantom. The phantom can be used to validate all neurological SPECT imaging applications. A simple modification of the phantom design to use thinner slabs would make it suitable for

  3. Technical Note: Development of a 3D printed subresolution sandwich phantom for validation of brain SPECT analysis

    Negus, Ian S.; Holmes, Robin B.; Thorne, Gareth C.; Saunders, Margaret [Department of Medical Physics and Bioengineering, University Hospitals Bristol NHS Foundation Trust, Bristol BS28HW (United Kingdom); Jordan, Kirsty C. [Department of Biomedical Engineering, University of Strathclyde, Glasgow G11XQ (United Kingdom); Nash, David A. [Department of Medical Physics, Portsmouth Hospitals NHS Trust, Portsmouth PO63LY (United Kingdom)

    2016-09-15

    Purpose: To make an adaptable, head shaped radionuclide phantom to simulate molecular imaging of the brain using clinical acquisition and reconstruction protocols. This will allow the characterization and correction of scanner characteristics, and improve the accuracy of clinical image analysis, including the application of databases of normal subjects. Methods: A fused deposition modeling 3D printer was used to create a head shaped phantom made up of transaxial slabs, derived from a simulated MRI dataset. The attenuation of the printed polylactide (PLA), measured by means of the Hounsfield unit on CT scanning, was set to match that of the brain by adjusting the proportion of plastic filament and air (fill ratio). Transmission measurements were made to verify the attenuation of the printed slabs. The radionuclide distribution within the phantom was created by adding {sup 99m}Tc pertechnetate to the ink cartridge of a paper printer and printing images of gray and white matter anatomy, segmented from the same MRI data. The complete subresolution sandwich phantom was assembled from alternate 3D printed slabs and radioactive paper sheets, and then imaged on a dual headed gamma camera to simulate an HMPAO SPECT scan. Results: Reconstructions of phantom scans successfully used automated ellipse fitting to apply attenuation correction. This removed the variability inherent in manual application of attenuation correction and registration inherent in existing cylindrical phantom designs. The resulting images were assessed visually and by count profiles and found to be similar to those from an existing elliptical PMMA phantom. Conclusions: The authors have demonstrated the ability to create physically realistic HMPAO SPECT simulations using a novel head-shaped 3D printed subresolution sandwich method phantom. The phantom can be used to validate all neurological SPECT imaging applications. A simple modification of the phantom design to use thinner slabs would make it suitable

  4. What should we mean by empirical validation in hypnotherapy: evidence-based practice in clinical hypnosis.

    Alladin, Assen; Sabatini, Linda; Amundson, Jon K

    2007-04-01

    This paper briefly surveys the trend of and controversy surrounding empirical validation in psychotherapy. Empirical validation of hypnotherapy has paralleled the practice of validation in psychotherapy and the professionalization of clinical psychology, in general. This evolution in determining what counts as evidence for bona fide clinical practice has gone from theory-driven clinical approaches in the 1960s and 1970s through critical attempts at categorization of empirically supported therapies in the 1990s on to the concept of evidence-based practice in 2006. Implications of this progression in professional psychology are discussed in the light of hypnosis's current quest for validation and empirical accreditation.

  5. Validation of Left Ventricular Ejection Fraction with the IQ•SPECT System in Small-Heart Patients.

    Yoneyama, Hiroto; Shibutani, Takayuki; Konishi, Takahiro; Mizutani, Asuka; Hashimoto, Ryosuke; Onoguchi, Masahisa; Okuda, Koichi; Matsuo, Shinro; Nakajima, Kenichi; Kinuya, Seigo

    2017-09-01

    The IQ•SPECT system, which is equipped with multifocal collimators ( SMART ZOOM) and uses ordered-subset conjugate gradient minimization as the reconstruction algorithm, reduces the acquisition time of myocardial perfusion imaging compared with conventional SPECT systems equipped with low-energy high-resolution collimators. We compared the IQ•SPECT system with a conventional SPECT system for estimating left ventricular ejection fraction (LVEF) in patients with a small heart (end-systolic volume IQ•SPECT. End-systolic volume, end-diastolic volume, and LVEF were calculated using quantitative gated SPECT (QGS) and cardioREPO software. We compared the LVEF from gated myocardial perfusion SPECT to that from echocardiographic measurements. Results: End-diastolic volume, end-systolic volume, and LVEF as obtained from conventional SPECT, IQ•SPECT, and echocardiography showed a good to excellent correlation regardless of whether they were calculated using QGS or using cardioREPO. Although LVEF calculated using QGS significantly differed between conventional SPECT and IQ•SPECT (65.4% ± 13.8% vs. 68.4% ± 15.2%) ( P = 0.0002), LVEF calculated using cardioREPO did not (69.5% ± 10.6% vs. 69.5% ± 11.0%). Likewise, although LVEF calculated using QGS significantly differed between conventional SPECT and IQ•SPECT (75.0 ± 9.6 vs. 79.5 ± 8.3) ( P = 0.0005), LVEF calculated using cardioREPO did not (72.3% ± 9.0% vs. 74.3% ± 8.3%). Conclusion: In small-heart patients, the difference in LVEF between IQ•SPECT and conventional SPECT was less when calculated using cardioREPO than when calculated using QGS. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  6. Automatic segmentation of myocardium at risk from contrast enhanced SSFP CMR: validation against expert readers and SPECT

    Tufvesson, Jane; Carlsson, Marcus; Aletras, Anthony H.; Engblom, Henrik; Deux, Jean-François; Koul, Sasha; Sörensson, Peder; Pernow, John; Atar, Dan; Erlinge, David; Arheden, Håkan; Heiberg, Einar

    2016-01-01

    Efficacy of reperfusion therapy can be assessed as myocardial salvage index (MSI) by determining the size of myocardium at risk (MaR) and myocardial infarction (MI), (MSI = 1-MI/MaR). Cardiovascular magnetic resonance (CMR) can be used to assess MI by late gadolinium enhancement (LGE) and MaR by either T2-weighted imaging or contrast enhanced SSFP (CE-SSFP). Automatic segmentation algorithms have been developed and validated for MI by LGE as well as for MaR by T2-weighted imaging. There are, however, no algorithms available for CE-SSFP. Therefore, the aim of this study was to develop and validate automatic segmentation of MaR in CE-SSFP. The automatic algorithm applies surface coil intensity correction and classifies myocardial intensities by Expectation Maximization to define a MaR region based on a priori regional criteria, and infarct region from LGE. Automatic segmentation was validated against manual delineation by expert readers in 183 patients with reperfused acute MI from two multi-center randomized clinical trials (RCT) (CHILL-MI and MITOCARE) and against myocardial perfusion SPECT in an additional set (n = 16). Endocardial and epicardial borders were manually delineated at end-diastole and end-systole. Manual delineation of MaR was used as reference and inter-observer variability was assessed for both manual delineation and automatic segmentation of MaR in a subset of patients (n = 15). MaR was expressed as percent of left ventricular mass (%LVM) and analyzed by bias (mean ± standard deviation). Regional agreement was analyzed by Dice Similarity Coefficient (DSC) (mean ± standard deviation). MaR assessed by manual and automatic segmentation were 36 ± 10 % and 37 ± 11 %LVM respectively with bias 1 ± 6 %LVM and regional agreement DSC 0.85 ± 0.08 (n = 183). MaR assessed by SPECT and CE-SSFP automatic segmentation were 27 ± 10 %LVM and 29 ± 7 %LVM respectively with bias 2 ± 7 %LVM. Inter-observer variability was 0 ± 3 %LVM for manual delineation and

  7. Regional cerebral blood flow (RCBF) measurements by SPECT analysis of Xenon-133 transit: Validation of technique and clinical correlation

    Rezai, K.; Kirchner, P.; Armstrong, C.; Ehrhardt, J.; Damasio, H.; Adams, H.; Damasio, A.

    1984-01-01

    The SPECT system (Tomomatic-64) developed by a previous study for rCBF measurements with Xe-133 was validated with phantom simulations and clinical studies. A bi-compartmental flow phantom was developed consisting of a Xenon-133 pump connected in series to head and lung compartments. Flow rates between 0.2 and 1.4 brain volumes/min (20-140 cc/100ml/min) were tested against Tomomatic measurements by linear regression. Correlation was excellent (r=1.0) in the range of 0.2-1.2 (20-120 cc/100ml/min), representing flow rates which are most likely to be encountered in clinical studies. Flow rates above 1.2 (120 cc/100 ml/min) were significantly underestimated. 32 studies on 20 volunteers gave a mean normal flow of 72 (SD=12) cc/ 100g/min. Mean regional flow ranged from 62 in frontal lobes to 75 in central gray matter. Right-to-left variation was less than 5%. The lowest regional flow in a normal subject was 45 cc/100g/min. 68 studies were performed on 30 stroke patients. In 27 rCBF was less than 45 in affected brain areas for a sensitivity of 90% which improved to 97% when comparisons with contralateral brain were included. Initial CT scans were normal or non-diagnostic in 10, but showed CVA's in regions of reduced rCBF in 17 patients. rCBF abnormalities involved greater portions of brain than CT changes, often (8/17) including distant regions, unpredicted by CT or clinical studies but known to be strongly interconnected to the area of structural damage. SPECT estimates of rCBF appear to be a sensitive research and diagnostic tool and complement the structural information provided by CT

  8. Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and 99mTc-tetrofosmin: Method and validation.

    Shrestha, Uttam; Sciammarella, Maria; Alhassen, Fares; Yeghiazarians, Yerem; Ellin, Justin; Verdin, Emily; Boyle, Andrew; Seo, Youngho; Botvinick, Elias H; Gullberg, Grant T

    2017-02-01

    The objective of this study was to measure myocardial blood flow (MBF) in humans using 99m Tc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT). Dynamic SPECT using 99m Tc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients were used to determine the flow-extraction curve for 99m Tc-tefrofosmin while data from the remaining 7 patients were used for method validation. The nonlinear tracer correction parameters A and B for 99m Tc-tefrofosmin were estimated for the 9 patients by fitting the flow-extraction curve [Formula: see text] for K 1 values estimated with 99m Tc-tefrofosmin using SPECT and MBF values estimated with 13 N-NH 3 using PET. These parameters were then used to calculate MBF and coronary flow reserve (CFR) in three coronary territories (LAD, RCA, and LCX) using SPECT for an independent cohort of 7 patients. The results were then compared with that estimated with 13 N-NH 3 PET. The flow-dependent permeability surface-area product (PS) for 99m Tc-tefrofosmin was also estimated. The estimated flow-extraction parameters for 99m Tc-tefrofosmin were found to be A = 0.91 ± 0.11, B = 0.34 ± 0.20 (R 2  = 0.49). The range of MBF in LAD, RCA, and LCX was 0.44-3.81 mL/min/g. The MBF between PET and SPECT in the group of independent cohort of 7 patients showed statistically significant correlation, r = 0.71 (P < .001). However, the corresponding CFR correlation was moderate r = 0.39 yet statistically significant (P = .037). The PS for 99m Tc-tefrofosmin was (0.019 ± 0.10)*MBF + (0.32 ± 0.16). Dynamic cardiac SPECT using 99m Tc-tetrofosmin and a clinical two-headed SPECT/CT scanner can be a useful tool for estimation of MBF.

  9. Empirical Validation and Application of the Computing Attitudes Survey

    Dorn, Brian; Elliott Tew, Allison

    2015-01-01

    Student attitudes play an important role in shaping learning experiences. However, few validated instruments exist for measuring student attitude development in a discipline-specific way. In this paper, we present the design, development, and validation of the computing attitudes survey (CAS). The CAS is an extension of the Colorado Learning…

  10. Quantification of left ventricular regional functions using ECG-gated myocardial perfusion SPECT. Validation of left ventricular systolic functions

    Yamamoto, Akira; Takahashi, Naoto; Iwahara, Shin-ichiro; Munakata, Kazuo; Hosoya, Tetsuo

    2006-01-01

    We have developed a program to quantify regional left ventricular (LV) function and wall motion synchrony using electrocardiogram (ECG)-gated myocardial perfusion SPECT (MPS). This preliminary study was undertaken to validate the use of this program for estimating regional LV systolic function. Patients were subjected to MPS by 99m Tc-sestamibi at rest. The study included 20 patients who were confirmed to have a low probability of coronary artery disease (LPG; low probability group), 19 heart disease patients who were examined by MPS and equilibrium radionuclide angiography (ERNA) (ERG; ERNA group), and 24 patients who were examined by MPS and 2-dimensional echocardiography (2DE) (2DEG; 2DE group). The values of the ejection fraction (EF) and peak ejection rate (PER) were estimated. The global functions evaluated by this program were compared with those obtained by ERNA in the ERG. For regional assessment, the reference values of the functional indices were obtained for 17 LV segments in LPG. The Z score, (reference average value of the segment-patient's value of the segment)/reference standard deviation of the segment, was used for the evaluation of regional functions; a score equal to or greater than 2 was defined as abnormal. Semiquantitative visual interpretation of 2DE was used as the standard to assess wall motion. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these criteria and the relationship between 2DE grading and Z scoring were validated in 2DEG. The values of the global EF and PER evaluated by this program correlated with those determined by ERNA (r=0.76 and 0.58, respectively; p -10 ). The potential of this program to quantify the regional systolic function was validated. (author)

  11. Empirical Validation of Building Simulation Software : Modeling of Double Facades

    Kalyanova, Olena; Heiselberg, Per

    The work described in this report is the result of a collaborative effort of members of the International Energy Agency (IEA), Task 34/43: Testing and validation of building energy simulation tools experts group.......The work described in this report is the result of a collaborative effort of members of the International Energy Agency (IEA), Task 34/43: Testing and validation of building energy simulation tools experts group....

  12. Prognostic validation of a 17-segment score derived from a 20-segment score for myocardial perfusion SPECT interpretation.

    Berman, Daniel S; Abidov, Aiden; Kang, Xingping; Hayes, Sean W; Friedman, John D; Sciammarella, Maria G; Cohen, Ishac; Gerlach, James; Waechter, Parker B; Germano, Guido; Hachamovitch, Rory

    2004-01-01

    Recently, a 17-segment model of the left ventricle has been recommended as an optimally weighted approach for interpreting myocardial perfusion single photon emission computed tomography (SPECT). Methods to convert databases from previous 20- to new 17-segment data and criteria for abnormality for the 17-segment scores are needed. Initially, for derivation of the conversion algorithm, 65 patients were studied (algorithm population) (pilot group, n = 28; validation group, n = 37). Three conversion algorithms were derived: algorithm 1, which used mid, distal, and apical scores; algorithm 2, which used distal and apical scores alone; and algorithm 3, which used maximal scores of the distal septal, lateral, and apical segments in the 20-segment model for 3 corresponding segments of the 17-segment model. The prognosis population comprised 16,020 consecutive patients (mean age, 65 +/- 12 years; 41% women) who had exercise or vasodilator stress technetium 99m sestamibi myocardial perfusion SPECT and were followed up for 2.1 +/- 0.8 years. In this population, 17-segment scores were derived from 20-segment scores by use of algorithm 2, which demonstrated the best agreement with expert 17-segment reading in the algorithm population. The prognostic value of the 20- and 17-segment scores was compared by converting the respective summed scores into percent myocardium abnormal. Conversion algorithm 2 was found to be highly concordant with expert visual analysis by the 17-segment model (r = 0.982; kappa = 0.866) in the algorithm population. In the prognosis population, 456 cardiac deaths occurred during follow-up. When the conversion algorithm was applied, extent and severity of perfusion defects were nearly identical by 20- and derived 17-segment scores. The receiver operating characteristic curve areas by 20- and 17-segment perfusion scores were identical for predicting cardiac death (both 0.77 +/- 0.02, P = not significant). The optimal prognostic cutoff value for either 20

  13. Ecological Validity in Eye-Tracking: An Empirical Study

    Spinner, Patti; Gass, Susan M.; Behney, Jennifer

    2013-01-01

    Eye-trackers are becoming increasingly widespread as a tool to investigate second language (L2) acquisition. Unfortunately, clear standards for methodology--including font size, font type, and placement of interest areas--are not yet available. Although many researchers stress the need for ecological validity--that is, the simulation of natural…

  14. The Content Validity of Juvenile Psychopathy: An Empirical Examination

    Lynam, Donald R.; Derefinko, Karen J.; Caspi, Avshalom; Loeber, Rolf; Stouthamer-Loeber, Magda

    2007-01-01

    This study examined the content validity of a juvenile psychopathy measure, the Childhood Psychopathy Scale (CPS; D. R. Lynam, 1997), based on a downward translation of an adult instrument, the Hare Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991). The CPS was compared with two other indices of juvenile psychopathy: (a) an index derived…

  15. Empirical flow parameters : a tool for hydraulic model validity

    Asquith, William H.; Burley, Thomas E.; Cleveland, Theodore G.

    2013-01-01

    The objectives of this project were (1) To determine and present from existing data in Texas, relations between observed stream flow, topographic slope, mean section velocity, and other hydraulic factors, to produce charts such as Figure 1 and to produce empirical distributions of the various flow parameters to provide a methodology to "check if model results are way off!"; (2) To produce a statistical regional tool to estimate mean velocity or other selected parameters for storm flows or other conditional discharges at ungauged locations (most bridge crossings) in Texas to provide a secondary way to compare such values to a conventional hydraulic modeling approach. (3.) To present ancillary values such as Froude number, stream power, Rosgen channel classification, sinuosity, and other selected characteristics (readily determinable from existing data) to provide additional information to engineers concerned with the hydraulic-soil-foundation component of transportation infrastructure.

  16. Brain SPECT

    Feistel, H.

    1991-01-01

    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) [de

  17. Performance support system in higher engineering education - introduction and empirical validation

    Stoyanov, S.; Stoyanov, Slavi; Kommers, Petrus A.M.; Bastiaens, T.J.; Martinez Mediano, Catalina

    2008-01-01

    The paper defines and empirically validates the concept of performance support system in higher engineering education. The validation of the concept is based upon two studies: a pilot and an experiment, on the effect of performance support system on achievements and attitudes of students. The

  18. Portuguese validation of the Internet Addiction Test: An empirical study.

    Pontes, Halley M; Patrão, Ivone M; Griffiths, Mark D

    2014-06-01

    Research into Internet addiction (IA) has increased greatly over the last decade. Despite its various definitions and general lack of consensus regarding its conceptualisation amongst researchers, instruments for measuring this phenomenon have proliferated in a number of countries. There has been little research on IA in Portugal and this may be partly due to the absence of standardised measurement tools for assessing IA. This study attempted to address this issue by adapting a Portuguese version of the Internet Addiction Test (IAT) via a translation-back translation process and Confirmatory Factor Analysis in a sample of 593 Portuguese students that completed a Portuguese version of the IAT along with questions related to socio-demographic variables. The findings suggested that the IAT appears to be a valid and reliable instrument for measuring IA among Portuguese young adults as demonstrated by its satisfactory psychometric properties. However, the present findings also suggest the need to reword and update some of the IAT's items. Prevalence of IA found in the sample was 1.2% and is discussed alongside findings relating to socio-demographic correlates. Limitations and implications of the present study are also discussed. The present study calls for a reflection of the IAT while also contributing to a better understanding of the basic aspects of IA in the Portuguese community since many health practitioners are starting to realise that Internet use may pose a risk for some individuals.

  19. 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.

    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 <7%) and reproducible (interobserver concordance 0.99). For eight treatments, in cases of complex hepatic vascularization, the hepatic volumes based on angiography and CT led to a relative overestimation or underestimation of the vascularized hepatic volume by 43.2 ± 32.7% (5-87%) compared with SPECT/CT analyses. The vascularized liver volume taken into account calculated from SPECT/CT 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.

  20. Development and empirical validation of symmetric component measures of multidimensional constructs: customer and competitor orientation.

    Sørensen, Hans Eibe; Slater, Stanley F

    2008-08-01

    Atheoretical measure purification may lead to construct deficient measures. The purpose of this paper is to provide a theoretically driven procedure for the development and empirical validation of symmetric component measures of multidimensional constructs. Particular emphasis is placed on establishing a formalized three-step procedure for achieving a posteriori content validity. Then the procedure is applied to development and empirical validation of two symmetrical component measures of market orientation, customer orientation and competitor orientation. Analysis suggests that average variance extracted is particularly critical to reliability in the respecification of multi-indicator measures. In relation to this, the results also identify possible deficiencies in using Cronbach alpha for establishing reliable and valid measures.

  1. Validity of in vivo [123I]beta-CIT SPECT in detecting MDMA-induced neurotoxicity in rats

    de Win, Maartje M. L.; de Jeu, Rogier A. M.; de Bruin, Kora; Habraken, Jan B. A.; Reneman, Liesbeth; Booij, Jan; den Heeten, Gerard J.

    2004-01-01

    This study investigated the ability of a high-resolution pinhole single-photon emission computed tomography (SPECT) system, with [(123)I]beta-CIT as a radiotracer, to detect 3,4-methelenedioxymethamphetamine (MDMA, 'Ecstasy')-induced loss of serotonin transporters (SERTs) in the living rat brain. In

  2. Old wine in new bottles: validating the clinical utility of SPECT in predicting cognitive performance in mild traumatic brain injury.

    Romero, Kristoffer; Lobaugh, Nancy J; Black, Sandra E; Ehrlich, Lisa; Feinstein, Anthony

    2015-01-30

    The neural underpinnings of cognitive dysfunction in mild traumatic brain injury (TBI) are not fully understood. Consequently, patient prognosis using existing clinical imaging is somewhat imprecise. Single photon emission computed tomography (SPECT) is a frequently employed investigation in this population, notwithstanding uncertainty over the clinical utility of the data obtained. In this study, subjects with mild TBI underwent (99m)Tc-ECD SPECT scanning, and were administered a brief battery of cognitive tests and self-report symptom scales of concussion and emotional distress. Testing took place 2 weeks (n=84) and 1 year (n=49) post-injury. Multivariate analysis (i.e., partial least squares analysis) revealed that frontal perfusion in right superior frontal and middle frontal gyri predicted poorer performance on the Stroop test, an index of executive function, both at initial and follow-up testing. Conversely, SPECT scans categorized as normal or abnormal by radiologists did not differentiate cognitively impaired from intact subjects. These results demonstrate the clinical utility of SPECT in mild TBI, but only when data are subjected to blood flow quantification analysis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  3. A Proposed Methodology for the Conceptualization, Operationalization, and Empirical Validation of the Concept of Information Need

    Afzal, Waseem

    2017-01-01

    Introduction: The purpose of this paper is to propose a methodology to conceptualize, operationalize, and empirically validate the concept of information need. Method: The proposed methodology makes use of both qualitative and quantitative perspectives, and includes a broad array of approaches such as literature reviews, expert opinions, focus…

  4. Development and empirical validation of symmetric component measures of multi-dimensional constructs

    Sørensen, Hans Eibe; Slater, Stanley F.

    2008-01-01

    Atheoretical measure purification may lead to construct deficient measures. The purpose of this paper is to provide a theoretically driven procedure for the development and empirical validation of symmetric component measures of multi-dimensional constructs. We place particular emphasis on establ...

  5. An Empirical Validation of Building Simulation Software for Modelling of Double-Skin Facade (DSF)

    Larsen, Olena Kalyanova; Heiselberg, Per; Felsmann, Clemens

    2009-01-01

    buildings, but their accuracy might be limited in cases with DSFs because of the complexity of the heat and mass transfer processes within the DSF. To address this problem, an empirical validation of building models with DSF, performed with various building simulation tools (ESP-r, IDA ICE 3.0, VA114......Double-skin facade (DSF) buildings are being built as an attractive, innovative and energy efficient solution. Nowadays, several design tools are used for assessment of thermal and energy performance of DSF buildings. Existing design tools are well-suited for performance assessment of conventional......, TRNSYS-TUD and BSim) was carried out in the framework of IEA SHC Task 34 /ECBCS Annex 43 "Testing and Validation of Building Energy Simulation Tools". The experimental data for the validation was gathered in a full-scale outdoor test facility. The empirical data sets comprise the key-functioning modes...

  6. Validation of Multilevel Constructs: Validation Methods and Empirical Findings for the EDI

    Forer, Barry; Zumbo, Bruno D.

    2011-01-01

    The purposes of this paper are to highlight the foundations of multilevel construct validation, describe two methodological approaches and associated analytic techniques, and then apply these approaches and techniques to the multilevel construct validation of a widely-used school readiness measure called the Early Development Instrument (EDI;…

  7. Empirical validation of a real options theory based method for optimizing evacuation decisions within chemical plants.

    Reniers, G L L; Audenaert, A; Pauwels, N; Soudan, K

    2011-02-15

    This article empirically assesses and validates a methodology to make evacuation decisions in case of major fire accidents in chemical clusters. In this paper, a number of empirical results are presented, processed and discussed with respect to the implications and management of evacuation decisions in chemical companies. It has been shown in this article that in realistic industrial settings, suboptimal interventions may result in case the prospect to obtain additional information at later stages of the decision process is ignored. Empirical results also show that implications of interventions, as well as the required time and workforce to complete particular shutdown activities, may be very different from one company to another. Therefore, to be optimal from an economic viewpoint, it is essential that precautionary evacuation decisions are tailor-made per company. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. A New Statistical Method to Determine the Degree of Validity of Health Economic Model Outcomes against Empirical Data.

    Corro Ramos, Isaac; van Voorn, George A K; Vemer, Pepijn; Feenstra, Talitha L; Al, Maiwenn J

    2017-01-01

    The validation of health economic (HE) model outcomes against empirical data is of key importance. Although statistical testing seems applicable, guidelines for the validation of HE models lack guidance on statistical validation, and actual validation efforts often present subjective judgment of

  9. Empirical model development and validation with dynamic learning in the recurrent multilayer perception

    Parlos, A.G.; Chong, K.T.; Atiya, A.F.

    1994-01-01

    A nonlinear multivariable empirical model is developed for a U-tube steam generator using the recurrent multilayer perceptron network as the underlying model structure. The recurrent multilayer perceptron is a dynamic neural network, very effective in the input-output modeling of complex process systems. A dynamic gradient descent learning algorithm is used to train the recurrent multilayer perceptron, resulting in an order of magnitude improvement in convergence speed over static learning algorithms. In developing the U-tube steam generator empirical model, the effects of actuator, process,and sensor noise on the training and testing sets are investigated. Learning and prediction both appear very effective, despite the presence of training and testing set noise, respectively. The recurrent multilayer perceptron appears to learn the deterministic part of a stochastic training set, and it predicts approximately a moving average response. Extensive model validation studies indicate that the empirical model can substantially generalize (extrapolate), though online learning becomes necessary for tracking transients significantly different than the ones included in the training set and slowly varying U-tube steam generator dynamics. In view of the satisfactory modeling accuracy and the associated short development time, neural networks based empirical models in some cases appear to provide a serious alternative to first principles models. Caution, however, must be exercised because extensive on-line validation of these models is still warranted

  10. Empirical Performance of Cross-Validation With Oracle Methods in a Genomics Context.

    Martinez, Josue G; Carroll, Raymond J; Müller, Samuel; Sampson, Joshua N; Chatterjee, Nilanjan

    2011-11-01

    When employing model selection methods with oracle properties such as the smoothly clipped absolute deviation (SCAD) and the Adaptive Lasso, it is typical to estimate the smoothing parameter by m-fold cross-validation, for example, m = 10. In problems where the true regression function is sparse and the signals large, such cross-validation typically works well. However, in regression modeling of genomic studies involving Single Nucleotide Polymorphisms (SNP), the true regression functions, while thought to be sparse, do not have large signals. We demonstrate empirically that in such problems, the number of selected variables using SCAD and the Adaptive Lasso, with 10-fold cross-validation, is a random variable that has considerable and surprising variation. Similar remarks apply to non-oracle methods such as the Lasso. Our study strongly questions the suitability of performing only a single run of m-fold cross-validation with any oracle method, and not just the SCAD and Adaptive Lasso.

  11. Empirical Validation of a Thermal Model of a Complex Roof Including Phase Change Materials

    Stéphane Guichard

    2015-12-01

    Full Text Available This paper deals with the empirical validation of a building thermal model of a complex roof including a phase change material (PCM. A mathematical model dedicated to PCMs based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase the understanding of the thermal behavior of the whole building with PCM technologies. In order to empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model has been identified for optimization. The use of the generic optimization program called GenOpt® coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt® and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons of the thermal predictions with measurements are found to be acceptable and are presented.

  12. An Automated Defect Prediction Framework using Genetic Algorithms: A Validation of Empirical Studies

    Juan Murillo-Morera

    2016-05-01

    Full Text Available Today, it is common for software projects to collect measurement data through development processes. With these data, defect prediction software can try to estimate the defect proneness of a software module, with the objective of assisting and guiding software practitioners. With timely and accurate defect predictions, practitioners can focus their limited testing resources on higher risk areas. This paper reports the results of three empirical studies that uses an automated genetic defect prediction framework. This framework generates and compares different learning schemes (preprocessing + attribute selection + learning algorithms and selects the best one using a genetic algorithm, with the objective to estimate the defect proneness of a software module. The first empirical study is a performance comparison of our framework with the most important framework of the literature. The second empirical study is a performance and runtime comparison between our framework and an exhaustive framework. The third empirical study is a sensitivity analysis. The last empirical study, is our main contribution in this paper. Performance of the software development defect prediction models (using AUC, Area Under the Curve was validated using NASA-MDP and PROMISE data sets. Seventeen data sets from NASA-MDP (13 and PROMISE (4 projects were analyzed running a NxM-fold cross-validation. A genetic algorithm was used to select the components of the learning schemes automatically, and to assess and report the results. Our results reported similar performance between frameworks. Our framework reported better runtime than exhaustive framework. Finally, we reported the best configuration according to sensitivity analysis.

  13. Simulation of a multi-detector gamma camera for validation protocols of quantification the activity from SPECT images

    Lozano Sanchez, A.; Calderon Marin, C.; Gonzalez Gonzalez, J.

    2015-01-01

    The main sources that decreasing accuracy in the estimation of internal absorbed dose has been identified in the methods for the quantification of cumulated activity from scintigraphic imaging, likes the corrections required by the physical and instrumental phenomena related to the formation of those images. The results of the simulation of a dual detector gamma camera E.cam SIEMENS using the Monte Carlo code SIMIND to obtain tomographic SPECT projections are presented here. SIMIND will allow dealing with the contribution of physical interactions and instrumental effects during simulations. Energy resolution, spatial resolution and sensitivity planar were determined with real and simulated systems. The relative differences did not exceed 10%. Energy spectra simulated under different conditions (source in air and water) with the inclusion of interactions in the collimator and phantom were compared. The tomographic sensitivity of a volumetric phantom containing radioactive solutions of 99m Tc and 131 I were determined from real and simulated SPECT images. Two processing protocols were considered: with scatter correction ( 99m Tc dual energy window method and 131 I were calculated after corrections. The results, expressed in terms of the differences relative to the well-know activity value in the phantom inserts improves when attenuation and scattering corrections are applied, obtaining good agreement between the results for real and simulated systems. (Author)

  14. Measuring stakeholder participation in evaluation: an empirical validation of the Participatory Evaluation Measurement Instrument (PEMI).

    Daigneault, Pierre-Marc; Jacob, Steve; Tremblay, Joël

    2012-08-01

    Stakeholder participation is an important trend in the field of program evaluation. Although a few measurement instruments have been proposed, they either have not been empirically validated or do not cover the full content of the concept. This study consists of a first empirical validation of a measurement instrument that fully covers the content of participation, namely the Participatory Evaluation Measurement Instrument (PEMI). It specifically examines (1) the intercoder reliability of scores derived by two research assistants on published evaluation cases; (2) the convergence between the scores of coders and those of key respondents (i.e., authors); and (3) the convergence between the authors' scores on the PEMI and the Evaluation Involvement Scale (EIS). A purposive sample of 40 cases drawn from the evaluation literature was used to assess reliability. One author per case in this sample was then invited to participate in a survey; 25 fully usable questionnaires were received. Stakeholder participation was measured on nominal and ordinal scales. Cohen's κ, the intraclass correlation coefficient, and Spearman's ρ were used to assess reliability and convergence. Reliability results ranged from fair to excellent. Convergence between coders' and authors' scores ranged from poor to good. Scores derived from the PEMI and the EIS were moderately associated. Evidence from this study is strong in the case of intercoder reliability and ranges from weak to strong in the case of convergent validation. Globally, this suggests that the PEMI can produce scores that are both reliable and valid.

  15. U-tube steam generator empirical model development and validation using neural networks

    Parlos, A.G.; Chong, K.T.; Atiya, A.

    1992-01-01

    Empirical modeling techniques that use model structures motivated from neural networks research have proven effective in identifying complex process dynamics. A recurrent multilayer perception (RMLP) network was developed as a nonlinear state-space model structure along with a static learning algorithm for estimating the parameter associated with it. The methods developed were demonstrated by identifying two submodels of a U-tube steam generator (UTSG), each valid around an operating power level. A significant drawback of this approach is the long off-line training times required for the development of even a simplified model of a UTSG. Subsequently, a dynamic gradient descent-based learning algorithm was developed as an accelerated alternative to train an RMLP network for use in empirical modeling of power plants. The two main advantages of this learning algorithm are its ability to consider past error gradient information for future use and the two forward passes associated with its implementation. The enhanced learning capabilities provided by the dynamic gradient descent-based learning algorithm were demonstrated via the case study of a simple steam boiler power plant. In this paper, the dynamic gradient descent-based learning algorithm is used for the development and validation of a complete UTSG empirical model

  16. Measurement of absolute myocardial blood flow in humans using dynamic cardiac SPECT and99mTc-tetrofosmin: Method and validation

    Shrestha, U; Sciammarella, M; Alhassen, F; Yeghiazarians, Y; Ellin, J; Verdin, E; Boyle, A; Seo, Y; Botvinick, EH; Gullberg, GT

    2017-01-01

    © 2015, American Society of Nuclear Cardiology. Background: The objective of this study was to measure myocardial blood flow (MBF) in humans using 99m Tc-tetrofosmin and dynamic single-photon emission computed tomography (SPECT). Methods: Dynamic SPECT using 99m Tc-tetrofosmin and dynamic positron emission tomography (PET) was performed on a group of 16 patients. The SPECT data were reconstructed using a 4D-spatiotemporal iterative reconstruction method. The data corresponding to 9 patients w...

  17. Empirical validation of the New Zealand serious non-fatal injury outcome indicator for 'all injury'

    Cryer, Colin; Davie, Gabrielle S; Gulliver, Pauline J

    2018-01-01

    Our purpose was to empirically validate the official New Zealand (NZ) serious non-fatal 'all injury' indicator. To that end, we aimed to investigate the assumption that cases selected by the indicator have a high probability of admission. Using NZ hospital in-patient records, we identified serious...... injury diagnoses were calculated and inference made to New Zealand. The admission probabilities were 0.82, 0.89 and 0.90 for the regions of Canada, Denmark and Greece, respectively. This work provides evidence that the threshold set for the official New Zealand serious non-fatal injury indicator for 'all...

  18. Measuring SSRI occupancy of SERT using the novel tracer [{sup 123}I]ADAM: a SPECT validation study

    Erlandsson, Kjell; Lui, Dominic; Townsend, Caroline E.; Ell, Peter J. [Middlesex Hospital, Institute of Nuclear Medicine, University College London, London (United Kingdom); Sivananthan, Tharani; Mu, Song; Lucas, Richard [Lilly Research Centre, Eli Lilly and Company, Windlesham, Surrey (United Kingdom); Spezzi, Andrea; Warrington, Steven [Central Middlesex Hospital, Hammersmith Medicines Research, London (United Kingdom)

    2005-11-01

    Serotonergic brain regions play a crucial role in the modulation of emotion, and serotonergic dysfunction may contribute to several neurological disorders. [{sup 123}I]ADAM is a novel SPECT tracer which binds with high affinity to serotonin transporters (SERT). The objective of this study was to compare different methods for the quantification of tracer binding and to develop a simplified single-scan protocol for this tracer, as well as to investigate its potential for characterisation of the transporter occupancy versus plasma concentration curve of a selective serotonin re-uptake inhibitor (SSRI). Dynamic SPECT scans were performed on 16 healthy volunteers after administration of {proportional_to}150 MBq [{sup 123}I]ADAM. Data were acquired from the time of injection until {proportional_to}5.5 h after injection in 30- or 45-min sessions. Each subject was scanned twice: with and without pre-treatment with the SSRI citalopram in various dosage regimens. The plasma concentration of citalopram (C{sub p}) was determined from venous samples. Images were reconstructed by filtered back-projection with scatter and attenuation correction. Tracer binding was quantified for midbrain, striatum and thalamus using cerebellum as a reference region. Quantification was done by kinetic modelling, graphical analysis and multi-linear regression, as well as by the ratio method, with binding potential (BP{sub 2}) as the outcome measure. The SERT occupancy by citalopram was determined relative to the baseline scan for each subject, and the occupancy versus C{sub p} curve was fitted with the E{sub max} model. The highest binding of [{sup 123}I]ADAM was in midbrain (mean baseline BP{sub 2}{+-}SD=1.31{+-}0.29), with lower binding in thalamus (0.79{+-}0.16) and striatum (0.66{+-}0.13). There was good agreement between BP{sub 2} values obtained by different quantification methods. Using the ratio method, the best agreement with kinetic modelling was obtained with data from the time interval

  19. Measuring SSRI occupancy of SERT using the novel tracer [123I]ADAM: a SPECT validation study

    Erlandsson, Kjell; Lui, Dominic; Townsend, Caroline E.; Ell, Peter J.; Sivananthan, Tharani; Mu, Song; Lucas, Richard; Spezzi, Andrea; Warrington, Steven

    2005-01-01

    Serotonergic brain regions play a crucial role in the modulation of emotion, and serotonergic dysfunction may contribute to several neurological disorders. [ 123 I]ADAM is a novel SPECT tracer which binds with high affinity to serotonin transporters (SERT). The objective of this study was to compare different methods for the quantification of tracer binding and to develop a simplified single-scan protocol for this tracer, as well as to investigate its potential for characterisation of the transporter occupancy versus plasma concentration curve of a selective serotonin re-uptake inhibitor (SSRI). Dynamic SPECT scans were performed on 16 healthy volunteers after administration of ∝150 MBq [ 123 I]ADAM. Data were acquired from the time of injection until ∝5.5 h after injection in 30- or 45-min sessions. Each subject was scanned twice: with and without pre-treatment with the SSRI citalopram in various dosage regimens. The plasma concentration of citalopram (C p ) was determined from venous samples. Images were reconstructed by filtered back-projection with scatter and attenuation correction. Tracer binding was quantified for midbrain, striatum and thalamus using cerebellum as a reference region. Quantification was done by kinetic modelling, graphical analysis and multi-linear regression, as well as by the ratio method, with binding potential (BP 2 ) as the outcome measure. The SERT occupancy by citalopram was determined relative to the baseline scan for each subject, and the occupancy versus C p curve was fitted with the E max model. The highest binding of [ 123 I]ADAM was in midbrain (mean baseline BP 2 ±SD=1.31±0.29), with lower binding in thalamus (0.79±0.16) and striatum (0.66±0.13). There was good agreement between BP 2 values obtained by different quantification methods. Using the ratio method, the best agreement with kinetic modelling was obtained with data from the time interval [200,260] min after injection. The fitting of the midbrain occupancy curve

  20. Clinical assessment of hepatic functional reserve using 99mTc DTPA galactosyl human serum albumin SPECT to prognosticate chronic hepatic diseases. Validation of the use of SPECT and a new indicator

    Onodera, Yuya; Tamaki, Nagara; Miyasaka, Kazuo; Takahashi, Kazuei; Sugai, Yukio; Togashi, Tadashi

    2003-01-01

    It is generally known that scintigraphy of 99m Tc diethylenetriamine pentaacetic acid-galactosyl human serum albumin ( 99m Tc-GSA) is useful for assessing hepatic functional reserve. For hepatic functional indicators, the index of the calculated planar image has been used in previous studies. However, there have been few reports that suggest that the indicators calculated from static SPECT data would be useful for the assessment of hepatic function. The aims of this study were to establish a simple method for assessing hepatic functional reserve using the liver SPECT of 99m Tc-GSA and to apply this method for rich stratification in patients with chronic hepatic diseases. A liver phantom (a 50% concentration of 99m Tc solution) was used to compare the planar and SPECT methods. According to the definition of the new indicator, the liver SPECT of 99m Tc-GSA was divided by a syringe SPECT of 99m Tc-GSA and was called the liver uptake ratio (LUR). We correlated the LUR and the liver uptake ratio calculated according to the blood-sampling method. 99m Tc-GSA SPECT was performed in 137 patients with hepatic diseases, including chronic hepatic diseases, and 20 healthy volunteers. The LUR was correlated between the formed subtypes for all subjects. The acquired phantom-count ratio calculated by the SPECT method was more accurate than that acquired by the planar method. A good correlation was obtained between the LUR and the blood-sampling method (r=0.971). The LUR was significantly lower in subjects with severe cirrhosis than in healthy subjects or those with chronic hepatitis and mild cirrhosis, and it was significantly lower in subjects with chronic hepatitis and mild cirrhosis than in healthy subjects. The LUR was significantly correlated with other hepatic function tests. Based on LUR, the chronic hepatic diseases were divided into two groups: Group A, with LURs 30% and higher, and Group B, with LURs below 30%. An LUR of 30% marked the 25th percentile of the mild

  1. Proposed Core Competencies and Empirical Validation Procedure in Competency Modeling: Confirmation and Classification.

    Baczyńska, Anna K; Rowiński, Tomasz; Cybis, Natalia

    2016-01-01

    Competency models provide insight into key skills which are common to many positions in an organization. Moreover, there is a range of competencies that is used by many companies. Researchers have developed core competency terminology to underline their cross-organizational value. The article presents a theoretical model of core competencies consisting of two main higher-order competencies called performance and entrepreneurship. Each of them consists of three elements: the performance competency includes cooperation, organization of work and goal orientation, while entrepreneurship includes innovativeness, calculated risk-taking and pro-activeness. However, there is lack of empirical validation of competency concepts in organizations and this would seem crucial for obtaining reliable results from organizational research. We propose a two-step empirical validation procedure: (1) confirmation factor analysis, and (2) classification of employees. The sample consisted of 636 respondents (M = 44.5; SD = 15.1). Participants were administered a questionnaire developed for the study purpose. The reliability, measured by Cronbach's alpha, ranged from 0.60 to 0.83 for six scales. Next, we tested the model using a confirmatory factor analysis. The two separate, single models of performance and entrepreneurial orientations fit quite well to the data, while a complex model based on the two single concepts needs further research. In the classification of employees based on the two higher order competencies we obtained four main groups of employees. Their profiles relate to those found in the literature, including so-called niche finders and top performers. Some proposal for organizations is discussed.

  2. Empirical validation of the English version of the Fear of Cancer Recurrence Inventory.

    Lebel, Sophie; Simard, Sebastien; Harris, Cheryl; Feldstain, Andrea; Beattie, Sara; McCallum, Megan; Lefebvre, Monique; Savard, Josée; Devins, Gerald M

    2016-02-01

    Cancer patients report that help in managing fear of cancer recurrence (FCR) is one of their greatest unmet needs. Research on FCR has been limited by the very few validated, multi-dimensional measures of this construct. One exception is the Fear of Cancer Recurrence Inventory (FCRI), originally developed and empirically validated in French. The present study validated the English version of the FCRI. The FCRI was translated into English using a forward-backward translation procedure and pilot-tested with 17 English-speaking cancer patients. Cross-cultural equivalency of the French and English versions was established by administering both forms to 42 bilingual cancer patients. Last, 350 English-speaking breast, colon, prostate, or lung cancer patients were asked to complete the FCRI. A subsample (n = 135) was mailed the FCRI again one month later to evaluate test-retest reliability. The English translation of the FCRI was well accepted by participants. There was no item-bias when comparing bilingual participants' answers on both versions. A confirmatory factor analysis supported the hypothesized seven-factor structure. The English version has high internal consistency (α = .96 for the total scale and .71-.94 for the subscales) and test-retest reliability (r = .88 for the total scale and 56-.87 for the subscales). The English version of the FCRI is a reliable and valid measure of FCR applicable to breast, colon, prostate, and lung cancer patients. Its multi-dimensional nature makes it an attractive research and clinical tool to further our knowledge of FCR.

  3. A New Statistical Method to Determine the Degree of Validity of Health Economic Model Outcomes against Empirical Data.

    Corro Ramos, Isaac; van Voorn, George A K; Vemer, Pepijn; Feenstra, Talitha L; Al, Maiwenn J

    2017-09-01

    The validation of health economic (HE) model outcomes against empirical data is of key importance. Although statistical testing seems applicable, guidelines for the validation of HE models lack guidance on statistical validation, and actual validation efforts often present subjective judgment of graphs and point estimates. To discuss the applicability of existing validation techniques and to present a new method for quantifying the degrees of validity statistically, which is useful for decision makers. A new Bayesian method is proposed to determine how well HE model outcomes compare with empirical data. Validity is based on a pre-established accuracy interval in which the model outcomes should fall. The method uses the outcomes of a probabilistic sensitivity analysis and results in a posterior distribution around the probability that HE model outcomes can be regarded as valid. We use a published diabetes model (Modelling Integrated Care for Diabetes based on Observational data) to validate the outcome "number of patients who are on dialysis or with end-stage renal disease." Results indicate that a high probability of a valid outcome is associated with relatively wide accuracy intervals. In particular, 25% deviation from the observed outcome implied approximately 60% expected validity. Current practice in HE model validation can be improved by using an alternative method based on assessing whether the model outcomes fit to empirical data at a predefined level of accuracy. This method has the advantage of assessing both model bias and parameter uncertainty and resulting in a quantitative measure of the degree of validity that penalizes models predicting the mean of an outcome correctly but with overly wide credible intervals. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  4. Uncertainty analysis and validation of environmental models. The empirically based uncertainty analysis

    Monte, Luigi; Hakanson, Lars; Bergstroem, Ulla; Brittain, John; Heling, Rudie

    1996-01-01

    The principles of Empirically Based Uncertainty Analysis (EBUA) are described. EBUA is based on the evaluation of 'performance indices' that express the level of agreement between the model and sets of empirical independent data collected in different experimental circumstances. Some of these indices may be used to evaluate the confidence limits of the model output. The method is based on the statistical analysis of the distribution of the index values and on the quantitative relationship of these values with the ratio 'experimental data/model output'. Some performance indices are described in the present paper. Among these, the so-called 'functional distance' (d) between the logarithm of model output and the logarithm of the experimental data, defined as d 2 =Σ n 1 ( ln M i - ln O i ) 2 /n where M i is the i-th experimental value, O i the corresponding model evaluation and n the number of the couplets 'experimental value, predicted value', is an important tool for the EBUA method. From the statistical distribution of this performance index, it is possible to infer the characteristics of the distribution of the ratio 'experimental data/model output' and, consequently to evaluate the confidence limits for the model predictions. This method was applied to calculate the uncertainty level of a model developed to predict the migration of radiocaesium in lacustrine systems. Unfortunately, performance indices are affected by the uncertainty of the experimental data used in validation. Indeed, measurement results of environmental levels of contamination are generally associated with large uncertainty due to the measurement and sampling techniques and to the large variability in space and time of the measured quantities. It is demonstrated that this non-desired effect, in some circumstances, may be corrected by means of simple formulae

  5. Assessing the empirical validity of alternative multi-attribute utility measures in the maternity context

    Morrell Jane

    2009-05-01

    Full Text Available Abstract Background Multi-attribute utility measures are preference-based health-related quality of life measures that have been developed to inform economic evaluations of health care interventions. The objective of this study was to compare the empirical validity of two multi-attribute utility measures (EQ-5D and SF-6D based on hypothetical preferences in a large maternity population in England. Methods Women who participated in a randomised controlled trial of additional postnatal support provided by trained community support workers represented the study population for this investigation. The women were asked to complete the EQ-5D descriptive system (which defines health-related quality of life in terms of five dimensions: mobility, self care, usual activities, pain/discomfort and anxiety/depression and the SF-36 (which defines health-related quality of life, using 36 items, across eight dimensions: physical functioning, role limitations (physical, social functioning, bodily pain, general health, mental health, vitality and role limitations (emotional at six months postpartum. Their responses were converted into utility scores using the York A1 tariff set and the SF-6D utility algorithm, respectively. One-way analysis of variance was used to test the hypothetically-constructed preference rule that each set of utility scores differs significantly by self-reported health status (categorised as excellent, very good, good, fair or poor. The degree to which EQ-5D and SF-6D utility scores reflected alternative dichotomous configurations of self-reported health status and the Edinburgh Postnatal Depression Scale score was tested using the relative efficiency statistic and receiver operating characteristic (ROC curves. Results The mean utility score for the EQ-5D was 0.861 (95% CI: 0.844, 0.877, whilst the mean utility score for the SF-6D was 0.809 (95% CI: 0.796, 0.822, representing a mean difference in utility score of 0.052 (95% CI: 0.040, 0

  6. Empirical validation of the CRAFFT Abuse Screening Test in a Spanish sample.

    Rial, Antonio; Kim-Harris, Sion; Knight, John R; Araujo, Manuel; Gómez, Patricia; Braña, Teresa; Varela, Jesús; Golpe, Sandra

    2018-01-15

    The CRAFFT Substance Abuse Screening Instrument, developed by the Center for Adolescents Substance Abuse Research (CeASAR) (Knight et al., 1999), is a screening tool for high-risk alcohol and drug risk consumption designed for use with adolescents. Since its publication it has been the subject of translations and validations in different countries, populations and contexts that have demonstrated its enormous potential. However, there is still no empirical validation study that would ensure its good psychometric performance in Spain. The aim of this paper is to develop an adapted version of the CRAFFT in Spanish and to analyze its psychometric properties in a sample of Spanish adolescents. For this purpose an individual interview was conducted on 312 adolescents aged between 12 and 18 years of age (M = 15.01; SD = 1.83) from the Galician community. The interview included a part of the Adolescent Diagnostic Interview (ADI) and the Problem Oriented Screening Instrument for Teenagers (POSIT). The results obtained, similar to those found in other countries, allow us to report that the Spanish version of the CRAFFT has a good psychometric behaviorproperties. It was found to have a satisfactory internal consistency with a Cronbach’s alpha value of .74. In terms of sensitivity and specificity, values of 74.4% and 96.4% respectively, were obtained and the area under the ROC curve was .946. The Spanish version of the CRAFFT is made available to researchers and professionals in the field of addictive behaviors, so that it can be used with the necessary psychometric guarantees.

  7. Validation and empirical correction of MODIS AOT and AE over ocean

    N. A. J. Schutgens

    2013-09-01

    Full Text Available We present a validation study of Collection 5 MODIS level 2 Aqua and Terra AOT (aerosol optical thickness and AE (Ångström exponent over ocean by comparison to coastal and island AERONET (AErosol RObotic NETwork sites for the years 2003–2009. We show that MODIS (MODerate-resolution Imaging Spectroradiometer AOT exhibits significant biases due to wind speed and cloudiness of the observed scene, while MODIS AE, although overall unbiased, exhibits less spatial contrast on global scales than the AERONET observations. The same behaviour can be seen when MODIS AOT is compared against Maritime Aerosol Network (MAN data, suggesting that the spatial coverage of our datasets does not preclude global conclusions. Thus, we develop empirical correction formulae for MODIS AOT and AE that significantly improve agreement of MODIS and AERONET observations. We show these correction formulae to be robust. Finally, we study random errors in the corrected MODIS AOT and AE and show that they mainly depend on AOT itself, although small contributions are present due to wind speed and cloud fraction in AOT random errors and due to AE and cloud fraction in AE random errors. Our analysis yields significantly higher random AOT errors than the official MODIS error estimate (0.03 + 0.05 τ, while random AE errors are smaller than might be expected. This new dataset of bias-corrected MODIS AOT and AE over ocean is intended for aerosol model validation and assimilation studies, but also has consequences as a stand-alone observational product. For instance, the corrected dataset suggests that much less fine mode aerosol is transported across the Pacific and Atlantic oceans.

  8. Contributions to the empirical validation and adaptation to Spanish of the mentalist task of strange stories

    Aguilar, María José

    2014-08-01

    Full Text Available The theory of the mind is a core capacity in the social development of people that allows us to infer what another is thinking or feeling and behaving in a manner appropriate to a social situation. One of the main criticisms made to instruments measuring Theory of Mind, is that their results are not reflected in the situations of everyday life. In 1994, Happe created a test trying to overcome the constraints. The aim of this paper was to generate empirical evidence contributing to the validation and Spanish adaptation of the mind theory test named Strange Stories of Happé, used to assess the capability to recognise non literal senses. Results revealed a good internal consistency of the test. The factorial analysis showed five factors that explained the 54% of the variance of data. Significant associations were found between non literal senses and social sensibility tests. Happé Strange stories are attempts to analyze aspects that come into play in everyday life and are an appropriate tool for evaluating the Theory of mind.

  9. SPECT assay of radiolabeled monoclonal antibodies

    Jaszczak, R.J.

    1992-02-01

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

  10. Brain SPECT. SPECT in der Gehirndiagnostik

    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).

  11. SPECT in psychiatry. SPECT in der Psychiatrie

    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.)

  12. Empirical validation and proof of added value of MUSICA's tropospheric δD remote sensing products

    Schneider, M.; González, Y.; Dyroff, C.; Christner, E.; Wiegele, A.; Barthlott, S.; García, O. E.; Sepúlveda, E.; Hase, F.; Andrey, J.; Blumenstock, T.; Guirado, C.; Ramos, R.; Rodríguez, S.

    2015-01-01

    The project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) integrates tropospheric water vapour isotopologue remote sensing and in situ observations. This paper presents a first empirical validation of MUSICA's H2O and δD remote sensing products, generated from ground-based FTIR (Fourier transform infrared), spectrometer and space-based IASI (infrared atmospheric sounding interferometer) observation. The study is made in the area of the Canary Islands in the subtropical northern Atlantic. As reference we use well calibrated in situ measurements made aboard an aircraft (between 200 and 6800 m a.s.l.) by the dedicated ISOWAT instrument and on the island of Tenerife at two different altitudes (at Izaña, 2370 m a.s.l., and at Teide, 3550 m a.s.l.) by two commercial Picarro L2120-i water isotopologue analysers. The comparison to the ISOWAT profile measurements shows that the remote sensors can well capture the variations in the water vapour isotopologues, and the scatter with respect to the in situ references suggests a δD random uncertainty for the FTIR product of much better than 45‰ in the lower troposphere and of about 15‰ for the middle troposphere. For the middle tropospheric IASI δD product the study suggests a respective uncertainty of about 15‰. In both remote sensing data sets we find a positive δD bias of 30-70‰. Complementing H2O observations with δD data allows moisture transport studies that are not possible with H2O observations alone. We are able to qualitatively demonstrate the added value of the MUSICA δD remote sensing data. We document that the δD-H2O curves obtained from the different in situ and remote sensing data sets (ISOWAT, Picarro at Izaña and Teide, FTIR, and IASI) consistently identify two different moisture transport pathways to the subtropical north eastern Atlantic free troposphere.

  13. Validation of an empirically based instrument for the assessment of the quality of teaching in medicine

    Prescher, Anja

    2016-01-01

    Measuring the quality of teaching is a necessary prerequisite for the evaluation and development of medical education and thus for high-quality patient care. Corresponding quality indicators can make the feedback for teachers comprehensible. A completely empirically based instrument for the assessment of the quality of teaching in medicine has not yet been described. Ten empirically based criteria from the field of general pedagogy were developed: clear structure, amount of true learning time...

  14. Brain SPECT in children

    Guyot, M.; Baulieu, J.L.

    1996-01-01

    Brain SPECT in child involves specific trends regarding the patient cooperation, irradiation, resolution and especially interpretation because of the rapid scintigraphic modifications related to the brain maturation. In a general nuclear medicine department, child brain SPECT represents about 2 % of the activity. The choice indications are the perfusion children: thallium and MIBI in brain tumours, pharmacological and neuropsychological interventions. In the future, brain dedicated detectors and new radiopharmaceuticals will promote the development of brain SPECT in children. (author)

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

    Lee, Sang Kun; Lee, Dong Soo

    2003-01-01

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

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

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

    2003-02-01

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

  17. Naturalistic Developmental Behavioral Interventions: Empirically Validated Treatments for Autism Spectrum Disorder

    Schreibman, Laura; Dawson, Geraldine; Stahmer, Aubyn C.; Landa, Rebecca; Rogers, Sally J.; McGee, Gail G.; Kasari, Connie; Ingersoll, Brooke; Kaiser, Ann P.; Bruinsma, Yvonne; McNerney, Erin; Wetherby, Amy; Halladay, Alycia

    2015-01-01

    Earlier autism diagnosis, the importance of early intervention, and development of specific interventions for young children have contributed to the emergence of similar, empirically supported, autism interventions that represent the merging of applied behavioral and developmental sciences. "Naturalistic Developmental Behavioral Interventions…

  18. Traditional Arabic & Islamic medicine: validation and empirical assessment of a conceptual model in Qatar.

    AlRawi, Sara N; Khidir, Amal; Elnashar, Maha S; Abdelrahim, Huda A; Killawi, Amal K; Hammoud, Maya M; Fetters, Michael D

    2017-03-14

    Evidence indicates traditional medicine is no longer only used for the healthcare of the poor, its prevalence is also increasing in countries where allopathic medicine is predominant in the healthcare system. While these healing practices have been utilized for thousands of years in the Arabian Gulf, only recently has a theoretical model been developed illustrating the linkages and components of such practices articulated as Traditional Arabic & Islamic Medicine (TAIM). Despite previous theoretical work presenting development of the TAIM model, empirical support has been lacking. The objective of this research is to provide empirical support for the TAIM model and illustrate real world applicability. Using an ethnographic approach, we recruited 84 individuals (43 women and 41 men) who were speakers of one of four common languages in Qatar; Arabic, English, Hindi, and Urdu, Through in-depth interviews, we sought confirming and disconfirming evidence of the model components, namely, health practices, beliefs and philosophy to treat, diagnose, and prevent illnesses and/or maintain well-being, as well as patterns of communication about their TAIM practices with their allopathic providers. Based on our analysis, we find empirical support for all elements of the TAIM model. Participants in this research, visitors to major healthcare centers, mentioned using all elements of the TAIM model: herbal medicines, spiritual therapies, dietary practices, mind-body methods, and manual techniques, applied singularly or in combination. Participants had varying levels of comfort sharing information about TAIM practices with allopathic practitioners. These findings confirm an empirical basis for the elements of the TAIM model. Three elements, namely, spiritual healing, herbal medicine, and dietary practices, were most commonly found. Future research should examine the prevalence of TAIM element use, how it differs among various populations, and its impact on health.

  19. Autonomous e-coaching in the wild: Empirical validation of a model-based reasoning system

    Kamphorst, B.A.; Klein, M.C.A.; van Wissen, A.

    2014-01-01

    Autonomous e-coaching systems have the potential to improve people's health behaviors on a large scale. The intelligent behavior change support system eMate exploits a model of the human agent to support individuals in adopting a healthy lifestyle. The system attempts to identify the causes of a person's non-adherence by reasoning over a computational model (COMBI) that is based on established psychological theories of behavior change. The present work presents an extensive, monthlong empiric...

  20. PHILOSOPHICAL VALIDITY, THEORETICAL, NORMATIVE AND EMPIRICAL PARADIGM OF GENERAL PRINCIPLES OF GOOD GOVERNANCE (AUPB AS A REVIEW OF PRESIDENTIAL IMPEACHMENT

    Nadir Nadir

    2017-03-01

    Full Text Available Philosophical validity showed of the Principles of Good Governance (AUPB as A review to Presidential impeachment, is a principle of AUPB that contains ethical normative values used as the foundation of good governance, clean and respectable, moreover to complement the shortcomings and ambiguities in law. Technically, the application of AUPB by the judges of the Constitutional Court (MK-RI can be approached through induction and deduction legal reasoning. The method of implementing AUPB by the judges of the Constitutional Court (MK-RI is accomplished by deductive at first, meaning that the special rules is focused more to the certain field of law, then these are deducted based on its basic rules and deducted again into the rules of substantive, and deducted again into the rules of cases. After that, it starts to applicate the rules of case based on the concrete case by the judge, because of the nature of the judges of the Constitutional Court (MK-RI is kholifah fil'ardi as the representative of God on earth to uphold the law and justice. While theoretically AUPB is valid, the judge ius curia Novit as a verdict maker to perform legal discovery (rechtsvinding. Empirically AUPB is valid, it can be seen from the cases of impeachment against the President of the United States William Jefferson Clinton, on suspicion of "abominably act" (misdemeanors. Additionally, AUPB empirically has been tested through jurisprudence since Amtenarenwet 1929 officially applied on March 1, 1933. Centrale Raad van Beroep, in his verdict on June 22, 1933, and the jurisprudence verdict of Hoge Raad on November 13, 1936, and the jurisprudence verdict of Hoge Raad 1919. While the normative validity is based on the leading legal doctrine, that AUPB is positioned as the unwritten laws that must be obeyed by the government, and AUPB considered as a part of positive law. Moreover, in Indonesia AUPB incarnates in various legislations even though his name is remained as principal.

  1. On the validity of empirical potentials for simulating radiation damage in graphite: a benchmark

    Latham, C D; McKenna, A J; Trevethan, T P; Heggie, M I; Rayson, M J; Briddon, P R

    2015-01-01

    In this work, the ability of methods based on empirical potentials to simulate the effects of radiation damage in graphite is examined by comparing results for point defects, found using ab initio calculations based on density functional theory (DFT), with those given by two state of the art potentials: the Environment-Dependent Interatomic Potential (EDIP) and the Adaptive Intermolecular Reactive Empirical Bond Order potential (AIREBO). Formation energies for the interstitial, the vacancy and the Stone–Wales (5775) defect are all reasonably close to DFT values. Both EDIP and AIREBO can thus be suitable for the prompt defects in a cascade, for example. Both potentials suffer from arefacts. One is the pinch defect, where two α-atoms adopt a fourfold-coordinated sp 3 configuration, that forms a cross-link between neighbouring graphene sheets. Another, for AIREBO only, is that its ground state vacancy structure is close to the transition state found by DFT for migration. The EDIP fails to reproduce the ground state self-interstitial structure given by DFT, but has nearly the same formation energy. Also, for both potentials, the energy barriers that control diffusion and the evolution of a damage cascade, are not well reproduced. In particular the EDIP gives a barrier to removal of the Stone–Wales defect as 0.9 eV against DFT's 4.5 eV. The suite of defect structures used is provided as supplementary information as a benchmark set for future potentials. (paper)

  2. Empirical validation of the Horowitz Multiple Systemic Infectious Disease Syndrome Questionnaire for suspected Lyme disease.

    Citera, Maryalice; Freeman, Phyllis R; Horowitz, Richard I

    2017-01-01

    Lyme disease is spreading worldwide, with multiple Borrelia species causing a broad range of clinical symptoms that mimic other illnesses. A validated Lyme disease screening questionnaire would be clinically useful for both providers and patients. Three studies evaluated such a screening tool, namely the Horowitz Multiple Systemic Infectious Disease Syndrome (MSIDS) Questionnaire. The purpose was to see if the questionnaire could accurately distinguish between Lyme patients and healthy individuals. Study 1 examined the construct validity of the scale examining its factor structure and reliability of the questionnaire among 537 individuals being treated for Lyme disease. Study 2 involved an online sample of 999 participants, who self-identified as either healthy (N=217) or suffering from Lyme now (N=782) who completed the Horowitz MSIDS Questionnaire (HMQ) along with an outdoor activity survey. We examined convergent validity among components of the scale and evaluated discriminant validity with the Big Five personality characteristics. The third study compared a sample of 236 patients with confirmed Lyme disease with an online sample of 568 healthy individuals. Factor analysis results identified six underlying latent dimensions; four of these overlapped with critical symptoms identified by Horowitz - neuropathy, cognitive dysfunction, musculoskeletal pain, and fatigue. The HMQ showed acceptable levels of internal reliability using Cronbach's coefficient alpha and exhibited evidence of convergent and divergent validity. Components of the HMQ correlated more highly with each other than with unrelated traits. The results consistently demonstrated that the HMQ accurately differentiated those with Lyme disease from healthy individuals. Three migratory pain survey items (persistent muscular pain, arthritic pain, and nerve pain/paresthesias) robustly identified individuals with verified Lyme disease. The results support the use of the HMQ as a valid, efficient, and low

  3. SPECT in psychiatry

    Barocka, A.; Feistel, H.; Ebert, D.; Lungershausen, E.

    1993-01-01

    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 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.) [de

  4. Experimental validation of new empirical models of the thermal properties of food products for safe shipping

    Hamid, Hanan H.; Mitchell, Mark; Jahangiri, Amirreza; Thiel, David V.

    2018-04-01

    Temperature controlled food transport is essential for human safety and to minimise food waste. The thermal properties of food are important for determining the heat transfer during the transient stages of transportation (door opening during loading and unloading processes). For example, the temperature of most dairy products must be confined to a very narrow range (3-7 °C). If a predefined critical temperature is exceeded, the food is defined as spoiled and unfit for human consumption. An improved empirical model for the thermal conductivity and specific heat capacity of a wide range of food products was derived based on the food composition (moisture, fat, protein, carbohydrate and ash). The models that developed using linear regression analysis were compared with the published measured parameters in addition to previously published theoretical and empirical models. It was found that the maximum variation in the predicated thermal properties leads to less than 0.3 °C temperature change. The correlation coefficient for these models was 0.96. The t-Stat test ( P-value >0.99) demonstrated that the model results are an improvement on previous works. The transient heat transfer based on the food composition and the temperature boundary conditions was found for a Camembert cheese (short cylindrical shape) using a multiple dimension finite difference method code. The result was verified using the heat transfer today (HTT) educational software which is based on finite volume method. The core temperature rises from the initial temperature (2.7 °C) to the maximum safe temperature in ambient air (20.24 °C) was predicted to within about 35.4 ± 0.5 min. The simulation results agree very well ( +0.2 °C) with the measured temperature data. This improved model impacts on temperature estimation during loading and unloading the trucks and provides a clear direction for temperature control in all refrigerated transport applications.

  5. The Safety Culture Enactment Questionnaire (SCEQ): Theoretical model and empirical validation.

    de Castro, Borja López; Gracia, Francisco J; Tomás, Inés; Peiró, José M

    2017-06-01

    This paper presents the Safety Culture Enactment Questionnaire (SCEQ), designed to assess the degree to which safety is an enacted value in the day-to-day running of nuclear power plants (NPPs). The SCEQ is based on a theoretical safety culture model that is manifested in three fundamental components of the functioning and operation of any organization: strategic decisions, human resources practices, and daily activities and behaviors. The extent to which the importance of safety is enacted in each of these three components provides information about the pervasiveness of the safety culture in the NPP. To validate the SCEQ and the model on which it is based, two separate studies were carried out with data collection in 2008 and 2014, respectively. In Study 1, the SCEQ was administered to the employees of two Spanish NPPs (N=533) belonging to the same company. Participants in Study 2 included 598 employees from the same NPPs, who completed the SCEQ and other questionnaires measuring different safety outcomes (safety climate, safety satisfaction, job satisfaction and risky behaviors). Study 1 comprised item formulation and examination of the factorial structure and reliability of the SCEQ. Study 2 tested internal consistency and provided evidence of factorial validity, validity based on relationships with other variables, and discriminant validity between the SCEQ and safety climate. Exploratory Factor Analysis (EFA) carried out in Study 1 revealed a three-factor solution corresponding to the three components of the theoretical model. Reliability analyses showed strong internal consistency for the three scales of the SCEQ, and each of the 21 items on the questionnaire contributed to the homogeneity of its theoretically developed scale. Confirmatory Factor Analysis (CFA) carried out in Study 2 supported the internal structure of the SCEQ; internal consistency of the scales was also supported. Furthermore, the three scales of the SCEQ showed the expected correlation

  6. Using Office Discipline Referral Data for Decision Making about Student Behavior in Elementary and Middle Schools: An Empirical Evaluation of Validity

    Irvin, Larry K.; Horner, Robert H.; Ingram, Kimberly; Todd, Anne W.; Sugai, George; Sampson, Nadia Katul; Boland, Joseph B.

    2006-01-01

    In this evaluation we used Messick's construct validity as a conceptual framework for an empirical study assessing the validity of use, utility, and impact of office discipline referral (ODR) measures for data-based decision making about student behavior in schools. The Messick approach provided a rubric for testing the fit of our theory of use of…

  7. Empirical validation of Polish guidelines for the management of acute streptococcal pharyngitis in children.

    Mazur, Elżbieta; Bochyńska, Ewa; Juda, Marek; Kozioł-Montewka, Maria

    2014-01-01

    Group A Streptococcus (GAS) pharyngitis is currently the only commonly occurring form of acute pharyngitis for which antibiotic therapy is definitely indicated. Polish guidelines advocate the use of modified Centor score (MCS) to assess the probability of GAS pharyngitis. They advise performing throat culture or rapid antigen detection test (RADT) in children with score 2-3 in MCS and treating with antibiotic only those in whom GAS was detected. Negative RADT results should be confirmed by culture. In children with score 4, the guidelines allow to introduce empiric antibiotic therapy. Phenoxymethyl penicillin is recommended as a drug of choice to treat GAS pharyngitis. The aim of our study was to evaluate the accuracy of strategy recommended by Polish guidelines in identifying those children with acute pharyngitis who require antibiotic treatment. Hence, diagnostic values of score 4 in MCS and RADT were assessed using throat culture as a reference standard. Phenoxymethyl penicillin efficacy in GAS eradication and prevention of post-streptococcal complications were estimated as well. Ninety children between 2 and 15 years of age with acute pharyngitis symptoms suggesting GAS etiology (MCS ≥ 2), participated in our study. At the initial visit MCS was evaluated and two throat swabs were collected to perform RADT and culture. In children with GAS pharyngitis treated with penicillin, microbiological cure was assessed by performing two control throat cultures. Next, children were under observation for 3 months. Positive predictive value of score 4 in MCS turned out to be 48.05% (95% CI: 36.5-59.7%). RADT sensitivity, specificity and diagnostic accuracy proved to be 100%, 96%, and 98%, respectively. GAS eradication rate in children treated with penicillin turned out to be 92.5%. No post-streptococcal sequelae occurred in any child in 3-month observation. Empiric antibiotic therapy in children with score 4 in MCS will result in significant overtreatment of those with

  8. On the theoretical development of new creep resistant alloys and their empirical validation

    Gaude-Fugarolas, D.; Regent, N.; Carlan, Y. de

    2008-01-01

    In anticipation to the present revival of nuclear power, and to obtain more efficient, secure and environmentally-friendly power plants, new families of high temperature resistant, low activation materials are under development. This work presents an example of work performed at CEA during the development of novel ferrito-martensitic reduced activation alloys for Generation IV and Fusion applications. In the past, the process of designing a new material was mostly heuristic, requiring repeated experimental trial and error, but nowadays, synergies between the accuracy of current scientific knowledge in thermodynamics and transformation kinetics and increased computer capacity enables us to design successful new alloys using minimal empirical feedback. This work presents this comprehensive and multi-model approach to alloy and microstructure design. The CALPHAD method, thermo-kinetic modelling of precipitation reactions and artificial neural network analysis are combined in the development of new alloys having their compositions and microstructures optimised for maximum creep resistance. To complete this work, a selection of the alloys designed has been cast and the results obtained during alloy design and the modelling of various heat treatments have been verified. Optical and electronic microscopy have been used to characterise the microstructure. Uniaxial tensile tests have been used to measure the mechanical performance of the alloys presented at room, service and higher temperatures. The characterisation of the behaviour of the material in service conditions is underway with relaxation and creep tests. (authors)

  9. Empirical Validation of a Hypothesis of the Hormetic Selective Forces Driving the Evolution of Longevity Regulation Mechanisms

    Alejandra Gomez-Perez

    2016-12-01

    Full Text Available Exogenously added lithocholic bile acid and some other bile acids slow down yeast chronological aging by eliciting a hormetic stress response and altering mitochondrial functionality. Unlike animals, yeast cells do not synthesize bile acids. We therefore hypothesized that bile acids released into an ecosystem by animals may act as interspecies chemical signals that generate selective pressure for the evolution of longevity regulation mechanisms in yeast within this ecosystem. To empirically verify our hypothesis, in this study we carried out a 3-step process for the selection of long-lived yeast species by a long-term exposure to exogenous lithocholic bile acid. Such experimental evolution yielded 20 long-lived mutants, 3 of which were capable of sustaining their considerably prolonged chronological lifespans after numerous passages in medium without lithocholic acid. The extended longevity of each of the 3 long-lived yeast species was a dominant polygenic trait caused by mutations in more than two nuclear genes. Each of the 3 mutants displayed considerable alterations to the age-related chronology of mitochondrial respiration and showed enhanced resistance to chronic oxidative, thermal and osmotic stresses. Our findings empirically validate the hypothesis suggesting that hormetic selective forces can drive the evolution of longevity regulation mechanisms within an ecosystem.

  10. The Development and Empirical Validation of an E-based Supply Chain Strategy Optimization Model

    Kotzab, Herbert; Skjoldager, Niels; Vinum, Thorkil

    2003-01-01

    Examines the formulation of supply chain strategies in complex environments. Argues that current state‐of‐the‐art e‐business and supply chain management, combined into the concept of e‐SCM, as well as the use of transaction cost theory, network theory and resource‐based theory, altogether can...... be used to form a model for analyzing supply chains with the purpose of reducing the uncertainty of formulating supply chain strategies. Presents e‐supply chain strategy optimization model (e‐SOM) as a way to analyze supply chains in a structured manner as regards strategic preferences for supply chain...... design, relations and resources in the chains with the ultimate purpose of enabling the formulation of optimal, executable strategies for specific supply chains. Uses research results for a specific supply chain to validate the usefulness of the model....

  11. Predictive Validity of an Empirical Approach for Selecting Promising Message Topics: A Randomized-Controlled Study

    Lee, Stella Juhyun; Brennan, Emily; Gibson, Laura Anne; Tan, Andy S. L.; Kybert-Momjian, Ani; Liu, Jiaying; Hornik, Robert

    2016-01-01

    Several message topic selection approaches propose that messages based on beliefs pretested and found to be more strongly associated with intentions will be more effective in changing population intentions and behaviors when used in a campaign. This study aimed to validate the underlying causal assumption of these approaches which rely on cross-sectional belief–intention associations. We experimentally tested whether messages addressing promising themes as identified by the above criterion were more persuasive than messages addressing less promising themes. Contrary to expectations, all messages increased intentions. Interestingly, mediation analyses showed that while messages deemed promising affected intentions through changes in targeted promising beliefs, messages deemed less promising also achieved persuasion by influencing nontargeted promising beliefs. Implications for message topic selection are discussed. PMID:27867218

  12. Empirical Derivation and Validation of a Clinical Case Definition for Neuropsychological Impairment in Children and Adolescents.

    Beauchamp, Miriam H; Brooks, Brian L; Barrowman, Nick; Aglipay, Mary; Keightley, Michelle; Anderson, Peter; Yeates, Keith O; Osmond, Martin H; Zemek, Roger

    2015-09-01

    Neuropsychological assessment aims to identify individual performance profiles in multiple domains of cognitive functioning; however, substantial variation exists in how deficits are defined and what cutoffs are used, and there is no universally accepted definition of neuropsychological impairment. The aim of this study was to derive and validate a clinical case definition rule to identify neuropsychological impairment in children and adolescents. An existing normative pediatric sample was used to calculate base rates of abnormal functioning on eight measures covering six domains of neuropsychological functioning. The dataset was analyzed by varying the range of cutoff levels [1, 1.5, and 2 standard deviations (SDs) below the mean] and number of indicators of impairment. The derived rule was evaluated by bootstrap, internal and external clinical validation (orthopedic and traumatic brain injury). Our neuropsychological impairment (NPI) rule was defined as "two or more test scores that fall 1.5 SDs below the mean." The rule identifies 5.1% of the total sample as impaired in the assessment battery and consistently targets between 3 and 7% of the population as impaired even when age, domains, and number of tests are varied. The NPI rate increases in groups known to exhibit cognitive deficits. The NPI rule provides a psychometrically derived method for interpreting performance across multiple tests and may be used in children 6-18 years. The rule may be useful to clinicians and scientists who wish to establish whether specific individuals or clinical populations present within expected norms versus impaired function across a battery of neuropsychological tests.

  13. [Myokard-Perfusions-SPECT. Myocardial perfusion SPECT - Update S1 guideline].

    Lindner, Oliver; Bengel, Frank; Burchert, Wolfgang; Dörr, Rolf; Hacker, Marcus; Schäfer, Wolfgang; Schäfers, Michael A; Schmidt, Matthias; Schwaiger, Markus; Vom Dahl, Jürgen; Zimmermann, Rainer

    2017-08-14

    The S1 guideline for myocardial perfusion SPECT has been published by the Association of the Scientific Medical Societies in Germany (AWMF) and is valid until 2/2022. This paper is a short summary with comments on all chapters and subchapters wich were modified and amended.

  14. Empirical validation of the S-Score algorithm in the analysis of gene expression data

    Archer Kellie J

    2006-03-01

    Full Text Available Abstract Background Current methods of analyzing Affymetrix GeneChip® microarray data require the estimation of probe set expression summaries, followed by application of statistical tests to determine which genes are differentially expressed. The S-Score algorithm described by Zhang and colleagues is an alternative method that allows tests of hypotheses directly from probe level data. It is based on an error model in which the detected signal is proportional to the probe pair signal for highly expressed genes, but approaches a background level (rather than 0 for genes with low levels of expression. This model is used to calculate relative change in probe pair intensities that converts probe signals into multiple measurements with equalized errors, which are summed over a probe set to form the S-Score. Assuming no expression differences between chips, the S-Score follows a standard normal distribution, allowing direct tests of hypotheses to be made. Using spike-in and dilution datasets, we validated the S-Score method against comparisons of gene expression utilizing the more recently developed methods RMA, dChip, and MAS5. Results The S-score showed excellent sensitivity and specificity in detecting low-level gene expression changes. Rank ordering of S-Score values more accurately reflected known fold-change values compared to other algorithms. Conclusion The S-score method, utilizing probe level data directly, offers significant advantages over comparisons using only probe set expression summaries.

  15. Low-dose single acquisition rest {sup 99m}Tc/stress {sup 201}Tl myocardial perfusion SPECT protocol: phantom studies and clinical validation

    Dey, Thomas [RWTH Aachen University, Institute of Imaging and Computer Vision, Aachen (Germany); Backus, Barbra E.; Romijn, R.Leo [St. Antonius Hospital, Department of Nuclear Medicine, Nieuwegein (Netherlands); Wieczorek, Herfried [Philips Research, Eindhoven (Netherlands); Verzijlbergen, J.F. [St. Antonius Hospital, Department of Nuclear Medicine, Nieuwegein (Netherlands); Erasmus Medical Center, Department of Nuclear Medicine, Rotterdam (Netherlands)

    2014-03-15

    We developed and tested a single acquisition rest {sup 99m}Tc-sestamibi/stress {sup 201}Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT). The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress {sup 99m}Tc and rest {sup 99m}Tc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available. Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected {sup 201}Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the {sup 201}Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and {sup 99m}Tc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the {sup 99m}Tc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients

  16. Low-dose single acquisition rest 99mTc/stress 201Tl myocardial perfusion SPECT protocol: phantom studies and clinical validation

    Dey, Thomas; Backus, Barbra E.; Romijn, R.Leo; Wieczorek, Herfried; Verzijlbergen, J.F.

    2014-01-01

    We developed and tested a single acquisition rest 99m Tc-sestamibi/stress 201 Tl dual isotope protocol (SDI) with the intention of improving the clinical workflow and patient comfort of myocardial perfusion single photon emission computed tomography (SPECT). The technical feasibility of SDI was evaluated by a series of anthropomorphic phantom studies on a standard SPECT camera. The attenuation map was created by a moving transmission line source. Iterative reconstruction including attenuation correction, resolution recovery and Monte Carlo simulation of scatter was used for simultaneous reconstruction of dual tracer distribution. For clinical evaluation, patient studies were compared to stress 99m Tc and rest 99m Tc reference images acquired in a 2-day protocol. Clinical follow-up examinations like coronary angiography (CAG) and fractional flow reserve (FFR) were included in the assessment if available. Phantom studies demonstrated the technical feasibility of SDI. Artificial lesions inserted in the phantom mimicking ischaemia could be clearly identified. In 51/53 patients, the image quality was adequate for clinical evaluation. For the remaining two obese patients with body mass index > 32 the injected 201 Tl dose of 74 MBq was insufficient for clinical assessment. In answer to this the 201 Tl dose was adapted for obese patients in the rest of the study. In 31 patients, SDI and 99m Tc reference images resulted in equivalent clinical assessment. Significant differences were found in 20 patients. In 18 of these 20 patients additional examinations were available. In 15 patients the diagnosis based on the SDI images was confirmed by the results of CAG or FFR. In these patients the SDI images were more accurate than the 99m Tc reference study. In three patients minor ischaemic lesions were detected by SDI but were not confirmed by CAG. In one of these cases this was probably caused by pronounced apical thinning. For two patients no relevant clinical follow

  17. Brain SPECT in childhood

    Tranquart, F.; Saliba, E.; Prunier, C.; Baulieu, F.; Besnard, J.C.; Guilloteau, D.; Baulieu, J.L.

    2001-01-01

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

  18. Empirical Validation of Heat Transfer Performance Simulation of Graphite/PCM Concrete Materials for Thermally Activated Building System

    Jin-Hee Song

    2017-01-01

    Full Text Available To increase the heat capacity in lightweight construction materials, a phase change material (PCM can be introduced to building elements. A thermally activated building system (TABS with graphite/PCM concrete hollow core slab is suggested as an energy-efficient technology to shift and reduce the peak thermal load in buildings. An evaluation of heat storage and dissipation characteristics of TABS in graphite/PCM concrete has been conducted using dynamic simulations, but empirical validation is necessary to acceptably predict the thermal behavior of graphite/PCM concrete. This study aimed to validate the thermal behavior of graphite/PCM concrete through a three-dimensional transient heat transfer simulation. The simulation results were compared to experimental results from previous studies of concrete and graphite/PCM concrete. The overall thermal behavior for both materials was found to be similar to experiment results. Limitations in the simulation modeling, which included determination of the indoor heat transfer coefficient, assumption of constant thermal conductivity with temperature, and assumption of specimen homogeneity, led to slight differences between the measured and simulated results.

  19. Benchmarking Supplier Development: An Empirical Case Study of Validating a Framework to Improve Buyer-Supplier Relationship

    Shahzad Khuram

    2016-03-01

    Full Text Available In today’s dynamic business environment, firms are required to utilize efficiently and effectively all the useful resources to gain competitive advantage. Supplier development has evolved as an important strategic instrument to improve buyer supplier relationships. For that reason, this study focuses on providing the strategic significance of supplier development approaches to improve business relationships. By using qualitative research method, an integrated framework of supplier development and buyer-supplier relationship development has been tested and validated in a Finnish case company to provide empirical evidence. It particularly investigates how supplier development approaches can develop buyer-supplier relationships. The study present a set of propositions that identify significant supplier development approaches critical for the development of buyer-supplier relationships and develop a theoretical framework that specifies how these different supplier development approaches support in order to strengthen the relationships. The results are produced from an in-depth case study by implementing the proposed research framework. The findings reveal that supplier development strategies i.e., supplier incentives and direct involvements strongly effect in developing buyer-supplier relationships. Further research may focus on considering in-depth investigation of trust and communication factors along with propositions developed in the study to find out general applicability in dynamic business environment. Proposed integrated framework along with propositions is a unique combination of useful solutions for tactical and strategic management’s decision making and also valid for academic researchers to develop supplier development theories.

  20. SPECT in psychiatry

    Kasper, S.; Gruenwald, F.; Walter, H.; Klemm, E.; Podreka, I.; Biersack, H.J.

    1994-01-01

    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.) [de

  1. Applications of cerebral SPECT

    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.

  2. Usefulness of brain SPECT

    Raynaud, C.; Rancurel, G.; Kieffer, E.; Ricard, S.; Askienazy, S.; Moretti, J.L.; Bourdoiseau, M.; Rapin, J.; Soussaline, F.

    1983-01-01

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

  3. Brain spect imaging

    Lee, R.G.L.; Hill, T.C.; Holman, B.L.

    1989-01-01

    This paper discusses how the rapid development of single-photon radiopharmaceuticals has given new life to tomographic brain imaging in nuclear medicine. Further developments in radiopharmaceuticals and refinements in neuro-SPECT (single-photon emission computed tomography) instrumentation should help to reinstate brain scintigraphy as an important part of neurologic diagnosis. SPECT of the brain evolved from experimentation using prototype instrumentation during the early 1960s. Although tomographic studies provided superior diagnostic accuracy when compared to planar techniques, the arrival of X-ray CT of the head resulted in the rapid demise of technetium brain imaging

  4. Ventilation-perfused studies using SPECT

    Zwijnenburg, A.

    1989-01-01

    A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

  5. Radiopharmaceuticals for brain - SPECT

    Moretti, J.L.

    1992-01-01

    Perfusion tracers for brain SPECT imaging suitable for regional cerebral blood flow measurement and regional cerebral blood volume determination, with respect to their ability to pass the blood-brain-barrier, are described. Problems related t the use of specific radiotracers to map receptors distribution in the brain are also discussed in this lecture. 9 figs, 6 tabs

  6. Tests of regional elemental tracers of pollution aerosols. 1. Distinctness of regional signatures, stability during transport, and empirical validation

    Lowenthal, D.H.; Wunschel, K.R.; Rahn, K.A.

    1988-01-01

    The two major requirements for a successful regional tracer system are distinctness of signatures and stability of signatures during transport. Dissimilarity of the five regional signatures from eastern North America is shown by collinearity diagnostics and by apportionment of synthetic samples generated randomly. Stability of regional signatures during transport is shown first by use of tracer elements in coarse and fine aerosol to predict the maximum possible change of ratios from particle-size effects alone and then by examination of actual changes in signatures during transport from the Midwest to Underhill, VT. Two recent empirical validations of the tracer system are presented: qualitative agreement of pulses of mid-western aerosol in Vermont with pulses of perfluorocarbon tracer gas released in Ohio during CAPTEX '83 and reproduction of our three major northeastern and mid-western signatures by other investigators. The tracer system currently uses the seven elements As, Se, Sb, Zn, In, noncrustal Mn, and noncrustal V as measured by instrumental neutron activation

  7. Comparison of gated blood pool SPECT and spiral multidetector computed tomography in the assessment of right ventricular functional parameters. Validation with first-pass radionuclide angiography

    Lee, Jung S.; Kim, Seong-Jang; Kim, In-Ju; Kim, Yong-Ki; Choo, Ki S.; Lee, Jun S.

    2007-01-01

    The aim of this study was to compare gated blood pool single photon emission computed tomography (SPECT) (GBPS) and multidetector row computed tomography (MDCT) for the determination of right ventricular ejection fraction (RVEF) and right ventricular volumes (RVV) and to compare first-pass radionuclide angiography (FP-RNA) as the gold standard. Twenty consecutive patients (11 men, 9 women) referred for MDCT for the evaluation of the presence of coronary artery disease underwent FP-RNA and GBPS. The mean right ventricular end-diastolic volume (EDV) calculated with GBPS revealed a statistically significant lower value than that of MDCT. The mean right ventricular end-systolic volume (ESV) calculated with GBPS was also lower than that of MDCT. A comparison of right ventricular EDV from GBPS and MDCT yielded a correlation coefficient of 0.5972. Right ventricular ESV between GBPS and MDCT showed a correlation coefficient of 0.5650. The mean RVEFs calculated with FP-RNA (39.8%±4.0%), GBPS (43.7%±6.9%), and MDCT (40.4%±7.7%) showed no statistical differences (Kruskal-Wallis statistics 4.538, P=0.1034). A comparison of RVEFs from FP-RNA and GBPS yielded a correlation coefficient of 0.7251; RVEFs between FP-RNA and MDCT showed a correlation coefficient of 0.6166 and between GBPS and MDCT showed a correlation coefficient of 0.6367. The RVEF, EDV, and ESV calculated by GBPS had good correlation with those obtained with MDCT. In addition, there were no statistical differences of RVEF calculated from FP-RNA, GBPS, and MDCT. However, with regard to RVV, EDV and ESV from GBPS revealed statistically significantly lower values than those of MDCT. Although reasonable correlations among these modalities were obtained, the agreement among these three modalities was not good enough for interchangeable use in the clinical setting. Also, these results should be confirmed in patients with cardiac diseases in future larger population-based studies. (author)

  8. Mnemonic activation by SPECT

    Migneco, O.; Darcourt, J.; Benoit, M; Malandain, G.; Thirion, J.P.; Robert, Ph.; Vidal, R.; Desvignes, Ph.; Benoliel, J.; Ayache, N.; Bussiere, F.

    1997-01-01

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

  9. Empirical assessment of the validity limits of the surface wave full ray theory using realistic 3-D Earth models

    Parisi, Laura

    2016-02-10

    The surface wave full ray theory (FRT) is an efficient tool to calculate synthetic waveforms of surface waves. It combines the concept of local modes with exact ray tracing as a function of frequency, providing a more complete description of surface wave propagation than the widely used great circle approximation (GCA). The purpose of this study is to evaluate the ability of the FRT approach to model teleseismic long-period surface waveforms (T ∼ 45–150 s) in the context of current 3-D Earth models to empirically assess its validity domain and its scope for future studies in seismic tomography. To achieve this goal, we compute vertical and horizontal component fundamental mode synthetic Rayleigh waveforms using the FRT, which are compared with calculations using the highly accurate spectral element method. We use 13 global earth models including 3-D crustal and mantle structure, which are derived by successively varying the strength and lengthscale of heterogeneity in current tomographic models. For completeness, GCA waveforms are also compared with the spectral element method. We find that the FRT accurately predicts the phase and amplitude of long-period Rayleigh waves (T ∼ 45–150 s) for almost all the models considered, with errors in the modelling of the phase (amplitude) of Rayleigh waves being smaller than 5 per cent (10 per cent) in most cases. The largest errors in phase and amplitude are observed for T ∼ 45 s and for the three roughest earth models considered that exhibit shear wave anomalies of up to ∼20 per cent, which is much larger than in current global tomographic models. In addition, we find that overall the GCA does not predict Rayleigh wave amplitudes well, except for the longest wave periods (T ∼ 150 s) and the smoothest models considered. Although the GCA accurately predicts Rayleigh wave phase for current earth models such as S20RTS and S40RTS, FRT\\'s phase errors are smaller, notably for the shortest wave periods considered (T

  10. Metabolic imaging using SPECT

    Taki, Junichi; Matsunari, Ichiro

    2007-01-01

    In normal condition, the heart obtains more than two-thirds of its energy from the oxidative metabolism of long chain fatty acids, although a wide variety of substrates such as glucose, lactate, ketone bodies and amino acids are also utilised. In ischaemic myocardium, on the other hand, oxidative metabolism of free fatty acid is suppressed and anaerobic glucose metabolism plays a major role in residual oxidative metabolism. Therefore, metabolic imaging can be an important technique for the assessment of various cardiac diseases and conditions. In SPECT, several iodinated fatty acid traces have been introduced and studied. Of these, 123 I-labelled 15-(p-iodophenyl)3-R, S-methylpentadecanoic acid (BMIPP) has been the most commonly used tracer in clinical studies, especially in some of the European countries and Japan. In this review article, several fatty acid tracers for SPECT are characterised, and the mechanism of uptake and clinical utility of BMIPP are discussed in detail. (orig.)

  11. The origins of SPECT and SPECT/CT

    Hutton, Brian F. [University College London, Institute of Nuclear Medicine, London (United Kingdom); University of Wollongong, Centre for Medical Radiation Physics, Wollongong, NSW (Australia)

    2014-05-15

    Single photon emission computed tomography (SPECT) has a long history of development since its initial demonstration by Kuhl and Edwards in 1963. Although clinical utility has been dominated by the rotating gamma camera, there have been many technological innovations with the recent popularity of organ-specific dedicated SPECT systems. The combination of SPECT and CT evolved from early transmission techniques used for attenuation correction with the initial commercial systems predating the release of PET/CT. The development and acceptance of SPECT/CT has been relatively slow with continuing debate as to what cost/performance ratio is justified. Increasingly, fully diagnostic CT is combined with SPECT so as to facilitate optimal clinical utility. (orig.)

  12. Empirically Derived Dehydration Scoring and Decision Tree Models for Children With Diarrhea: Assessment and Internal Validation in a Prospective Cohort Study in Dhaka, Bangladesh

    Levine, Adam C; Glavis-Bloom, Justin; Modi, Payal; Nasrin, Sabiha; Rege, Soham; Chu, Chieh; Schmid, Christopher H; Alam, Nur H

    2015-01-01

    Introduction: Diarrhea remains one of the most common and most deadly conditions affecting children worldwide. Accurately assessing dehydration status is critical to determining treatment course, yet no clinical diagnostic models for dehydration have been empirically derived and validated for use in resource-limited settings. Methods: In the Dehydration: Assessing Kids Accurately (DHAKA) prospective cohort study, a random sample of children under 5 with acute diarrhea was enrolled between Feb...

  13. Individual patient dosimetry using quantitative SPECT imaging

    Gonzalez, J.; Oliva, J.; Baum, R.; Fisher, S.

    2002-01-01

    An approach is described to provide individual patient dosimetry for routine clinical use. Accurate quantitative SPECT imaging was achieved using appropriate methods. The volume of interest (VOI) was defined semi-automatically using a fixed threshold value obtained from phantom studies. The calibration factor to convert the voxel counts from SPECT images into activity values was determine from calibrated point source using the same threshold value as in phantom studies. From selected radionuclide the dose within and outside a sphere of voxel dimension at different distances was computed through dose point-kernels to obtain a discrete absorbed dose kernel representation around the volume source with uniform activity distribution. The spatial activity distribution from SPECT imaging was convolved with this kernel representation using the discrete Fourier transform method to yield three-dimensional absorbed dose rate distribution. The accuracy of dose rates calculation was validated by software phantoms. The absorbed dose was determined by integration of the dose rate distribution for each volume of interest (VOI). Parameters for treatment optimization such as dose rate volume histograms and dose rate statistic are provided. A patient example was used to illustrate our dosimetric calculations

  14. Are Model Transferability And Complexity Antithetical? Insights From Validation of a Variable-Complexity Empirical Snow Model in Space and Time

    Lute, A. C.; Luce, Charles H.

    2017-11-01

    The related challenges of predictions in ungauged basins and predictions in ungauged climates point to the need to develop environmental models that are transferable across both space and time. Hydrologic modeling has historically focused on modelling one or only a few basins using highly parameterized conceptual or physically based models. However, model parameters and structures have been shown to change significantly when calibrated to new basins or time periods, suggesting that model complexity and model transferability may be antithetical. Empirical space-for-time models provide a framework within which to assess model transferability and any tradeoff with model complexity. Using 497 SNOTEL sites in the western U.S., we develop space-for-time models of April 1 SWE and Snow Residence Time based on mean winter temperature and cumulative winter precipitation. The transferability of the models to new conditions (in both space and time) is assessed using non-random cross-validation tests with consideration of the influence of model complexity on transferability. As others have noted, the algorithmic empirical models transfer best when minimal extrapolation in input variables is required. Temporal split-sample validations use pseudoreplicated samples, resulting in the selection of overly complex models, which has implications for the design of hydrologic model validation tests. Finally, we show that low to moderate complexity models transfer most successfully to new conditions in space and time, providing empirical confirmation of the parsimony principal.

  15. Comparison of Stepped Care Delivery Against a Single, Empirically Validated Cognitive-Behavioral Therapy Program for Youth With Anxiety: A Randomized Clinical Trial.

    Rapee, Ronald M; Lyneham, Heidi J; Wuthrich, Viviana; Chatterton, Mary Lou; Hudson, Jennifer L; Kangas, Maria; Mihalopoulos, Cathrine

    2017-10-01

    Stepped care is embraced as an ideal model of service delivery but is minimally evaluated. The aim of this study was to evaluate the efficacy of cognitive-behavioral therapy (CBT) for child anxiety delivered via a stepped-care framework compared against a single, empirically validated program. A total of 281 youth with anxiety disorders (6-17 years of age) were randomly allocated to receive either empirically validated treatment or stepped care involving the following: (1) low intensity; (2) standard CBT; and (3) individually tailored treatment. Therapist qualifications increased at each step. Interventions did not differ significantly on any outcome measures. Total therapist time per child was significantly shorter to deliver stepped care (774 minutes) compared with best practice (897 minutes). Within stepped care, the first 2 steps returned the strongest treatment gains. Stepped care and a single empirically validated program for youth with anxiety produced similar efficacy, but stepped care required slightly less therapist time. Restricting stepped care to only steps 1 and 2 would have led to considerable time saving with modest loss in efficacy. Clinical trial registration information-A Randomised Controlled Trial of Standard Care Versus Stepped Care for Children and Adolescents With Anxiety Disorders; http://anzctr.org.au/; ACTRN12612000351819. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  16. Usefulness of change ratio map in 99mTc-HMPAO SPECT with acetazolamide enhancement

    Yamamoto, Naoyuki

    1996-01-01

    Although a sequential 99m Tc-HMPAO SPECT technique with Diamox test (seq-SPECT) is a simple and time-saving procedure to assess brain perfusion reserve, the influence of the first dose of the tracer on the second one is not negligible. Therefore, a subtraction of the rest-SPECT from the 2nd SPECT is widely-used. However, subtracted SPECT images not only need to be corrected for the injected dose and the radiochemical purity due to inherent instability of HMPAO but also are usually degraded in quality. This study was undertaken to resolve these problems utilizing a change ratio (CR) map. The CR map was obtained by dividing 2nd SPECT by rest-SPECT. Prior to subtraction, the 2nd SPECT was normalized with the ratio of the mean whole brain counts between both SPECTs. To validate CR map, 7 patients were studied with both seq-SPECT and 133 Xe inhalation CBF measurement (Xe-CBF). The right to left count ratio obtained from the ROIs placed on MCA territory of CR map correlated well with that from Xe-CBF (r=0.89, p<0.01). Fifty-three patients with stroke underwent the seq-SPECT which was compared with the cerebral angiography (CAG) and classified into 4 groups according to the CR map. In 25 patients, all of the rest-, the subtracted-SPECT and the CR map did not show any difference between the affected side and the contralateral normal side. Seven patients with normal rest-SPECT showed decreased subtracted-SPECT counts and CR on the affected side. Three of them showed more than 75% stenosis on CAG. Four patients with the decreased counts both at the rest-and the subtracted-SPECT revealed no difference on the CR map suggesting the matched decrease of both blood flow and metabolism in the affected side. In conclusion, the CR map was a simple and useful method to evaluate the brain perfusion reserve with the seq-SPECT. (author)

  17. Empirical likelihood

    Owen, Art B

    2001-01-01

    Empirical likelihood provides inferences whose validity does not depend on specifying a parametric model for the data. Because it uses a likelihood, the method has certain inherent advantages over resampling methods: it uses the data to determine the shape of the confidence regions, and it makes it easy to combined data from multiple sources. It also facilitates incorporating side information, and it simplifies accounting for censored, truncated, or biased sampling.One of the first books published on the subject, Empirical Likelihood offers an in-depth treatment of this method for constructing confidence regions and testing hypotheses. The author applies empirical likelihood to a range of problems, from those as simple as setting a confidence region for a univariate mean under IID sampling, to problems defined through smooth functions of means, regression models, generalized linear models, estimating equations, or kernel smooths, and to sampling with non-identically distributed data. Abundant figures offer vi...

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

    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

  19. Silicon Detectors for PET and SPECT

    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

  20. Neuropsychiatry: PET and SPECT

    Quintana F, Juan Carlos

    2002-01-01

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

  1. Attenuation correction for SPECT

    Hosoba, Minoru

    1986-01-01

    Attenuation correction is required for the reconstruction of a quantitative SPECT image. A new method for detecting body contours, which are important for the correction of tissue attenuation, is presented. The effect of body contours, detected by the newly developed method, on the reconstructed images was evaluated using various techniques for attenuation correction. The count rates in the specified region of interest in the phantom image by the Radial Post Correction (RPC) method, the Weighted Back Projection (WBP) method, Chang's method were strongly affected by the accuracy of the contours, as compared to those by Sorenson's method. To evaluate the effect of non-uniform attenuators on the cardiac SPECT, computer simulation experiments were performed using two types of models, the uniform attenuator model (UAM) and the non-uniform attenuator model (NUAM). The RPC method showed the lowest relative percent error (%ERROR) in UAM (11 %). However, 20 to 30 percent increase in %ERROR was observed for NUAM reconstructed with the RPC, WBP, and Chang's methods. Introducing an average attenuation coefficient (0.12/cm for Tc-99m and 0.14/cm for Tl-201) in the RPC method decreased %ERROR to the levels for UAM. Finally, a comparison between images, which were obtained by 180 deg and 360 deg scans and reconstructed from the RPC method, showed that the degree of the distortion of the contour of the simulated ventricles in the 180 deg scan was 15 % higher than that in the 360 deg scan. (Namekawa, K.)

  2. A Reliable and Valid Weighted Scoring Instrument for Use in Grading APA-Style Empirical Research Report

    Greenberg, Kathleen Puglisi

    2012-01-01

    The scoring instrument described in this article is based on a deconstruction of the seven sections of an American Psychological Association (APA)-style empirical research report into a set of learning outcomes divided into content-, expression-, and format-related categories. A double-weighting scheme used to score the report yields a final grade…

  3. Empirical Validation of the Importance of Employees' Learning Motivation for Workplace E-Learning in Taiwanese Organisations

    Chen, Hsiu-Ju; Kao, Chia-Hung

    2012-01-01

    E-learning systems, adopted by organisations for employee training to enhance employees' performance, are characterised by self-directed, autonomous learning. Learning motivation is then of importance in the design of e-learning practices in workplace. However, empirical study of the alignment of e-learning with individual learning needs and…

  4. Complexity and accuracy of image registration methods in SPECT-guided radiation therapy

    Yin, L S; Duzenli, C; Moiseenko, V [Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1 (Canada); Tang, L; Hamarneh, G [Computing Science, Simon Fraser University, 9400 TASC1, Burnaby, BC, V5A 1S6 (Canada); Gill, B [Medical Physics, Vancouver Cancer Centre, BC Cancer Agency, 600 West 10th Ave, Vancouver, BC, V5Z 4E6 (Canada); Celler, A; Shcherbinin, S [Department of Radiology, University of British Columbia, 828 West 10th Ave, Vancouver, BC, V5Z 1L8 (Canada); Fua, T F; Thompson, A; Sheehan, F [Radiation Oncology, Vancouver Cancer Centre, BC Cancer Agency, 600 West 10th Ave, Vancouver, BC, V5Z 4E6 (Canada); Liu, M [Radiation Oncology, Fraser Valley Cancer Centre, BC Cancer Agency, 13750 9th Ave, Surrey, BC, V3V 1Z2 (Canada)], E-mail: lyin@bccancer.bc.ca

    2010-01-07

    The use of functional imaging in radiotherapy treatment (RT) planning requires accurate co-registration of functional imaging scans to CT scans. We evaluated six methods of image registration for use in SPECT-guided radiotherapy treatment planning. Methods varied in complexity from 3D affine transform based on control points to diffeomorphic demons and level set non-rigid registration. Ten lung cancer patients underwent perfusion SPECT-scans prior to their radiotherapy. CT images from a hybrid SPECT/CT scanner were registered to a planning CT, and then the same transformation was applied to the SPECT images. According to registration evaluation measures computed based on the intensity difference between the registered CT images or based on target registration error, non-rigid registrations provided a higher degree of accuracy than rigid methods. However, due to the irregularities in some of the obtained deformation fields, warping the SPECT using these fields may result in unacceptable changes to the SPECT intensity distribution that would preclude use in RT planning. Moreover, the differences between intensity histograms in the original and registered SPECT image sets were the largest for diffeomorphic demons and level set methods. In conclusion, the use of intensity-based validation measures alone is not sufficient for SPECT/CT registration for RTTP. It was also found that the proper evaluation of image registration requires the use of several accuracy metrics.

  5. Test anxiety and the validity of cognitive tests: A confirmatory factor analysis perspective and some empirical findings

    Wicherts, J.M.; Zand Scholten, A.

    2010-01-01

    The validity of cognitive ability tests is often interpreted solely as a function of the cognitive abilities that these tests are supposed to measure, but other factors may be at play. The effects of test anxiety on the criterion related validity (CRV) of tests was the topic of a recent study by

  6. Evaluation of left ventricular function using electrocardiographically gated myocardial SPECT with (123)I-labeled fatty acid analog.

    Nanasato, M; Ando, A; Isobe, S; Nonokawa, M; Hirayama, H; Tsuboi, N; Ito, T; Hirai, M; Yokota, M; Saito, H

    2001-12-01

    Electrocardiographically (ECG) gated myocardial SPECT with (99m)Tc-tetrofosmin has been used widely to assess left ventricular (LV) function. However, the accuracy of variables using ECG gated myocardial SPECT with beta-methyl-p-(123)I-iodophenylpentadecanoic acid (BMIPP) has not been well defined. Thirty-six patients (29 men, 7 women; mean age, 61.6 +/- 15.6 y) with ischemic heart disease underwent ECG gated myocardial SPECT with (123)I-BMIPP and with (99m)Tc-tetrofosmin and left ventriculography (LVG) within 1 wk. LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), and LV end-systolic volume (LVESV) were determined on gated SPECT using commercially available software for automatic data analysis. These volume-related items on LVG were calculated with an area-length method and were estimated by 2 independent observers to evaluate interobserver validity. The regional wall motion with these methods was assessed visually. LVEF was 41.1% +/- 12.5% on gated SPECT with (123)I-BMIPP, 44.5% +/- 13.1% on gated SPECT with (99m)Tc-tetrofosmin, and 46.0% +/- 12.7% on LVG. Global LV function and regional wall motion between both gated SPECT procedures had excellent correlation (LVEF, r = 0.943; LVEDV, r = 0.934; LVESV, r = 0.952; regional wall motion, kappa = 0.92). However, the correlations of global LV function and regional wall motion between each gated SPECT and LVG were significantly lower. Gated SPECT with (123)I-BMIPP showed the same interobserver validity as gated SPECT with (99m)Tc-tetrofosmin. Gated SPECT with (123)I-BMIPP provides high accuracy with regard to LV function and is sufficiently applicable for use in clinical SPECT. This technique can simultaneously reveal myocardial fatty acid metabolism and LV function, which may be useful to evaluate various cardiac diseases.

  7. Serial SPECT in children with partial epilepsy

    Hosoya, Machiko; Ushiku, Hideo

    1995-01-01

    We performed serial single-photon emission CT (SPECT) with N-isopropyl-p-( 123 I)-Iodoamphetamine to measure the regional cerebral blood flow (rCBF) in 15 children with partial epilepsy. SPECT showed focal changes in 14 cases. Ten cases had abnormalities in the initial SPECT and another four cases in the second test. The cases with normal rCBF in initial SPECT had been tested in an early phase after the onset, and then decreased rCBF were observed in the second SPECT. The cases with both abnormal rCBF in the initial SPECT and improved rCBF in the second SPECT showed good prognosis in clinico-electrophysiological evolutions. In cases with abnormal changes of rCBF in the second SPECT, clinical prognosis was found to be not so good. These findings suggest that serial SPECT may be used to follow the course of epilepsy. (author)

  8. Sci—Thur AM: YIS - 09: Validation of a General Empirically-Based Beam Model for kV X-ray Sources

    Poirier, Y. [CancerCare Manitoba (Canada); University of Calgary (Canada); Sommerville, M.; Johnstone, C.D. [San Diego State University (United States); Gräfe, J.; Nygren, I.; Jacso, F. [Tom Baker Cancer Centre (Canada); Khan, R.; Villareal-Barajas, J.E. [University of Calgary (Canada); Tom Baker Cancer Centre (Canada); Tambasco, M. [University of Calgary (Canada); San Diego State University (United States)

    2014-08-15

    Purpose: To present an empirically-based beam model for computing dose deposited by kilovoltage (kV) x-rays and validate it for radiographic, CT, CBCT, superficial, and orthovoltage kV sources. Method and Materials: We modeled a wide variety of imaging (radiographic, CT, CBCT) and therapeutic (superficial, orthovoltage) kV x-ray sources. The model characterizes spatial variations of the fluence and spectrum independently. The spectrum is derived by matching measured values of the half value layer (HVL) and nominal peak potential (kVp) to computationally-derived spectra while the fluence is derived from in-air relative dose measurements. This model relies only on empirical values and requires no knowledge of proprietary source specifications or other theoretical aspects of the kV x-ray source. To validate the model, we compared measured doses to values computed using our previously validated in-house kV dose computation software, kVDoseCalc. The dose was measured in homogeneous and anthropomorphic phantoms using ionization chambers and LiF thermoluminescent detectors (TLDs), respectively. Results: The maximum difference between measured and computed dose measurements was within 2.6%, 3.6%, 2.0%, 4.8%, and 4.0% for the modeled radiographic, CT, CBCT, superficial, and the orthovoltage sources, respectively. In the anthropomorphic phantom, the computed CBCT dose generally agreed with TLD measurements, with an average difference and standard deviation ranging from 2.4 ± 6.0% to 5.7 ± 10.3% depending on the imaging technique. Most (42/62) measured TLD doses were within 10% of computed values. Conclusions: The proposed model can be used to accurately characterize a wide variety of kV x-ray sources using only empirical values.

  9. Empirical model for chlorophyll-a determination in inland waters from the forthcoming Sentinel-2 and 3. Validation from HICO images

    J. Delegido

    2014-06-01

    Full Text Available Chlorophyll-a concentration is one of the main indicators of inland waters quality. Using CHRIS/PROBA images and in situ data obtained in four lakes in Colombia and Spain, we obtained empirical models for the estimation of chlorophyll-a concentration, which can be directly applied to future images of MSI Sentinel-2 and OLCI Sentinel-3 sensors. The models, based on spectral band indices, were validated with data from the hyperspectral sensor HICO, onboard of the International Space Station.

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

    Gnanasegaran, Gopinath; Ballinger, James R.

    2014-01-01

    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.)

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

    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.)

  12. Measurement of informal care: an empirical study into the valid measurement of time spent on informal caregiving.

    Berg, Bernard van den; Spauwen, Pol

    2006-01-01

    The incorporation of informal care into economic evaluations of health care is troublesome. The debate focuses on the valuation of time spent on informal caregiving, while time measurement, a related and may be even a more important issue, tends to be neglected. Valid time measurement is a necessary

  13. Computer-aided assessment of aviation pilots attention: Design of an integrated test and its empirical validation

    Rosario Cannavò

    2016-01-01

    In this paper, we present a battery of seven computerized tests, encompassing classical and innovative solutions inspired by the literature in the field, for the integrated measurement of the attention factors of aviation pilots. The computer software is validated by means of an experimental trial with 50 experienced aviation pilots and 50 untrained people as controls. Statistical analyzes confirm that the instrument can effectively classify aviation pilots, and identify a subset of distinctive attention factors that could be used for monitoring their duty.

  14. New Empirical Evidence on the Validity and the Reliability of the Early Life Stress Questionnaire in a Polish Sample.

    Sokołowski, Andrzej; Dragan, Wojciech Ł

    2017-01-01

    Background: The Early Life Stress Questionnaire (ELSQ) is widely used to estimate the prevalence of negative events during childhood, including emotional, physical, verbal, sexual abuse, negligence, severe conflicts, separation, parental divorce, substance abuse, poverty, and so forth. Objective: This study presents the psychometric properties of the Polish adaptation of the ELSQ. It also verifies if early life stress (ELS) is a good predictor of psychopathology symptoms during adulthood. Materials and Methods: We analyzed data from two samples. Sample 1 was selected by random quota method from across the country and included 609 participants aged 18-50 years, 306 women (50.2%) and 303 men (49.8%). Sample 2 contained 503 young adults (253 women and 250 men) aged 18-25. Confirmatory and exploratory factor analyses were used to measure ELSQ internal consistency. The validity was based on the relation to psychopathological symptoms and substance misuse. Results: Results showed good internal consistency and validity. Exploratory factor analysis indicates a six-factor structure of the ELSQ. ELS was related to psychopathology in adulthood, including depressive, sociophobic, vegetative as well as pain symptoms. ELSQ score correlated also with alcohol use, but not nicotine dependence. Moreover, ELS was correlated with stress in adulthood. Conclusion: The findings indicate that the Polish version of the ELSQ is a valid and reliable instrument for assessing ELS in the Polish population and may be applied in both clinical and community samples.

  15. Practical reconstruction protocol for quantitative 90Y bremsstrahlung SPECT/CT

    Siman, W.; Mikell, J. K.; Kappadath, S. C.

    2016-01-01

    Purpose: To develop a practical background compensation (BC) technique to improve quantitative 90 Y-bremsstrahlung single-photon emission computed tomography (SPECT)/computed tomography (CT) using a commercially available imaging system. Methods: All images were acquired using medium-energy collimation in six energy windows (EWs), ranging from 70 to 410 keV. The EWs were determined based on the signal-to-background ratio in planar images of an acrylic phantom of different thicknesses (2–16 cm) positioned below a 90 Y source and set at different distances (15–35 cm) from a gamma camera. The authors adapted the widely used EW-based scatter-correction technique by modeling the BC as scaled images. The BC EW was determined empirically in SPECT/CT studies using an IEC phantom based on the sphere activity recovery and residual activity in the cold lung insert. The scaling factor was calculated from 20 clinical planar 90 Y images. Reconstruction parameters were optimized in the same SPECT images for improved image quantification and contrast. A count-to-activity calibration factor was calculated from 30 clinical 90 Y images. Results: The authors found that the most appropriate imaging EW range was 90–125 keV. BC was modeled as 0.53× images in the EW of 310–410 keV. The background-compensated clinical images had higher image contrast than uncompensated images. The maximum deviation of their SPECT calibration in clinical studies was lowest (<10%) for SPECT with attenuation correction (AC) and SPECT with AC + BC. Using the proposed SPECT-with-AC + BC reconstruction protocol, the authors found that the recovery coefficient of a 37-mm sphere (in a 10-mm volume of interest) increased from 39% to 90% and that the residual activity in the lung insert decreased from 44% to 14% over that of SPECT images with AC alone. Conclusions: The proposed EW-based BC model was developed for 90 Y bremsstrahlung imaging. SPECT with AC + BC gave improved lesion detectability and activity

  16. Practical reconstruction protocol for quantitative {sup 90}Y bremsstrahlung SPECT/CT

    Siman, W.; Mikell, J. K.; Kappadath, S. C., E-mail: skappadath@mdanderson.org [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States)

    2016-09-15

    Purpose: To develop a practical background compensation (BC) technique to improve quantitative {sup 90}Y-bremsstrahlung single-photon emission computed tomography (SPECT)/computed tomography (CT) using a commercially available imaging system. Methods: All images were acquired using medium-energy collimation in six energy windows (EWs), ranging from 70 to 410 keV. The EWs were determined based on the signal-to-background ratio in planar images of an acrylic phantom of different thicknesses (2–16 cm) positioned below a {sup 90}Y source and set at different distances (15–35 cm) from a gamma camera. The authors adapted the widely used EW-based scatter-correction technique by modeling the BC as scaled images. The BC EW was determined empirically in SPECT/CT studies using an IEC phantom based on the sphere activity recovery and residual activity in the cold lung insert. The scaling factor was calculated from 20 clinical planar {sup 90}Y images. Reconstruction parameters were optimized in the same SPECT images for improved image quantification and contrast. A count-to-activity calibration factor was calculated from 30 clinical {sup 90}Y images. Results: The authors found that the most appropriate imaging EW range was 90–125 keV. BC was modeled as 0.53× images in the EW of 310–410 keV. The background-compensated clinical images had higher image contrast than uncompensated images. The maximum deviation of their SPECT calibration in clinical studies was lowest (<10%) for SPECT with attenuation correction (AC) and SPECT with AC + BC. Using the proposed SPECT-with-AC + BC reconstruction protocol, the authors found that the recovery coefficient of a 37-mm sphere (in a 10-mm volume of interest) increased from 39% to 90% and that the residual activity in the lung insert decreased from 44% to 14% over that of SPECT images with AC alone. Conclusions: The proposed EW-based BC model was developed for {sup 90}Y bremsstrahlung imaging. SPECT with AC + BC gave improved lesion

  17. SPECT in Focal Epilepsies

    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.

  18. SPECT imaging with resolution recovery

    Bronnikov, A. V.

    2011-01-01

    Single-photon emission computed tomography (SPECT) is a method of choice for imaging spatial distributions of radioisotopes. Many applications of this method are found in nuclear industry, medicine, and biomedical research. We study mathematical modeling of a micro-SPECT system by using a point-spread function (PSF) and implement an OSEM-based iterative algorithm for image reconstruction with resolution recovery. Unlike other known implementations of the OSEM algorithm, we apply en efficient computation scheme based on a useful approximation of the PSF, which ensures relatively fast computations. The proposed approach can be applied with the data acquired with any type of collimators, including parallel-beam fan-beam, cone-beam and pinhole collimators. Experimental results obtained with a micro SPECT system demonstrate high efficiency of resolution recovery. (authors)

  19. Organ volume estimation using SPECT

    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...

  20. PET and SPECT in neurology

    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.

  1. PET and SPECT in neurology

    Dierckx, Rudi A.J.O.; Ghent Univ.; Vries, Erik F.J. de; Waarde, Aren van; Otte, Andreas

    2014-01-01

    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.

  2. Normal anatomy of lung perfusion SPECT scintigraphy

    Moskowitz, G.W.; Levy, L.M.

    1987-01-01

    Ten patients studies for possible pulmonary embolic disease had normal lung perfusion planar and SPECT scintigraphy. A computer program was developed to superimpose the CT scans on corresponding SPECT images. Superimposition of CT scans on corresponding SPECT transaxial cross-sectional images, when available, provides the needed definition and relationships of adjacent organs. SPECT transaxial sections provide clear anatomic definition of perfusion defects without foreground and background lung tissue superimposed. The location, shape, and size of the perfusion defects can be readily assessed by SPECT. An algorithm was developed for the differentiation of abnormal pulmonary perfusion patterns from normal structures on variation

  3. Empirical validation of statistical parametric mapping for group imaging of fast neural activity using electrical impedance tomography.

    Packham, B; Barnes, G; Dos Santos, G Sato; Aristovich, K; Gilad, O; Ghosh, A; Oh, T; Holder, D

    2016-06-01

    Electrical impedance tomography (EIT) allows for the reconstruction of internal conductivity from surface measurements. A change in conductivity occurs as ion channels open during neural activity, making EIT a potential tool for functional brain imaging. EIT images can have  >10 000 voxels, which means statistical analysis of such images presents a substantial multiple testing problem. One way to optimally correct for these issues and still maintain the flexibility of complicated experimental designs is to use random field theory. This parametric method estimates the distribution of peaks one would expect by chance in a smooth random field of a given size. Random field theory has been used in several other neuroimaging techniques but never validated for EIT images of fast neural activity, such validation can be achieved using non-parametric techniques. Both parametric and non-parametric techniques were used to analyze a set of 22 images collected from 8 rats. Significant group activations were detected using both techniques (corrected p  <  0.05). Both parametric and non-parametric analyses yielded similar results, although the latter was less conservative. These results demonstrate the first statistical analysis of such an image set and indicate that such an analysis is an approach for EIT images of neural activity.

  4. [Validity of axis III "Conflicts" of Operationalized Psychodynamic Diagnostics (OPD-1)--empirical results and conclusions for OPD-2].

    Schneider, Gudrun; Mendler, Till; Heuft, Gereon; Burgmer, Markus

    2008-01-01

    Using specific psychometric instruments, we investigate criteria-related validity of axis III ("conflicts") of OPD-1 by a priori formulated hypotheses concerning the relations to the main conflict/mode. A consecutive sample of 105 psychotherapy inpatients was examined using self-assessment scales (Inventory of Interpersonal Problems; Rosenberg Self-Esteem Scale, Test of Self-Conscious Affect; Toronto Alexithymia-Scale; Frankfurt Self Concept Scales) and videotaped OPD research interviews in the first week after admission to the hospital. Two OPD-certified raters first rated the interviews independently, then in a consensus rating. Due to the different frequency of the main conflict and mode, evaluation of 4 of 7 conflicts was possible. The a priori hypotheses could be confirmed for the conflicts Dependence versus Autonomy (both modes), Submission versus Control (active mode), Desire for Care versus Autarchy (active mode), and Self-Value (passive mode). Confirmation of the a priori hypotheses indicates validity of axis III (Conflicts) of OPD. We discuss the small numbers of some conflicts, the comparison of expert rating OPD with self-assessment and the meaning of the results for OPD-2.

  5. Radiopharmaceuticals for SPECT cancer detection

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

    2016-08-02

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

  6. Lymphoscintigraphic sentinel node identification in patients with breast cancer: the role of SPECT-CT

    Lerman, H.; Metser, U.; Lievshitz, G.; Sperber, F.; Shneebaum, S.; Even-Sapir, E.

    2006-01-01

    Lymph node status is a major factor in determining the stage, appropriate therapy and outcome in patients with breast cancer. It is therefore of clinical importance to accurately identify all sentinel nodes (SNs) for each individual tumour before surgery. The purpose of this study was to assess the role of SPECT-CT lymphoscintigraphy in SN identification in patients with breast cancer. Lymphoscintigraphy comprising planar and SPECT-CT acquisition was performed in 157 consecutive patients with breast cancer (mean age 54.7±10.6, range 27-81 years) with a palpable mass (n=100), with a non-palpable mass (n=52) or post lumpectomy (n=5). Planar and SPECT-CT images were interpreted separately and the two imaging techniques were compared with respect to their ability to identify hot nodes. Planar imaging alone was negative for identification of hot nodes in 15% of the patients. SPECT-CT alone was negative in 10% and both techniques were negative in 9% of the patients. Forty-six of the total of 361 (13%) hot nodes identified by lymphoscintigraphy were detected only on SPECT-CT, including 21 nodes obscured by the scattered radiation from the injection site, nine adjacent nodes misinterpreted on planar images as a single node and 16 nodes which were missed on planar images and detected on SPECT data. SPECT-CT detected additional sites of drainage unexpected on planar images, including axillary (n=23 patients), internal mammary (n=5 patients), interpectoral (n=3 patients) and intramammary (n=2 patients) lymph node sites. Fourteen of the 329 (4%) hot lesions seen on planar images were false positive non-nodal sites of uptake that were accurately assessed by SPECT-CT and further validated by surgery. In a single patient, SPECT-CT was negative while planar images identified the SN. (orig.)

  7. Validation of new empirical model for self-leveling behavior of cylindrical particle beds based on experimental database

    Morita, Koji; Matsumoto, Tatsuya; Taketa, Shohei; Nishi, Shinpei; Cheng, Songbai; Suzuki, Tohru; Tobita, Yoshiharu

    2014-01-01

    During a material relocation phase of core disruptive accidents (CDAs) in sodium cooled fast reactors (SFRs), debris beds can be formed in the lower plenum region due to rapid quenching and fragmentation of molten core materials. Heat removal from debris beds is crucial to achieve so called in-vessel retention (IVR) of degraded core materials. Coolant boiling in the beds may lead to leveling of their mound shape, and then changes coolability of the beds with decay heat as well as neutronic characteristics. To clarify the mechanisms underlying this self-leveling behavior, several series of experiments using simulant materials has been performed in collaboration between Japan Atomic Energy Agency (JAEA) and Kyushu University in Japan. In the present study, experiments in a cylindrical system were employed to develop experimental data on self-leveling process of particle beds. In the experiments, to simulate the coolant boiling due to the decay heat in fuel, nitrogen gas was percolated uniformly through the bottom of the particle bed with a conical shape mound using a gas injection method. Time variations in bed height during the self-leveling process were measured for key experimental parameters on particle size, density and sphericity, and gas flow rate. Using a dimensional analysis approach, a new model was proposed to correlate the experimental data on transient bed height with an empirical equation using a characteristic time of self-leveling development and a terminal equilibrium height of the bed. It was demonstrated that the proposed model predicts self-leveling development of particle beds with reasonable accuracy in the present ranges of experimental conditions. (author)

  8. A SPECT study in internal carotid artery occlusion: Discrepancies between flow image and neurologic deficits

    Moriwaki, H.; Hougaku, H.; Matsuda, I.; Kusunoki, M.; Shirai, J.

    1989-01-01

    A SPECT (single photon emission computed tomography) study in internal carotid artery (ICA) occlusion was performed in 6 patients. The validity of iodoamphetamine (IMP) SPECT study in the evaluation of cerebral blood flow (CBF) or neurologic function is still controversial. In this study, the authors showed several cases in whom SPECT images of brain were not compatible with their neurologic deficits. In 2 typical cases, a large low-density area was observed in the non-dominant hemisphere in computed tomography (CT) scan, but no apparent motor-sensory deficits in left limbs were present. In these patients, SPECT study also revealed flow reduction in the affected side of the brain. So there was a possibility that an IMP brain image could not always reflect CBF, which maintains neurologic function of the brain

  9. Typology of Couples Entering Alcohol Behavioral Couple Therapy: An Empirical Approach and Test of Predictive Validity on Treatment Response.

    Ladd, Benjamin O; McCrady, Barbara S

    2016-01-01

    This study aimed to examine whether classification of couples in which one partner has an alcohol problem is similar to that reported in the general couples literature. Typologies of couples seeking alcohol behavioral couple therapy (ABCT) were developed via hierarchical cluster analysis using behavioral codes of couple interactions during their first ABCT session. Four couples types based on in-session behavior were established reliably, labeled avoider, validator, hostile, and ambivalent-detached. These couple types resembled couples types found in previous research. Couple type was associated with baseline relationship satisfaction, but not alcohol use. Results suggest heterogeneity in couples with alcohol problems presenting to treatment; further study is needed to investigate the function of alcohol within these different types. © 2015 American Association for Marriage and Family Therapy.

  10. Empirically Derived Dehydration Scoring and Decision Tree Models for Children With Diarrhea: Assessment and Internal Validation in a Prospective Cohort Study in Dhaka, Bangladesh.

    Levine, Adam C; Glavis-Bloom, Justin; Modi, Payal; Nasrin, Sabiha; Rege, Soham; Chu, Chieh; Schmid, Christopher H; Alam, Nur H

    2015-08-18

    Diarrhea remains one of the most common and most deadly conditions affecting children worldwide. Accurately assessing dehydration status is critical to determining treatment course, yet no clinical diagnostic models for dehydration have been empirically derived and validated for use in resource-limited settings. In the Dehydration: Assessing Kids Accurately (DHAKA) prospective cohort study, a random sample of children under 5 with acute diarrhea was enrolled between February and June 2014 in Bangladesh. Local nurses assessed children for clinical signs of dehydration on arrival, and then serial weights were obtained as subjects were rehydrated. For each child, the percent weight change with rehydration was used to classify subjects with severe dehydration (>9% weight change), some dehydration (3-9%), or no dehydration (Dehydration Score and DHAKA Dehydration Tree, respectively. Models were assessed for their accuracy using the area under their receiver operating characteristic curve (AUC) and for their reliability through repeat clinical exams. Bootstrapping was used to internally validate the models. A total of 850 children were enrolled, with 771 included in the final analysis. Of the 771 children included in the analysis, 11% were classified with severe dehydration, 45% with some dehydration, and 44% with no dehydration. Both the DHAKA Dehydration Score and DHAKA Dehydration Tree had significant AUCs of 0.79 (95% CI = 0.74, 0.84) and 0.76 (95% CI = 0.71, 0.80), respectively, for the diagnosis of severe dehydration. Additionally, the DHAKA Dehydration Score and DHAKA Dehydration Tree had significant positive likelihood ratios of 2.0 (95% CI = 1.8, 2.3) and 2.5 (95% CI = 2.1, 2.8), respectively, and significant negative likelihood ratios of 0.23 (95% CI = 0.13, 0.40) and 0.28 (95% CI = 0.18, 0.44), respectively, for the diagnosis of severe dehydration. Both models demonstrated 90% agreement between independent raters and good

  11. Co-registered perfusion SPECT/CT: Utility for prediction of improved postoperative outcome in lung volume reduction surgery candidates

    Takenaka, Daisuke; Ohno, Yoshiharu; Koyama, Hisanobu; Nogami, Munenobu; Onishi, Yumiko; Matsumoto, Keiko; Yoshikawa, Takeshi; Matsumoto, Sumiaki; Sugimura, Kazuro

    2010-01-01

    Purpose: To directly compare the capabilities of perfusion scan, SPECT, co-registered SPECT/CT, and quantitatively and qualitatively assessed MDCT (i.e. quantitative CT and qualitative CT) for predicting postoperative clinical outcome for lung volume reduction surgery (LVRS) candidates. Materials and methods: Twenty-five consecutive candidates (19 men and six women, age range: 42-72 years) for LVRS underwent preoperative CT and perfusion scan with SPECT. Clinical outcome of LVRS for all subjects was also assessed by determining the difference between pre- and postoperative forced expiratory volume in 1 s (FEV 1 ) and 6-min walking distance (6MWD). All SPECT examinations were performed on a SPECT scanner, and co-registered to thin-section CT by using commercially available software. On planar imaging, SPECT and SPECT/CT, upper versus lower zone or lobe ratios (U/Ls) were calculated from regional uptakes between upper and lower lung fields in the operated lung. On quantitatively assessed CT, U/L for all subjects was assessed from regional functional lung volumes. On qualitatively assessed CT, planar imaging, SPECT and co-registered SPECT/CT, U/Ls were assessed with a 4-point visual scoring system. To compare capabilities of predicting clinical outcome, each U/L was statistically correlated with the corresponding clinical outcome. Results: Significantly fair or moderate correlations were observed between quantitatively and qualitatively assessed U/Ls obtained with all four methods and clinical outcomes (-0.60 ≤ r ≤ -0.42, p < 0.05). Conclusion: Co-registered perfusion SPECT/CT has better correlation with clinical outcome in LVRS candidates than do planar imaging, SPECT or qualitatively assessed CT, and is at least as valid as quantitatively assessed CT.

  12. Co-registered perfusion SPECT/CT: Utility for prediction of improved postoperative outcome in lung volume reduction surgery candidates

    Takenaka, Daisuke [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.j [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan); Koyama, Hisanobu [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan); Nogami, Munenobu [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan); Division of Image-Based Medicine, Institute of Biomedical Research and Innovation, 2-2, Minatojima Minamimachi Chuo-ku, Kobe, Hyogo, 650-0047 (Japan); Onishi, Yumiko [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan); Matsumoto, Keiko [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan); Department of Radiology, University of Yamanashi, 1110 Shimogato, Chuo, Yamanashi, 409-3898 (Japan); Yoshikawa, Takeshi; Matsumoto, Sumiaki; Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017 (Japan)

    2010-06-15

    Purpose: To directly compare the capabilities of perfusion scan, SPECT, co-registered SPECT/CT, and quantitatively and qualitatively assessed MDCT (i.e. quantitative CT and qualitative CT) for predicting postoperative clinical outcome for lung volume reduction surgery (LVRS) candidates. Materials and methods: Twenty-five consecutive candidates (19 men and six women, age range: 42-72 years) for LVRS underwent preoperative CT and perfusion scan with SPECT. Clinical outcome of LVRS for all subjects was also assessed by determining the difference between pre- and postoperative forced expiratory volume in 1 s (FEV{sub 1}) and 6-min walking distance (6MWD). All SPECT examinations were performed on a SPECT scanner, and co-registered to thin-section CT by using commercially available software. On planar imaging, SPECT and SPECT/CT, upper versus lower zone or lobe ratios (U/Ls) were calculated from regional uptakes between upper and lower lung fields in the operated lung. On quantitatively assessed CT, U/L for all subjects was assessed from regional functional lung volumes. On qualitatively assessed CT, planar imaging, SPECT and co-registered SPECT/CT, U/Ls were assessed with a 4-point visual scoring system. To compare capabilities of predicting clinical outcome, each U/L was statistically correlated with the corresponding clinical outcome. Results: Significantly fair or moderate correlations were observed between quantitatively and qualitatively assessed U/Ls obtained with all four methods and clinical outcomes (-0.60 {<=} r {<=} -0.42, p < 0.05). Conclusion: Co-registered perfusion SPECT/CT has better correlation with clinical outcome in LVRS candidates than do planar imaging, SPECT or qualitatively assessed CT, and is at least as valid as quantitatively assessed CT.

  13. Empirical support for DSM-IV schizoaffective disorder: clinical and cognitive validators from a large patient sample.

    DeRosse, Pamela; Burdick, Katherine E; Lencz, Todd; Siris, Samuel G; Malhotra, Anil K

    2013-01-01

    The diagnosis of schizoaffective disorder has long maintained an uncertain status in psychiatric nosology. Studies comparing clinical and biological features of patients with schizoaffective disorder to patients with related disorders [e.g., schizophrenia and bipolar disorder] can provide an evidence base for judging the validity of the diagnostic category. However, because most prior studies of schizoaffective disorder have only evaluated differences between groups at a static timepoint, it is unclear how these disorders may be related when the entire illness course is taken into consideration. We ascertained a large cohort [N = 993] of psychiatric patients with a range of psychotic diagnoses including schizophrenia with no history of major affective episodes [SZ-; N = 371], schizophrenia with a superimposed mood syndrome [SZ+; N = 224], schizoaffective disorder [SAD; N = 129] and bipolar I disorder with psychotic features [BPD+; N = 269]. Using cross-sectional data we designed key clinical and neurocognitive dependent measures that allowed us to test longitudinal hypotheses about the differences between these diagnostic entities. Large differences between diagnostic groups on several demographic and clinical variables were observed. Most notably, groups differed on a putative measure of cognitive decline. Specifically, the SAD group demonstrated significantly greater post-onset cognitive decline compared to the BP+ group, with the SZ- and SZ+ group both exhibiting levels of decline intermediate to BPD+ and SAD. These results suggest that schizoaffective disorder may possess distinct features. Contrary to earlier formulations, schizoaffective disorder may be a more severe form of illness.

  14. PET and SPECT in psychiatry

    Dierckx, Rudi A.J.O.; Otte, Andreas; Vries, Erik F.J. de; Waarde, Aren van

    2014-01-01

    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

    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. PET and SPECT in psychiatry

    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.

  17. The Cognitive Assessment Interview (CAI): development and validation of an empirically derived, brief interview-based measure of cognition.

    Ventura, Joseph; Reise, Steven P; Keefe, Richard S E; Baade, Lyle E; Gold, James M; Green, Michael F; Kern, Robert S; Mesholam-Gately, Raquelle; Nuechterlein, Keith H; Seidman, Larry J; Bilder, Robert M

    2010-08-01

    Practical, reliable "real world" measures of cognition are needed to supplement neurocognitive performance data to evaluate possible efficacy of new drugs targeting cognitive deficits associated with schizophrenia. Because interview-based measures of cognition offer one possible approach, data from the MATRICS initiative (n=176) were used to examine the psychometric properties of the Schizophrenia Cognition Rating Scale (SCoRS) and the Clinical Global Impression of Cognition in Schizophrenia (CGI-CogS). We used classical test theory methods and item response theory to derive the 10-item Cognitive Assessment Interview (CAI) from the SCoRS and CGI-CogS ("parent instruments"). Sources of information for CAI ratings included the patient and an informant. Validity analyses examined the relationship between the CAI and objective measures of cognitive functioning, intermediate measures of cognition, and functional outcome. The rater's score from the newly derived CAI (10 items) correlate highly (r=.87) with those from the combined set of the SCoRS and CGI-CogS (41 items). Both the patient (r=.82) and the informant (r=.95) data were highly correlated with the rater's score. The CAI was modestly correlated with objectively measured neurocognition (r=-.32), functional capacity (r=-.44), and functional outcome (r=-.32), which was comparable to the parent instruments. The CAI allows for expert judgment in evaluating a patient's cognitive functioning and was modestly correlated with neurocognitive functioning, functional capacity, and functional outcome. The CAI is a brief, repeatable, and potentially valuable tool for rating cognition in schizophrenia patients who are participating in clinical trials. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Empirical support for DSM-IV schizoaffective disorder: clinical and cognitive validators from a large patient sample.

    Pamela DeRosse

    Full Text Available The diagnosis of schizoaffective disorder has long maintained an uncertain status in psychiatric nosology. Studies comparing clinical and biological features of patients with schizoaffective disorder to patients with related disorders [e.g., schizophrenia and bipolar disorder] can provide an evidence base for judging the validity of the diagnostic category. However, because most prior studies of schizoaffective disorder have only evaluated differences between groups at a static timepoint, it is unclear how these disorders may be related when the entire illness course is taken into consideration.We ascertained a large cohort [N = 993] of psychiatric patients with a range of psychotic diagnoses including schizophrenia with no history of major affective episodes [SZ-; N = 371], schizophrenia with a superimposed mood syndrome [SZ+; N = 224], schizoaffective disorder [SAD; N = 129] and bipolar I disorder with psychotic features [BPD+; N = 269]. Using cross-sectional data we designed key clinical and neurocognitive dependent measures that allowed us to test longitudinal hypotheses about the differences between these diagnostic entities.Large differences between diagnostic groups on several demographic and clinical variables were observed. Most notably, groups differed on a putative measure of cognitive decline. Specifically, the SAD group demonstrated significantly greater post-onset cognitive decline compared to the BP+ group, with the SZ- and SZ+ group both exhibiting levels of decline intermediate to BPD+ and SAD.These results suggest that schizoaffective disorder may possess distinct features. Contrary to earlier formulations, schizoaffective disorder may be a more severe form of illness.

  19. Effect of bypass on the motor activation SPECT compared to the acetazolamide SPECT

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

    2002-03-01

    The authors evaluated and analyzed motor activation single photon emission computed tomography (M-SPECT) in ischemic cerebrovascular disease compared to resting and acetazolamide (ACZ) activated SPECT studies. Seventeen cases with STA-MCA bypass performed for ischemic cerebrovascular disease were examined. The SPECT studies consisting of resting, ACZ activation, and motor activation stages were performed before bypass, at 1 month, and 3 months after bypass. The result of the M-SPECT was expressed as negative or positive. Before bypass: In all 17 cases, SPECT studies of the affected side showed reduction of resting cerebral blood flow (CBF) and reduction of cerebrovascular reserve capacity (CVRC). Eight cases were positive in the M-SPECT study. One week after bypass: The resting CBF increased in seven cases. Four showed preoperative positive M-SPECT. Eight cases showed improvement of the CVRC. Twelve cases were positive in M-SPECT, and two were negative in the preoperative M-SPECT. Three months after bypass: Thirteen cases showed improvement in the resting CBF, and fourteen cases showed improvement of the CVRC. Fourteen cases were positive in the M-SPECT, and among these, 6 were negative in the preoperative M-SPECT. There was a discrepancy between the improvement in CVRC and M-SPECT. M-SPECT study can provide information about the degree of hemodynamic compromise and effect of bypass surgery. (author)

  20. Effect of bypass on the motor activation SPECT compared to the acetazolamide SPECT

    Kawaguchi, Shoichiro; Iwahashi, Hideaki; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime

    2002-01-01

    The authors evaluated and analyzed motor activation single photon emission computed tomography (M-SPECT) in ischemic cerebrovascular disease compared to resting and acetazolamide (ACZ) activated SPECT studies. Seventeen cases with STA-MCA bypass performed for ischemic cerebrovascular disease were examined. The SPECT studies consisting of resting, ACZ activation, and motor activation stages were performed before bypass, at 1 month, and 3 months after bypass. The result of the M-SPECT was expressed as negative or positive. Before bypass: In all 17 cases, SPECT studies of the affected side showed reduction of resting cerebral blood flow (CBF) and reduction of cerebrovascular reserve capacity (CVRC). Eight cases were positive in the M-SPECT study. One week after bypass: The resting CBF increased in seven cases. Four showed preoperative positive M-SPECT. Eight cases showed improvement of the CVRC. Twelve cases were positive in M-SPECT, and two were negative in the preoperative M-SPECT. Three months after bypass: Thirteen cases showed improvement in the resting CBF, and fourteen cases showed improvement of the CVRC. Fourteen cases were positive in the M-SPECT, and among these, 6 were negative in the preoperative M-SPECT. There was a discrepancy between the improvement in CVRC and M-SPECT. M-SPECT study can provide information about the degree of hemodynamic compromise and effect of bypass surgery. (author)

  1. Voxel-by-voxel analysis of ECD-brain SPECT can separate penumbra from irreversibly damaged tissue at the acute phase of stroke

    Darcourt, J.; Migneco, O.; David, O.; Bussiere, F.; Mahagne, M.H.; Dunac, A.; Baron, J.C.

    2002-01-01

    Aim. At the acute phase of ischemic stroke, the target of treatment is still salvageable hypoperfused cerebral tissue; so called penumbra. We tested the possibility of separating on early ECD brain SPECT penumbral voxels (P) from irreversibly damaged damaged tissue (IDT). We used ECD which is not only a perfusion tracer but also a metabolic marker. Materials and methods. We prospectively studied 18 patients who underwent ECD-SPECT within the 12 hours following a first-ever acute middle cerebral artery stroke. Neurological evaluation was performed using the Orgogozo's scale at admission and 3 months later in order to calculate and evolution index (IE%) (Martinez-Vila et al.). SPECT data were obtained using a triple head camera equipped with fan beam collimators one hour after injection of 1000 MBq of 99mTc-ECD. On reconstructed images gray matter voxels were automatically segmented. Contralateral healthy hemisphere was used as reference leading to the identification of 3 cortical voxel types: normal (N-SPECT) above 80%; penumbra (P-SPECT) between 80% and 40% and IDT (IDT-SPECT) below 40%. 10 patients also underwent a T2 weighted 3D MRI study at 3 months. Cortical voxels with hypersignal served as reference for IDT (IDT-MRI) the others were considered normal (N-MRI). SPECT and MRI data were co-registered. Therefore each voxel belonged to one of 6 categories (3 SPECT x 2 MRI). Results. (1) The SPECT thresholds were validated on the MRI subgroup. 99% of the N-SPECT voxels were normal on late MRI. 84% of IDT-SPECT voxels corresponded to IDT-MRI. 89% of P-SPECT voxels were normal on late MRI and 11% corresponded to IDT on late MRI. Other categories of voxels (N-SPECT IDT-MRI and IDT-SPECT N-MRI) represented less than 5%. (2) Percentages of each voxel SPECT type was correlated with the EI% on the entire population (Spearman test). P-SPECT extent correlated with EI% improvement (p<0.001) and IDT-SPECT with EI% worsening (p<0.001). Conclusion. Analysis of ECD cortical

  2. Using Modeling and Simulation to Predict Operator Performance and Automation-Induced Complacency With Robotic Automation: A Case Study and Empirical Validation.

    Wickens, Christopher D; Sebok, Angelia; Li, Huiyang; Sarter, Nadine; Gacy, Andrew M

    2015-09-01

    The aim of this study was to develop and validate a computational model of the automation complacency effect, as operators work on a robotic arm task, supported by three different degrees of automation. Some computational models of complacency in human-automation interaction exist, but those are formed and validated within the context of fairly simplified monitoring failures. This research extends model validation to a much more complex task, so that system designers can establish, without need for human-in-the-loop (HITL) experimentation, merits and shortcomings of different automation degrees. We developed a realistic simulation of a space-based robotic arm task that could be carried out with three different levels of trajectory visualization and execution automation support. Using this simulation, we performed HITL testing. Complacency was induced via several trials of correctly performing automation and then was assessed on trials when automation failed. Following a cognitive task analysis of the robotic arm operation, we developed a multicomponent model of the robotic operator and his or her reliance on automation, based in part on visual scanning. The comparison of model predictions with empirical results revealed that the model accurately predicted routine performance and predicted the responses to these failures after complacency developed. However, the scanning models do not account for the entire attention allocation effects of complacency. Complacency modeling can provide a useful tool for predicting the effects of different types of imperfect automation. The results from this research suggest that focus should be given to supporting situation awareness in automation development. © 2015, Human Factors and Ergonomics Society.

  3. Clinical evaluation of SPECT in cerebrovascular disease

    Oshibuchi, Masao; Satoh, Mitsutaka; Kanda, Tetsuro; Nishi, Fumiaki; Yamane, Kanji; Fujimatsu, Masahiko; Edamitsu, Satoshi; Anno, Yasuro; Ohtake, Hisashi.

    1989-01-01

    In 131 patients with cerebrovascular disease, regional cerebral blood flow were determined by 123 I-IMP (N-isopropyl ( 123 I)-iodoamphetamine) or 99m Tc-HM-PAO ( 99m Tc (d, 1)-hexamethyl propyleneamine oxime) SPECT and findings were compared with those of X-CT or MRI. The perfusion deficit detected by SPECT was larger than the deficit by X-CT or MRI in every case. The perfusion deficit area was more clearly demonstrated by SPECT than by X-CT or MRI in patients with acute cerebral infarction. The hypoperfusion area determined by 123 I-IMP SPECT was wider than that by 99m Tc-HM-PAO SPECT. The crossed cerebellar diaschisis was observed in 56 out of 131 cases (43%). The results of operation were quantitatively evaluated by 123 I-IMP SPECT in 25 patients. (author)

  4. SPECT and PET imaging in epilepsy

    Semah, F.

    2007-01-01

    Positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging are very useful for the management of patients with medically refractory partial epilepsy. Presurgical evaluation of patients with medically refractory partial epilepsy often included PET imaging using FDG. The use of SPECT in these patients adds some more information and gives the clinicians the possibility of having ictal imaging. Furthermore, PET and SPECT imaging are performed to better understand the pathophysiology of epilepsy. (authors)

  5. In vivo regional quantitation of intrathoracic /sup 99m/Tc using SPECT: concise communication

    Osborne, D.; Jaszczak, R.; Coleman, R.E.; Greer, K.; Lischko, M.

    1982-01-01

    A whole-body single-photon emission computed tomographic system (SPECT) was used to quantitate the activities of a series of /sup 99m/Tc point sources in the dog's thorax and to evaluate attenuation of a uniform esophageal line source containing a known concentration of /sup 99m/Tc. A first-order attenuation correction and an empirically derived attenuation coefficient of 0.09 cm-1 were used in the SPECT analyses of the intrathoracic point sources. The relationship between SPECT measurements of multiple point-source activities and the same sources measured in air was linear over a range of 100 to 1000 muCi (slope 1.08; R2 coefficient of determination 0.97). These data are sufficiently accurate to allow an estimate of the regional activity of radiopharmaceutical in the dog's thorax and justify their use in experimental quantitation of regional pulmonary perfusion

  6. Functional mechanism of lung mosaic CT attenuation: assessment with deep-inspiration breath-hold perfusion SPECT-CT fusion imaging and non-breath-hold Technegas SPECT.

    Suga, K; Yasuhiko, K; Iwanaga, H; Tokuda, O; Matsunaga, N

    2009-01-01

    The functional mechanism of lung mosaic computed tomography attenuation (MCA) in pulmonary vascular disease (PVD) and obstructive airway disease (OAD) has not yet been fully clarified. To clarify the mechanism of MCA in these diseases by assessing the relationship between regional lung function and CT attenuation change at MCA sites with the use of automated deep-inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images and non-breath-hold Technegas SPECT. Subjects were 42 PVD patients (31 pulmonary thromboembolism, four primary/two secondary pulmonary hypertension, and five Takayasu arteritis), 12 OAD patients (five acute asthma, four obliterative bronchiolitis, and three bronchiectasis), and 12 normal controls, all of whom had MCA on DIBrH CT. The relationship between regional lung function and CT attenuation change at the lung slices with MCA was assessed using DIBrH perfusion SPECT-CT fusion images and non-breath-hold Technegas SPECT. The severity of perfusion defects with or without MCA was quantified by regions-of-interest analysis. On DIBrH CT and perfusion SPECT, in contrast to no noticeable CT attenuation abnormality and fairly uniform perfusion in controls, 60 MCA and 274 perfusion defects in PVD patients, and 18 MCA and 61 defects in OAD patients were identified, with a total of 77 ventilation defects on Technegas SPECT in all patients. SPECT-CT correlation showed that, throughout the 78 MCA sites of all patients, lung perfusion was persistently decreased at low CT attenuation and preserved at intervening high CT attenuation, while lung ventilation was poorly correlated with CT attenuation change. The radioactivity ratios of reduced perfusion and the intervening preserved perfusion at the 78 perfusion defects with MCA were significantly lower than those at the remaining 257 defects without MCA (P<0.0001). Although further validation is required, our results indicate that heterogeneous pulmonary arterial

  7. HMPAO-SPECT in cerebral seizures

    Gruenwald, F.; Bockisch, A.; Reichmann, K.; Ammari, B.; Hotze, A.; Biersack, H.J.; Durwen, H.; Buelau, P.; Elger, C.E.; Rohde, A.; Penin, H.

    1988-01-01

    In nine patients with suspected psychogenic seizures and in three patients with proven epileptic seizures HMPAO-SPECT was performed prior to and during seizure. In the patients with lateron-proven psychogenic seizures no, or only slight, changes of regional cerebral blood flow were found. Patients with proven epilepsy revealed partly normal findings interictally but during seizure a markedly increased circumscript blood flow was found in all patients. Even though PET is superior to SPECT with respect to spatial resolution, in the diagnosis of seizures HMPAO-SPECT has the advantage of enabling injection of the tracer during the seizure and the performance of the SPECT study subsequently. (orig.) [de

  8. High resolution SPECT imaging for visualization of intratumoral heterogeneity using a SPECT/CT scanner dedicated for small animal imaging

    Umeda, Izumi O.; Tani, Kotaro; Tsuda, Keisuke

    2012-01-01

    Tumor interiors are never homogeneous and in vivo visualization of intratumoral heterogeneity would be an innovation that contributes to improved cancer therapy. But, conventional nuclear medicine tests have failed to visualize heterogeneity in vivo because of limited spatial resolution. Recently developed single photon emission computed tomographic (SPECT) scanners dedicated for small animal imaging are of interest due to their excellent spatial resolution of 111 In and simulations of actual small animal imaging. The optimal conditions obtained were validated by in vivo imaging of sarcoma 180-bearing mice. Larger number of counts must be obtained within limited acquisition time to visualize tumor heterogeneity in vivo in animal imaging, compared to cases that simply detect tumors. At an acquisition time of 30 min, better image quality was obtained with pinhole apertures diameter of 1.4 mm than of 1.0 mm. The obtained best spatial resolution was 1.3 mm, it was acceptable for our purpose, though a little worse than the best possible performance of the scanner (1.0 mm). Additionally, the reconstruction parameters, such as noise suppression, voxel size, and iteration/subset number, needed to be optimized under the limited conditions and were different from those found under the ideal condition. The minimal radioactivity concentration for visualization of heterogeneous tumor interiors was estimated to be as high as 0.2-0.5 MBq/mL. Liposomes containing 111 In met this requirement and were administered to tumor-bearing mice. SPECT imaging successfully showed heterogeneous 111 In distribution within the tumors in vivo with good spatial resolution. A threshold of 0.2 MBq/g for clear visualization of tumor heterogeneity was validated. Autoradiograms obtained ex vivo of excised tumors confirmed that the in vivo SPECT images accurately depicted the heterogeneous intratumoral accumulation of liposomes. Intratumoral heterogeneity was successfully visualized under the optimized

  9. An environment-dependent semi-empirical tight binding model suitable for electron transport in bulk metals, metal alloys, metallic interfaces, and metallic nanostructures. I. Model and validation

    Hegde, Ganesh, E-mail: ghegde@purdue.edu; Povolotskyi, Michael; Kubis, Tillmann; Klimeck, Gerhard, E-mail: gekco@purdue.edu [Network for Computational Nanotechnology (NCN), Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Boykin, Timothy [Department of Electrical and Computer Engineering, University of Alabama, Huntsville, Alabama (United States)

    2014-03-28

    Semi-empirical Tight Binding (TB) is known to be a scalable and accurate atomistic representation for electron transport for realistically extended nano-scaled semiconductor devices that might contain millions of atoms. In this paper, an environment-aware and transferable TB model suitable for electronic structure and transport simulations in technologically relevant metals, metallic alloys, metal nanostructures, and metallic interface systems are described. Part I of this paper describes the development and validation of the new TB model. The new model incorporates intra-atomic diagonal and off-diagonal elements for implicit self-consistency and greater transferability across bonding environments. The dependence of the on-site energies on strain has been obtained by appealing to the Moments Theorem that links closed electron paths in the system to energy moments of angular momentum resolved local density of states obtained ab initio. The model matches self-consistent density functional theory electronic structure results for bulk face centered cubic metals with and without strain, metallic alloys, metallic interfaces, and metallic nanostructures with high accuracy and can be used in predictive electronic structure and transport problems in metallic systems at realistically extended length scales.

  10. An environment-dependent semi-empirical tight binding model suitable for electron transport in bulk metals, metal alloys, metallic interfaces, and metallic nanostructures. I. Model and validation

    Hegde, Ganesh; Povolotskyi, Michael; Kubis, Tillmann; Klimeck, Gerhard; Boykin, Timothy

    2014-01-01

    Semi-empirical Tight Binding (TB) is known to be a scalable and accurate atomistic representation for electron transport for realistically extended nano-scaled semiconductor devices that might contain millions of atoms. In this paper, an environment-aware and transferable TB model suitable for electronic structure and transport simulations in technologically relevant metals, metallic alloys, metal nanostructures, and metallic interface systems are described. Part I of this paper describes the development and validation of the new TB model. The new model incorporates intra-atomic diagonal and off-diagonal elements for implicit self-consistency and greater transferability across bonding environments. The dependence of the on-site energies on strain has been obtained by appealing to the Moments Theorem that links closed electron paths in the system to energy moments of angular momentum resolved local density of states obtained ab initio. The model matches self-consistent density functional theory electronic structure results for bulk face centered cubic metals with and without strain, metallic alloys, metallic interfaces, and metallic nanostructures with high accuracy and can be used in predictive electronic structure and transport problems in metallic systems at realistically extended length scales

  11. An environment-dependent semi-empirical tight binding model suitable for electron transport in bulk metals, metal alloys, metallic interfaces, and metallic nanostructures. I. Model and validation

    Hegde, Ganesh; Povolotskyi, Michael; Kubis, Tillmann; Boykin, Timothy; Klimeck, Gerhard

    2014-03-01

    Semi-empirical Tight Binding (TB) is known to be a scalable and accurate atomistic representation for electron transport for realistically extended nano-scaled semiconductor devices that might contain millions of atoms. In this paper, an environment-aware and transferable TB model suitable for electronic structure and transport simulations in technologically relevant metals, metallic alloys, metal nanostructures, and metallic interface systems are described. Part I of this paper describes the development and validation of the new TB model. The new model incorporates intra-atomic diagonal and off-diagonal elements for implicit self-consistency and greater transferability across bonding environments. The dependence of the on-site energies on strain has been obtained by appealing to the Moments Theorem that links closed electron paths in the system to energy moments of angular momentum resolved local density of states obtained ab initio. The model matches self-consistent density functional theory electronic structure results for bulk face centered cubic metals with and without strain, metallic alloys, metallic interfaces, and metallic nanostructures with high accuracy and can be used in predictive electronic structure and transport problems in metallic systems at realistically extended length scales.

  12. Learned Effectiveness: An Empirical Validation.

    Wells, Tracey L.

    All too often when issues arise concerning the "underclass," African Americans, and more specifically African American males are disproportionately represented in that description. Black males have been referred to as endangered in areas of education, economics, health and overall self-efficacy. This data would suggest hopelessness in…

  13. SPECT of aged backache patients

    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.).

  14. SPECT of aged backache patients

    Ito, Shigehiko; Nishikimi, Junzo; Mizuno, Naokado; Watanabe, Kentaro; Kondo, Masaki; Ozaki, Satoshi; Urasaki, Tetsuya; Muro, Toshiyuki

    1995-01-01

    Single photon emission computed tomography (SPECT) using 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. 99m Tc-HMDP (740 MBq) was intravenously injected and regular SPECT was performed at 3 hours. Gamma camera was performed for about 10 seconds with 5deg intervals, and 36 steps (180deg) of collection was completed after about 6 minutes. The radioisotope accumulation, the presence or absence of sthenia, and its site were evaluated. Forty-seven (88.7%) patients showed excessive accumulation, i.e., 40 (75.5%) in peripheral vertebral osteophyte, 31 (58.5%) in vertebral articulations, and 10 (18.9%) in whole vertebral body. Significantly increased bilateral excessive accumulation was admitted in the vertebral articulations of sliding disc in degenerative spondylolisthesis. SPECT is considered useful in understanding the pathophysiology of degenerative lumber diseases. (S.Y.)

  15. Labeled receptor ligands for spect

    Kung, H.F.

    1989-01-01

    Receptor specific imaging agents for single photon emission computed tomography (SPECT) can potentially be useful in the understanding of basic biochemistry and pharmacology of receptors. SPECT images may also provide tools for evaluation of density and binding kinetics of a specific receptor, information important for diagnosis and patient management. Basic requirements for receptor imaging agents are: (a) they are labeled with short-lived isotopes, (b) they show high selectivity and specific uptake, (c) they exhibit high target/background ratio, and (d) they can be modeled to obtain quantitative information. Several good examples of CNS receptor specific ligands labeled with I-123 have been developed, including iodoQNB, iodoestrogen iodobenzadiazepine, iodobenazepine, iodobenzamides for muscarinic, estrogen benzadiazepine, D-1 and D-2 dopamine receptors. With the advent of newer and faster SPECT imaging devices, it may be feasible to quantitate the receptor density by in vivo imaging techniques. These new brain imaging agents can provide unique diagnostic information, which may not be available through other imaging modalities, such as CT and MRI

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

    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.

  17. SPECT/CT and pulmonary embolism

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

    2014-05-15

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

  18. Can perfusion SPECT aid CTPA interpretation?

    Gradinscak, D. J.; Roach, P.; Bailey, E.; Kueh, S.

    2009-01-01

    Full text:Objective: To determine whether fusion of perfusion SPECT and CTPA improves the diagnostic accuracy of CTPA. Methods: 35 patients with suspected PE who underwent both CTPA and SPECT V/Q within 48 hours were included. Of these, the majority (n=30) had PE as determined by the V/Q SPECT scan and the others (n=5) were negative for PE. The clinical reports of CTPA were reviewed and pulmonary emboli tabulated based on anatomical location. A second radiologist, blinded to the results of the clinical read and the V/Q SPECT scan, reviewed the CTPA with and without perfusion SPECT fusion for assistance. Results: A total 57 PE were reported on the clinical reports and 60 PE identified on the blinded read. Fused CTPA/perfursion SPECT images identified a further 5 PE not identified on the clinical read (8% increase) and 2 PE not identified on the blinded read (3% increase). The additional emboli detected resulted in a change in final diagnosis from PE negative to PE positive in 2 patients (6%) compared with the clinical read and 1 patient (3%) compared with the blinded read without SPECT fusion. Conclusion: Fused CTPA-SPECT perfusion improves the sensitivity of CTPA for the detection of PE in a small number of patients. Fused data may help guide the radiologist to identify sites of PE on CTPA.

  19. Clinical applications of SPECT-CT

    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.

  20. MR guided spatial normalization of SPECT scans

    Crouch, B.; Barnden, L.R.; Kwiatek, R.

    2010-01-01

    Full text: In SPECT population studies where magnetic resonance (MR) scans are also available, the higher resolution of the MR scans allows for an improved spatial normalization of the SPECT scans. In this approach, the SPECT images are first coregistered to their corresponding MR images by a linear (affine) transformation which is calculated using SPM's mutual information maximization algorithm. Non-linear spatial normalization maps are then computed either directly from the MR scans using SPM's built in spatial normalization algorithm, or, from segmented TI MR images using DARTEL, an advanced diffeomorphism based spatial normalization algorithm. We compare these MR based methods to standard SPECT based spatial normalization for a population of 27 fibromyalgia patients and 25 healthy controls with spin echo T 1 scans. We identify significant perfusion deficits in prefrontal white matter in FM patients, with the DARTEL based spatial normalization procedure yielding stronger statistics than the standard SPECT based spatial normalization. (author)

  1. Brain imaging during seizure: ictal brain SPECT

    Kottamasu, Sambasiva Rao

    1997-01-01

    The role of single photon computed tomography (SPECT) in presurgical localization of medically intractable complex partial epilepsy (CPE) in children is reviewed. 99m Technetium neurolite, a newer lipophylic agent with a high first pass brain extraction and little or no redistribution is injected during a seizure, while the child is monitored with a video recording and continuous EEG and SPECT imaging is performed in the next 1-3 hours with the images representing regional cerebral profusion at the time of injection. On SPECT studies performed with radiopharmaceutical injected during a seizure, ictal focus is generally hypervascular. Other findings on ictal brain SPECT include hypoperfusion of adjacent cerebral cortex and white matter, hyperperfusion of contralateral motor cortex, hyperperfusion of ipsilateral basal ganglia and thalamus, brain stem and contralateral cerebellum. Ictal brain SPECT is non-invasive, cost effective and highly sensitive for localization of epileptic focus in patients with intractable CPE. (author)

  2. Clinical assessment of SPECT/CT co-registration image fusion

    Zhou Wen; Luan Zhaosheng; Peng Yong

    2004-01-01

    Objective: Study the methodology of the SPECT/CT co-registration image fusion, and Assessment the Clinical application value. Method: 172 patients who underwent SPECT/CT image fusion during 2001-2003 were studied, 119 men, 53 women. 51 patients underwent 18FDG image +CT, 26 patients underwent 99m Tc-RBC Liver pool image +CT, 43 patients underwent 99mTc-MDP Bone image +CT, 18 patients underwent 99m Tc-MAA Lung perfusion image +CT. The machine is Millium VG SPECT of GE Company. All patients have been taken three steps image: X-ray survey, X-ray transmission and nuclear emission image (Including planer imaging, SPECT or 18 F-FDG of dual head camera) without changing the position of the patients. We reconstruct the emission image with X-ray map and do reconstruction, 18FDG with COSEM and 99mTc with OSEM. Then combine the transmission image and the reconstructed emission image. We use different process parameters in deferent image methods. The accurate rate of SPECT/CT image fusion were statistics, and compare their accurate with that of single nuclear emission image. Results: The nuclear image which have been reconstructed by X-ray attenuation and OSEM are apparent better than pre-reconstructed. The post-reconstructed emission images have no scatter lines around the organs. The outline between different issues is more clear than before. The validity of All post-reconstructed images is better than pre-reconstructed. SPECT/CT image fusion make localization have worthy bases. 138 patients, the accuracy of SPECT/CT image fusion is 91.3% (126/138), whereas 60(88.2%) were found through SPECT/CT image fusion, There are significant difference between them(P 99m Tc- RBC-SPECT +CT image fusion, but 21 of them were inspected by emission image. In BONE 99m Tc -MDP-SPECT +CT image fusion, 4 patients' removed bone(1-6 months after surgery) and their relay with normal bone had activity, their morphologic and density in CT were different from normal bones. 11 of 20 patients who could

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

    Wu, Chao; Have, Frans van der; Vastenhouw, Brendan; Beekman, Freek J.; Dierckx, Rudi A.J.O.; Paans, Anne M.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 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 Chang-based method using body outline contours obtained with optical cameras. Here we develop and experimentally validate a practical method for attenuation correction based on a Chang first-order method. This approach has the advantage that it is employed after, and therefore independently from, iterative reconstruction. Therefore, no new system matrix has to be calculated for each specific animal. Experiments with phantoms and animals were performed with a high-resolution focusing multi-pinhole SPECT system (U-SPECT-II, MILabs, The Netherlands). This SPECT system provides three additional optical camera images of the animal for each SPECT scan from which the animal contour can be estimated. Phantom experiments demonstrated that an average quantification error of -18.7% was reduced to -1.7% when both window-based scatter correction and Chang correction based on the body outline from optical images were applied. Without scatter and attenuation correction, quantification errors in a sacrificed rat containing sources with known activity ranged from -23.6 to -9.3%. These errors were reduced to values between -6.3 and +4.3% (with an average magnitude of 2.1%) after applying scatter and Chang attenuation correction. We conclude that the modified Chang correction based on body contour combined with window-based scatter correction is a practical method for obtaining small-animal SPECT images with high quantitative accuracy. (orig.)

  4. Quantitative Analysis of cardiac SPECT

    Nekolla, S.G.; Bengel, F.M.

    2004-01-01

    The quantitative analysis of myocardial SPECT images is a powerful tool to extract the highly specific radio tracer uptake in these studies. If compared to normal data bases, the uptake values can be calibrated on an individual basis. Doing so increases the reproducibility of the analysis substantially. Based on the development over the last three decades starting from planar scinitigraphy, this paper discusses the methods used today incorporating the changes due to tomographic image acquisitions. Finally, the limitations of these approaches as well as consequences from most recent hardware developments, commercial analysis packages and a wider view of the description of the left ventricle are discussed. (orig.)

  5. SPECT og PET i neurobiologien

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

    1997-01-01

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

  6. Quantitative estimation of myocardial thickness by the wall thickness map with Tl-201 myocardial SPECT and its clinical use

    Sekiai, Yasuhiro; Sawai, Michihiko; Murayama, Susumu

    1988-01-01

    To estimate the wall thickness of left ventricular myocardium objectively and quantitatively, we adopted the device of wall thickness map (WTM) with Tl-201 myocardial SPECT. For validation on measuring left ventricular wall thickness with SPECT, fundamental studies were carried out with phantom models, and clinical studies were performed in 10 cases comparing the results from SPECT with those in echocardiography. To draw the WTM, left ventricular wall thickness was measured using the cut off method from SPECT images obtained at 5.6 mm intervals from the base and middle of left ventricle: short-axis image for the base and middle of left ventricle and vertical and horizontal long-axis images for the apical region. Wall thickness was defined from the number of pixel above the cut off level. Results of fundamental studies disclosed that it is impossible to evaluate the thickness of less than 10 mm by Tl-201 myocardial SPECT but possible to discriminate wall thickness of 10 mm, 15 mm, and 20 mm by Tl-201 myocardial SPECT. Echocardiographic results supported the validity of WTM, showing a good linear correlation (r = 0.96) between two methods on measuring wall thickness of left ventricle. We conclude that the WTM applied in this report may be useful for objective and quantitative estimation of myocardial hypertrophy. (author)

  7. Automatic lung segmentation in functional SPECT images using active shape models trained on reference lung shapes from CT.

    Cheimariotis, Grigorios-Aris; Al-Mashat, Mariam; Haris, Kostas; Aletras, Anthony H; Jögi, Jonas; Bajc, Marika; Maglaveras, Nicolaos; Heiberg, Einar

    2018-02-01

    Image segmentation is an essential step in quantifying the extent of reduced or absent lung function. The aim of this study is to develop and validate a new tool for automatic segmentation of lungs in ventilation and perfusion SPECT images and compare automatic and manual SPECT lung segmentations with reference computed tomography (CT) volumes. A total of 77 subjects (69 patients with obstructive lung disease, and 8 subjects without apparent perfusion of ventilation loss) performed low-dose CT followed by ventilation/perfusion (V/P) SPECT examination in a hybrid gamma camera system. In the training phase, lung shapes from the 57 anatomical low-dose CT images were used to construct two active shape models (right lung and left lung) which were then used for image segmentation. The algorithm was validated in 20 patients, comparing its results to reference delineation of corresponding CT images, and by comparing automatic segmentation to manual delineations in SPECT images. The Dice coefficient between automatic SPECT delineations and manual SPECT delineations were 0.83 ± 0.04% for the right and 0.82 ± 0.05% for the left lung. There was statistically significant difference between reference volumes from CT and automatic delineations for the right (R = 0.53, p = 0.02) and left lung (R = 0.69, p automatic quantification of wide range of measurements.

  8. Contralateral thalamic hypoperfusion on brain perfusion SPECT

    Lee, Seok Mo; Bae, Sang Kyun; Yoo, Kyung Moo; Yum, Ha Yong

    2000-01-01

    Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

  9. SPECT of the brain: Present and future

    Fazio, F.; Lenzi, G.L.

    1986-01-01

    In both PET and SPECT, most of the studies and the models have been addressed to two organs: brain and heart. So far, brain has certainly been investigated more. The several comparisons between planar scintigraphy and SPECT, between X-ray TCT and SPECT, and also between PET and SPECT, have tended to consider SPECT a cheap but scarcely useful tool for a nuclear medicine section. Again the authors feel that this is due to the fact that SPECT is really a ''physiological tomography'', with little known about its physiology or how it is measured. Thus the present state of the art of SPECT of the brain is characterized by a collection of data and reports on brain imaging and by a slowly growing basic understanding of the utilized modes. The introduction of a new brain-imaging radiopharmaceutical is immediately signaled by its ''first clinical application'' without parallel studies on the kinetics, the metabolic degradation, and the real suitability of the molecule as a tracer for measurement of regional CBF. Only a few attempts seek to narrow this discussion between clinic and biology, and the authors like to emphasize the need for nuclear medicine people to dedicate more time and effort

  10. Simulated Design Strategies for SPECT Collimators to Reduce the Eddy Currents Induced by MRI Gradient Fields

    Samoudi, Amine M.; Van Audenhaege, Karen; Vermeeren, Günter; Verhoyen, Gregory; Martens, Luc; Van Holen, Roel; Joseph, Wout

    2015-10-01

    Combining single photon emission computed tomography (SPECT) with magnetic resonance imaging (MRI) requires the insertion of highly conductive SPECT collimators inside the MRI scanner, resulting in an induced eddy current disturbing the combined system. We reduced the eddy currents due to the insert of a novel tungsten collimator inside transverse and longitudinal gradient coils. The collimator was produced with metal additive manufacturing, that is part of a microSPECT insert for a preclinical SPECT/MRI scanner. We characterized the induced magnetic field due to the gradient field and adapted the collimators to reduce the induced eddy currents. We modeled the x-, y-, and z-gradient coil and the different collimator designs and simulated them with FEKO, a three-dimensional method of moments / finite element methods (MoM/FEM) full-wave simulation tool. We used a time analysis approach to generate the pulsed magnetic field gradient. Simulation results show that the maximum induced field can be reduced by 50.82% in the final design bringing the maximum induced magnetic field to less than 2% of the applied gradient for all the gradient coils. The numerical model was validated with measurements and was proposed as a tool for studying the effect of a SPECT collimator within the MRI gradient coils.

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

    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

    LV functional parameters obtained with a one-eighth acquisition time were statistically comparable to the previously validated one-fourth time protocol using IQ-SPECT. Shorter acquisition times without loss of diagnostic accuracy provide improved patient comfort and streamlined departmental efficiency. (orig.)

  12. Wide beam reconstruction for half-dose or half-time cardiac gated SPECT acquisitions: optimization of resources and reduction in radiation exposure

    Marcassa, Claudio; Campini, Riccardo; Zoccarato, Orazio; Calza, Paolo

    2011-01-01

    A new iterative reconstruction algorithm (WBR trademark) has been recently proposed for cardiac single photon emission computed tomography (SPECT). The WBR trademark technology is designed to reduce noise, improving lesion identification without affecting the image resolution, allowing SPECT studies with reduced count statistic. This allows for either half-time (HT) or half-dose (HD) cardiac SPECT, with image quality and quantitative data comparable to standard-time (ST) or standard-dose (SD) SPECT. Few data exist on the comparison between conventional filtered backprojection (FBP) and this new algorithm in a clinical setting. The aim of this study was to compare the performance of FBP and WBR trademark. Phantoms studies were performed to compare spatial resolution and contrast recovery with FBP, ordered subset expectation maximization (OSEM) and WBR trademark. A group of 92 patients, with different cardiac pathology, scheduled for a stress-rest SPECT were studied: 52 patients (group A) were injected with a SD of tracer and underwent both ST and HT SPECT; 40 patients (group B) were injected with a half dose of tracer and underwent ST SPECT and immediately after an additional SPECT at double time/projection (DT), to compensate for the low count statistic. A 2-day 99m Tc-sestamibi protocol was used in all patients. SD/ST and HD/DT SPECT were reconstructed with a conventional FBP; SD/HT and HD/ST SPECT were reconstructed with WBR trademark. The summed stress score (SSS) and summed rest score (SRS) were calculated; the left ventricular ejection fraction (LVEF) was automatically derived. In group A (SD), no significant differences were observed between ST FBP SPECT and HT WBR trademark in SSS (11.1 and 11.7, respectively) and SRS (9.4 and 10.3, respectively, NS). LVEF on rest acquisitions was also comparable (50% on ST SPECT and 49% on HT SPECT, NS); LVEF on post-stress studies in HT SPECT (46%) was lower than ST SPECT (50%), although not statistically significant. In

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

    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.

  14. Inglorious Empire

    Khair, Tabish

    2017-01-01

    Review of 'Inglorious Empire: What the British did to India' by Shashi Tharoor, London, Hurst Publishers, 2017, 296 pp., £20.00......Review of 'Inglorious Empire: What the British did to India' by Shashi Tharoor, London, Hurst Publishers, 2017, 296 pp., £20.00...

  15. A CT-based method for fully quantitative TI SPECT

    Willowson, Kathy; Bailey, Dale; Baldock, Clive

    2009-01-01

    Full text: Objectives: To develop and validate a method for quantitative 2 0 l TI SPECT data based on corrections derived from X-ray CT data, and to apply the method in the clinic for quantitative determination of recurrence of brain tumours. Method: A previously developed method for achieving quantitative SPECT with 9 9 m Tc based on corrections derived from xray CT data was extended to apply to 2 0 l Tl. Experimental validation was performed on a cylindrical phantom by comparing known injected activity and measured concentration to quantitative calculations. Further evaluation was performed on a RSI Striatal Brain Phantom containing three 'lesions' with activity to background ratios of 1: 1, 1.5: I and 2: I. The method was subsequently applied to a series of scans from patients with suspected recurrence of brain tumours (principally glioma) to determine an SUV-like measure (Standardised Uptake Value). Results: The total activity and concentration in the phantom were calculated to within 3% and I % of the true values, respectively. The calculated values for the concentration of activity in the background and corresponding lesions of the brain phantom (in increasing ratios) were found to be within 2%,10%,1% and 2%, respectively, of the true concentrations. Patient studies showed that an initial SUV greater than 1.5 corresponded to a 56% mortality rate in the first 12 months, as opposed to a 14% mortality rate for those with a SUV less than 1.5. Conclusion: The quantitative technique produces accurate results for the radionuclide 2 0 l Tl. Initial investigation in clinical brain SPECT suggests correlation between quantitative uptake and survival.

  16. SPECT quantification of regional radionuclide distributions

    Jaszczak, R.J.; Greer, K.L.; Coleman, R.E.

    1986-01-01

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

  17. Brain SPECT in psychiatry: Delusion or reality?

    Pavel, D.G.; Davis, G.; Epstein, P.; Kohn, R.; Antonino, F.; Devore-Best, S.; Craita, I.; Liu, P.

    2002-01-01

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

  18. Brain SPECT imaging in temporal lobe epilepsy

    Krausz, Y.; Yaffe, S.; Atlan, H.; Cohen, D.; Konstantini, S.; Meiner, Z.

    1991-01-01

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

  19. Role of brain SPECT in epilepsy exploration

    Biraben, A.; Bernard, AM.

    1996-01-01

    The management of epileptic patients is currently developing in relation with the introduction of video EEG and the opening of medical centers dedicated to epilepsy. The role of SPECT is now well established to assess the temporal and spatial dynamic phenomena during seizures. Ictal SPECT has technical and organisational requirements but is a very sensitive method, which appears to be superior to other available imaging techniques. (author)

  20. Technical approach to improvement of SPECT images

    Fukukita, Hiroyoshi

    1985-01-01

    At present, a large number of SPECT systems are being widely used in Japan, hence, it is reasonable for us to know the physical and imaging characteristics of these SPECT devices, and also to recommend the optimum utility of SPECT systems. For this reason, a survey respect of characteristics of the commercialy available SPECT devices was carried out. In addition to this, various factors which have significant influence over SPECT image quality, such as, data acquisition matrix, reconstruction filter, γ-ray attenuation correction and daily quality control procedure, were also investigated. The materials used for this study are PET/SPECT phantom, Alderson liver phantom filled with Tc-99m solution, and either LFOV-E or ZLC-7500 interfaced to Scintipac 2400 minicomputer with 256 K byte of memory. Following are the results of this study. 1) The suitable data acquisition procedure was 128 x 128 matrix for linear sampling and approximately 64 views for angular sampling. 2) Reconstructed image using pre-processing filter with Wiener and Butterworth filters provided high quality image as compared with the Ramp filter. 3) Weighted backprojection method (WBP) proposed by Tanaka was superior to other methods, such as Sorenson method and Chang method in the object with non-uniform distribution of radionuclide. 4) It was found that uniformity correction of gamma camera and precise adjustment of the center of rotation are most important to maintain the images with a high quality. (author)

  1. Clinical value of SPECT/CT for evaluation of patients with painful knees after total knee arthroplasty- a new dimension of diagnostics?

    Hirschmann, Michael T; Konala, Praveen; Iranpour, Farhad; Kerner, Anna; Rasch, Helmut; Friederich, Niklaus F

    2011-01-01

    Abstract Background The purpose of our study was to evaluate the clinical value of hybrid SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA). Methods Twenty-three painful knees in patients following primary TKA were assessed using Tc-99m-HDP-SPECT/CT. Rotational, sagittal and coronal position of the TKA was assessed on 3D-CT reconstructions. The level of the SPECT-tracer uptake (0-10) and its anatomical distribution was mapped using a validated localization sch...

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

    Sui, Osamu; Kimura, Nazuna; Soeki; Takeshi; Takeichi, Naoki; Shinohara, Hisanori; Tamura, Yoshiyuki; Fukuda, Nobuo

    1997-01-01

    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)

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

    Golestani, Reza; Dierckx, Rudi A.J.O. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); Wu, Chao [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University Medical Center Utrecht, Image Sciences Institute and Rudolf Magnus Institute of Neurosciences, Utrecht (Netherlands); Tio, Rene A. [University Medical Center Groningen, Thorax Center, Department of Cardiology, Groningen (Netherlands); University Medical Center Groningen, Cardiovascular Imaging Group, P.O. Box 30001, Groningen (Netherlands); Zeebregts, Clark J. [University Medical Center Groningen, Department of Surgery, Division of Vascular Surgery, Groningen (Netherlands); University Medical Center Groningen, Cardiovascular Imaging Group, P.O. Box 30001, Groningen (Netherlands); Petrov, Artiom D. [University of California, Irvine, Division of Cardiology, School of Medicine, Irvine, California (United States); Beekman, Freek J. [University Medical Center Utrecht, Image Sciences Institute and Rudolf Magnus Institute of Neurosciences, Utrecht (Netherlands); Delft University of Technology, Faculty of Applied Sciences, Section Radiation Detection and Medical Imaging, Delft (Netherlands); MILabs, Utrecht (Netherlands); Boersma, Hendrikus H. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University Medical Center Groningen, Department of Clinical and Hospital Pharmacy, Hanzeplein 1, P.O. Box 30001, Groningen (Netherlands); University Medical Center Groningen, Cardiovascular Imaging Group, P.O. Box 30001, Groningen (Netherlands); Slart, Riemer H.J.A. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands); University Medical Center Groningen, Cardiovascular Imaging Group, P.O. Box 30001, Groningen (Netherlands)

    2010-09-15

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

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

    Golestani, Reza; Dierckx, Rudi A.J.O.; Wu, Chao; Tio, Rene A.; Zeebregts, Clark J.; Petrov, Artiom D.; Beekman, Freek J.; Boersma, Hendrikus H.; Slart, Riemer H.J.A.

    2010-01-01

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

  5. Geometric Calibration and Image Reconstruction for a Segmented Slant-Hole Stationary Cardiac SPECT System.

    Mao, Yanfei; Yu, Zhicong; Zeng, Gengsheng L

    2015-06-01

    A dedicated stationary cardiac single-photon emission computed tomography (SPECT) system with a novel segmented slant-hole collimator has been developed. The goal of this paper is to calibrate this new imaging geometry with a point source. Unlike the commercially available dedicated cardiac SPECT systems, which are specialized and can be used only to image the heart, our proposed cardiac system is based on a conventional SPECT system but with a segmented slant-hole collimator replacing the collimator. For a dual-head SPECT system, 2 segmented collimators, each with 7 sections, are arranged in an L-shaped configuration such that they can produce a complete cardiac SPECT image with only one gantry position. A calibration method was developed to estimate the geometric parameters of each collimator section as well as the detector rotation radius, under the assumption that the point source location is calculated using the central-section data. With a point source located off the rotation axis, geometric parameters for each collimator section can be estimated independently. The parameters estimated individually are further improved by a joint objective function that uses all collimator sections simultaneously and incorporates the collimator symmetry information. Estimation results and images reconstructed from estimated parameters are presented for both simulated and real data acquired from a prototype collimator. The calibration accuracy was validated by computer simulations with an error of about 0.1° for the slant angles and about 1 mm for the rotation radius. Reconstructions of a heart-insert phantom did not show any image artifacts of inaccurate geometric parameters. Compared with the detector's intrinsic resolution, the estimation error is small and can be ignored. Therefore, the accuracy of the calibration is sufficient for cardiac SPECT imaging. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  6. Design of common software for quality control of SPECT

    Li Xiaohua; Gao Ruzhen; Chen Shengzu

    1993-01-01

    The goal of this study is to design a common testing system for SPECT quality control according to NEMA standard. Using the system, the performances of different types of SPECT can be tested, so that the acceptance testing, performance comparing and routine quality control for SPECT can be normalized. The system was based on IBM PC series of microcomputer. Testing data are acquired from various types of SPECT, then transferred into IBM PC through interface and tested with an unique testing program. Two parts were included: interface and SPECT testing program. It emphatically studied the managing program of RS232 interface, designing skills and the mathematic patterns of SPECT testing program. The system which was composed of 11 subroutines can be used to measure the performances for both gamma camera and SPECT. The system was tested on OMEGA 500/MCS 560 SPECT and the results showed that it is effective, accurate and easy to use

  7. SPECT/CT workflow and imaging protocols

    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.)

  8. SPECT/CT workflow and imaging protocols

    Beckers, Catherine; Hustinx, Roland

    2014-01-01

    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.)

  9. First validation of myocardial flow reserve assessed by dynamic 99mTc-sestamibi CZT-SPECT camera: head to head comparison with 15O-water PET and fractional flow reserve in patients with suspected coronary artery disease. The WATERDAY study.

    Agostini, Denis; Roule, Vincent; Nganoa, Catherine; Roth, Nathaniel; Baavour, Raphael; Parienti, Jean-Jacques; Beygui, Farzin; Manrique, Alain

    2018-07-01

    We assessed the feasibility of myocardial blood flow (MBF) and flow reserve (MFR) estimation using dynamic SPECT with a novel CZT camera in patients with stable CAD, in comparison with 15 O-water PET and fractional flow reserve (FFR). Thirty patients were prospectively included and underwent FFR measurements in the main coronary arteries (LAD, LCx, RCA). A stenosis ≥50% was considered obstructive and a FFR abnormal if ≤0.8. All patients underwent a dynamic rest/stress 99m Tc-sestamibi CZT-SPECT and 15 O-water PET for MBF and MFR calculation. Net retention kinetic modeling was applied to SPECT data to estimate global uptake values, and MBF was derived using Leppo correction. Ischemia by PET and CZT-SPECT was considered present if MFR was lower than 2 and 2.1, respectively. CZT-SPECT yielded higher stress and rest MBF compared to PET for global and LAD and LCx territories, but not in RCA territory. MFR was similar in global and each vessel territory for both modalities. The sensitivity, specificity, accuracy, positive and negative predictive value of CZT-SPECT were, respectively, 83.3, 95.8, 93.3, 100 and 85.7% for the detection of ischemia and 58.3, 84.6, 81.1, 36.8 and 93% for the detection of hemodynamically significant stenosis (FFR ≤ 0.8). Dynamic 99m Tc-sestamibi CZT-SPECT was technically feasible and provided similar MFR compared to 15 O-water PET and high diagnostic value for detecting impaired MFR and abnormal FFR in patients with stable CAD.

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

    Sharma, Punit; Kumar, Rakesh; Singh, Harmandeep; Bal, Chandrasekhar; Malhotra, Arun; Julka, Pramod Kumar; Thulkar, Sanjay

    2012-01-01

    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 (κ = 0.426), while almost perfect agreement was seen for CT (κ = 0.834) and SPECT-CT (κ = 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.)

  11. Functional Mechanism of Lung Mosaic CT Attenuation: Assessment with Deep-Inspiration Breath-Hold Perfusion SPECT-CT Fusion Imaging and Non-Breath-Hold Technegas SPECT

    Suga, K.; Yasuhiko, K.; Iwanaga, H.; Tokuda, O.; Matsunaga, N.

    2009-01-01

    Background: The functional mechanism of lung mosaic computed tomography attenuation (MCA) in pulmonary vascular disease (PVD) and obstructive airway disease (OAD) has not yet been fully clarified. Purpose: To clarify the mechanism of MCA in these diseases by assessing the relationship between regional lung function and CT attenuation change at MCA sites with the use of automated deep-inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images and non-breath-hold Technegas SPECT. Material and Methods: Subjects were 42 PVD patients (31 pulmonary thromboembolism, four primary/two secondary pulmonary hypertension, and five Takayasu arteritis), 12 OAD patients (five acute asthma, four obliterative bronchiolitis, and three bronchiectasis), and 12 normal controls, all of whom had MCA on DIBrH CT. The relationship between regional lung function and CT attenuation change at the lung slices with MCA was assessed using DIBrH perfusion SPECT-CT fusion images and non-breath-hold Technegas SPECT. The severity of perfusion defects with or without MCA was quantified by regions-of-interest analysis. Results: On DIBrH CT and perfusion SPECT, in contrast to no noticeable CT attenuation abnormality and fairly uniform perfusion in controls, 60 MCA and 274 perfusion defects in PVD patients, and 18 MCA and 61 defects in OAD patients were identified, with a total of 77 ventilation defects on Technegas SPECT in all patients. SPECT-CT correlation showed that, throughout the 78 MCA sites of all patients, lung perfusion was persistently decreased at low CT attenuation and preserved at intervening high CT attenuation, while lung ventilation was poorly correlated with CT attenuation change. The radioactivity ratios of reduced perfusion and the intervening preserved perfusion at the 78 perfusion defects with MCA were significantly lower than those at the remaining 257 defects without MCA (P<0.0001). Conclusion: Although further validation is

  12. Functional Mechanism of Lung Mosaic CT Attenuation: Assessment with Deep-Inspiration Breath-Hold Perfusion SPECT-CT Fusion Imaging and Non-Breath-Hold Technegas SPECT

    Suga, K.; Yasuhiko, K. (Dept. of Radiology, St. Hill Hospital, Ube, Yamaguchi (Japan)); Iwanaga, H.; Tokuda, O.; Matsunaga, N. (Dept. of Radiology, Yamaguchi Univ. School of Medicine, Ube, Yamaguchi (Japan))

    2009-01-15

    Background: The functional mechanism of lung mosaic computed tomography attenuation (MCA) in pulmonary vascular disease (PVD) and obstructive airway disease (OAD) has not yet been fully clarified. Purpose: To clarify the mechanism of MCA in these diseases by assessing the relationship between regional lung function and CT attenuation change at MCA sites with the use of automated deep-inspiratory breath-hold (DIBrH) perfusion single-photon emission computed tomography (SPECT)-CT fusion images and non-breath-hold Technegas SPECT. Material and Methods: Subjects were 42 PVD patients (31 pulmonary thromboembolism, four primary/two secondary pulmonary hypertension, and five Takayasu arteritis), 12 OAD patients (five acute asthma, four obliterative bronchiolitis, and three bronchiectasis), and 12 normal controls, all of whom had MCA on DIBrH CT. The relationship between regional lung function and CT attenuation change at the lung slices with MCA was assessed using DIBrH perfusion SPECT-CT fusion images and non-breath-hold Technegas SPECT. The severity of perfusion defects with or without MCA was quantified by regions-of-interest analysis. Results: On DIBrH CT and perfusion SPECT, in contrast to no noticeable CT attenuation abnormality and fairly uniform perfusion in controls, 60 MCA and 274 perfusion defects in PVD patients, and 18 MCA and 61 defects in OAD patients were identified, with a total of 77 ventilation defects on Technegas SPECT in all patients. SPECT-CT correlation showed that, throughout the 78 MCA sites of all patients, lung perfusion was persistently decreased at low CT attenuation and preserved at intervening high CT attenuation, while lung ventilation was poorly correlated with CT attenuation change. The radioactivity ratios of reduced perfusion and the intervening preserved perfusion at the 78 perfusion defects with MCA were significantly lower than those at the remaining 257 defects without MCA (P<0.0001). Conclusion: Although further validation is

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

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

    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 eight cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (p < 0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with defect, EXG-SPECT improved the defect contrast and definition. The dual respiratory–cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (p < 0.05) compared to EXG-SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased

  14. What 'empirical turn in bioethics'?

    Hurst, Samia

    2010-10-01

    Uncertainty as to how we should articulate empirical data and normative reasoning seems to underlie most difficulties regarding the 'empirical turn' in bioethics. This article examines three different ways in which we could understand 'empirical turn'. Using real facts in normative reasoning is trivial and would not represent a 'turn'. Becoming an empirical discipline through a shift to the social and neurosciences would be a turn away from normative thinking, which we should not take. Conducting empirical research to inform normative reasoning is the usual meaning given to the term 'empirical turn'. In this sense, however, the turn is incomplete. Bioethics has imported methodological tools from empirical disciplines, but too often it has not imported the standards to which researchers in these disciplines are held. Integrating empirical and normative approaches also represents true added difficulties. Addressing these issues from the standpoint of debates on the fact-value distinction can cloud very real methodological concerns by displacing the debate to a level of abstraction where they need not be apparent. Ideally, empirical research in bioethics should meet standards for empirical and normative validity similar to those used in the source disciplines for these methods, and articulate these aspects clearly and appropriately. More modestly, criteria to ensure that none of these standards are completely left aside would improve the quality of empirical bioethics research and partly clear the air of critiques addressing its theoretical justification, when its rigour in the particularly difficult context of interdisciplinarity is what should be at stake.

  15. Clinical applications of SPECT/CT: advantages and limitations

    Rigo, P.

    2006-01-01

    The application of hybrid SPECT cameras in Nuclear Medicine follows the revolutionary introduction of PET/CT. This review focuses on the advantages and limitations of SPECT/CT in its various clinical indications. It appears that SPECT/CT will be a clear factor of progress for Nuclear Medicine. (author)

  16. A simple method for measurement of cerebral blood flow using 123I-IMP SPECT with calibrated standard input function by one point blood sampling. Validation of calibration by one point venous blood sampling as a substitute for arterial blood sampling

    Ito, Hiroshi; Akaizawa, Takashi; Goto, Ryoui

    1994-01-01

    In a simplified method for measurement of cerebral blood flow using one 123 I-IMP SPECT scan and one point arterial blood sampling (Autoradiography method), input function is obtained by calibrating a standard input function by one point arterial blood sampling. A purpose of this study is validation of calibration by one point venous blood sampling as a substitute for one point arterial blood sampling. After intravenous infusion of 123 I-IMP, frequent arterial and venous blood sampling were simultaneously performed on 12 patients of CNS disease without any heart and lung disease and 5 normal volunteers. The radioactivity ratio of venous whole blood which obtained from cutaneous cubital vein to arterial whole blood were 0.76±0.08, 0.80±0.05, 0.81±0.06, 0.83±0.11 at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivities were always 20% lower than those of arterial blood radioactivity during 50 min. However, the ratio which obtained from cutaneous dorsal hand vein to artery were 0.93±0.02, 0.94±0.05, 0.98±0.04, 0.98±0.03, at 10, 20, 30, 50 min after 123 I-IMP infusion, respectively. The venous blood radioactivity was consistent with artery. These indicate that arterio-venous difference of radioactivity in a peripheral cutaneous vein like a dorsal hand vein is minimal due to arteriovenous shunt in palm. Therefore, a substitution by blood sampling from cutaneous dorsal hand vein for artery will be possible. Optimized time for venous blood sampling evaluated by error analysis was 20 min after 123 I-IMP infusion, which is 10 min later than that of arterial blood sampling. (author)

  17. SPECT in patients with cortical visual loss.

    Silverman, I E; Galetta, S L; Gray, L G; Moster, M; Atlas, S W; Maurer, A H; Alavi, A

    1993-09-01

    Single-photon emission computed tomography (SPECT) with 99mTc-hexamethylpropyleneamine oxime (HMPAO) was used to investigate changes in cerebral blood flow in seven patients with cortical visual impairment. Traumatic brain injury (TBI) was the cause of cortical damage in two patients, cerebral ischemia in two patients and carbon monoxide (CO) poisoning, status epilepticus and Alzheimer's Disease (AD) each in three separate patients. The SPECT scans of the seven patients were compared to T2-weighted magnetic resonance image (MRI) scans of the brain to determine the correlation between functional and anatomical findings. In six of the seven patients, the qualitative interpretation of the SPECT studies supported the clinical findings (i.e., the visual field defect) by revealing altered regional cerebral blood flow (rCBF) in the appropriate regions of the visual pathway. MR scans in all of the patients, on the other hand, were either normal or disclosed smaller lesions than those detected by SPECT. We conclude that SPECT may reveal altered rCBF in patients with cortical visual impairment of various etiologies, even when MRI studies are normal or nondiagnostic.

  18. Noninvasive evaluation of ischemic stroke with SPECT

    Gomez, C.R.; Malik, M.M.; Gomez, S.M.; Wingkun, E.C.

    1988-01-01

    Technetium Tc 99m DTPA single photon emission computerized tomography (SPECT) brain scans of 20 patients with acute ischemic stroke were reviewed retrospectively and compared with clinical and radiologic (CT) data. Fourteen of the patients had abnormal SPECT studies. The abnormal findings were demonstrated by static views in eight patients, by the flow study in one patient, and by both sets of images in the other five patients. All abnormalities correlated with the clinical syndrome of presentation, and only two of the patients had no corresponding lesions on CT. Of the six patients with normal SPECT scans, two had abnormal CT studies, and in the other four, no lesions were shown at all. The ability of /sup 99m/Tc DTPA SPECT to display cerebral infarctions appears to be, at best, comparable to that of CT. SPECT also provides qualitative information regarding flow dynamics in the affected hemisphere of some patients (6/20 in our review). This, we believe, represents the objective demonstration of the preexisting insufficient collateral flow in the hemisphere at risk for ischemic stroke

  19. Quantitative organ visualization using SPECT

    Kircos, L.T.; Carey, J.E. Jr.; Keyes, J.W. Jr.

    1987-01-01

    Quantitative organ visualization (QOV) was performed using single photon emission computed tomography (SPECT). Organ size was calculated from serial, contiguous ECT images taken through the organ of interest with image boundaries determined using a maximum directional gradient edge finding technique. Organ activity was calculated using ECT counts bounded by the directional gradient, imaging system efficiency, and imaging time. The technique used to perform QOV was evaluated using phantom studies, in vivo canine liver, spleen, bladder, and kidney studies, and in vivo human bladder studies. It was demonstrated that absolute organ activity and organ size could be determined with this system and total imaging time restricted to less than 45 min to an accuracy of about +/- 10% providing the minimum dimensions of the organ are greater than the FWHM of the imaging system and the total radioactivity within the organ of interest exceeds 15 nCi/cc for dog-sized torsos. In addition, effective half-lives of approximately 1.5 hr or greater could be determined

  20. Contrast detail phantom for SPECT

    Cabrejas, M.L. de; Arashiro, J G; Giannone, C. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Camuyrano, M; Nohara, G [Universidad de Buenos Aires, Buenos Aires (Argentina). Facultad Ciencias Exactas

    1996-06-01

    A new low variable contrast phantom for single photon emission computed tomography (SPECT) was constructed, tested and compared with other existing phantoms. It contains simulated cylindrical lesions of four different diameters (D{sub i}), embedded in a cylindrical scattering medium and a uniform section to evaluate tomographic uniformity. The concentration of tracer in the simulated lesions and the scattering medium (background) can be varied to simulate hot and cold lesions. Different applications of the phantom were tested, including determination of the minimum object contrast (OCm) necessary to detect lesions as a function of lesion size, lesion type (hot or cold) and acquisition and processing protocols by visual inspection. This parameter allows categorization of instruments comparing an `image quality index` (IQI). Preliminary comparison with the Britten contrast processing method showed that the detectable OCm was of the same order of magnitude, but the presented device seems more suitable for training and intercomparison purposes. The constructed phantom, of simple design, has proved to be useful for acquisition and processing condition evaluation, OCm estimation and external quality control. (author). 11 refs, 4 figs.

  1. Inverse Monte Carlo: a unified reconstruction algorithm for SPECT

    Floyd, C.E.; Coleman, R.E.; Jaszczak, R.J.

    1985-01-01

    Inverse Monte Carlo (IMOC) is presented as a unified reconstruction algorithm for Emission Computed Tomography (ECT) providing simultaneous compensation for scatter, attenuation, and the variation of collimator resolution with depth. The technique of inverse Monte Carlo is used to find an inverse solution to the photon transport equation (an integral equation for photon flux from a specified source) for a parameterized source and specific boundary conditions. The system of linear equations so formed is solved to yield the source activity distribution for a set of acquired projections. For the studies presented here, the equations are solved using the EM (Maximum Likelihood) algorithm although other solution algorithms, such as Least Squares, could be employed. While the present results specifically consider the reconstruction of camera-based Single Photon Emission Computed Tomographic (SPECT) images, the technique is equally valid for Positron Emission Tomography (PET) if a Monte Carlo model of such a system is used. As a preliminary evaluation, experimentally acquired SPECT phantom studies for imaging Tc-99m (140 keV) are presented which demonstrate the quantitative compensation for scatter and attenuation for a two dimensional (single slice) reconstruction. The algorithm may be expanded in a straight forward manner to full three dimensional reconstruction including compensation for out of plane scatter

  2. Distributed 3-D iterative reconstruction for quantitative SPECT

    Ju, Z.W.; Frey, E.C.; Tsui, B.M.W.

    1995-01-01

    The authors describe a distributed three dimensional (3-D) iterative reconstruction library for quantitative single-photon emission computed tomography (SPECT). This library includes 3-D projector-backprojector pairs (PBPs) and distributed 3-D iterative reconstruction algorithms. The 3-D PBPs accurately and efficiently model various combinations of the image degrading factors including attenuation, detector response and scatter response. These PBPs were validated by comparing projection data computed using the projectors with that from direct Monte Carlo (MC) simulations. The distributed 3-D iterative algorithms spread the projection-backprojection operations for all the projection angles over a heterogeneous network of single or multi-processor computers to reduce the reconstruction time. Based on a master/slave paradigm, these distributed algorithms provide dynamic load balancing and fault tolerance. The distributed algorithms were verified by comparing images reconstructed using both the distributed and non-distributed algorithms. Computation times for distributed 3-D reconstructions running on up to 4 identical processors were reduced by a factor approximately 80--90% times the number of the processors participating, compared to those for non-distributed 3-D reconstructions running on a single processor. When combined with faster affordable computers, this library provides an efficient means for implementing accurate reconstruction and compensation methods to improve quality and quantitative accuracy in SPECT images

  3. SPECT I-123 iodoamphetamine brain imaging

    Tikofsky, R.S.; Liebman, A.; Hellman, R.S.; Collier, B.D.; Voslar, A.M.

    1988-01-01

    SPECT/IMP studies of 100 patients with a presumptive diagnosis of dementia were performed with a rotating gamma camera 15-20 minutes after intravenous injection of 3.5 mCi of IMP. Of these studies, 43 were interpreted as normal for age; 28 demonstrated decreased but not absent activity bilaterally in posterior parietal/occipital regions (consistent with Alzheimer-type dementia); 28 showed unilateral abnormalities in regional cerebral blood flow consistent with cerebrovascular disease; and one had mixed findings. Based on SPECT/IMP results, further diagnostic testing and/or management would be altered for 72% of patients, suggesting that SPECT/IMP provides valuable data, not available on clinical examination, to guide the evaluation and management of demented patients

  4. Stereotactic radiosurgery planning with ictal SPECT images

    Ackerly, T.; RMIT University, Bundoora, VIC; Geso, M.; O'Keefe, G.; Smith, R.

    2004-01-01

    This paper is motivated by a clinical requirement to utilise ictal SPECT images for target localisation in stereotactic radiosurgery treatment planning using the xknife system which only supports CT and MRI images. To achieve this, the SPECT images were converted from raw (pixel data only) format into a part 10 compliant DICOM CT fileset. The minimum requirements for the recasting of a raw format image as DICOM CT or MRI data set are described in detail. The method can be applied to the importation of raw format images into any radiotherapy treatment planning system that supports CT or MRI import. It is demonstrated that the combination of the low spatial resolution SPECT images, depicting functional information, with high spatial resolution MRI images, which show the structural information, is suitable for stereotactic radiosurgery treatment planning. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

  5. Brain SPECT in severs traumatic head injury

    Beaulieu, F.; Eder, V.; Pottier, J.M.; Baulieu, J.L.; Fournier, P.; Legros, B.; Chiaroni, P.; Dalonneau, M.

    2000-01-01

    The aim of this work was to compare the results of the early brain scintigraphy in traumatic brain injury to the long term neuropsychological behavior. Twenty four patients had an ECD-Tc99m SPECT, within one month after the trauma; scintigraphic abnormalities were evaluated according to a semi-quantitative analysis. The neuropsychological clinical investigation was interpreted by a synthetic approach to evaluate abnormalities related to residual motor deficit, frontal behavior, memory and language disorders. Fourteen patients (58%) had sequela symptoms. SPECT revealed 80 abnormalities and CT scan only 31. Statistical analysis of uptake values showed significantly lower uptake in left basal ganglia and brain stem in patients with sequela memory disorders. We conclude that the brain perfusion scintigraphy is able to detect more lesions than CT and that it could really help to predict the neuropsychological behavior after severe head injury. Traumatology could become in the future a widely accepted indication of perfusion SPECT. (authors)

  6. Comparison of Single-Photon Emission Computed Tomography-Computed Tomography (SPECT/CT) and Conventional Planar Lymphoscintigraphy for Sentinel Node Localization in Patients with Cutaneous Malignancies.

    Doepker, Matthew P; Yamamoto, Maki; Applebaum, Matthew A; Patel, Nupur U; Jaime Montilla-Soler, M; Sarnaik, Amod A; Wayne Cruse, C; Sondak, Vernon K; Zager, Jonathan S

    2017-02-01

    Accurate preoperative lymphoscintigraphy is vital to performing sentinel lymph node biopsy (SLNB) for cutaneous malignancies. Potential advantages of single-photon emission computed tomography with integrated computed tomography (SPECT/CT) include the ability to readily identify aberrant drainage patterns as well as provide the surgeon with three-dimensional anatomic landmarks not seen on conventional planar lymphoscintigraphy (PLS). Patients with cutaneous malignancies who underwent SLNB with preoperative imaging using both SPECT/CT and PLS from 2011 to 2014 were identified. Both SPECT/CT and PLS were obtained in 351 patients (median age, 69 years; range, 5-94 years) with cutaneous malignancies (melanoma = 300, Merkel cell carcinoma = 33, squamous cell carcinoma = 8, other = 10) after intradermal injection of 99m technetium sulfur colloid (median dose 300 µCi). A mean of 4.3 hot spots were identified on SPECT/CT compared to 3.0 on PLS (p CT and PLS, while 172 (49 %) had additional hot spots identified on SPECT/CT compared to only 24 (6.8 %) additional on PLS. SPECT/CT demonstrated additional nodal basins in 103 patients (29.4 %), compared to only 11 patients (3.1 %) with additional basins on PLS. SPECT/CT is a useful adjunct that can help with sentinel node localization in challenging cases. It identified additional hot spots not seen on PLS in almost 50 % of patients. Because PLS identified hot spots not seen on SPECT/CT in 6.8 % of patients, we recommend using both modalities jointly. Long-term follow-up will be required to validate the clinical significance of the additional hot spots identified by SPECT/CT.

  7. SPECT and PET imaging in epilepsia

    Landvogt, C.

    2007-01-01

    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, 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

  8. Scatter and attenuation correction in SPECT

    Ljungberg, Michael

    2004-01-01

    The adsorbed dose is related to the activity uptake in the organ and its temporal distribution. Measured count rate with scintillation cameras is related to activity through the system sensitivity, cps/MBq. By accounting for physical processes and imaging limitations we can measure the activity at different time points. Correction for physical factor, such as attenuation and scatter is required for accurate quantitation. Both planar and SPECT imaging can be used to estimate activities for radiopharmaceutical dosimetry. Planar methods have been the most widely used but is a 2D technique. With accurate modelling for imagine in iterative reconstruction, SPECT methods will prove to be more accurate

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

    Noguchi, Hiroshi; Kawaguchi, Shoichiro; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime

    1999-01-01

    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)

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

    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)

  11. Advances in SPECT Instrumentation (Including Small Animal Scanners). Chapter 4

    Di Domenico, G.; Zavattini, G.

    2009-01-01

    Fundamental major efforts have been devoted to the development of positron emission tomography (PET) imaging modality over the last few decades. Recently, a novel surge of interest in single photon emission computed tomography (SPECT) technology has occurred, particularly after the introduction of the hybrid SPECT-CT imaging system. This has led to a flourishing of investigations in new types of detectors and collimators, and to more accurate refinement of reconstruction algorithms. Along with SPECT-CT, new, fast gamma cameras have been developed for dedicated cardiac imaging. The existing gap between PET and SPECT in sensitivity and spatial resolution is progressively decreasing, and this trend is particularly apparent in the field of small animal imaging where the most important advances have been reported in SPECT tomographs. An outline of the basic features of SPECT technology, and of recent developments in SPECT instrumentation for both clinical applications and basic biological research on animal models is described. (author)

  12. Evaluation of usefulness of bone SPECT for lumbar spondylolysis

    Watanabe, Osamu; Hashimoto, Manabu; Tomura, Noriaki; Watarai, Jiro

    2002-01-01

    The purpose of this study was to evaluate the usefulness of 99m Tc-MDP SPECT (bone SPECT) for lumbar spondylolysis. We analyzed 11 cases with 17 lesions. All cases were compared using plain radiography, computed tomography (CT), planar bone scintigraphy (PBS), and bone SPECT. Four lesions that showed a wide defect on CT were negative on bone SPECT and may have been chronic lesions. Thirteen lesions that were positive on bone SPECT were narrow or showed no defect on CT and may have been early lesions. Two cases showed no defect on CT but were positive on bone SPECT, and one of them progressed to bilateral spondylolysis after one year. This may have been a very early lesion. Thus bone SPECT is useful for the diagnosis of lumbar spondylolysis, especially in its early stage. (author)

  13. Evaluation of usefulness of bone SPECT for lumbar spondylolysis

    Watanabe, Osamu; Hashimoto, Manabu; Tomura, Noriaki; Watarai, Jiro [Akita Univ. (Japan). School of Medicine

    2002-07-01

    The purpose of this study was to evaluate the usefulness of {sup 99m}Tc-MDP SPECT (bone SPECT) for lumbar spondylolysis. We analyzed 11 cases with 17 lesions. All cases were compared using plain radiography, computed tomography (CT), planar bone scintigraphy (PBS), and bone SPECT. Four lesions that showed a wide defect on CT were negative on bone SPECT and may have been chronic lesions. Thirteen lesions that were positive on bone SPECT were narrow or showed no defect on CT and may have been early lesions. Two cases showed no defect on CT but were positive on bone SPECT, and one of them progressed to bilateral spondylolysis after one year. This may have been a very early lesion. Thus bone SPECT is useful for the diagnosis of lumbar spondylolysis, especially in its early stage. (author)

  14. Empirical Hamiltonians

    Peggs, S.; Talman, R.

    1987-01-01

    As proton accelerators get larger, and include more magnets, the conventional tracking programs which simulate them run slower. The purpose of this paper is to describe a method, still under development, in which element-by-element tracking around one turn is replaced by a single man, which can be processed far faster. It is assumed for this method that a conventional program exists which can perform faithful tracking in the lattice under study for some hundreds of turns, with all lattice parameters held constant. An empirical map is then generated by comparison with the tracking program. A procedure has been outlined for determining an empirical Hamiltonian, which can represent motion through many nonlinear kicks, by taking data from a conventional tracking program. Though derived by an approximate method this Hamiltonian is analytic in form and can be subjected to further analysis of varying degrees of mathematical rigor. Even though the empirical procedure has only been described in one transverse dimension, there is good reason to hope that it can be extended to include two transverse dimensions, so that it can become a more practical tool in realistic cases

  15. Clinical application of cardiac SPECT

    Nishimura, Shigeyuki

    1999-01-01

    Single-photon emission computed tomography (SPECT) has replaced planar imaging techniques for myocardial scintigraphy. Thallium-201 was the dominant agent employed for myocardial perfusion imaging. Today new technetium-99m labelled radionuclides have been used as excellent alternatives to 201 Tl for detection of coronary artery disease, prognostification, and even assessment of myocardial viability. Pharmacologic stress imaging using either dipyridamole, adenosine or dobutamine is a substitute for exercise stress. Accurate determination of myocardial viability is vitally important for clinical decision making for patients with LV dysfunction who will most benefit from revascularization. Stunned and hibernated myocardium may result in profound regional LTV dysfunction in absence of necrosis. The various approach such as stress-redistribution-reinjection imaging, rest-redistribution imaging and stress-redistribution-24 hours delayed imaging has been utilized to assess myocardial viability with 201 Tl. Quantitative assessment of 99m Tc MIBI uptake reflect the degree of viability. 123 I-Metaiodobenzylguanidine (MIBG), an analog of norepinephrine, has been used for scintigraphic assessment of regional cardiac adrenergic innervation. Cardiac sympathetic denervation, assessed by 123 I-MIBG, due to ischemia in non-Q myocardial infarction and unstable angina has been shown. Quantitative cardiac MIBG scintigram was shown to have prognostic value in patients with severe congestive heart failure. 23 I-BMIPP (ρ-methyl-iodophenyl pentadecanoic acid) has been used to assess myocardial fatty acid utilization. BMIPP has the memory function of ischemia in unstable angina, since decreased BMIPP uptake persists several days after ischemic episode. Nuclear cardiology in Japan has experienced an expansion in the techniques including use of new radionuclides, 99m Tc perfusion agents, 123 I-MIBG and 23 I-BMIPP and in associated clinical application to the various cardiac diseases

  16. Application of SPECT to psychiatry

    Matsuda, Hiroshi

    1999-01-01

    Brain perfusion SPECT using 99m Tc-ethyl-cysteinate dimer ( 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 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 99m Tc-ECD were useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

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

    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

  18. Aggregation, Validation, and Generalization of Qualitative Data - Methodological and Practical Research Strategies Illustrated by the Research Process of an empirically Based Typology.

    Weis, Daniel; Willems, Helmut

    2017-06-01

    The article deals with the question of how aggregated data which allow for generalizable insights can be generated from single-case based qualitative investigations. Thereby, two central challenges of qualitative social research are outlined: First, researchers must ensure that the single-case data can be aggregated and condensed so that new collective structures can be detected. Second, they must apply methods and practices to allow for the generalization of the results beyond the specific study. In the following, we demonstrate how and under what conditions these challenges can be addressed in research practice. To this end, the research process of the construction of an empirically based typology is described. A qualitative study, conducted within the framework of the Luxembourg Youth Report, is used to illustrate this process. Specifically, strategies are presented which increase the likelihood of generalizability or transferability of the results, while also highlighting their limitations.

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

    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.

  20. Comparative analysis of the sensitivity of the scanner rSPECT: using GAMOS: a Geant4-based framework

    Martinez Turtos, Rosana; Diaz Garcia, Angelina; Abreu Alfonso, Yamiel; Arteche, Jossue; Leyva Pernia, Diana

    2012-01-01

    The molecular imaging of cellular processes in vivo using preclinical animal studies and SPECT technique is one of the main reasons for the design of new devices with high spatial resolution. As an auxiliary tool, Monte Carlo simulation has allowed the characterization and optimization of those medical imaging systems effectively. At present there is a new simulation framework called GAMOS (GEANT4-based Architecture for Medicine-Oriented Simulations); which code, libraries and particle transport method correspond to those developed by GEANT4 and contains specific applications for nuclear medicine. This tool has been already validated for PET technique by comparison with experimental data, while not yet been done the correct evaluation of GAMOS for SPECT systems. Present work have demonstrated the potential of GAMOS in obtaining simulated realistic data using this nuclear imaging technique. For this purpose, simulation of a novel installation 'rSPECT' ,dedicated to the study of rodents, has been done. The study comprises the collimation and detection geometries and the fundamental characteristics of the previous published experimental measurements for rSPECT installation. Studies have been done using 99mTc and 20% energy window. Sensitivity values obtained by simulation revealed an acceptable agreement with experimental values. Therefore we can conclude that simulation results have shown good agreement with the real data. This fact allowed to estimate the behavior of the new GEANT4 simulation platform 'GAMOS' in SPECT applications and have demonstrated the feasibility of reproducing experimental data. (author)

  1. PET and SPECT of neurobiological systems

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

    2014-04-01

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

  2. Chilaiditi's syndrome demonstrated by SPECT/CT

    Nalini S Perumal

    2009-11-01

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

  3. SPECT and PET in Eating Disorders

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

    2014-01-01

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

  4. Methodology for ventilation/perfusion SPECT

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

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

  5. Brain SPECT with Tl-201 DDC

    Bruine, J.F. de.

    1988-01-01

    The development, animal and human experiments and the first clinical results of a new blood flow tracer thallium-201 diethyldithiocarbamate (Tl-201 DDC) are discussed for functional brain imaging with single-photon emission computed tomography (SPECT). 325 refs.; 43 figs.; 22 tabs

  6. Anything wrong with brain SPECT? Not really

    Pavel, D.G.; Davis, G.; Craita, I.; Liu, P.

    2002-01-01

    Aim: Despite increased evidence about the usefulness of Brain SPECT in Neuro-Psychiatry, it continues to represent only a low percentage of Nuclear Medicine procedures. The prevalent perception is that it is an inadequate diagnostic tool, and/or is not changing patient management. There are objective reasons for this, as the lack of awareness by Psychiatrists about the value of SPECT, but most important is the frequently poor quality of images provided. This can be due to inadequate gamma cameras but is mostly due to poor quality software. Materials and Methods: High resolution brain SPECT via triple head gamma camera, super-high resolution fan beam collimator and Tc-HMPAO. A combination of commercial software and local optimization was used for the final displays as well as for realignment of sequential brain SPECT studies. Results: We found out that 6 basic software improvements are needed to generate a final display where features can be clearly distinguished and which can be also easily assimilated by the referring physician. 1) Color scales: simple and efficient tools needed to generate user friendly and semiquantitative color shades as needed. Unfortunately various color scales may be needed depending on printer and paper used. 2): 3 D displays allowing, multiple standardized thresholdings, any number of groupings, differential coloring (with functional meaning) and adequate labeling. Should be completely or at least mostly automatic. 3) Automatic realignment of sequential studies: such programs exist in various forms (free WWW versions, proprietary Beta versions, etc.) but are still not supplied by the gamma camera vendors for general use. Should provide SPECT -SPECT and SPECT MRI options. 4) Localization of structures and slices a) Triangulation of structures and b) Identification of section location. 5) Graphics improvement for generating any number of optimized summary displays to accompany reports. 6) Availability of voxel based quantification software

  7. Brain pertechnetate SPECT in perinatal asphyxia

    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.

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

    Kim, Hwa-Young; Gelfand, Michael J.; Sharp, Susan E.

    2011-01-01

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

  9. Impact of Cognitive Abilities and Prior Knowledge on Complex Problem Solving Performance – Empirical Results and a Plea for Ecologically Valid Microworlds

    Heinz-Martin Süß

    2018-05-01

    Full Text Available The original aim of complex problem solving (CPS research was to bring the cognitive demands of complex real-life problems into the lab in order to investigate problem solving behavior and performance under controlled conditions. Up until now, the validity of psychometric intelligence constructs has been scrutinized with regard to its importance for CPS performance. At the same time, different CPS measurement approaches competing for the title of the best way to assess CPS have been developed. In the first part of the paper, we investigate the predictability of CPS performance on the basis of the Berlin Intelligence Structure Model and Cattell’s investment theory as well as an elaborated knowledge taxonomy. In the first study, 137 students managed a simulated shirt factory (Tailorshop; i.e., a complex real life-oriented system twice, while in the second study, 152 students completed a forestry scenario (FSYS; i.e., a complex artificial world system. The results indicate that reasoning – specifically numerical reasoning (Studies 1 and 2 and figural reasoning (Study 2 – are the only relevant predictors among the intelligence constructs. We discuss the results with reference to the Brunswik symmetry principle. Path models suggest that reasoning and prior knowledge influence problem solving performance in the Tailorshop scenario mainly indirectly. In addition, different types of system-specific knowledge independently contribute to predicting CPS performance. The results of Study 2 indicate that working memory capacity, assessed as an additional predictor, has no incremental validity beyond reasoning. We conclude that (1 cognitive abilities and prior knowledge are substantial predictors of CPS performance, and (2 in contrast to former and recent interpretations, there is insufficient evidence to consider CPS a unique ability construct. In the second part of the paper, we discuss our results in light of recent CPS research, which predominantly

  10. Impact of Cognitive Abilities and Prior Knowledge on Complex Problem Solving Performance – Empirical Results and a Plea for Ecologically Valid Microworlds

    Süß, Heinz-Martin; Kretzschmar, André

    2018-01-01

    The original aim of complex problem solving (CPS) research was to bring the cognitive demands of complex real-life problems into the lab in order to investigate problem solving behavior and performance under controlled conditions. Up until now, the validity of psychometric intelligence constructs has been scrutinized with regard to its importance for CPS performance. At the same time, different CPS measurement approaches competing for the title of the best way to assess CPS have been developed. In the first part of the paper, we investigate the predictability of CPS performance on the basis of the Berlin Intelligence Structure Model and Cattell’s investment theory as well as an elaborated knowledge taxonomy. In the first study, 137 students managed a simulated shirt factory (Tailorshop; i.e., a complex real life-oriented system) twice, while in the second study, 152 students completed a forestry scenario (FSYS; i.e., a complex artificial world system). The results indicate that reasoning – specifically numerical reasoning (Studies 1 and 2) and figural reasoning (Study 2) – are the only relevant predictors among the intelligence constructs. We discuss the results with reference to the Brunswik symmetry principle. Path models suggest that reasoning and prior knowledge influence problem solving performance in the Tailorshop scenario mainly indirectly. In addition, different types of system-specific knowledge independently contribute to predicting CPS performance. The results of Study 2 indicate that working memory capacity, assessed as an additional predictor, has no incremental validity beyond reasoning. We conclude that (1) cognitive abilities and prior knowledge are substantial predictors of CPS performance, and (2) in contrast to former and recent interpretations, there is insufficient evidence to consider CPS a unique ability construct. In the second part of the paper, we discuss our results in light of recent CPS research, which predominantly utilizes the

  11. Empirical validation of building simulation programs - Swiss contribution to IEA Task 34, Annex 43; Empirische Validierung von Gebaeudesimulationsprogrammen. Schweizer Beitrag zu IEA Task 34 / Annex 43. Schlussbericht

    Loutzenhiser, P.; Manz, H. (eds.)

    2006-11-15

    This comprehensive, illustrated final report for the Swiss Federal Office of Energy (SFOE) reports on work carried out on the validation of building simulation programs. the purpose of this project was to create a data set for use when evaluating the accuracy of models for glazing units and windows with and without shading devices. A series of eight experiments that subsequently increased in complexity were performed in an outdoor test cell located on the Swiss Federal Laboratories for Material Testing and Research (EMPA) campus in Duebendorf, Switzerland. Particular emphasis was placed on accurately determining the test cell characteristics. The report presents information on experimental set-ups, their validation and the methodology used. Further chapters describe particular experiments made, including transient characterisation, evaluation of irradiation models on tiled facades, as well as those made on glazing units with various types of shading and blinds. The thermal properties of windows are looked at. The results of experiments made with four different models, HELIOS, EnergyPlus, DOE-2.1E and IDA-ICE, are discussed.

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

    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

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

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

    2014-01-01

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

  14. Evaluation of left ventricular ejection fraction from radial long-axis tomography. A new reconstruction algorithm for ECG-gated technetium-99m Sestamibi SPECT

    Tsujimura, Eiichiro; Kusuoka, Hideo; Uehara, Toshiisa

    1997-01-01

    Radial long-axis tomography can provide views similar to contrast left ventriculography (LVG) including the basal and apical areas of the left ventricle, not possible in routine short-axis tomography. We applied this method to ECG-gated Tc-99m Sestamibi (MIBI) myocardial SPECT images to estimate the left ventricular ejection fraction (LVEF). ECG-gated Tc-99m MIBI SPECT was performed with a temporal resolution of 10 frames per R-R interval. LVEF was calculated on the basis of left ventricular volume estimates at end diastole (ED) and end systole (ES) with using an ellipsoid body model. To validate this method, LVEF's derived from ECG-gated Tc-99m MIBI SPECT were compared with those from LVG in 11 patients with coronary artery disease. There was a close linear correlation between LVEF values calculated from Tc-99m MIBI SPECT and those from LVG (r=0.89, p<0.001), although the gated SPECT underestimated LVEF compared to LVG. The technique showed excellent reproducibility (intra-observer variability, r=0.96, p<0.001; inter-observer variability, r=0.71, p<0.005). The radial long-axis tomography technique gives a good estimate of LVEF, in agreement with estimates based on LVG. ECG-gated Tc-99m MIBI SPECT can, therefore, be applicable to assess myocardial perfusion and ventricular function at the same time. (author)

  15. Evaluation of left ventricular ejection fraction from radial long-axis tomography. A new reconstruction algorithm for ECG-gated technetium-99m Sestamibi SPECT

    Tsujimura, Eiichiro; Kusuoka, Hideo; Uehara, Toshiisa [Osaka Univ. (Japan). Faculty of Medicine] [and others

    1997-08-01

    Radial long-axis tomography can provide views similar to contrast left ventriculography (LVG) including the basal and apical areas of the left ventricle, not possible in routine short-axis tomography. We applied this method to ECG-gated Tc-99m Sestamibi (MIBI) myocardial SPECT images to estimate the left ventricular ejection fraction (LVEF). ECG-gated Tc-99m MIBI SPECT was performed with a temporal resolution of 10 frames per R-R interval. LVEF was calculated on the basis of left ventricular volume estimates at end diastole (ED) and end systole (ES) with using an ellipsoid body model. To validate this method, LVEF`s derived from ECG-gated Tc-99m MIBI SPECT were compared with those from LVG in 11 patients with coronary artery disease. There was a close linear correlation between LVEF values calculated from Tc-99m MIBI SPECT and those from LVG (r=0.89, p<0.001), although the gated SPECT underestimated LVEF compared to LVG. The technique showed excellent reproducibility (intra-observer variability, r=0.96, p<0.001; inter-observer variability, r=0.71, p<0.005). The radial long-axis tomography technique gives a good estimate of LVEF, in agreement with estimates based on LVG. ECG-gated Tc-99m MIBI SPECT can, therefore, be applicable to assess myocardial perfusion and ventricular function at the same time. (author)

  16. Preliminary results of the empirical validation of daily increments in otoliths of jack mackerel Trachurus symmetricus murphyi (Nichols, 1920 marked with oxytetracycline

    Miguel Araya

    2003-12-01

    Full Text Available The frequency of microincrement formation in sagittae otoliths of jack mackerel Trachurus symmetricus was validated using experiments on captive fish. Adult jack mackerel were injected with a dose of 100 mg of oxytetracycline/kg of fish. A second injection was performed 30 days later. The fish were then sacrificed and their sagittae otoliths were extracted. Thin sections of the otoliths were prepared and observed through an epifluorescent microscope using ultraviolet light. Two fluorescent marks corresponding to the two injections were clearly visible. The average number of microincrements between the two fluorescent marks was 29 (n=10; S.D.=1.63 and the median was 29.3. The Wilcoxon signed-rank test indicated that this value was not significantly different from 30. This result indicates that microincrements in otoliths of adult jack mackerel of between 28.4 and 37.7 cm fork length are formed with a daily frequency.

  17. Traits across the personality hierarchy differentially relate to positive and negative affect: Evidence for the predictive validity of empirically derived meta-traits.

    Hengartner, Michael P; Graf, Markus; Schreiber, Marc

    2017-05-01

    There is increasing interest in the construct validity of higher-order domains of the Big Five personality traits. A total of 831 persons from the Swiss population completed the International Personality Item Pool and an adaptation of the Positive and Negative Affect Scales. Using Goldberg's bass-ackwards method, we found evidence for the general factor of personality (GFP) and the two meta-traits of positive emotionality (blend of low neuroticism and high extraversion) and constraint (blend of high agreeableness and conscientiousness). In association with positive affect, the explanatory power of the GFP (r = 0.43) and positive emotionality (r = 0.37) was largely superior to extraversion (r = 0.24), conscientiousness (r = 0.18), agreeableness (r = 0.09) and openness (r = 0.04), although not neuroticism (r = -0.34). In association with negative affect, neuroticism (r = 0.41), the GFP (r = -0.36) and positive emotionality (r = -0.35) were the most powerful single predictors. We conclude that the higher-order structure of personality is best explained by the meta-traits of positive emotionality and constraint, which correspond closely to the well-established superfactors of internalizing and externalizing. We further demonstrate that these have substantial criterion validity when broad positive and negative affect is the outcome of interest. These findings help to relate Big Five meta-traits to pathological personality. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  18. The clinical use of brain SPECT imaging in neuropsychiatry

    Amen, Daniel G; Wu, Joseph C; Carmichael, Blake

    2003-01-01

    This article reviews the literature on brain SPECT imaging in brain trauma, dementia, and temporal lobe epilepsy. Brain SPECT allows clinicians the ability to view cerebral areas of healthy, low, and excessive perfusion. This information can be correlated with what is known about the function or dysfunction of each area. SPECT has a number of advantages over other imaging techniques, including wider availability, lower cost, and high quality resolution with multi-headed cameras. There are a number of issues that compromise the effective use of SPECT, including low quality of some imaging cameras, and variability of image rendering and readings (Au)

  19. Influence of void on image quality of industrial SPECT

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

    2013-01-01

    Industrial single photon emission computed tomography (SPECT) is a promising technique to determine the dynamic behavior of industrial process media and has been developed in the Korea Atomic Energy Research Institute. The present study evaluated the influence of a void, which is presence in multiphase reactors of industrial process, on the image quality of an industrial SPECT. The results are very encouraging; that is, the performance of the industrial SPECT system is little influenced by the presence of a void, which means that industrial SPECT is an appropriate tool to estimate the dynamic characteristics of the process media in a water-air phase bubble column with a static gas sparger

  20. The effect of Compton scattering on quantitative SPECT imaging

    Beck, J.W.; Jaszczak, R.J.; Starmer, C.F.

    1982-01-01

    A Monte Carlo code has been developed to simulate the response of a SPECT system. The accuracy of the code has been verified and has been used in this research to study and illustrate the effects of Compton scatter on quantitative SPECT measurements. The effects of Compton scattered radiation on gamma camera response have been discussed by several authors, and will be extended to rotating gamma camera SPECT systems. The unique feature of this research includes the pictorial illustration of the Compton scattered and the unscattered components of the photopeak data on SPECT imaging by simulating phantom studies with and without Compton scatter

  1. Methods of gated-blood-pool-spect data processing

    Kosa, I.; Mester, J.; Tanaka, M.; Csernay, L.; Mate, E.; Szasz, K.

    1991-01-01

    Three techniques of gated SPECT were evaluated. The methods of Integral SPECT (ISPECT), enddyastole-endsystole SPECT (ED-ES SPECT) and Fourier SPECT were adapted and developed on the Hungarian nuclear medicine data processing system microSEGAMS. The methods are based on data reduction before back projection which results in processing times acceptable for the clinical routine. The clinical performance of the introduced techniques was tested in 10 patients with old posterior myocardial infarction and in 5 patients without cardiac disease. The left ventricular ejection faction determined by ISPECT correlated well with the planar values. The correlation coefficient was 0.89. The correlation coefficient of EF values determined by ED-ES SPECT and planar radionuclide ventriculography was lower (0.70). For the identification of left ventricular wall motion abnormalities ED-ES SPECT and Fourier SPECT exhibited a favourable performance, but ISPECT only moderate suitability. In the detection of regional phase delay Fourier-SPECT demonstrated higher sensitivity than the planar radionuclide ventriculography. (author) 4 refs.; 3 figs.; 2 tabs

  2. I-123 Iofetamine SPECT scan in children with neurological disorders

    Flamini, J.R.; Konkol, R.J.; Wells, R.G.; Sty, J.R.

    1990-01-01

    I-123 Iofetamine (IMP) single photon emission computed tomography (SPECT) imaging of the brain in 42 patients (ages 14 days to 23 years) was compared with other localizing studies in children with neurological diseases. All had an EEG and at least one imaging study of the brain (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Seventy-eight percent of the patients had an EEG within 24-72 hours of the IMP-SPECT scan. Thirty-five (83%) had a history of seizures, and the remainder had other neurological conditions without a history of seizures. In most cases, a normal EEG reading with normal CT or MRI result predicted a normal SPECT study. When the EEG was abnormal the majority of the IMP-SPECT scans were abnormal and localized the abnormality to the same region. A comparison with CT and MRI showed that structural abnormalities involving the cortex were usually well demonstrated with IMP-SPECT imaging. Structural lesions confined to the white matter were generally not detectable with IMP-SPECT. In a few cases, SPECT scans revealed abnormalities in deep brain areas not identified by EEG. IMP-SPECT imaging is a valuable technique for the detection and localization of abnormal cerebral metabolic activity in children with seizure disorders. A correlation with CT or MRI is essential for proper interpretation of abnormalities detected with IMP SPECT imaging

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

    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.

  4. Measurement of lung water with SPECT

    Chu, R.Y.L.; Ficken, V.J.; Ekeh, S.U.; Ryals, C.J.; Allen, E.W.; Basmadjian, G.

    1990-01-01

    This paper investigates the use of iodoantipyrine (IAP) labeled with radioactive iodine (I-123) and single photon emission tomography (SPECT) to measure lung water. I-123 IAP was injected intravenously to six New Zealand White rabbits under anesthesia. After 1 hour, Tc-99m macroaggregates of albumin (MAA) were injected. SPECT imaging was performed in dual-energy mode. After a blood sample was drawn, the animals were sacrificed, and the lungs were removed. Blood samples were assayed for radioactivity. The lungs were weighed, dried, and weighted again to determine water content. The product of area defined by MAA in a tomogram and IAP count rate of central pixels of that region in the corresponding tomogram was taken as the relative amount of IAP in each lung

  5. Methodology for ventilation/perfusion SPECT

    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...

  6. New SPECT and PET dementia tracers

    Vergote, J.; Chalon, S.; Emond, P.; Vercouillie, J.; Guilloteau, D.; Vergote, J.; Guilloteau, D.; Pappata, J.S.

    2009-01-01

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

  7. SPECT/CT in pediatric patient management

    Nadel, Helen R.

    2014-01-01

    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.)

  8. Hybrid SPECT/CT imaging in neurology.

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

    2014-01-01

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

  9. SPECT/CT in pediatric patient management

    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.)

  10. Empirical Hamiltonians

    Peggs, S.; Talman, R.

    1986-08-01

    As proton accelerators get larger, and include more magnets, the conventional tracking programs which simulate them run slower. At the same time, in order to more carefully optimize the higher cost of the accelerators, they must return more accurate results, even in the presence of a longer list of realistic effects, such as magnet errors and misalignments. For these reasons conventional tracking programs continue to be computationally bound, despite the continually increasing computing power available. This limitation is especially severe for a class of problems in which some lattice parameter is slowly varying, when a faithful description is only obtained by tracking for an exceedingly large number of turns. Examples are synchrotron oscillations in which the energy varies slowly with a period of, say, hundreds of turns, or magnet ripple or noise on a comparably slow time scale. In these cases one may with to track for hundreds of periods of the slowly varying parameter. The purpose of this paper is to describe a method, still under development, in which element-by-element tracking around one turn is replaced by a single map, which can be processed far faster. Similar programs have already been written in which successive elements are ''concatenated'' with truncation to linear, sextupole, or octupole order, et cetera, using Lie algebraic techniques to preserve symplecticity. The method described here is rather more empirical than this but, in principle, contains information to all orders and is able to handle resonances in a more straightforward fashion

  11. Adaptive Angular Sampling for SPECT Imaging

    Li, Nan; Meng, Ling-Jian

    2011-01-01

    This paper presents an analytical approach for performing adaptive angular sampling in single photon emission computed tomography (SPECT) imaging. It allows for a rapid determination of the optimum sampling strategy that minimizes image variance in regions-of-interest (ROIs). The proposed method consists of three key components: (a) a set of close-form equations for evaluating image variance and resolution attainable with a given sampling strategy, (b) a gradient-based algor...

  12. Brain perfusion SPECT in dementia syndromes

    Libus, P.; Stupalova, J.; Kuzelka, I.; Konrad, J.

    2002-01-01

    Aim: Brain perfusion SPECT is used in differential diagnostics of dementia syndromes. First of all the aim is to distinguish vascular dementia from degenerative dementia and to differentiate dementia from delirium, psychiatric syndromes, depression and secondary dementia, which is important in relation to therapy. The purpose of our study was to detect significance of BP SPECT and include it into the diagnostic process in dementia syndromes. Materials and methods: 51 women and 63 men aged 55 - 88 were evaluated in the study. The patients correspond to the general criteria of dementia diagnosis. They were sent to the examination by neurological, internal and psychiatric departments and out-patient departments. All patients were examined by 99mTc ECD SPECT using a double head camera PRISM 200 VP with LEHR collimator. The scintigraphic data were evaluated by the visual and semiquantitative analysis. Results: It was established that most patients in our group had vascular dementia, while Alzheimer's disease was second. In other groups we found out dementia at strategic infarct location, e.g. in gyrus angularis in the dominant hemisphere, frontal temporal lobe dementia and alcoholic dementia. Twenty-four patients had a normal diagnosis. Fifteen of them had a somatic reason of the delirious state and were re-classified into pseudodementia. Nine patients were not diagnostically included and the examination will repeated in four months time. Conclusion: We have found out a good applicability of brain perfusion SPECT in dementia syndromes diagnosis in our work. The best diagnosticable and most specific were the findings in multi-infarct dementia, Alzheimer's disease and frontal temporal lobe dementia. When vascular dementia is concerned we can even distinguish dementia at strategic infarction location, e.g. in thalamus, basal frontal telencefalon, in gyrus angularis of the dominant hemisphere, etc

  13. Neuropharmacological studies with SPECT in neuropsychiatric disorders

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

    2000-10-01

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

  14. Single photon emission computerized tomography (SPECT)

    Ganatra, R.D.

    1992-01-01

    Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as 123 I and 99 Tc m that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

  15. Neuropharmacological studies with SPECT in neuropsychiatric disorders

    Heinz, Andreas; Jones, Douglas W.; Raedler, Thomas; Coppola, Richard; Knable, Michael B.; Weinberger, Daniel R.

    2000-01-01

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

  16. Single photon emission computerized tomography (SPECT)

    Ganatra, R D

    1993-12-31

    Tomography in nuclear medicine did not originate after the introduction of X-ray computerized tomography (CT). Even in the days of rectilinear scanner, tomography was attempted with multiple detector heads rotating around the patient, but the counts at each plane were never very high to obtain a satisfactory image. A high resolution focusing collimator can look at different depths but taking several slices in one projection was a time consuming process. Rectilinear scanners lose lot of counts in the collimator to look at one point, at on time, in one plane. It is true that attempts to do tomography with gamma camera really got a boost after the success of CT. By that time, algorithms for doing reconstruction of images also were highly refined and for advanced. Clinical application of SPECT has become widespread now, because of the development of suitable radiopharmaceuticals and improvement in instrumentation. The SPECT provides a direct measure of regional organ function and is performed with nuclides such as {sup 123}I and {sup 99}Tc{sup m} that emit a mono-image photon during their decay. SPECT is far less expensive than positron emission tomography

  17. Blood lipid levels and SPECT of myocardium perfusion to type 2 asymptomatic diabetic patients

    Pena Quian, Yamile; Fernandez-Britto Rodriguez, Jose; Coca Perez, Marco A; Batista Cuellar, Juan F; Rochela Vazquez, Luis Manuel

    2006-01-01

    SPECT, coronary angiography and laboratories test were performed on 31 asymptomatic type 2 diabetes patients, in order to determine the relationship among the lipid levels in blood and the results of the SPECT. Patients were classified in two groups (positive SPECT or negative SPECT). Simple descriptive statistics were calculated for all variables in both groups. Positive SPECT was detected in 35,5% of the patients and negative SPECT in 64,5%.The coronary angiography and SPECT showed good correlation. Low values of HDLc showed significant association with the positive results of the SPECT. The logistical regression showed an increment of the capacity to predict a positive SPECT if the values of HDLc are used. Conclusion: The present investigation demonstrated a significant association among the low levels of HDLc in blood and the positive results of the SPECT. The low values of HDLc could predict the possibility of a positive SPECT in asymptomatic diabetic type 2 patients (au)

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

    Verger, Antoine; Karcher, Gilles; Imbert, Laetitia; Yagdigul, Yalcine; Roch, Veronique; Fay, Renaud; Djaballah, Wassila; Rouzet, Francois; Le Guludec, Dominique; Fourquet, Nicolas; Poussier, Sylvain; Marie, Pierre-Yves

    2014-01-01

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

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

    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.

  20. Dopamine-transporter SPECT and Dopamine-D2-receptor SPECT in basal ganglia diseases

    Hesse, S.; Barthel, H.; Seese, A.; Sabri, O.

    2007-01-01

    The basal ganglia comprise a group of subcortical nuclei, which are essential for motor control. Dysfunction of these areas, especially in dopaminergic transmission, results in disordered movement and neurological diseases such as Parkinson's disease, Wilson's disease, or Huntington disease. Positron emission tomography and single photon emission computed tomography (SPECT) have enhanced the understanding of the underlying pathophysiology, but they much more contribute to the early differential diagnosis of patients suffering from Parkinsonian syndrome in routine care. The present article provides dopamine transporter and D 2 receptor SPECT findings in selected movement disorders. (orig.)

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

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

    2010-04-01

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

  2. An empirically derived dietary pattern associated with breast cancer risk is validated in a nested case-control cohort from a randomized primary prevention trial.

    Hidaka, Brandon H; Kimler, Bruce F; Fabian, Carol J; Carlson, Susan E

    2017-02-01

    We reported an association between cytologic atypia, a reversible biomarker of breast cancer risk, and lower omega-3/omega-6 fatty acid ratio in blood and breast tissue. Our goal was to develop and validate a dietary pattern index in this high-risk sample of U.S. women, and test its capacity to predict incidence in a nested case-control cohort of Canadian women from a randomized trial of a low-fat dietary intervention for primary prevention of breast cancer. Food intake was measured by food frequency questionnaire in the U.S. sample (n = 65) and multiple dietary recalls in the Canadian sample (n = 220 cases; 440 controls). Principal component analysis identified a dietary pattern associated with atypia. We measured differences among dietary pattern tertiles in (a) fatty acid composition in blood lipids and breast tissue in the U.S. sample, and (b) risk of breast cancer subtypes in the Canadian cohort. Registered under ClinicalTrials.gov Identifier: NCT00148057. A Modern diet was characterized as consuming more grains, dairy, and sugar and less vegetables, fish and poultry; these women had lower tissue omega-3 fatty acids and higher omega-6 and trans fatty acids. The low-fat intervention increased the likelihood of a Modern diet after randomization. A Modern diet at baseline and post-randomization was associated with estrogen-receptor negative (ER-) breast cancer risk among those at least 160 cm tall. A Traditional diet (the reciprocal of Modern) at baseline was associated with lower ER-positive (ER+) risk in the comparison group, but not the low-fat intervention group. A Modern diet (high in grains, dairy, and sugar and low in vegetables, fish, and poultry) is associated with ER- breast cancer risk among taller women. Recommending dietary fat reduction may have untoward effects on breast cancer risk. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

  3. Implementation and Evaluation of Pinhole SPECT

    MacArtain Anne Marie

    2002-08-01

    The aim of this work was to implement Pinhole SPECT into a working Nuclear Medicine department. It has been reported that pinhole SPECT has been successfully performed to visualise pathology in ankle bones using gamma camera and the images were constructed using a standard filtered back-projection algorithm (Bahk YW, 1998). The objective of this study was to produce and evaluate this technique with the equipment available in the nuclear medicine department. The system performance was assessed using both the low-energy high resolution and the pinhole collimators. Phantoms constructed using capillary tubes, filled with technetium 99m (pertechnetate) were imaged in different arrays to identify possible limitations in the reconstruction software. A thyroid phantom with hot and cold inserts was also imaged. Data was acquired in ''tep-and-shoot'' mode as the camera was rotated 180 degrees or 360 degrees around the phantom. Images were reconstructed using standard parallel back-projection algorithm and a weighted backprojection algorithm (Nowak). An attempt was made to process images of the phantom in Matlab using the Iradon function modified by application of a cone-beam type algorithm (Feldkamp L, 1984). Visual comparison of static images between the pinhole and the LEHR collimators showed the expected improved spatial resolution of the pinhole images. Pinhole SPECT images should be reconstructed using the appropriate cone beam algorithm. However, it was established that reconstructing pinhole SPECT images using a standard parallel backprojection algorithm yielded results which were deemed to be clinically useful. The Nowak algorithm results were a distinct improvement on those achieved with the parallel backprojection algorithm. Likewise the results from the cone beam algorithm were better than the former but not as good as those obtained from the Nowak algorithm. This was due to the fact that the cone beam algorithm did not include a weighting factor. Implementation

  4. Use of quantitative SPECT/CT reconstruction in 99mTc-sestamibi imaging of patients with renal masses.

    Jones, Krystyna M; Solnes, Lilja B; Rowe, Steven P; Gorin, Michael A; Sheikhbahaei, Sara; Fung, George; Frey, Eric C; Allaf, Mohamad E; Du, Yong; Javadi, Mehrbod S

    2018-02-01

    Technetium-99m ( 99m Tc)-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) has previously been shown to allow for the accurate differentiation of benign renal oncocytomas and hybrid oncocytic/chromophobe tumors (HOCTs) apart from other malignant renal tumor histologies, with oncocytomas/HOCTs showing high uptake and renal cell carcinoma (RCC) showing low uptake based on uptake ratios from non-quantitative single-photon emission computed tomography (SPECT) reconstructions. However, in this study, several tumors fell close to the uptake ratio cutoff, likely due to limitations in conventional SPECT/CT reconstruction methods. We hypothesized that application of quantitative SPECT/CT (QSPECT) reconstruction methods developed by our group would provide more robust separation of hot and cold lesions, serving as an imaging framework on which quantitative biomarkers can be validated for evaluation of renal masses with 99m Tc-sestamibi. Single-photon emission computed tomography data were reconstructed using the clinical Flash 3D reconstruction and QSPECT methods. Two blinded readers then characterized each tumor as hot or cold. Semi-quantitative uptake ratios were calculated by dividing lesion activity by background renal activity for both Flash 3D and QSPECT reconstructions. The difference between median (mean) hot and cold tumor uptake ratios measured 0.655 (0.73) with the QSPECT method and 0.624 (0.67) with the conventional method, resulting in increased separation between hot and cold tumors. Sub-analysis of 7 lesions near the separation point showed a higher absolute difference (0.16) between QPSECT and Flash 3D mean uptake ratios compared to the remaining lesions. Our finding of improved separation between uptake ratios of hot and cold lesions using QSPECT reconstruction lays the foundation for additional quantitative SPECT techniques such as SPECT-UV in the setting of renal 99m Tc-sestamibi and other SPECT/CT exams. With robust

  5. A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT

    Qian Jianguo; Bradley, Eric L.; Majewski, Stan; Popov, Vladimir; Saha, Margaret S.; Smith, Mark F.; Weisenberger, Andrew G.; Welsh, Robert E.

    2008-01-01

    We have designed and built a small-animal single-photon emission computed tomography (SPECT) imaging system equipped with parallel-hole and multipinhole collimators and capable of circular or helical SPECT. Copper-beryllium parallel-hole collimators suitable for imaging the ∼35 keV photons from the decay of 125 I have been built and installed to achieve useful spatial resolution over a range of object-detector distances and to reduce imaging time on our dual-detector array. To address the resolution limitations in the parallel-hole SPECT and the sensitivity and limited field of view of single-pinhole SPECT, we have incorporated multipinhole circular and helical SPECT in addition to expanding the parallel-hole SPECT capabilities. The pinhole SPECT system is based on a 110 mm diameter circular detector equipped with a pixellated NaI(Tl) scintillator array (1x1x5 mm 3 /pixel). The helical trajectory is accomplished by two stepping motors controlling the rotation of the detector-support gantry and displacement of the animal bed along the axis of rotation of the gantry. Results obtained in SPECT studies of various phantoms show an enlarged field of view, very good resolution and improved sensitivity using multipinhole circular or helical SPECT. Collimators with one, three and five, 1-mm-diameter pinholes have been implemented and compared in these tests. Our objective is to develop a system on which one may readily select a suitable mode of either parallel-hole SPECT or pinhole circular or helical SPECT for a variety of small animal imaging applications

  6. Frequencies and implications of discordant findings of interictal SPECT and itcal SPECT in patients with intractable epilepsy

    Lee, D. S.; Lee, S. K.; Jeong, J. K.; Lee, M. C.; Ko, C. S.

    1997-01-01

    Interictal SPECT could be used at best as a reference image to ictal SPECT, and cause sometimes confusion if it had given unexplained discordant findings from ictal SPECT. We investigated implications of discordant findings which occurred in 26 among 268 which found their epileptogenic zones using ictal EEG and/or operative outcome. Sensitivity of interictal SPECT was only 36%. Among these 268, 69 patients had no structural lesions on MR, 14 of whom had decreased perfusion on interictal SPECT (8 trues and 6 falses (adjacent or contralateral)). Structural lesion were found in 199 on MR, 103 of whom had decreased perfusion (89 trues and 14 falses). Among 26 having discordant cases, 10 interictal SPECT were proved wrong after operation and/or invasive EEG and the other 16 were on speculation using PET and ictal EEG. Ictal hyperperfusion was observed in 14 patients in these interictal SPECT. Six ictal studies were found postictal accompanied by contralateral propagation or not. Two patients had dual pathology, and the remaining 2 unknown. Interictal SPECT was done on the 2nd day after ictal study(24), the 3rd day (18), the 4th day(16), the 5th day (23). Four among 24 interictal studies (17%) of the 2nd day and the other 4 among 57 of 3rd to 5th day revealed ictal hyperperfusion on interictal SPECT. Six interictal studies (2.7% among 221) acquired on the indifferent day showed also ictal hyperperfusion. We could suggest that the next day is not desirable for interictal SPECT after ictal study, as ictal hyperperfusion on interictal study confounded more than postictal findings of ictal SPECT in the discrete localization than reassuring ictal study

  7. Frequencies and implications of discordant findings of interictal SPECT and itcal SPECT in patients with intractable epilepsy

    Lee, D S; Lee, S K; Jeong, J K; Lee, M C; Ko, C S [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

    1997-07-01

    Interictal SPECT could be used at best as a reference image to ictal SPECT, and cause sometimes confusion if it had given unexplained discordant findings from ictal SPECT. We investigated implications of discordant findings which occurred in 26 among 268 which found their epileptogenic zones using ictal EEG and/or operative outcome. Sensitivity of interictal SPECT was only 36%. Among these 268, 69 patients had no structural lesions on MR, 14 of whom had decreased perfusion on interictal SPECT (8 trues and 6 falses (adjacent or contralateral)). Structural lesion were found in 199 on MR, 103 of whom had decreased perfusion (89 trues and 14 falses). Among 26 having discordant cases, 10 interictal SPECT were proved wrong after operation and/or invasive EEG and the other 16 were on speculation using PET and ictal EEG. Ictal hyperperfusion was observed in 14 patients in these interictal SPECT. Six ictal studies were found postictal accompanied by contralateral propagation or not. Two patients had dual pathology, and the remaining 2 unknown. Interictal SPECT was done on the 2nd day after ictal study(24), the 3rd day (18), the 4th day(16), the 5th day (23). Four among 24 interictal studies (17%) of the 2nd day and the other 4 among 57 of 3rd to 5th day revealed ictal hyperperfusion on interictal SPECT. Six interictal studies (2.7% among 221) acquired on the indifferent day showed also ictal hyperperfusion. We could suggest that the next day is not desirable for interictal SPECT after ictal study, as ictal hyperperfusion on interictal study confounded more than postictal findings of ictal SPECT in the discrete localization than reassuring ictal study.

  8. Exact Reconstruction From Uniformly Attenuated Helical Cone-Beam Projections in SPECT

    Gullberg, Grant T.; Huang, Qiu; You, Jiangsheng; Zeng, Gengsheng L.

    2008-01-01

    In recent years the development of cone-beam reconstruction algorithms has been an active research area in x-ray computed tomography (CT), and significant progress has been made in the advancement of algorithms. Theoretically exact and computationally efficient analytical algorithms can be found in the literature. However, in single photon emission computed tomography (SPECT), published cone-beam reconstruction algorithms are either approximate or involve iterative methods. The SPECT reconstruction problem is more complicated due to degradations in the imaging detection process, one of which is the effect of attenuation of gamma ray photons. Attenuation should be compensated for to obtain quantitative results. In this paper, an analytical reconstruction algorithm for uniformly attenuated cone-beam projection data is presented for SPECT imaging. The algorithm adopts the DBH method, a procedure consisting of differentiation and backprojection followed by a finite inverse cosh-weighted Hilbert transform. The significance of the proposed approach is that a selected region of interest can be reconstructed even with a detector with a reduced field of view. The algorithm is designed for a general trajectory. However, to validate the algorithm, a numerical study was performed using a helical trajectory. The implementation is efficient and the simulation result is promising

  9. Kernel integration scatter model for parallel beam gamma camera and SPECT point source response

    Marinkovic, P.M.

    2001-01-01

    Scatter correction is a prerequisite for quantitative single photon emission computed tomography (SPECT). In this paper a kernel integration scatter Scatter correction is a prerequisite for quantitative SPECT. In this paper a kernel integration scatter model for parallel beam gamma camera and SPECT point source response based on Klein-Nishina formula is proposed. This method models primary photon distribution as well as first Compton scattering. It also includes a correction for multiple scattering by applying a point isotropic single medium buildup factor for the path segment between the point of scatter an the point of detection. Gamma ray attenuation in the object of imaging, based on known μ-map distribution, is considered too. Intrinsic spatial resolution of the camera is approximated by a simple Gaussian function. Collimator is modeled simply using acceptance angles derived from the physical dimensions of the collimator. Any gamma rays satisfying this angle were passed through the collimator to the crystal. Septal penetration and scatter in the collimator were not included in the model. The method was validated by comparison with Monte Carlo MCNP-4a numerical phantom simulation and excellent results were obtained. The physical phantom experiments, to confirm this method, are planed to be done. (author)

  10. Improved accuracy in estimation of left ventricular function parameters from QGS software with Tc-99m tetrofosmin gated-SPECT. A multivariate analysis

    Okizaki, Atsutaka; Shuke, Noriyuki; Sato, Junichi; Ishikawa, Yukio; Yamamoto, Wakako; Kikuchi, Kenjiro; Aburano, Tamio

    2003-01-01

    The purpose of this study was to verify whether the accuracy of left ventricular parameters related to left ventricular function from gated-SPECT improved or not, using multivariate analysis. Ninety-six patients with cardiovascular diseases were studied. Gated-SPECT with the quantitative gated SPECT (QGS) software and left ventriculography (LVG) were performed to obtain left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV). Then, multivariate analyses were performed to determine empirical formulas for predicting these parameters. The calculated values of left ventricular parameters were compared with those obtained directly from the QGS software and LVG. Multivariate analyses were able to improve accuracy in estimation of LVEF, EDV and ESV. Statistically significant improvement was seen in LVEF (from r=0.6965 to r=0.8093, p<0.05). Although not statistically significant, improvements in correlation coefficients were seen in EDV (from r=0.7199 to r=0.7595, p=0.2750) and ESV (from r=0.5694 to r=0.5871, p=0.4281). The empirical equations with multivariate analysis improved the accuracy in estimating LVEF from gated-SPECT with the QGS software. (author)

  11. Pre-evaluation study in SPECT images using a phantom

    Rebelo, Marina de Sa; Furuie, Sergio Shiguemi; Abe, Rubens; Moura, Lincoln

    1996-01-01

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

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

    Lee, Hyang Woon; Hong, Seung Bong; Tae, Woo Suk; Kim, Sang Eun; Seo, Dae Won; Jeong, Seung Cheol; Yi, Ji Young; Hong, Seung Chyul

    2000-01-01

    To investigate the various ictal perfusion patterns and find the relationships between clinical factors and different perfusion patterns. Interictal and ictal SPECT and SPECT subtraction were performed in 61 patients with partial epilepsy. Both positive images showing ictal hyperperfusion and negative images revealing ictal hypoperfusion were obtained by SPECT subtraction. The ictal perfusion patterns of subtracted SPECT were classified into focal hyperperfusion, hyperperfusion-plus, combined hyperperfusion-hypoperfusion, and focal hypoperfusion only. The concordance rates with epileptic focus were 91.8% in combined analysis of ictal hyperperfusion and hypoperfusion images of subtracted SPECT, 85.2% in hyperperfusion images only of subtracted SPECT, and 68.9% in conventional ictal SPECT analysis. Ictal hypoperfusion occurred less frequently in temporal lobe epilepsy (TLE) than extratemporal lobe epilepsy. Mesial temporal hyperperfusion alone was seen only in mesial TLE while lateral temporal hyperperfusion alone was observed only in neocortical TLE. Hippocampal sclerosis had much lower incidence of ictal hypoperfusion than any other pathology. Some patients showed ictal hypoperfusion at epileptic focus with ictal hyperperfusion in the neighboring brain regions where ictal discharges propagated. Hypoperfusion as well as hyperperfusion in ictal SPECT should be considered for localizing epileptic focus. Although the mechanism of ictal hypoperfusion could be an intra-ictal early exhaustion of seizure focus or a steal phenomenon by the propagation of ictal discharges to adjacent brain areas, further study is needed to elucidate it.=20

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

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

    2000-06-01

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

  14. The assessment of whole body bone SPECT in oncology

    Scortechini, Shonika

    2009-01-01

    Full text: Objectives: To assess the significance and practicability of oncology whole body bone SPECT as part of the standard skeletal survey and its impact on the traditional planar whole body bone imaging protocol. Method: Three consenting oncology patients were injected with a standard adult dose of Tc-99m MOP. Delayed Imaging of whole body sweep and SPECT acquisitions were performed on a Siemens Symbia T6. The patient was positioned supine with arms down with a SPECT scan length covering vortex to thighs. SPECT data was reconstructed and a single whole body zipped file created. Normal SPECT slices along with a cine/MIP of the zipped data were created for review. Results: Both image data sets were reviewed to assess if SPECT provided any further diagnostic clinical information not apparent in planer imaging. In our limited review, whole body SPECT did not add extra value to the planar whole body scans performed; it did however demonstrate vertebral involvement with greater resolution. The processing software and system limitations in seamlessly knitting data sets (creating image artefacts) was a major limiting factor in not pursuing further studies. Conclusion: Both imaging techniques offer differing advantages and limitations, however due to image artefact in the triple knitted SPECT approach with current software technology, it cannot be substituted for whole body imaging at this time.

  15. Correction of head motion artifacts in SPECT with fully 3-D OS-EM reconstruction

    Fulton, R.R.

    1998-01-01

    Full text: A method which relies on continuous monitoring of head position has been developed to correct for head motion in SPECT studies of the brain. Head position and orientation are monitored during data acquisition by an inexpensive head tracking system (ADL-1, Shooting Star Technology, Rosedale, British Colombia). Motion correction involves changing the projection geometry to compensate for motion (using data from the head tracker), and reconstructing with a fully 3-D OS-EM algorithm. The reconstruction algorithm can accommodate any number of movements and any projection geometry. A single iteration of 3-D OS-EM using all available projections provides a satisfactory 3-D reconstruction, essentially free of motion artifacts. The method has been validated in studies of the 3-D Hoffman brain phantom. Multiple 36- degree acquisitions, each with the phantom in a different position, were performed on a Trionix triple head camera. Movements were simulated by combining projections from the different acquisitions. Accuracy was assessed by comparison with a motion-free reconstruction, visually and by calculating mean squared error (MSE). Motion correction reduced distortion perceptibly and, depending on the motions applied, improved MSE by up to an order of magnitude. Three-dimensional reconstruction of the 128 x 128 x 128 data set took 2- minutes on a SUN Ultra 1 workstation. This motion correction technique can be retro-fitted to existing SPECT systems and could be incorporated in future SPECT camera designs. It appears to be applicable in PET as well as SPECT, to be able to correct for any head movements, and to have the potential to improve the accuracy of tomographic brain studies under clinical imaging conditions

  16. SP-ECT imaging and its physical study

    Kinoshita, Fujimi

    1983-01-01

    Recently, more than a hundred hospitals are provided with SPECT system for clinical examination in Japan. However, a standardization of measuring method and performance test of the systems is ont yet made. We have been studying some basic problems of SPECT system with special phantoms originaly designed by ourselves. We got a conclusion that a standardized phantom is necessary for comparing performances between SPECT systems. In clinical experiences with 3,332 cases, we think that SPECT image combined with conventional image presents much more informations for accurate diagnosis, especially in brain, bone and tumor imagings. Synthesized image of SPECT and XCT, double tracer image and transmission image are useful to visualize the body contour and the clinical diagnosis. (author)

  17. Study on SPECT image for children with cerebral infarction

    Xie Wenhuang; Xie Zhichun; Chen Yucai; Lin Haoxue; Zheng Aidong; Xie Hui

    1998-01-01

    To explore the diagnostic value of SPECT image for children with cerebral infarction (CCI), comparative research was made on 26 cases undergoing regional cerebral perfusion (rCP) image between SPECT imaging and CT scanning. The results showed that the rCP in the infarct and its distant area was decreased. The positive rate of SPECT and CT were 92.3% (24/26) and 84.5% (22/26) respectively. The difference was not significant (P = 0.67, P>0.05). But, the positive rate of SPECT image 2 days after onset in 9 CCI was 100% (9/9), significantly higher than 55.6% (5/9) in CT scanning (P = 0.04, P<0.05). These findings suggested that the SPECT imaging is a sensitive method for the early diagnosis of CCI, and also helpful for observation of the therapeutic effect and evaluation of the prognosis

  18. Radionuclide cisternography: SPECT and 3D-rendering. Radionuklidzisternographie: SPECT- und 3D-Technik

    Henkes, H; Huber, G; Piepgras, U [Universitaet des Saarlandes, Homburg/Saar (Germany, F.R.). Abt. fuer Neuroradiologie; Hierholzer, J [Freie Univ. Berlin (Germany, F.R.). Strahlenklinik und Poliklinik; Cordes, M [British Columbia Univ., Vancouver, BC (Canada). Belzberg Lab. of Neuroscience

    1991-10-01

    Radionuclide cisternography is indicated in the clinical work-up for hydrocephalus, when searching for CSF leaks, and when testing whether or not intracranial cystic lesions are communicating with the adjacent subarachnoid space. This paper demonstrates the feasibility and diagnostic value of SPECT and subsequent 3D surface rendering in addition to conventional rectilinear CSF imaging in eight patients. Planar images allowed the evaluation of CSF circulation and the detection of CSF fistula. They were advantageous in examinations 48 h after application of {sup 111}In-DTPA. SPECT scans, generated 4-24 h after tracer application, were superior in the delineation of basal cisterns, especially in early scans; this was helpful in patients with pooling due to CSF fistula and in cystic lesions near the skull base. A major drawback was the limited image quality of delayed scans, when the SPECT data were degraded by a low count rate. 3D surface rendering was easily feasible from SPECT data and yielded high quality images. The presentation of the spatial distribution of nuclide-contaminated CSF proved especially helpful in the area of the basal cisterns. (orig.).

  19. Wide beam reconstruction for half-dose or half-time cardiac gated SPECT acquisitions: optimization of resources and reduction in radiation exposure

    Marcassa, Claudio [S. Maugeri Fnd, IRCCS, Scientific Institute of Veruno, Cardiology Department (Italy); Campini, Riccardo; Zoccarato, Orazio; Calza, Paolo [S. Maugeri Fnd, IRCCS, Scientific Institute of Veruno, Nuclear Medicine Department (Italy)

    2011-03-15

    A new iterative reconstruction algorithm (WBR trademark) has been recently proposed for cardiac single photon emission computed tomography (SPECT). The WBR trademark technology is designed to reduce noise, improving lesion identification without affecting the image resolution, allowing SPECT studies with reduced count statistic. This allows for either half-time (HT) or half-dose (HD) cardiac SPECT, with image quality and quantitative data comparable to standard-time (ST) or standard-dose (SD) SPECT. Few data exist on the comparison between conventional filtered backprojection (FBP) and this new algorithm in a clinical setting. The aim of this study was to compare the performance of FBP and WBR trademark. Phantoms studies were performed to compare spatial resolution and contrast recovery with FBP, ordered subset expectation maximization (OSEM) and WBR trademark. A group of 92 patients, with different cardiac pathology, scheduled for a stress-rest SPECT were studied: 52 patients (group A) were injected with a SD of tracer and underwent both ST and HT SPECT; 40 patients (group B) were injected with a half dose of tracer and underwent ST SPECT and immediately after an additional SPECT at double time/projection (DT), to compensate for the low count statistic. A 2-day {sup 99m}Tc-sestamibi protocol was used in all patients. SD/ST and HD/DT SPECT were reconstructed with a conventional FBP; SD/HT and HD/ST SPECT were reconstructed with WBR trademark. The summed stress score (SSS) and summed rest score (SRS) were calculated; the left ventricular ejection fraction (LVEF) was automatically derived. In group A (SD), no significant differences were observed between ST FBP SPECT and HT WBR trademark in SSS (11.1 and 11.7, respectively) and SRS (9.4 and 10.3, respectively, NS). LVEF on rest acquisitions was also comparable (50% on ST SPECT and 49% on HT SPECT, NS); LVEF on post-stress studies in HT SPECT (46%) was lower than ST SPECT (50%), although not statistically significant

  20. Comparison between CT perfusion and Tc-99m ECD SPECT in the assessment of cerebrovascular reserve: a case study

    Crouch, J.; Wood, C.; Campbell, A.; McCarthy, M.; Dunne, M.; Bynevelt, M.; Lenzo, N.

    2003-01-01

    Full text: Brain perfusion is sensitively assessed by cerebral SPECT imaging utilising perfusion agents such as Tc-99m HMPAO and Tc-99m ethyl cysteinate dimer (ECD). Positron emission tomography can accurately assess and quantify brain perfusion and MRI can also be used for perfusion assessment. Both MRI and PET however are currently limited by cost and availability. A new technique utilising CT with contrast has been developed to assess and quantitate cerebral perfusion. The technique utilises arterial input information and deconvolution analysis to develop quantifiable measures of perfusion and contrast transit. The technique has been validated for acute stroke assessment and is being assessed for other possible applications. We present a case study comparison of this technique with cerebral SPECT perfusion using Tc-99m ECD in the assessment of cerebrovasular reserve. In each case, the CT and SPECT studies were performed pre- and post-acetazolamide and the SPECT study was statistically compared with a normal database utilising an automated brain perfusion statistical analysis package (NeurostatT). We discuss the correlation found between techniques, their strengths, weaknesses and possible future roles. Copyright (2003) The Australian and New Zealand Society of Nuclear Medicine Inc

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

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

    2015-07-15

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

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

    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

  3. SPECT myocardial blood flow quantitation toward clinical use: a comparative study with "1"3N-Ammonia PET myocardial blood flow quantitation

    Hsu, Bailing; Hu, Lien-Hsin; Yang, Bang-Hung; Ting, Chien-Hsin; Huang, Wen-Sheng; Chen, Lung-Ching; Chen, Yen-Kung; Hung, Guang-Uei; Wu, Tao-Cheng

    2017-01-01

    The aim of this study was to evaluate the accuracy of myocardial blood flow (MBF) quantitation of "9"9"mTc-Sestamibi (MIBI) single photon emission computed tomography (SPECT) compared with "1"3N-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"2: MBF = 0.92, MFR = 0.78; regional R"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. (orig.)

  4. Support vector machine-based classification of neuroimages in Alzheimer’s disease: direct comparison of FDG-PET, rCBF-SPECT and MRI data acquired from the same individuals

    Luiz K. Ferreira

    2017-10-01

    Full Text Available Objective: To conduct the first support vector machine (SVM-based study comparing the diagnostic accuracy of T1-weighted magnetic resonance imaging (T1-MRI, F-fluorodeoxyglucose-positron emission tomography (FDG-PET and regional cerebral blood flow single-photon emission computed tomography (rCBF-SPECT in Alzheimer’s disease (AD. Method: Brain T1-MRI, FDG-PET and rCBF-SPECT scans were acquired from a sample of mild AD patients (n=20 and healthy elderly controls (n=18. SVM-based diagnostic accuracy indices were calculated using whole-brain information and leave-one-out cross-validation. Results: The accuracy obtained using PET and SPECT data were similar. PET accuracy was 68∼71% and area under curve (AUC 0.77∼0.81; SPECT accuracy was 68∼74% and AUC 0.75∼0.79, and both had better performance than analysis with T1-MRI data (accuracy of 58%, AUC 0.67. The addition of PET or SPECT to MRI produced higher accuracy indices (68∼74%; AUC: 0.74∼0.82 than T1-MRI alone, but these were not clearly superior to the isolated neurofunctional modalities. Conclusion: In line with previous evidence, FDG-PET and rCBF-SPECT more accurately identified patients with AD than T1-MRI, and the addition of either PET or SPECT to T1-MRI data yielded increased accuracy. The comparable SPECT and PET performances, directly demonstrated for the first time in the present study, support the view that rCBF-SPECT still has a role to play in AD diagnosis.

  5. {sup 99m}Tc-HMPAO Brain SPECT in Seizure Disorder: Comparison Brain SPECT, MRI / CT and EEG

    Yang, Hyung In [Kyunghee University Hospital, Seoul (Korea, Republic of); Im, Ju Hyuk; Choi, Chang Woon; Lee, Dong Soo; Chung, June Key; No, Jae Kyu; Lee, Myung Chul; Koh, Chang Soon [Seoul National University Hospital, Seoul (Korea, Republic of)

    1994-03-15

    We studied 115 patients with seizure who had been performed brain SPECT brain MRI of CT and EEG. To evaluate the pattern of brain SPECT in seizure patients 28 of them had secondary epilepsies, 87 had primary epilepsies. In primary epilepsies, 42 were generalized seizure and 45 were partial seizure. The causes of secondary epilepsies were congenital malformation, cerebromalacia, cerebral infarction ultiple sclerosis, AV-malformation. granuloma and etc, in order. In 28 secondary epilepsies, 25 of them, brain SPECT lesions was concordant with MRI or CT lesions. 3 were disconcordant. The brain SPECT findings of generalized seizure were normal in 22 patients, diffuse irregular decreased perfusion in 8, decreased in frontal cortex in 4. temporal in 5 and frontotemporal in 3. In 45 partial seizure, 19 brain SPECT were concordant with EEG (42.4%).

  6. 99mTc-HMPAO Brain SPECT in Seizure Disorder: Comparison Brain SPECT, MRI / CT and EEG

    Yang, Hyung In; Im, Ju Hyuk; Choi, Chang Woon; Lee, Dong Soo; Chung, June Key; No, Jae Kyu; Lee, Myung Chul; Koh, Chang Soon

    1994-01-01

    We studied 115 patients with seizure who had been performed brain SPECT brain MRI of CT and EEG. To evaluate the pattern of brain SPECT in seizure patients 28 of them had secondary epilepsies, 87 had primary epilepsies. In primary epilepsies, 42 were generalized seizure and 45 were partial seizure. The causes of secondary epilepsies were congenital malformation, cerebromalacia, cerebral infarction ultiple sclerosis, AV-malformation. granuloma and etc, in order. In 28 secondary epilepsies, 25 of them, brain SPECT lesions was concordant with MRI or CT lesions. 3 were disconcordant. The brain SPECT findings of generalized seizure were normal in 22 patients, diffuse irregular decreased perfusion in 8, decreased in frontal cortex in 4. temporal in 5 and frontotemporal in 3. In 45 partial seizure, 19 brain SPECT were concordant with EEG (42.4%).

  7. Myocardial Perfusion SPECT 2015 in Germany

    Burchert, Wolfgang; Schäfer, Wolfgang; Hacker, Marcus

    2016-01-01

    Summary Aim The working group Cardiovascular Nuclear Medicine of the German Society of Nuclear Medicine presents the results of the 7th survey of myocardial perfusion SPECT (MPS) of the reporting year 2015. Method 268 questionnaires (173 practices [PR], 67 hospitals [HO], 28 university hospitals [UH]) were evaluated. Results of the last survey from 2012 are set in squared brackets. Results MPS of 121 939 [105 941] patients were reported. 98 % [95 %] of all MPS were performed with Tc-99m radiopharmaceuticals and 2 % [5 %] with Tl-201. 78 % [79 %] of all patients were studied in PR, 14 % [15 %] in HO, and 8 % [6 %] in UH. A pharmacological stress test was performed in 43 % [39 %] (22 % [24 %] adenosine, 20 % [9 %] regadenoson, 1% [6 %] dipyridamole or dobutamine). Attenuation correction was applied in 25 % [2009: 10 %] of MPS. Gated SPECT was performed in 78 % [70 %] of all rest MPS, in 80 % [73 %] of all stress and in 76 % [67 %] of all stress and rest MPS. 53 % [33 %] of all nuclear medicine departments performed MPS scoring by default, whereas 24 % [41 %] did not apply any quantification. 31 % [26 %] of all departments noticed an increase in their counted MPS and 29 % [29 %] no changes. Data from 89 departments which participated in all surveys showed an increase in MPS count of 11.1 % (PR: 12.2 %, HO: 4.8 %, UH: 18.4 %). 70 % [60 %] of the MPS were requested by ambulatory care cardiologists. Conclusion The 2015 MPS survey reveals a high-grade adherence of routine MPS practice to current guidelines. The positive trend in MPS performance and number of MPS already observed in 2012 continues. Educational training remains necessary in the field of SPECT scoring. PMID:27909712

  8. IMP-SPECT at patients with hallucinations

    Podreka, I.; Mamoli, B.; Lesch, O.; Suess, E.; Wimberger, D.; Mayr, N.; Havelec, L.; Mueller, C.; Steiner, M.; Deecke, L.

    1986-01-01

    IMP-SPECT was performed in 14 normal volunteers. A 'regional index=RI' of tracer distribution was calculated for 18 regions in each hemisphere RI=(cts/voxel ROI)/(mean cts/voxel of all ROI's). 30 seizure patients (E) and 12 patients with acoustic, partialy also visual hallucinations (H) were investigated. Regions were defined as hypo- or hyperperfused if the RI exceeded the value of the corresponding normal-RI +- 2 std. EEG was recorded in all (E). 93.3% of EEG-findings were abnormal, 50% showed a focus, 46.7% paroxysmal activity. SPECT detected in 93.3% of (E) hypoperfused regions, mostly located in the temporal lobe. All (H) had decreased rCBF, predominantly in the frontal cortex. ANOVA and t-test revealed significant RI-differences in the frontal lobe, both hippocampi, right and left inferior occipital cortex, and right anterior basal ganglia. (H) had lower RI's in frontal lobes, higher RI's in both hippocampal regions as well as inferior occipital regions and anterior basal ganglia Differences between (E) and (H) were found in the frontal lobe ((H)sub(→)), right superior temporal region ((H)sup(→)), left hippocampus ((H)sup(→)), both inferior occipital regions ((H)sup(→)) and right anterior basal ganglia ((H)sup(→)). The study shows that by means of IMP-SPECT hypo- and hyperperfused areas can be detected in the hemispheres of (E) and (H), corresponding to disturbed brain function. Higher hippocampal CBF in (E) and (H) may be related to the role of this limbic structure in generation of seizures and psychotic states. Hallucinations are associated with increased CBF in the right temporal and associative visual cortex. (Author)

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

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

    2014-01-01

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

  10. An automatic MRI/SPECT registration algorithm using image intensity and anatomical feature as matching characters: application on the evaluation of Parkinson's disease

    Lee, J.-D.; Huang, C.-H.; Weng, Y.-H.; Lin, K.-J.; Chen, C.-T.

    2007-01-01

    Single-photon emission computed tomography (SPECT) of dopamine transporters with 99m Tc-TRODAT-1 has recently been proposed to offer valuable information in assessing the functionality of dopaminergic systems. Magnetic resonance imaging (MRI) and SPECT imaging are important in the noninvasive examination of dopamine concentration in vivo. Therefore, this investigation presents an automated MRI/SPECT image registration algorithm based on a new similarity metric. This similarity metric combines anatomical features that are characterized by specific binding, the mean count per voxel in putamens and caudate nuclei, and the distribution of image intensity that is characterized by normalized mutual information (NMI). A preprocess, a novel two-cluster SPECT normalization algorithm, is also presented for MRI/SPECT registration. Clinical MRI/SPECT data from 18 healthy subjects and 13 Parkinson's disease (PD) patients are involved to validate the performance of the proposed algorithms. An appropriate color map, such as 'rainbow,' for image display enables the two-cluster SPECT normalization algorithm to provide clinically meaningful visual contrast. The proposed registration scheme reduces target registration error from >7 mm for conventional registration algorithm based on NMI to approximately 4 mm. The error in the specific/nonspecific 99m Tc-TRODAT-1 binding ratio, which is employed as a quantitative measure of TRODAT receptor binding, is also reduced from 0.45±0.22 to 0.08±0.06 among healthy subjects and from 0.28±0.18 to 0.12±0.09 among PD patients

  11. SPECT/CT and pulmonary embolism

    Mortensen, Jann; Borgwardt, Henrik Gutte

    2014-01-01

    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......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...

  12. Brain SPECT in neurology: A critical review

    Bartenstein, P.; Essen Univ.; Weiller, C.; Essen Univ.

    1994-01-01

    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.) [de

  13. Realising the SPECT capability of a rotating gamma camera: an alternative approach

    Morris, P.B.; Sloboda, R.S.; Malik, M.H.

    1984-01-01

    The present paper demonstrates that the SPECT capability of the GE 400T and DEC Gamma-11 combination can be realised without any additional hardware. It is shown that projection data can be collected using acquisition software which already exists as an integral part of the Gamma-11 system. A description of the software which was developed to perform the image reconstruction is also given. The results of two phantom studies verify the validity of the method, which is currently being used regularly in non-routine clinical investigations of the brain and liver. (author)

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

    Campbell, R.S.D.; Grainger, A.J.; Hide, I.G.; Papastefanou, S.; Greenough, C.G.

    2005-01-01

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

  15. Clinical applications of SPECT/CT in imaging the extremities

    Huellner, Martin W.; Strobel, Klaus

    2014-01-01

    Today, SPECT/CT is increasingly used and available in the majority of larger nuclear medicine departments. Several applications of SPECT/CT as a supplement to or replacement for traditional conventional bone scintigraphy have been established in recent years. SPECT/CT of the upper and lower extremities is valuable in many conditions with abnormal bone turnover due to trauma, inflammation, infection, degeneration or tumour. SPECT/CT is often used in patients if conventional radiographs are insufficient, if MR image quality is impaired due to metal implants or in patients with contraindications to MR. In complex joints such as those in the foot and wrist, SPECT/CT provides exact anatomical correlation of pathological uptake. In many cases SPECT increases the sensitivity and CT the specificity of the study, increasing confidence in the final diagnosis compared to planar images alone. The CT protocol should be adapted to the clinical question and may vary from very low-dose (e.g. attenuation correction only), to low-dose for anatomical correlation, to normal-dose protocols enabling precise anatomical resolution. The aim of this review is to give an overview of SPECT/CT imaging of the extremities with a focus on the hand and wrist, knee and foot, and for evaluation of patients after joint arthroplasty. (orig.)

  16. Quantitative assessment of 201TlCl myocardial SPECT

    Uehara, Toshiisa

    1987-01-01

    Clinical evaluation of the quantitative analysis of Tl-201 myocardial tomography by SPECT (Single Photon Emission Computed Tomography) was performed in comparison with visual evaluation. The method of quantitative analysis has been already reported in our previous paper. In this study, the program of re-standardization in the case of lateral myocardial infarction was added. This program was useful mainly for the evaluation of lesions in the left circumflex coronary artery. Regarding the degree of diagnostic accuracy of myocardial infarction in general, quantitative evaluation of myocardial SPECT images was highest followed by visual evaluation of myocardial SPECT images, and visual evaluation of myocardial planar images. However, in the case of anterior myocardial infarction, visual evaluation of myocardial SPECT images has almost the same detectability as quantitative evaluation of myocardial SPECT images. In the case of infero-posterior myocardial infarction, quantitative evaluation was superior to visual evaluation. As for specificity, quantitative evaluation of SPECT images was slightly inferior to visual evaluation of SPECT images. An infarction map was made by quantitative analysis and this enabled us to determine the infarction site, extent and degree according to easily recognizable patterns. As a result, the responsible coronary artery lesion could be inferred correctly and the calculated infarction score could be correlated with the residual left ventricular function after myocardial infarction. (author)

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

    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. Clinical applications of SPECT/CT in imaging the extremities

    Huellner, Martin W. [University Hospital Zurich, Department of Medical Radiology, Division of Nuclear Medicine, Zurich (Switzerland); Strobel, Klaus [Lucerne Cantonal Hospital, Department of Nuclear Medicine and Radiology, Lucerne (Switzerland)

    2014-05-15

    Today, SPECT/CT is increasingly used and available in the majority of larger nuclear medicine departments. Several applications of SPECT/CT as a supplement to or replacement for traditional conventional bone scintigraphy have been established in recent years. SPECT/CT of the upper and lower extremities is valuable in many conditions with abnormal bone turnover due to trauma, inflammation, infection, degeneration or tumour. SPECT/CT is often used in patients if conventional radiographs are insufficient, if MR image quality is impaired due to metal implants or in patients with contraindications to MR. In complex joints such as those in the foot and wrist, SPECT/CT provides exact anatomical correlation of pathological uptake. In many cases SPECT increases the sensitivity and CT the specificity of the study, increasing confidence in the final diagnosis compared to planar images alone. The CT protocol should be adapted to the clinical question and may vary from very low-dose (e.g. attenuation correction only), to low-dose for anatomical correlation, to normal-dose protocols enabling precise anatomical resolution. The aim of this review is to give an overview of SPECT/CT imaging of the extremities with a focus on the hand and wrist, knee and foot, and for evaluation of patients after joint arthroplasty. (orig.)

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

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

    2005-02-01

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

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

    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

  1. SPECT/CT Fusion in the Diagnosis of Hyperparathyroidism

    Monzen, Yoshio; Tamura, Akihisa; Okazaki, Hajime; Kurose, Taichi; Kobayashi, Masayuki; Kuraoka, Masatsugu

    2015-01-01

    In this study, we aimed to analyze the relationship between the diagnostic ability of fused single photon emission computed tomography/ computed tomography (SPECT/CT) images in localization of parathyroid lesions and the size of adenomas or hyperplastic glands. Five patients with primary hyperparathyroidism (PHPT) and 4 patients with secondary hyperparathyroidism (SHPT) were imaged 15 and 120 minutes after the intravenous injection of technetium99m-methoxyisobutylisonitrile ( 99m Tc-MIBI). All patients underwent surgery and 5 parathyroid adenomas and 10 hyperplastic glands were detected. Pathologic findings were correlated with imaging results. The SPECT/CT fusion images were able to detect all parathyroid adenomas even with the greatest axial diameter of 0.6 cm. Planar scintigraphy and SPECT imaging could not detect parathyroid adenomas with an axial diameter of 1.0 to 1.2 cm. Four out of 10 (40%) hyperplastic parathyroid glands were diagnosed, using planar and SPECT imaging and 5 out of 10 (50%) hyperplastic parathyroid glands were localized, using SPECT/CT fusion images. SPECT/CT fusion imaging is a more useful tool for localization of parathyroid lesions, particularly parathyroid adenomas, in comparison with planar and or SPECT imaging

  2. SPECT with [99mTc]-d,l-hexamethyl-propylene amine oxime (HM-PAO) compared with regional cerebral blood flow measured by PET

    Yonekura, Y; Nishizawa, S; Mukai, Thomas Søgaard

    1988-01-01

    In order to validate the use of technetium-99m-d,l-hexamethylpropyleneamine oxime (HM-PAO) as a flow tracer, a total of 21 cases were studied with single photon emission computerized tomography (SPECT), and compared to regional cerebral blood flow (rCBF) measured by position emission tomography...... (PET) using the oxygen-15 CO2 inhalation technique. Although HM-PAO SPECT and rCBF PET images showed a similar distribution pattern the HM-PAO SPECT image showed less contrast between high and low activity flow regions than the rCBF image and a nonlinear relationship between HM-PAO activity and r......CBF was shown. Based on the assumption of flow-dependent backdiffusion of HM-PAO from the brain, we applied a "linearization algorithm" to correct the HM-PAO SPECT images. The corrected HM-PAO SPECT images revealed a good linear correlation with rCBF (r = 0.901, p less than 0.001). The results indicated HM-PAO...

  3. Clinical value of SPECT/CT for evaluation of patients with painful knees after total knee arthroplasty- a new dimension of diagnostics?

    Rasch Helmut

    2011-02-01

    Full Text Available Abstract Background The purpose of our study was to evaluate the clinical value of hybrid SPECT/CT for the assessment of patients with painful total knee arthroplasty (TKA. Methods Twenty-three painful knees in patients following primary TKA were assessed using Tc-99m-HDP-SPECT/CT. Rotational, sagittal and coronal position of the TKA was assessed on 3D-CT reconstructions. The level of the SPECT-tracer uptake (0-10 and its anatomical distribution was mapped using a validated localization scheme. Univariate analysis (Wilcoxon-Mann-Whitney, Spearmean`s-rho test, p Results SPECT/CT imaging changed the suspected diagnosis and the proposed treatment in 19/23 (83% knees. Progression of patellofemoral OA (n = 11, loosening of the tibial (n = 3 and loosening of the femoral component (n = 2 were identified as the leading causes of pain after TKA. Patients with externally rotated tibial trays showed higher tracer uptake in the medial patellar facet (p = 0.049 and in the femur (p = 0.051. Patients with knee pain due to patellofemoral OA showed significantly higher tracer uptake in the patella than others (p Conclusions SPECT/CT was very helpful in establishing the diagnosis and guiding subsequent management in patients with painful knees after TKA, particularly in patients with patellofemoral problems and malpositioned or loose TKA.

  4. Rapid gated Thallium-201 perfusion SPECT - clinically feasible?

    Wadhwa, S.S.; Mansberg, R.; Fernandes, V.B.; Wilkinson, D.; Abatti, D.

    1998-01-01

    Full text: Standard dose energy window optimised Thallium-201 (Tl-201) SPECT has about half the counts of a standard dose from Technetium-99m Sestamibi (Tc99m-Mibi) gated perfusion SPECT. This study investigates the clinical feasibility of rapid energy window optimised Tl-201 gated perfusion SPECT (gated-TI) and compares quantitative left ventricular ejection fraction (LVEF) and visually assessed image quality for wall motion and thickening to analogous values obtained from Tc99m-Mibi gated perfusion SPECT (gated - mibi). Methods: We studied 60 patients with a rest gated Tl-201 SPECT (100 MBq, 77KeV peak, 34% window, 20 sec/projection) followed by a post stress gated Sestamibi SPECT (1GBq, 140KeV, 20% window, 20 sec/projection) separate dual isotope protocol. LVEF quantitation was performed using commercially available software (SPECTEF, General Electric). Visual grading of image quality for wall thickening and motion was performed using a three-point scale (excellent, good and poor). Results: LVEF for gated Tl-201 SPECT was 59.6 ± 12.0% (Mean ± SD). LVEF for gated Sestamibi SPECT was 60.4 ±11.4% (Mean ± SD). These were not significantly different (P=0.27, T-Test). There was good correlation (r=0.9) between gated-TI and gated-mibi LVEF values. The quality of gated-Tl images was ranked as excellent, good and poor in 12, 50 and 38% of the patients respectively. Image quality was better in gated-mibi SPECT, with ratings of 12, 62 and 26% respectively. Conclusion: Rapid gated Thallium-201 acquisition with energy window optimisation can be effectively performed on majority of patients and offers the opportunity to assess not only myocardial perfusion and function, as with Technetium based agents, but also viability using a single day one isotope protocol

  5. Improvements in SPECT technology for cerebral imaging

    Esser, P.D.

    1985-01-01

    Advancement in three major areas of SPECT (single photon emission computed tomography) technology have resulted in improved image quality for cerebral studies. In the first area, single-crystal camera electronics, extensive use of microprocessors, custom digital circuitry, an data bus architecture have allowed precise external control of all gantry motions and improved signal processing. The new digital circuitry permits energy, uniformity, and linearity corrections to be an integral part of the processing electronics. Calibration of these correlations is controlled by algorithms stored in the camera's memory. The second area of improved SPECT technology is camera collimation and related imaging techniques. In this area, system resolution has been improved without loss of sensitivity by decreasing the air gap between patient and collimator surface. Since cerebral studies characteristically image high-contrast regions less than 1 cm in size, image quality has been improved by increasing collimator resolution even at the expense of sensitivity. Increased resolution also improved image contrast for studies using 123 I-labeled pharmaceuticals with 3% to 4% 124 I contamination. 65 references

  6. Rheumatoid arthritis: Clinical, SPECT and MRI investigations

    Ascoli, G.; Cinti, P.; Nonni, M.; Rossi, B.

    2002-01-01

    Aim: To demonstrate psychometric test and neuroimaging technic capacity in subclinical conditions of cerebral affection in patients with rheumatoid arthritis; to demonstrate agreement between topographic cerebral site and morphological signs in neuroimaging study; to evaluate agreement between cognitive deficits and rheumatoid severity. Material and Method: We have enrolled 20 patients, 17 pts. (85%) showed low score evocative for executive function limitation; 6 pts. (33%) showed attention anomaly, movement organization and verbal fluency. SPECT acquisition shows frontal lobe uptake in 95% (19/20 pts.) extended to parietal lobs in 42% (8/19pts.); 1 pt. Shows normal uptake and very high score. RMN study shows a specific sign of leukoencephalopaty in 35% (7/20pts.) and liquoral spaces increased in 25% (5/20 pts.). Conclusions: Frequent cognitive functions alteration during rheumatoid arthritis; very high topographic agreement between cognitive deficits and cerebral perfusion uptake showed by SPECT study; significant correlation between severity index and disease activity and cognitive deterioration; necessity of further longitudinal study for greater number of patient; pathogenetic disconnect mechanism cortical-subcortical by vasculitic reason or deafferentation jointed to negative interaction between motor limit and cognitive deficit

  7. Patient position matching between SPECT and CT

    Eubig, C.; Lodhi, L.M.; Trueblood, J.H.; Kingsbury, T.; Burke, G.; Flickenger, F.

    1990-01-01

    Since the authors had previously developed an ability for accurate repositioning of patients by means of video imaging of their external features, it was their purpose to determine if separate video systems placed in SPECT and CT rooms could be positioned and a calibration procedure for each modality developed to assure easy identification and acquisition of corresponding congruent axial image sections through the patient. A video frame grabber is used to acquire an image of the patient in one room and superimpose it on a similar image of the patient in the other room. A radioactive ruler visible at CT images obtained with a gamma camera computer, and a CT scout image are used to adjust the initial relative position of the video cameras and calibrate the acquisition parameters of both systems. The success of this alignment procedure was tested with a body phantom. The body phantom studies indicate that this method of positioning the patient and acquiring corresponding aligned CT and SPECT axial sections can be successful where internal organ shift between the acquisitions is minimal. This should lead to a reduction of the time and computer resources necessary to fuse or superimpose images of corresponding patient sections acquired with different modalities

  8. The cost effectiveness of 123I-FP-CIT SPECT imaging in patients with an uncertain clinical diagnosis of parkinsonism

    Laere, Koen van; Everaert, Ludwig; Annemans, Lieven; Gonce, Michel; Vandenberghe, Wim; Vander Borght, Thierry

    2008-01-01

    123 I-N-ω-fluoropropyl-2-β-carboxymethoxy-3β-(4-iodophenyl )nortropane ( 123 I-FP-CIT) Single-photon emission computed tomography (SPECT) has been suggested to be a useful diagnostic adjunct in patients with clinically uncertain parkinsonism. We developed a pharmaco-economic (PE) model, evaluating the cost effectiveness of adding 123 I-FP-CIT SPECT to the diagnostic workup. As the model was developed before application of the diagnostic technique in real practice, a predictive validity assessment was performed based on data from a large nationwide patient registry in these patients. A PE model, using a Markov state transition model, was created, based on literature-derived and clinical expert panel data. Effects were expressed as adequately treated years (ATY). Key input data were compared to the real-life patterns in a nationwide multi-centre clinical setting, based on a complete national registry of 1,701 consecutive patients. The change in initial diagnosis and alteration of management of the patient after SPECT were registered. In the PE model, it was calculated that management would change in 48.5% of patients by SPECT and that, over a 5-year period, 1.2 ATYs could be gained at a yearly additional cost of EUR72. From the studied 1,701 patients, nigrostriatal degeneration was observed in 59.8%, the initial diagnosis was changed in 51.5%, management was altered in 49%, and cost effectiveness was increased to EUR358 per ATY. Good correspondence between assumed and observed changes in patient management was found, indicating that 123 I-FP-CIT SPECT is influential in diagnosis and management of patients with uncertain clinical diagnosis of parkinsonism. This can be achieved at a marginal added cost to the health insurance and leads to a significant gain in ATY. (orig.)

  9. Interactions of collimation, sampling and filtering on spect spatial resolution

    Tsui, B.M.W.; Jaszczak, R.J.

    1984-01-01

    The major factors which affect the spatial resolution of single-photon emission computer tomography (SPECT) include collimation, sampling and filtering. A theoretical formulation is presented to describe the relationship between these factors and their effects on the projection data. Numerical calculations were made using commercially available SPECT systems and imaging parameters. The results provide an important guide for proper selection of the collimator-detector design, the imaging and the reconstruction parameters to avoid unnecessary spatial resolution degradation and aliasing artifacts in the reconstructed image. In addition, the understanding will help in the fair evaluation of different SPECT systems under specific imaging conditions

  10. The role of brain SPECT in children with epilepsy

    Liu Xingdang; Liu Yongchang; Lin Xiangtong

    1996-01-01

    The rCBF brain SPECT with 99m Tc-HMPAO was performed in 15 children with interictal epilepsy, and some cases were compared with EEG, X-ray CT and MRI. The results showed that the positive rate of SPECT was the highest (93.33%,), then the EEG (92.31%), and the CT and MRI were the lowest (66.67% and 75%). This study indicated that brain SPECT was an effective method for diagnosis and foci localization in epileptic children, and also was useful to the study of prognosis and relationship between changes of rCBF and progress in clinical pictures

  11. The future of SPECT in a time of PET

    Jansen, Floris P.; Vanderheyden, Jean-Luc

    2007-01-01

    As positron emission tomography (PET) imaging is becoming more prevalent in clinical practice, it is reasonable to ask if there will be a role for single photon emission computed tomography (SPECT) in the future. This article considers that question, focusing on areas where SPECT can differentiate itself from PET for fundamental reasons: breadth of available radionuclides, simultaneous imaging of multiple agents, cost-effectiveness and adaptability to specific imaging situations. The conclusion is that SPECT will continue to evolve and exist alongside PET and will grow the field of molecular imaging with improved efficiency and patient workflow

  12. Atlas of Skeletal SPECT/CT Clinical Images

    2016-01-01

    The atlas focuses specifically on single photon emission computed tomography/computed tomography (SPECT/CT) in musculoskeletal imaging, and thus illustrates the inherent advantages of the combination of the metabolic and anatomical component in a single procedure. In addition, the atlas provides information on the usefulness of several sets of specific indications. The publication, which serves more as a training tool rather than a textbook, will help to further integrate the SPECT and CT experience in clinical practice by presenting a series of typical cases with many different patterns of SPECT/CT seen in bone scintigraphy

  13. Transmission computed tomography data acquisition with a SPECT system

    Greer, K.L.; Harris, C.C.; Jaszczak, R.J.; Coleman, R.E.; Hedlund, L.W.; Floyd, C.E.; Manglos, S.H.

    1987-01-01

    Phantom and animal transmission computed tomography (TCT) scans were performed with a camera-based single photon emission computed tomography (SPECT) system to determine system linearity as a function of object density, which is important in the accurate determination of attenuation coefficients for SPECT attenuation compensation. Results from phantoms showed promise in providing a linear relationship in measuring density while maintaining good image resolution. Animal images were essentially free of artifacts. Transmission computed tomography scans derived from a SPECT system appear to have the potential to provide data suitable for incorporation in an attenuation compensation algorithm at relatively low (calculated) radiation doses to the subjects

  14. HM-PAO SPECT in the diagnosis of cerebrovascular disease

    Cordes, M.; Rummeny, E.; Reissmann, M.; Fox, K.; Panitz, N.; Pfannenstiel, P.

    1987-01-01

    Single photon emission computed tomography (SPECT) after injection of 99m-Tc-HM-PAO was used to examine 34 patients whose clinical findings could not exclude a cerebrovascular disease. In all patients an X-ray computed tomography examination was inconclusive for the clinical-neurological findings. The regional cerebral bloodflow was pathologically disturbed in 10 of 34 patients in the HM-PAO SPECT examination. The detection of the regional cerebral bloodflow with HM-PAO SPECT is helpful in the diagnosis of cerebrovascular disease. (orig.) [de

  15. Ventilation/perfusion SPECT or SPECT/CT for lung function imaging in patients with pulmonary emphysema?

    Froeling, Vera; Heimann, Uwe; Huebner, Ralf-Harto; Kroencke, Thomas J; Maurer, Martin H; Doellinger, Felix; Geisel, Dominik; Hamm, Bernd; Brenner, Winfried; Schreiter, Nils F

    2015-07-01

    To evaluate the utility of attenuation correction (AC) of V/P SPECT images for patients with pulmonary emphysema. Twenty-one patients (mean age 67.6 years) with pulmonary emphysema who underwent V/P SPECT/CT were included. AC/non-AC V/P SPECT images were compared visually and semiquantitatively. Visual comparison of AC/non-AC images was based on a 5-point likert scale. Semiquantitative comparison assessed absolute counts per lung (aCpLu) and lung lobe (aCpLo) for AC/non-AC images using software-based analysis; percentage counts (PC = (aCpLo/aCpLu) × 100) were calculated. Correlation between AC/non-AC V/P SPECT images was analyzed using Spearman's rho correlation coefficient; differences were tested for significance with the Wilcoxon rank sum test. Visual analysis revealed high conformity for AC and non-AC V/P SPECT images. Semiquantitative analysis of PC in AC/non-AC images had an excellent correlation and showed no significant differences in perfusion (ρ = 0.986) or ventilation (ρ = 0.979, p = 0.809) SPECT/CT images. AC of V/P SPECT images for lung lobe-based function imaging in patients with pulmonary emphysema do not improve visual or semiquantitative image analysis.

  16. Incremental value of 99mTc-HYNIC-TOC SPECT/CT over whole-body planar scintigraphy and SPECT in patients with neuroendocrine tumours.

    Trogrlic, Mate; Težak, Stanko

    2017-06-12

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

  17. Patient motion correction for single photon emission computed tomography (SPECT)

    Geckle, W.J.; Becker, L.C.; Links, J.M.; Frank, T.

    1986-01-01

    An investigation has been conducted to develop and validate techniques for the correction of projection images in SPECT studies of the myocardium subject to misalignment due to voluntary patient motion. The problem is frequently encountered due to the uncomfortable position the patient must assume during the 30 minutes required to obtain a 180 degree set of projection images. The reconstruction of misaligned projections can lead to troublesome artifacts in reconstructed images and degrade the diagnostic potential of the procedure. Significant improvement in the quality of heart reconstructions has been realized with the implementation of an algorithm to provide detection of and correction for patient motion. Normal, involuntary motion is not corrected for, however, since such movement is below the spatial resolution of the thallium imaging system under study. The algorithm is based on a comparison of the positions of an object in a set of projection images to the known, sinusoidal trajectory of an off-axis fixed point in space. Projection alignment, therefore, is achieved by shifting the position of a point or set of points in a projection image to the sinusoid of a fixed position in space

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

    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

  19. SPECT for smokers brain perfusion evaluation; SPECT para avaliacao da perfusao cerebral em fumantes

    Maliska, C.M.; Martins, E.F.; Barros, D.S.; Lopes, M.M.S.; Lourenco, C.; Goncalves, S.; Goncalves, M.B.; Miranda, M.M.B.G.; Neto, L.M.; Penque, E.; Antonucci, J.B. [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil)

    2002-07-01

    Cigarette smoking increases brain stroke risk, however,five to fifteen years after ceasing this habit, brain perfusion recovers normal pattern. We propose to compare brain perfusion patterns performing brain SPECT scans of smokers and non-smokers. Thirteen volunteers age range 20-30 years old) composed of six non-smokers and seven smokers were studied by brain scans (SPECT).We used ECD- {sup 99m} Tc radiolabelled as recommended by the manufacturer. All patients received 740 MBq of the radiopharmaceutical through intravenous injection, with their eyes opened and their ears unplugged, in a quiet room. We used a one head SPECT camera ( General Electric/ StarCam 4000 and Siemens/ E.Cam) with low-energy ultrahigh resolution collimator. Imaging begin 40 minutes after tracer injection. For reconstruction we used a Butterworth filter.The preliminary results showed brain perfusion deficit areas on five of the smokers while all non- smokers had normal brain perfusion scans. We believe that smoking increases the possibility of brain perfusion deficits. (author)

  20. Brain lesion analysis using three-dimensional SPECT imaging

    Shibata, Iekado; Onagi, Atsuo; Kuroki, Takao

    1995-01-01

    A three-headed gamma camera (PRISM 3000) is capable to scan the protocol of early dynamic SPECT and to analyze two radioisotopes at the same time. We have framed three-dimensional brain SPECT images for several brain diseases by using the Application Visualization System (AVS). We carried out volume measurements in brain tumors and/or AVMs by applying this methodology. Thallium-201 and/or 123I-IMP were used for brain SPECT imaging. The dynamic scan protocol was changed in accordance with the given disease. The protocol for brain tumors was derived from a preliminary comparative study with thallium-201 and 123I-IMP that had suggested a disparity in the detection of brain tumors and the differentiation between tumor tissue and normal brain. The three-dimension SPECT image represented the brain tumor or AVM in a striking fashion, and the changes with respect to tumor or AVM after radiosurgery or embolization were understood readily. (author)

  1. Initial Investigation of preclinical integrated SPECT and MR imaging.

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

    2010-02-01

    Single-photon emission computed tomography (SPECT) can provide specific functional information while magnetic resonance imaging (MRI) can provide high-spatial resolution anatomical information as well as complementary functional information. In this study, we utilized a dual modality SPECT/MRI (MRSPECT) system to investigate the integration of SPECT and MRI for improved image accuracy. The MRSPECT system consisted of a cadmium-zinc-telluride (CZT) nuclear radiation detector interfaced with a specialized radiofrequency (RF) coil that was placed within a whole-body 4 T MRI system. The importance of proper corrections for non-uniform detector sensitivity and Lorentz force effects was demonstrated. MRI data were utilized for attenuation correction (AC) of the nuclear projection data and optimized Wiener filtering of the SPECT reconstruction for improved image accuracy. Finally, simultaneous dual-imaging of a nude mouse was performed to demonstrated the utility of co-registration for accurate localization of a radioactive source.

  2. Clinical application of SPECT and PET in cerebrovascular disease

    Ra, Young Shin

    2003-01-01

    Single photon emission computed tomography(SPECT) and positron emission tomography(PET) are modern imaging techniques that allow for both qualitative are quantitative assessment of hemodynamic changes in cerebrovascular diseases. SPECT has been becoming an indispensable method to investigate regional cerebral blood flow because equipment and isotope are easily available in most general hospitals. Acetazolamide stress SPECT has also been proved to be useful to evaluate the cerebrovascular reserve of occlusive cerebrovascular diseases and to select surgical candidate. PET has gained wide spread clinical use in the evaluation of the hemodynamic and metabolic consequences of extracranial or intracranial arterial obstructive disease despite its complexity and limited availability. PET has been established as an invaluable tool in the pathophysilogy investigation of acute ischemic stroke. The potentials, limitations, and clinical applications of SPECT and PET in various cerebrovascular diseases will be discussed in this article with reviews of literatures

  3. High-resolution SPECT for small-animal imaging

    Qi Yujin

    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. (authors)

  4. Examination of brain function using PET and SPECT

    Sasaki, Yasuhito; Momose, Toshinitsu; Watanabe, Toshiaki; Oku, Shinya; Nishikawa, Junichi [Tokyo Univ. (Japan). Faculty of Medicine

    1996-12-31

    The purpose of the presentation is to elucidate the unique role of PET (positron emission computed tomography) and SPECT (single photon emission computed tomography) in assessing physiological and biochemical functions of the brain.

  5. 99mTc-HMPAO SPECT in brain death

    Tsuchida, Tatsuro; Sadato, Norihiro; Nishizawa, Sadahiko

    1993-01-01

    Brain single photon emission computed tomography (SPECT) with 99m Tc-d,l-hexamethyl-propyleneamine oxime (HMPAO) was performed twice in a 78-year-old man clinically diagnosed as brain death according to the standard criteria of the Japanese Ministry of Welfare. The first brain SPECT demonstrated the tracer accumulation in the brain, indicating preserved cerebral blood flow. The second brain SPECT performed 3 days later revealed cessation of the blood flow. In patients with preserved cerebral blood flow, the diagnosis of brain death cannot be made, even if they meet the existing criteria, because previous report noted the recovery in some of those patients. Brain perfusion SPECT plays an important role as a confirmatory test for the diagnosis of brain death. (author)

  6. Two dimensional polar display of cardiac blood pool SPECT

    Honda, Norinari; Machida, Kikuo; Mamiya, Toshio; Takahashi, Taku; Takishima, Teruo; Hasegawa, Noriko; Hashimoto, Masanori; Ohno, Ken

    1989-01-01

    A new method of ECG gated cardiac blood pool SPECT to illustrate the left ventricular (LV) wall motion in a single static image, two dimensional polar display (2DPD), was described. Circumferential profiles of the difference between end diastolic and end systolic short axis images of the LV were displayed in a similar way to the bull's eye plot of 201 Tl myocardial SPECT. The diagnoses by 2DPDs agreed with those by cinematic displays of ECG gated blood pool SPECT in 74 out of 84 segments (85.5%) of abnormal motion, and 155 out of 168 segments (80.3%) of normal motion. It is concluded that 2DPD can evaluate regional wall motion by a single static image in a significant number of patients, and is also useful in comparing with the bull's eye image of 201 Tl myorcardial SPECT. (orig.)

  7. Clinical application of SPECT and PET in cerebrovascular disease

    Ra, Young Shin [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    2003-02-01

    Single photon emission computed tomography(SPECT) and positron emission tomography(PET) are modern imaging techniques that allow for both qualitative are quantitative assessment of hemodynamic changes in cerebrovascular diseases. SPECT has been becoming an indispensable method to investigate regional cerebral blood flow because equipment and isotope are easily available in most general hospitals. Acetazolamide stress SPECT has also been proved to be useful to evaluate the cerebrovascular reserve of occlusive cerebrovascular diseases and to select surgical candidate. PET has gained wide spread clinical use in the evaluation of the hemodynamic and metabolic consequences of extracranial or intracranial arterial obstructive disease despite its complexity and limited availability. PET has been established as an invaluable tool in the pathophysilogy investigation of acute ischemic stroke. The potentials, limitations, and clinical applications of SPECT and PET in various cerebrovascular diseases will be discussed in this article with reviews of literatures.

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

    Damle, Nishikant Avinash; Kumar, Rakesh; Kumar, Praveen; Jaganthan, Sriram; Patnecha, Manish; Bal, Chandrasekhar; Bandopadhyaya, Gurupad; Malhotra, Arun

    2011-01-01

    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 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.

  9. Tc-99m MAG3 SPECT on transplanted kidney

    Ryu, Jong Gul; Kim, Soon; Zeon, Seok Kil

    1999-01-01

    This study was designed to evaluate the usefulness of a technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) single photon emission computed tomography (SPECT) performed on transplanted kidney. Thirty renal transplant patients were included in this study. Planar scan was performed for 30 minutes using 555 MBq Tc-99m MAG3. A post-voiding SPECT scan was acquired on the third, seventh, fourteenth and twenty eighth day after transplantation. SPECT scan showed interpretable image quality in 26 of 30 patients (86.7%) and 84 in 120 scans (70%). Fourteen of 26 patients with interpretable SPECT image showed decreased or increased radioactivity, but only 5 had abnormal findings on the planar scan. Focal SPECT defects were seen in allografts with normal function (n=3), acute tubular necrosis (n=3), and acute rejection (n=2). The defects are thought to reflect focally underperfused renal parenchyme or, in normal allografts, an artifact from uneven radioactivity distribution. Four of 10 paints with renal arterial variation showed focally decreased radioactivity and SPECT helped guide further studies that confirmed the exact cause. Five of 10 patients with acute tubular necrosis or acute rejection showed focally decreased radioactivity, but its relation to the patients' clinical course was not clear. Focally increased radioactivity was observed in 5 allografts with normal function and 1 with double ureter in which local clearance delay was observed. Tc-99m MAG3 SPECT renal scan can detect additional focal abnormalities compared to planar scan. Further study is necessary to elucidate the exact clinical significance of the SPECT findings

  10. MRI and SPECT findings in amyotrophic lateral sclerosis

    Ukada, F.; Sawada, H.; Seriu, N.; Shindou, K.; Nishitani, N.; Kameyama, M.

    1992-01-01

    MRI was performed in 21 patients and single photon emission computed tomography (SPECT) with N-isopropyl-p- 123 I iodoamphetamine in 16 patients, to visualize upper motor neurone lesions in amyotrophic lateral sclerosis. T2-weighted MRI revealed high signal along the course of the pyramidal tract in the internal capsule and cerebral peduncle in 4 of 21 patients. SPECT images were normal in 4 patients, but uptake was reduced in the cerebral cortex that includes the motor area in 11. (orig.)

  11. Brain SPECT using dipyridamole for evaluation of vascular reserve

    Kim, Su Zy; Park, Chan Hee; Yoon, Soo Hwan; Pai, Moon Sun; Yoon, Suk Nam; Cho, Kyung Kee

    1997-01-01

    Baseline and stress brain SPECT studies using CO 2 inhalation, acetazolamide (Diamox R ) and adenosine administrations have been used in the evaluation of cerebral vascular reserve. Recently dipyridamole (Persantine R ) which is one of the pharmacologic myocardial perfusion SPECT agents as a potent vasodilator is suggested as another cerebral vasodilator. IV Diamox R is not available in Korea. Therefore, the purpose of our study was to evaluate dipyridamole in stress brain SPECT in patients with Moya Moya disease. Eight patients with angiographically proven Moya Moya disease were studied. Their ages ranged from 7 to 62 year old. There were 4 males and 4 females. Each patient had a baseline and persantine brain SPECT studies with 1 to 3 days' interval. Dipyridamole was given intravenously at a dose of 0.56 mg/kg over 4 minutes while watching vital signs such as blood pressure, heart rate, and electrocardiogram. Three minutes after the completion of the infusion, 99mTc-ECD (0.2 mCi/Ib body weight) was injected. Brain SPECT was performed 30 minutes later using a tripple head gamma camera equipped with LEHR collimators. A total of 128 projections with an acquisition time of 30 second per projection was obtained and reconstructed by filtered back projections without attenuation correction. The difference between the baseline and persantine studies was analysed by visual and semiquantitavely. During the infusion of persantine, heart rate, blood pressure and side effects such as headache, chest discomfort were similar to the persantine myocardial SPECT studies. Five of eight patients showed a significant decrease in rCBF on persantine brain SPECT in comparison to the baseline study. The remaining three revealed no significant change in rCBF. Our study suggests that the dipyridamole stress brain SPECT is feasible and useful in assessing cerebral blood flow reserve. However we need to evaluate more number of patients in the future

  12. PET and SPECT investigations in Alzheimer's disease

    Asenbaum, S.

    2003-01-01

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

  13. Cerebral postischemic hyperperfusion in PET and SPECT

    Cho, Inn Ho

    2001-01-01

    Cerebral post-ischemic hyperperfusion has been observed at the acute and subacute periods of ischemic stroke. In the animal stroke model, early post-ischemic hyperperfusion is the mark of recanalization of the occluded artery with reperfusion. In the PET studies to both humans and experimental animals, early post-ischemic hyperperfusion is not a key factor in the development of tissue infarction and indicates the spontaneous reperfusion of the ischemic brain tissue without late infarction or with small infarction. But late post-ischemic hyperperfusion shows the worse prognosis with reperfusion injury associated with brain tissue necrosis. Early post-ischemic hyperperfusion defined by PET and SPECT may be useful in predicting the prognosis of ischemic stroke and the effect of thrombolytic therapy

  14. Cervical SPECT Camera for Parathyroid Imaging

    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.

  15. Myocardial perfusion SPECT imaging in patients with myocardial bridging

    Fang Wei; Qiu Hong; Yang Weixian; Wang Feng; He Zuoxiang

    2008-01-01

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

  16. Usefulness of hyperventilation myocardial SPECT for diagnosing vasospastic angina pectoris

    Tahara, Yorio; Shimoyama, Katsuya; Nishimura, Tooru; Sasaki, Akira; Taya, Makoto; Mizuno, Haruyoshi; Ono, Akifumi; Tsuya, Tsuneo; Ishikawa, Kyozo

    1990-01-01

    We evaluated the usefulness of hyperventilation myocardial scintigraphy (HV-SPECT) for diagnosing vasospastic angina pectoris. The subjects consisted of 11 patients with rest angina and 13 with rest and exertional angina in whom coronary spasm was demonstrated by coronary angiography, and 6 with exertional angina in whom a significant stenotic lesion was observed by coronary angiography. Hyperventilation was performed at a rate of 40/min for 5 minutes in all the patients. Ischemia was considered to be present when defect and redistribution were observed by SPECT. HV-SPECT revealed positive findings in 8 patients with rest angina (73%) and 9 with exertional and rest angina (69%) but only in 1 with exertional angina (17%). Ischemic ST changes on monitor ECG were observed in 13 of the 30 patients (43%); ST was enhanced in 4 patients and depressed in 9 patients. In the patients with rest angina, HV-SPECT induced ischemic findings more frequently than exercise SPECT (73% vs 55%). HV-SPECT seems to be useful as a non-invasive method for diagnosing angina pectoris resulting from coronary spasm. (author)

  17. Tc-99m Ciprofloxacin SPECT of Pulmonary Tuberculosis

    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.

  18. Importance of SPECT/CT for knee and hip joint prostheses; Stellenwert der SPECT/CT bei Knie- und Hueftgelenkprothesen

    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

  19. A collimator optimization method for quantitative imaging: application to Y-90 bremsstrahlung SPECT.

    Rong, Xing; Frey, Eric C

    2013-08-01

    general, the authors simulated multiple tumors of various sizes in the liver. The authors realistically simulated human anatomy using a digital phantom and the image formation process using a previously validated and computationally efficient method for modeling the image-degrading effects including object scatter, attenuation, and the full collimator-detector response (CDR). The scatter kernels and CDR function tables used in the modeling method were generated using a previously validated Monte Carlo simulation code. The hole length, hole diameter, and septal thickness of the obtained optimal collimator were 84, 3.5, and 1.4 mm, respectively. Compared to a commercial high-energy general-purpose collimator, the optimal collimator improved the resolution and FOM by 27% and 18%, respectively. The proposed collimator optimization method may be useful for improving quantitative SPECT imaging for radionuclides with complex energy spectra. The obtained optimal collimator provided a substantial improvement in quantitative performance for the microsphere radioembolization task considered.

  20. Evaluation of the diagnostic performance of SPECT coupled to tomodensitometry (SPECT-CT) in the daily practice of bone scintigraphy at the Nuclear Medical station of Nancy

    Netter, F.; Journo, A.; Mayer, J.C.; Grandpierre, S.; Daragon, N.; Karcher, G.; Olivier, P.; Scigliano, S.

    2008-01-01

    Objective: The purpose of our study was to evaluate the diagnostic performance of SPECT coupled to computed axial tomography (SPECT- CT) in our daily practice of bone scintigraphy. Subjects and methods: SPECT- CT obtained as a complement to the planar bone scintigraphy in 39 patients were studied. Each type of image was retrospectively read by two different observers: a nuclear medicine physician who was unaware of SPECT- CT results analysed planar bone scintigraphy, a second one who was unaware of planar bone scintigraphy results analysed SPECT- CT images. In this population of patients, 17 patients were addressed in an oncologic setting. The 22 other patients were addressed for pain of indeterminate origin without neoplastic context. Results: In 13% of the cases, SPECT- CT specified the precise location of increased uptake foci seen on planar bone scintigraphy. In 38% of cases, SPECT- CT confirmed a diagnosis suspected by the planar bone scintigraphy. In 10% of cases, SPECT- CT established a diagnosis that was uncertain with planar bone scintigraphy. In 26% of cases, SPECT- CT brought no additional information. Finally in 3% of cases, SPECT- CT proved to be more sensitive than planar images. Conclusion: Our study demonstrates the utility of SPECT- CT in the daily practice of bone scintigraphy, this complementary imaging study benefited to 74% of our patients. (authors)

  1. 123I-iomazenil brain receptor SPECT in focal epilepsy. In comparison with 99mTc-HMPAO brain SPECT, MRI and Video/EEG monitoring

    Xu Hao; Wang Tongge; Huang Li; Michael Cordes

    1998-01-01

    Purpose: To evaluate the clinical value of 123 I-Iomazenil brain receptor SPECT in diagnosis of focal epilepsy in comparison with 99m Tc-HMPAO brain SPECT, MRI and Video/EEG monitoring. Methods 123 I-Iomazenil brain receptor SPECT was performed on 40 patients with focal epilepsy. The results were compared with those obtained by 99m Tc-HMPAO brain SPECT, MRI and Video/EEG monitoring. Results: In 40 patients, the sensitivity of Video/EEG monitoring for localization of epileptogenic area was 95% (38/40). The sensitivity of 123 I-iomazenil brain receptor SPECT, 99m Tc-HMPAO brain SPECT and MRI for localization of epileptogenic area compared with Video/EEG monitoring ('gold standard') was 65.8%(25/38), 55.3%(21/38) and 47.4%(18/38), respectively. The localization of epileptogenic area with 123 I-Iomazenil brain receptor SPECT was in concordance with Video/EEG monitoring in 20 patients, 99m Tc-HMPAO brain SPECT in 15 patients and MRI in 16 patients, respectively. The sensitivity of 123 I-Iomazenil brain receptor SPECT combined with MRI for localization of epileptogenic area was 84.2%(32/38). Conclusions: 123 I-Iomazenil brain receptor SPECT is a useful method in detecting and localizing epileptogenic area. The combination of 123 I-Iomazenil brain receptor SPECT and MRI has a high sensitivity for detecting epileptogenic area

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

    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. Prospective study of p-[{sup 123}I]iodo-L-phenylalanine and SPECT for the evaluation of newly diagnosed cerebral lesions: specific confirmation of glioma

    Hellwig, Dirk; Schaefer, Andrea; Farmakis, Georgios; Grgic, Aleksandar; Kirsch, Carl-Martin [Saarland University Medical Center, Department of Nuclear Medicine, Homburg/Saar (Germany); Ketter, Ralf; Moringlane, Jean R.; Steudel, Wolf-Ingo [Saarland University Medical Center, Department of Neurosurgery, Homburg (Germany); Romeike, Bernd F.M. [Saarland University Medical Center, Institute of Neuropathology, Homburg (Germany); Friedrich-Schiller-University, Department of Neuropathology, Jena (Germany); Samnick, Samuel [Saarland University Medical Center, Department of Nuclear Medicine, Homburg/Saar (Germany); University of Wuerzburg, Department of Nuclear Medicine, Wuerzburg (Germany)

    2010-12-15

    The differentiation between gliomas, metastases and gliotic or inflammatory lesions by imaging techniques remains a challenge. Gliomas frequently exhibit increased uptake of radiolabelled amino acids and are thus amenable to PET or SPECT imaging. Recently, p-[{sup 123}I]iodo-L-phenylalanine (IPA) was validated for the visualization of glioma by SPECT and received orphan drug status. Here we investigated its diagnostic performance for differentiating indeterminate brain lesions. This prospective open study included 67 patients with newly diagnosed brain lesions suspicious for glioma (34 without and 33 with contrast enhancement in the MRI scan). Patients received 250 MBq IPA intravenously after overnight fasting. SPECT images at 30 min and 3 h post-injection were iteratively reconstructed and visually interpreted after image fusion with an MRI brain scan (fluid-attenuated inversion recovery sequence or T1-weighted contrast-enhanced image). Findings were correlated with results of stereotactic or open biopsies or serial imaging. Twenty-seven low-grade (2 WHO I, 25 WHO II) and 24 high-grade gliomas (1 WHO III, 23 WHO IV), 3 metastases originating from lung cancer as well as 13 non-neoplastic lesions were proven. All non-neoplastic lesions and all metastases were negative with IPA SPECT. Forty gliomas were true-positive (TP) and 11 false-negative (FN) findings (8 WHO II, 1 WHO III, 2 WHO IV) occurred. There were no false-positive (FP) findings. For the differentiation of primary brain tumours and non-neoplastic lesions, sensitivity and specificity were 78 and 100%. In 34 lesions without contrast enhancement in MRI, IPA SPECT resulted in 17 TP, 8 true-negative, 9 FN and no FP findings (sensitivity 65%, specificity 100%). In patients with suspected glioma, IPA SPECT shows a high specificity, but especially in low-grade gliomas FN findings may occur. Due to the high positive predictive value a positive finding allows a suspected glioma to be confirmed. (orig.)

  4. Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping.

    McGoron, Anthony J; Capille, Michael; Georgiou, Michael F; Sanchez, Pablo; Solano, Juan; Gonzalez-Brito, Manuel; Kuluz, John W

    2008-02-29

    Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. The focal effects of moderate traumatic brain injury (TBI) on cerebral blood flow (CBF) by SPECT cerebral blood perfusion (CBP) imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM). A significant area of hypoperfusion (P TBI. Statistical mapping of the reference microsphere CBF data confirms a focal decrease found with SPECT and SPM. The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques.

  5. Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

    McGoron, Anthony J; Capille, Michael; Georgiou, Michael F; Sanchez, Pablo; Solano, Juan; Gonzalez-Brito, Manuel; Kuluz, John W

    2008-01-01

    Assessment of cerebral blood flow (CBF) by SPECT could be important in the management of patients with severe traumatic brain injury (TBI) because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia), or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. The focal effects of moderate traumatic brain injury (TBI) on cerebral blood flow (CBF) by SPECT cerebral blood perfusion (CBP) imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM). A significant area of hypoperfusion (P < 0.01) was found as a response to the TBI. Statistical mapping of the reference microsphere CBF data confirms a focal decrease found with SPECT and SPM. The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques

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

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

    2017-08-15

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

  7. Diagnostic role of (99)Tc(m)-MDP SPECT/CT combined SPECT/MRI Multi modality imaging for early and atypical bone metastases.

    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.

  8. Brain perfusion SPECT with Brodmann areas analysis in differentiating frontotemporal dementia subtypes.

    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.

  9. Inter-observer variation of diagnosis of Alzheimer's disease by SPECT

    Oshima, Motoo; Machida, Kikuo; Koizumi, Kiyoshi

    2001-01-01

    SPECT shows characteristic distribution in Alzheimer's disease. The purpose of this study is to define inter-observer variations in the diagnosis of Alzheimer's disease. Fifty-seven patients, included 19 Alzheimer's disease were collected from four institutions. Five-graded score was used to interprete SPECT in 18 regions. Ten nuclear medicine physicians interpreted SPECT referred with MMSE and clinical information. Among 57 cases 19 Alzheimer's disease were selected in this study. Statistics were performed between SPECT score and MMSE score. In conclusion, inter-observer variation is present in SPECT interpretation. There was a good correlation SPECT and MMSE with proper brain SPECT physicians. They are superior to in the interpretation not only resident, but other specialists. Education in the interpretation of brain SPECT looks important. (author)

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

    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)

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

    Adak, S.; Vijaya Raj, K.K.; Mandal, S.

    2012-01-01

    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 [ 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 [ 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 makes them more

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

    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

  13. Single photon emission computed tomography (SPECT) in neurocysticercosis

    Braga, Francisco Jose H. N; Santos, Antonio C; Takanayagui, Oswaldo M; Agapejev, Svetlana; Maes, A

    2002-01-01

    Neurocysticercosis (NC) is a parasitic infectious disease caused by Taenia solium eggs that set in the brain. Its incidence is increasing both in the developing and the developed world, as a result of low economical and hygiene levels and immigration, respectively. Clinical manifestation of disease varies from no symptoms to epilepsy, increased intra-cranial pressure, arachnoiditis and dementia. In order to evaluate function (perfusion) of affected brains, we studied 40 patients (21 females and 19 males, 19-71 yo) by means of SPECT (ECD, ethyl cysteinate dimer, labelled with 99mTc) and with and without contrast CT. SPECT studies were all abnormal. No difference was noted between active and inactive disease. Two SPECT patterns were noted: a) several areas of focally reduced uptake, resulting from coalescent and big lesions and large destruction of brain tissue (small, isolated and symmetric cysts seen in CT were missed by SPECT); b) diffuse atrophy with reduction of the tracer uptake, associated with ventricle dilatation, corresponding to the cases where ventricular NC was important. Interestingly, we noted diffuse hypoperfusion, with the scintigraphic pattern of atrophy in 5 cases of massive parenchymal infection; in such cases, CT signs of atrophy were clearly less prominent. The first scintigraphic aspect can be explained by the destruction of large areas of brain, which produces focal absence of perfusion; generalised vasculitis and the destruction of large portions of brain tissue could explain the difference noted between the SPECT and the CT aspects in the 5 cases of massive parenchimal infection, and this may be interesting for prognosis. Dilatation of ventricles and Sylvian fissures were interestingly prominent in SPECT. SPECT may be of great value to evaluate brain perfusion in NC (Au)

  14. An Empirical Taxonomy of Crowdfunding Intermediaries

    Haas, Philipp; Blohm, Ivo; Leimeister, Jan Marco

    2014-01-01

    Due to the recent popularity of crowdfunding, a broad magnitude of crowdfunding intermediaries has emerged, while research on crowdfunding intermediaries has been largely neglected. As a consequence, existing classifications of crowdfunding intermediaries are conceptual, lack theoretical grounding, and are not empirically validated. Thus, we develop an empirical taxonomy of crowdfunding intermediaries, which is grounded in the theories of two-sided markets and financial intermediation. Integr...

  15. Empirical techniques in finance

    Bhar, Ramaprasad

    2005-01-01

    This book offers the opportunity to study and experience advanced empi- cal techniques in finance and in general financial economics. It is not only suitable for students with an interest in the field, it is also highly rec- mended for academic researchers as well as the researchers in the industry. The book focuses on the contemporary empirical techniques used in the analysis of financial markets and how these are implemented using actual market data. With an emphasis on Implementation, this book helps foc- ing on strategies for rigorously combing finance theory and modeling technology to extend extant considerations in the literature. The main aim of this book is to equip the readers with an array of tools and techniques that will allow them to explore financial market problems with a fresh perspective. In this sense it is not another volume in eco- metrics. Of course, the traditional econometric methods are still valid and important; the contents of this book will bring in other related modeling topics tha...

  16. Data-driven motion correction in brain SPECT

    Kyme, A.Z.; Hutton, B.F.; Hatton, R.L.; Skerrett, D.W.

    2002-01-01

    Patient motion can cause image artifacts in SPECT despite restraining measures. Data-driven detection and correction of motion can be achieved by comparison of acquired data with the forward-projections. By optimising the orientation of the reconstruction, parameters can be obtained for each misaligned projection and applied to update this volume using a 3D reconstruction algorithm. Digital and physical phantom validation was performed to investigate this approach. Noisy projection data simulating at least one fully 3D patient head movement during acquisition were constructed by projecting the digital Huffman brain phantom at various orientations. Motion correction was applied to the reconstructed studies. The importance of including attenuation effects in the estimation of motion and the need for implementing an iterated correction were assessed in the process. Correction success was assessed visually for artifact reduction, and quantitatively using a mean square difference (MSD) measure. Physical Huffman phantom studies with deliberate movements introduced during the acquisition were also acquired and motion corrected. Effective artifact reduction in the simulated corrupt studies was achieved by motion correction. Typically the MSD ratio between the corrected and reference studies compared to the corrupted and reference studies was > 2. Motion correction could be achieved without inclusion of attenuation effects in the motion estimation stage, providing simpler implementation and greater efficiency. Moreover the additional improvement with multiple iterations of the approach was small. Improvement was also observed in the physical phantom data, though the technique appeared limited here by an object symmetry. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

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

    Park, Hoon Hee; Lyu, Kwang Yeul; Kim, Tae Hyung; Shin, Ji Yun

    2012-01-01

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

  18. Left ventricular ejection fraction determined by gated Tl-201 perfusion SPECT and quantitative software

    Hyun, In Young; Kim, Sung Eun; Seo, Jeong Kee; Hong, Eui Soo; Kwan, Jun; Park, Keum Soo; Lee, Woo Hyung

    2000-01-01

    We compared estimates of ejection fraction (EF) determined by gated Tl-201 perfusion SPECT (g-Tl-SPECT) with those by gated blood pool (GBP) scan. Eighteen subjects underwent g-Tl-SPECT and GBP scan. After reconstruction of g-Tl-SPECT, we measured EF with Cedars software. The comparison of the EF with g-Tl-SPECT and GBP scan was assessed by correlation analysis and Bland Altman plot. The estimates of EF were significantly different (p<0.05) with g-Tl-SPECT (40%±14%) and GBP scan (43%±14%). There was an excellent correlation of EF between g-Tl-SPECT and GBP scan (r=3D0.94, p<0.001). The mean difference of EF between GBP scan and g-Tl-SPECT was +3.2%. Ninety-five percent limits of agreement were ±9.8%. EF between g-Tl-SPECT and GBP scan were in poor agreement. The estimates of EF by g-Tl-SPECT was well correlated with those by GBP scan. However, EF of g-Tl-SPECT doesn't agree with EF of GBP scan. EF of g-Tl-SPECT can't be used interchangeably with EF of GBP scan.=20

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

    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 kinase (HSVI-tk) reporter gene in rabbits myocardium by using the reporter probe 131 I-2'-fluoro-2'-deoxy-l-β-D-arabinofuranosyl-5-iodouracil ( 131 I-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 131 I-FIAU 600 μCi at Day 2 after intramyocardial transfection of Ad5-tk in 1xl0 9 , 5x10 8 , 1x10 8 , 5x10 7 and 1x10 7 pfu, and heart SPECT imaging was done at different hours. Rabbits of the 2nd were transferred various titers of Ad5-tk (1x10 9 , 5x10 8 , 1x10 8 , 5x10 7 , 1x10 7 pfu) to determine the threshold and optimal viral titer needed for detection of gene expression. Two days later, 131 I-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 transcription-polymerase chain reaction (RT-PCR) was used to verify the transferred HSVI-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 131 I-FIAU accumulation in rabbits injected with Ad5-tk in the anterolateral wall. The optimal images quality 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 5x10 7 pfu of virus titer. The result could be set better in 1-5x10 8 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 HSVI-tk/ 131 I-FIAU reporter gene/reporter probe system is feasible for cardiac SPECT reporter

  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

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

    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 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.

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

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

    2001-04-01

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

  3. The characteristics of SPECT images in childhood benign partial epilepsy

    Jia Shaowei; Liao Jianxiang; Liu Xiaoyan; Zheng Xiyuan; Qin Jiong; Pan Zhongyun; Zuo Qihua

    1998-01-01

    Purpose: To investigate childhood benign partial epilepsy (BPE) with SPECT. Methods: Double SPECT imaging was performed on 21 cases of BPE at the stage of wake (interval spike discharge) and sleep (spike discharge), under EEG monitoring. The transverse images were reconstructed after digital image subtraction. The quantitative analysis was conducted with brain flow change rate (BFCR) % mathematical model. Results: EEG monitoring demonstrated approximately normal background of 21 cases of BPE during the stage of wake, and spike discharge frequency markedly increased during the stage of sleep, 117 foci were showed by SPeCT in cases of BPE, and the average was 5.6 +- 1.6 foci/case. The characteristics of SPECT transverse images were 1) multiple foci of mirror, 2) mostly seen in Rolandic region, 3) circular symbol, 4) the radioactivity in foci decreased during the stage of wake (interval spike discharge) and increased during the stage of sleep (spike discharge). The concordance of SPECT and EEG was 93.1% (109/117 foci). The BFCR% of all epileptogenic foci exceeded normal limit (99% confidence interval). There was no correlation between the spike discharge frequency and BFCR% (r = 0.45, P>0.05). Conclusions: Regional cerebral blood flow and function were abnormal during the epileptogenic foci were discharging abnormally in BPE

  4. Single-Photon Emission Computed Tomography (SPECT) in childhood epilepsy

    Gulati, Sheffali; Kalra, Veena; Bal, C.S.

    2000-01-01

    The success of epilepsy surgery is determined strongly by the precise location of the epileptogenic focus. The information from clinical electrophysiological data needs to be strengthened by functional neuroimaging techniques. Single photon emission computed tomography (SPECT) available locally has proved useful as a localising investigation. It evaluates the regional cerebral blood flow and the comparison between ictal and interictal blood flow on SPECT has proved to be a sensitive nuclear marker for the site of seizure onset. Many studies justify the utility of SPECT in localising lesions to possess greater precision than interictal scalp EEG or anatomic neuroimaging. SPECT is of definitive value in temporal lobe epilepsy. Its role in extratemporal lobe epilepsy is less clearly defined. It is useful in various other generalized and partial seizure disorders including epileptic syndromes and helps in differentiating pseudoseizures from true seizures. The need for newer radiopharmaceutical agents with specific neurochemical properties and longer shelf life are under investigation. Subtraction ictal SPECT co-registered to MRI is a promising new modality. (author)

  5. 111In-Pentetreotide SPECT/CT in Pulmonary Carcinoid.

    Chiaravalloti, Agostino; Spanu, Angela; Danieli, Roberta; Dore, Francesca; Piras, Bastiana; Falchi, Antonio; Tavolozza, Mario; Madeddu, Giuseppe; Schillaci, Orazio

    2015-07-01

    We evaluated somatostatin receptor scintigraphy (SRS) with (111)In-pentetreotide incremental value in pulmonary carcinoid (PC) diagnosis compared to contrast enhanced Computed Tomography (ceCT). We enrolled 81 patients with ascertained PC, 39 at initial staging and 42 in follow-up; the primary tumor had already been excised in 68 cases. Single Photon emission Computed Tomography (SPECT) images were reconstructed with the iterative method and fused with non-enhanced Computed tomography (CT) images. Primary PC or metastatic lesions were ascertained in 55/81 patients and SPECT/CT was positive in 50/55 cases, while ceCT was positive in 44/55. Comparing SPECT/CT with ceCT results, we found a sensitivity of 96 vs. 87.5%, and specificity of 92% vs. 97% for the detection of primary lesion or recurrent disease. A total of 198 lesions were ascertained at SPECT/CT, while 161 at ceCT, with values of sensitivity and specificity of 85.5% and 84.6% for SRS and 75.2% and 90.5% respectively. (111)In-Pentetreotide SPECT/CT proved to be more sensitive and accurate than ceCT, thus enhancing its role in evaluating patients with PC. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  6. IQ-SPECT for thallium-201 myocardial perfusion imaging: effect of normal databases on quantification.

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

    2017-07-01

    Although IQ-single-photon emission computed tomography (SPECT) provides rapid acquisition and attenuation-corrected images, the unique technology may create characteristic distribution different from the conventional imaging. This study aimed to compare the diagnostic performance of IQ-SPECT using Japanese normal databases (NDBs) with that of the conventional SPECT for thallium-201 ( 201 Tl) myocardial perfusion imaging (MPI). A total of 36 patients underwent 1-day 201 Tl adenosine stress-rest MPI. Images were acquired with IQ-SPECT at approximately one-quarter of the standard time of conventional SPECT. Projection data acquired with the IQ-SPECT system were reconstructed via an ordered subset conjugate gradient minimizer method with or without scatter and attenuation correction (SCAC). Projection data obtained using the conventional SPECT were reconstructed via a filtered back projection method without SCAC. The summed stress score (SSS) was calculated using NDBs created by the Japanese Society of Nuclear Medicine working group, and scores were compared between IQ-SPECT and conventional SPECT using the acquisition condition-matched NDBs. The diagnostic performance of the methods for the detection of coronary artery disease was also compared. SSSs were 6.6 ± 8.2 for the conventional SPECT, 6.6 ± 9.4 for IQ-SPECT without SCAC, and 6.5 ± 9.7 for IQ-SPECT with SCAC (p = n.s. for each comparison). The SSS showed a strong positive correlation between conventional SPECT and IQ-SPECT (r = 0.921 and p IQ-SPECT with and without SCAC was also good (r = 0.907 and p IQ-SPECT without SCAC; and 88.5, 86.8, and 87.3%, respectively, for IQ-SPECT with SCAC, respectively. The area under the curve obtained via receiver operating characteristic analysis were 0.77, 0.80, and 0.86 for conventional SPECT, IQ-SPECT without SCAC, and IQ-SPECT with SCAC, respectively (p = n.s. for each comparison). When appropriate NDBs were used, the diagnostic performance of 201 Tl IQ-SPECT

  7. I-123 IBZM-SPECT: improved acquisition protocol with HR-collimator

    Sandrock, D.; Ivancevic, V.; Dopichaj-Menge, U.; Gruber, D.; Munz, D.

    2002-01-01

    protocol A and 3 patients with protocol B. These could not properly staged as normal or abnormal. Conclusion: The acquisition protocol using a HR collimator and a 128 x 128 matrix in I-123 IBZM-SPECT leads to a more valid determination of the dopamine D2 receptor status

  8. Receptor mapping in psychiatric patients with SPECT

    Schlegel, S.

    1997-01-01

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

  9. Quantitative SPECT reconstruction of iodine-123 data

    Gilland, D.R.; Jaszczak, R.J.; Greer, K.L.; Coleman, R.E.

    1991-01-01

    Many clinical and research studies in nuclear medicine require quantitation of iodine-123 ( 123 I) distribution for the determination of kinetics or localization. The objective of this study was to implement several reconstruction methods designed for single-photon emission computed tomography (SPECT) using 123 I and to evaluate their performance in terms of quantitative accuracy, image artifacts, and noise. The methods consisted of four attenuation and scatter compensation schemes incorporated into both the filtered backprojection/Chang (FBP) and maximum likelihood-expectation maximization (ML-EM) reconstruction algorithms. The methods were evaluated on data acquired of a phantom containing a hot sphere of 123 I activity in a lower level background 123 I distribution and nonuniform density media. For both reconstruction algorithms, nonuniform attenuation compensation combined with either scatter subtraction or Metz filtering produced images that were quantitatively accurate to within 15% of the true value. The ML-EM algorithm demonstrated quantitative accuracy comparable to FBP and smaller relative noise magnitude for all compensation schemes

  10. I-123 IMP SPECT in Parkinson's disease

    Kawabata, Keita; Tachibana, Kyudai; Sugita, Minoru

    1990-01-01

    To examine semiquantitatively regional cerebral blood flow, SPECT with N-isopropyl-p-[I-123]iodoamphetamine (I-123 IMP) was undertaken in 17 patients with Parkinson's disease. Seven patients with Alzheimer's disease and 9 senile control subjects were also imaged for comparison. Both the Parkinson's disease group and the Alzheimer's disease group had a decreased uptake of I-123 IMP in the frontal lobe, in comparison with the control group. A remarkably decreased uptake was seen in the lateral and parietal lobes in the group of Parkinson's disease associated with dementia, as well as in the Alzheimer's disease group. A significantly decreased uptake was observed in the frontal lobe, lateral lobe, thalamus, and basal ganglia in the Parkinson's disease group, irrespective of the presence or absence of dementia. For Parkinson's disease associated with dementia, there was much more significant decrease in I-123 IMP uptake. The pattern of regional cerebral blood flow in the Alzheimer's disease group was analogous to that in the Parkinson's disease group associated with dementia. This supports the hypothesis that Alzheimer's disease may be somewhat involved in the occurrence of dementia for Parkinson's disease. (N.K.)

  11. Dopamine transporter imaging in the aged rat: a [123I]FP-CIT SPECT study

    Niñerola-Baizán, Aida; Rojas, Santiago; Roé-Vellvé, Núria; Lomeña, Francisco; Ros, Domènec

    2015-01-01

    Introduction: Rodent models are extensively used to assess the biochemical and physiological changes associated with aging. They play a major role in the development of therapies for age-related pathologies such as Parkinson's disease. To validate the usefulness of these animal models in aging or age-related disease research, the consistency of cerebral aging processes across species must be evaluated. The dopaminergic system seems particularly susceptible to the aging process. One of the results of this susceptibility is a decline in striatal dopamine transporter (DAT) availability. Methods: We sought to ascertain whether similar age changes could be detected in-vivo in rats, using molecular imaging techniques such as single photon emission computed tomography (SPECT) with [ 123 I]FP-CIT. Results: A significant decrease of 17.21% in the striatal specific uptake ratio was observed in the aged rats with respect to the young control group. Conclusions: Our findings suggest that age-related degeneration in the nigrostriatal track is similar in humans and rats, which supports the use of this animal in models to evaluate the effect of aging on the dopaminergic system. Advances in Knowledge and Implications for patient Care: Our findings indicate that age-related degeneration in the nigrostriatal track is similar in humans and rats and that these changes can be monitored in vivo using small animal SPECT with [ 123 I]FP-CIT, which could facilitate the translational research in rat models of age related disorders of dopaminergic system

  12. Aperture correction with an asymmetrically trimmed gaussian weight in SPECT with a fan-beam collimator

    Kamiya, Ryo; Ogawa, Koichi

    2013-01-01

    The aim of the study is to improve the spatial resolution of single photon emission computed tomography (SPECT) images acquired with a fan-beam collimator. The aperture angle of a hole in the fan-beam collimator depends on the position of the collimator. To correct the aperture effect in an iterative image reconstruction, an asymmetrically trimmed Gaussian weight was used for a model. To confirm the validity of our method, point source phantoms and brain phantom were used in the simulation, and we applied the method to the clinical data. The results of the simulation showed that the spatial resolution of point sources improved from about 6 to 2 pixels full width at half maximum, and the corrected point sources were isotropic. The results of the simulation with the brain phantom showed that our proposed method could improve the spatial resolution of the phantom, and our method was effective for different fan-beam collimators with different focal lengths. The results of clinical data showed that the quality of the reconstructed image was improved with our proposed method. Our proposed aperture correction method with the asymmetrically trimmed Gaussian weighting function was effective in improving the spatial resolution of SPECT images acquired with the fan-beam collimator. (author)

  13. Correction for patient and organ movement in SPECT: application to exercise thallium-201 cardiac imaging

    Geckle, W.J.; Frank, T.L.; Links, J.M.; Becker, L.C.

    1988-01-01

    We describe a technique for correction of artifacts in exercise 201 Tl single photon emission computed tomography (SPECT) images arising from abrupt or gradual translational movement of the heart during acquisition. The procedure involves the tracking of the center of the heart in serial projection images using an algorithm which we call diverging squares. Each projection image is then realigned in the x-y plane so that the heart center conforms to the projected position of a fixed point in space. The shifted projections are reconstructed using the normal filtered backprojection algorithm. In validation studies, the motion correction procedure successfully eliminated movement artifacts in a heart phantom. Image quality was also improved in over one-half of 36 exercise thallium patient studies. The corrected images had smoother and more continuous left ventricular walls, greater clarity of the left ventricular cavity, and reduced streak artifacts. Rest injected or redistribution images, however, were often made worse, due to reduced heart to liver activity ratios and poor tracking of the heart center. Analysis of curves of heart position versus projection angle suggests that translation of the heart is common during imaging after exercise, and results from both abrupt patient movements, and a gradual upward shift of the heart. Our motion correction technique appears to represent a promising new approach for elimination of movement artifacts and enhancement of resolution in exercise 201 Tl cardiac SPECT images

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

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

    2014-03-15

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

  15. Clinical Significance of Brain SPECT in Zipeprol Abusers

    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.

  16. Problems in the optimum display of SPECT images

    Fielding, S.L.

    1988-01-01

    The instrumentation, computer hardware and software, and the image display system are all very important in the production of diagnostically useful SPECT images. Acquisition and processing parameters are discussed which can affect the quality of SPECT images. Regular quality control of the gamma camera and computer is important to keep the artifacts due to instrumentation to a minimum. The choice of reconstruction method will depend on the statistics in the study. The paper has shown that for high count rate studies, a high pass filter can be used to enhance the reconstructions. For lower count rate studies, pre-filtering is useful and the data can be reconstructed into thicker slices to reduce the effect of image noise. Finally, the optimum display for the images must be chosen, so that the information contained in the SPECT data can be easily perceived by the clinician. (orig.) [de

  17. SPECT and MRI in the diagnosis of epilepsy

    Gruenwald, F.; Biersack, H.J.; Bockisch, A.; Elger, C.E.; Durwen, H.F.; Penin, H.

    1989-01-01

    This study presents the results obtained using SPECT and MRI in epilepsy - mainly based on presurgical investigation in therapy-resistant cases of temporal lobe epilepsy. MRI was positive in 61% of 102 examined patients, SPECT was positive in 84%. In 46 patients with temporal lobe epilepsy subjected to partial temporal lobectomy was performed later on there was agreement of the results obtained with regard to the lateralisation in 74%. Although MRI, due to its sensitivity is superior to CT in diagnosis of epilepsy, CT should be performed in any case because some morphological changes - especially small arteriovenous malformations - are only seen in CT. MRI and SPECT should be considered as two complementary methods in epilepsy diagnosis, serving to evaluate morphology and function. A definite statement as to the predictive value of both methods remains to be made depending on a comparison of the results with the postoperative outcome referring to seizure frequency and cognitive function. (orig.) [de

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

    Dong Aisheng; Tian Jianming

    2005-01-01

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

  19. Practical method of breast attenuation correction for cardiac SPECT

    Oliveira, Anderson de; Nogueira, Tindyua; Gutterres, Ricardo Fraga; Megueriam, Berdj Aram; Santos, Goncalo Rodrigues dos

    2007-01-01

    The breast attenuation effects on SPECT (Single Photon Emission Tomography) myocardium perfusion procedures have been lately scope of continuous inquiry. The requested attenuation correction factors are usually achieved by transmission analysis, making up the exposure of a standard external source to the SPECT, as a routine step. However, its high cost makes this methodology not fully available to the most of nuclear medicines services in Brazil and abroad. To overcome the problem, a new trend is presented in this work, implementing computational models to balance the breast attenuation effects on the left ventricle anterior wall, during myocardium perfusion scintigraphy procedures with SPECT. A neural network was put on in order to provide the attenuation correction indexes, based upon the following patients individual biotypes features: mass, age, height, chest and breast thicknesses, heart size, as well as the imparted activity intake levels. (author)

  20. Practical method of breast attenuation correction for cardiac SPECT

    Oliveira, Anderson de; Nogueira, Tindyua; Gutterres, Ricardo Fraga [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao Geral de Instalacoes Medicas e Industriais (CGMI)]. E-mails: anderson@cnen.gov.br; tnogueira@cnen.gov.br; rguterre@cnen.gov.br; Megueriam, Berdj Aram [Instituto Nacional do Cancer (INCA), Rio de Janeiro, RJ (Brazil)]. E-mail: megueriam@hotmail.com; Santos, Goncalo Rodrigues dos [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)]. E-mail: goncalo@cnen.gov.br

    2007-07-01

    The breast attenuation effects on SPECT (Single Photon Emission Tomography) myocardium perfusion procedures have been lately scope of continuous inquiry. The requested attenuation correction factors are usually achieved by transmission analysis, making up the exposure of a standard external source to the SPECT, as a routine step. However, its high cost makes this methodology not fully available to the most of nuclear medicines services in Brazil and abroad. To overcome the problem, a new trend is presented in this work, implementing computational models to balance the breast attenuation effects on the left ventricle anterior wall, during myocardium perfusion scintigraphy procedures with SPECT. A neural network was put on in order to provide the attenuation correction indexes, based upon the following patients individual biotypes features: mass, age, height, chest and breast thicknesses, heart size, as well as the imparted activity intake levels. (author)

  1. Clinical Significance of Brain SPECT in Zipeprol Abusers

    Cho, Dai Ok; Kim, Jae Phil; Kim, Deog Yoon; Yang, Hyung In; Koh, Eun Mi; Kim, Kwang Won; Choi, Young Kil

    1993-01-01

    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.

  2. Preliminary application of brain perfusion SPECT imaging in schizophrenia

    Wu Zhixing; Guo Chanliu; Li Xingbao; Liang Rongxiang; Zhao Jun; Yan Tingxiu

    1996-01-01

    The clinical value of 99m Tc-ECD brain perfusion SPECT imaging was evaluated in patients with schizophrenia. 32 patients with schizophrenia and 21 normal controls were analyzed with 99m Tc-ECD SPECT. 93.8% (30/32) of the patients showed decreased regional cerebral blood flow (rCBF). There was normal rCBF in controls. In the patient group rCBF decreased significantly in bilateral frontal lobes, left temporal lobe and right basal ganglion. The rCBF of left temporal lobe was significantly lower than that of right temporal lobe. The decreasing rCBF was not significantly related to previous treatment and duration of illness. 99m Tc-ECD SPECT is useful for the study and diagnosis of patients with schizophrenia

  3. The potential value of a pictorial atlas for aid in the visual diagnosis of 123I FP-CIT SPECT scans

    Goethals, I.; Ham, H.; Dobbeleir, A.; D'Asseler, Y.; Santens, P.

    2009-01-01

    The aim of our study was to evaluate the value of a pictorial atlas of 123 I FP-CIT SPECT images for aid in the visual diagnosis. Patients, materials, methods: Sixty patients, of whom 20 were clinically diagnosed as 'non-parkinsonian' and 40 as having Parkinson's disease or any related disorder, were included in the study. An atlas consisting of 12 123 I FP-CIT SPECT images was constructed first. Validity of the atlas was investigated by performing a receiver operating characteristic (ROC) analysis with the clinical diagnosis as the gold standard. The remaining 48 SPECT images were visually assessed twice by 5 observers, first with and secondly without consulting the atlas, or vice versa. The added value of the atlas was investigated by comparing the diagnostic accuracy and the interobserver variability for both methods. Results: ROC analysis performed on the atlas yielded an area under the curve of 1 for a threshold discriminating between clinically non-parkinsonian and parkinsonian patients that was situated between image 4 and 5 of the atlas, For the diagnostic accuracy, we found that the area under the ROC curve was systematically higher if observers had access to the atlas compared to when they had not (Wilcoxon's test, p 123 I FP-CIT SPECT scans. (orig.)

  4. Empirical Test Case Specification

    Kalyanova, Olena; Heiselberg, Per

    This document includes the empirical specification on the IEA task of evaluation building energy simulation computer programs for the Double Skin Facades (DSF) constructions. There are two approaches involved into this procedure, one is the comparative approach and another is the empirical one. I....... In the comparative approach the outcomes of different software tools are compared, while in the empirical approach the modelling results are compared with the results of experimental test cases....

  5. Multimodality imaging: transfer and fusion of SPECT and MRI data

    Knesaurek, K.

    1994-01-01

    Image fusion is a technique which offers the best of both worlds. It unites the two basic types of medical images: functional body images(PET or SPECT scans), which provide physiological information, and structural images (CT or MRI), which provide an anatomic map of the body. Control-point based registration technique was developed and used. Tc-99m point sources were used as external markers in SPECT studies while, for MRI and CT imaging only anatomic landmarks were used as a control points. The MRI images were acquired on GE Signa 1.2 system and CT data on a GE 9800 scanner. SPECT studies were performed 1h after intravenous injection of the 740 MBq of the Tc-99m-HMPAO on the triple-headed TRIONIX gamma camera. B-spline and bilinear interpolation were used for the rotation, scaling and translation of the images. In the process of creation of a single composite image, in order to retain information from the individual images, MRI (or CT) image was scaled to one color range and a SPECT image to another. In some situations the MRI image was kept black-and-white while the SPECT image was pasted on top of it in 'opaque' mode. Most errors which propagate through the matching process are due to sample size, imperfection of the acquisition system, noise and interpolations used. Accuracy of the registration was investigated by SPECT-CT study performed on a phantom study. The results has shown that accuracy of the matching process is better, or at worse, equal to 2 mm. (author)

  6. SPECT/CT imaging in general orthopedic practice.

    Scharf, Stephen

    2009-09-01

    The availability of hybrid devices that combine the latest single-photon emission computed tomography (SPECT) imaging technology with multislice computed tomography (CT) scanning has allowed us to detect subtle, nonspecific abnormalities on bone scans and interpret them as specific focal areas of pathology. Abnormalities in the spine can be separated into those caused by pars fractures, facet joint arthritis, or osteophyte formation on vertebral bodies. Compression fractures can be distinguished from severe degenerative disease, both of which can cause intense activity across the spine on either planar or SPECT imaging. Localizing activity in patients who have had spinal fusion can provide tremendous insight into the causes of therapeutic failures. Infections of the spine now can be diagnosed with gallium SPECT/CT, despite the fact that gallium has long been abandoned because of its failure to detect spine infection on either planar or SPECT imaging. Small focal abnormalities in the feet and ankles can be localized well enough to make specific orthopedic diagnoses on the basis of their location. Moreover, when radiographic imaging provides equivocal or inadequate information, SPECT/CT can provide a road map for further diagnostic studies and has been invaluable in planning surgery. Our ability to localize activity within a bone or at an articular surface has allowed us to distinguish between fractures and joint disease. Increased activity associated with congenital anomalies, such as tarsal coalition and Bertolotti's syndrome have allowed us to understand the pathophysiology of these conditions, to confirm them as the cause of the patient's symptoms, and to provide information that is useful in determining appropriate clinical management. As our experience broadens, SPECT/CT will undoubtedly become an important tool in the evaluation and management of a wider variety of orthopedic patients.

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

    Li Jiaxiu

    1992-01-01

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

  8. Quantification in single photon emission computed tomography (SPECT)

    Buvat, Irene

    2005-01-01

    The objective of this lecture is to understand the possibilities and limitations of the quantitative analysis of single photon emission computed tomography (SPECT) images. It is also to identify the conditions to be fulfilled to obtain reliable quantitative measurements from images. Content: 1 - Introduction: Quantification in emission tomography - definition and challenges; quantification biasing phenomena; 2 - quantification in SPECT, problems and correction methods: Attenuation, scattering, un-stationary spatial resolution, partial volume effect, movement, tomographic reconstruction, calibration; 3 - Synthesis: actual quantification accuracy; 4 - Beyond the activity concentration measurement

  9. The use of SPECT in the study of depression

    Yu Jing; The Second Affiliated Hospital of Dalian Medical Univ., Dalian; Tang Yiyuan

    2007-01-01

    Functional imaging is an effective methods in the study of psychological disturbances. The SPECT imaging methods commonly used in the study of depression are cerebral blood flow imaging, cerebral metabolic imaging and neuroreceptor imaging, which reflect the cerebral blood perfusion, cerebral metabolism, and the distribution and function of neuroreceptors respectively. The techniques in data processing include and statistical parametric mapping. This review summarizes the feature of the imaging and data processing methods, the manifestation of SPECT images in depressive patients, the brain region with abnormal blood flow and the findings in neuroreceptor imaging; analyzes the problems in current reports and prospects future studies. (authors)

  10. HMPAO-SPECT during epileptic seizures: Early and late images

    Overbeck, B.; Gruenwald, F.; Bockisch, A.; Biersack, H.J.; Reinke, U.; Gratz, K.F.

    1990-01-01

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

  11. 1-123 iodoamphetamine SPECT findings in paranoid schizophrenia

    Simon, T.R.; Walker, B.S.; Matthieson, S.; Miller, C.D.; Raese, J.

    1989-01-01

    To find out if frontal metabolic and cerebral blood flow differ between normal subjects and patients with paranoid schizophrenia (PAR), the authors have examined regional synaptic amine metabolism. Using [I- 123]iodoamphetamine (IMP), the authors compared 85 subjects (61 PAR patients and 24 normal subjects) with single-head single-photon emission CT (SPECT). Virtually automatic analysis assigned relative tracer uptake to the frontal, anterior temporoparietal (TP), and posterior TP regions. Consistent with the visual inspection of two clinicians familiar with SPECT IMP images, this objective method yielded T-tests that showed higher relative frontal lobe ratios in normal subjects than in PAR patients (P =.03)

  12. Brain perfusion SPECT in children with frequent fits

    Heiskala, H.; Launes, J.; Pihko, H.; Nikkinen, P.; Santavuori, P.

    1993-01-01

    We studied 14 children with frequent fits using 99m Tc-HM-PAO single photon emission computed tomography (SPECT). There were 11 patients with partial secondary generalized epilepsy (PSGE) and 3 with Lennox-Gastaut syndrome (LGS). The typical regional cerebral blood flow (rCBF) finding in PSGE was a single area of abnormally low perfused cortex, and that in LGS, multiple hypoperfused areas. Clinically, the LGS patients were more severely affected. SPECT was more sensitive in detecting abnormalities than EEG, CT or MRI. Extensive impairment of rCBF may thus indicate unfavourable development of intellectual performance and poor seizure control. (author)

  13. Thyroid mass estimation in Grave's disease by SPECT

    Pant, G.S.; Sharma, S.K.; Kumar, R.; Pandey, A.K.; Gupta, A.K.

    2002-01-01

    Aim: One of the important parts of treatment of Grave's disease with I-131 is the delivery of accurate dose to the target volume. Three important parameters that need to be accurately measured for dosimetry are; the 24 hr thyroid uptake (%), the thyroid mass and effective half life of I-131 in the gland. In this presentation we describe the estimation thyroid mass by SPECT. We have standardised a method to estimated thyroid volume by SPECT using thyroid phantoms of different sizes and then used them for routine thyroid mass estimation in patients with Graves' disease. Materials and Methods: Due to variation in thyroid weight in patients with Grave's disease, we standardised the scintigraphic (SPECT) technique using thyroid phantoms of different volumes such as 5 ml, 9.5 ml, 10.5 ml, 35 ml, 80 ml, 101ml and 110 ml. Each phantom was filled with 99 mTc solution with different activity concentration (100 μCi, 300 μCi, 600 μCi and 1.0 μCi) and SPECT images were acquired on a VARICAM dual head camera in 128x128 matrix. The acquired data was processed using a standardised Metz filter but without attenuation or scatter correction. Coronal slices were used with suitable threshold for edge detection. An irregular ROI was plotted around each lobe and isthmus of the thyroid gland and the enclosed slice area was measured. The area measured from all the frames was added and multiplied by the slice thickness to get the volume of the thyroid gland. The estimated volume of each phantom was compared and correlated with its actual volume. The thyroid mass in 40 patients was estimated by SPECT and compared with that estimated by ultrasonography.Results and Conclusion: The results of thyroid mass estimation with SPECT in phantom study suggested a 30% threshold for all phantom volumes. However, 35% threshold was used in patients' images for estimating thyroid volume. The estimated volumes by scintigraphy were compared with that estimated by ultrasonography. A correlation coefficient

  14. The impact of exercise myocardial perfusion SPECT imaging on the selection of patients for coronary angiography

    Song Liping; He Zuoxiang; Liu Xiujie; Shi Rongfang; Liu Yunzhong; Tian Yueqin; Zhang Xiaoli; Qin Xuewen; Chen Jilin; Gao Runlin

    2001-01-01

    Objective: Exercise 99 Tc m -MIBI myocardial perfusion SPECT is accurate for the diagnosis of coronary artery disease (CAD). This study assessed the impact of exercise myocardial perfusion imaging on the selection of patients for coronary angiography. Methods: 2188 consecutive patients who underwent exercise myocardial perfusion SPECT in authors' department in 1999 were retrospectively analyzed. Among them, 1807 were men, 381 women (average age: 53.5 +- 7.2 years). Overall, exercise myocardial SPECT was normal in 1731 patients, abnormal in 359 cases, and equivocal in 98 patients. There were 141 patients who underwent CAG within 60 days after myocardial SPECT. Results: Overall, 12% of the patients with abnormal SPECT imaging underwent coronary angiography, but only 5% of the patients with a normal SPECT imaging did (P < 0.001). Among these 141 patients who underwent coronary angiography, significant coronary stenosis was present in 91% of the patients who had had an abnormal SPECT imaging, but only 8% of those who had had a normal SPECT imaging (P < 0.001). In those patients who underwent coronary angiography, revascularization rate was 25% for the patients with abnormal SPECT imaging, but only 1% for the patients with a normal SPECT imaging. Conclusion: The results of exercise myocardial perfusion SPECT have a significant impact on the selection of patients for coronary angiography and revascularization

  15. Is SPECT useful in imaging of abdominal inflammatory processes using 99mTc-HMPAO-WBCs?

    Smole, M.S.; Stantic, T.S.; Fettich, J.F.

    2002-01-01

    Aim: The aim of the study is to determine whether SPECT gives additional information in the assessment of inflammation of the abdominal region with labelled white blood cells as compared with usual planar imaging. Patients And Methods: SPECT and planar imaging was performed in 26 patients with suspected inflammatory process in the abdomen, within three hours after injection of autologous white blood cells labelled with 99m Tc HMPAO. Planar images where acquired as static spot images using high resolution low energy collimator on 256 x 256 matrix. SPECT was performed using the same collimator on 128 x 128 matrix in 128 projections. Filtered back projection was used for reconstruction and volume rendering was performed. Results: The lesions in the abdomen were classified as jejunum, colon ascendents, colon transversum, colon descendents, sigmoid, and lesions outside GIT. All lesions, which were seen on planar images, except one, were also seen on SPECT. Five equivocal lesions seen on planar images were reconfirmed as pathological on SPECT. Additionally SPECT revealed three lesions not seen on planar images. Fourteen lesions were seen by both imaging techniques. All together SPECT improved diagnostic accuracy of 99m Tc - HMPAO - WBC scintigraphy in 7/28 patients. Conclusion: more inflammatory lesions in the abdomen are revealed by SPECT and volume rendering, than by planar imaging equivocal lesions seen on planar images can be characterised as positive or negative by SPECT. SPECT artefacts can cause possible false positive results; therefore usual planar imaging cannot be omitted if SPECT is performed

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

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

    2009-05-15

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

  17. Utility of the cerebral SPECT in schizophrenia

    Heuguerot, C.H.; Lopez-Lerena, J.J.; Quagliata, A.; Hermida, J.C.; Oliveira, M.C.; Anastasia, H.

    2002-01-01

    Objective: To compare cortical and subcortical cerebral perfusion in schizophrenics patients with normal controls, and analyze the relation to clinical patterns and neuroleptic treatment. Method: 18 patients meeting DSM-IV criteria for schizophrenia under neuroleptic treatment (except 3 cases), evaluated with clinical scales (BPRS and PANSS). The control group included 5 subjects in good health. All subjects were studied with single photon emission computed tomography (SPECT) using technetium-99 etilencisteinato (99mTc-ECD) as a tracer. Region of interest (ROI) were defined in cerebral cortex and thalamus-basal ganglia areas. The cortical cerebral blood flow was measured with a quantitative analysis, expressed as a ratio of regional tracer uptake to occipital cortex uptake. In basal ganglia and thalamus, regional blood flow was evaluated with a semiquantitative methodology, defining categories. Results: Schizophrenics patients showed a significant reduction of perfusion on a left anterior frontal cortex ('hipofrontality') and global decrease of perfusion on left hemisphere. The interhemispheric (left/right) ratio of perfusion was incremented respect control group. In thalamic-basal ganglia complex, a significant hypoperfusion was found in neuroleptic-free patients and control group. On the other hand, neuroleptic-treated patients revealed normal or increased regional blood flow in thalamus and basal ganglia. Only the clinical item 'thought disorder' had significant high correlation with perfusion on left structures (left anterior frontal, left lateral frontal, left temporo-parietal); the other items correlated with right structures. Conclusions: The findings suggest a pattern o left cerebral hypoperfusion in patients with an incremented interhemispheric ratio of cerebral blood flow. The pivotal role of thalamic and basal ganglia areas in the pathophysiology of schizophrenia and neuroleptic action was reaffirmed; apparently, perfusion in thalamic-basal ganglia

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

    Shibata, Yasushi; Akimoto, Manabu; Matsushita, Akira; Yamamoto, Tetsuya; Takano, Shingo; Matsumura, Akira

    2010-01-01

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

  19. Empirical Philosophy of Science

    Mansnerus, Erika; Wagenknecht, Susann

    2015-01-01

    knowledge takes place through the integration of the empirical or historical research into the philosophical studies, as Chang, Nersessian, Thagard and Schickore argue in their work. Building upon their contributions we will develop a blueprint for an Empirical Philosophy of Science that draws upon...... qualitative methods from the social sciences in order to advance our philosophical understanding of science in practice. We will regard the relationship between philosophical conceptualization and empirical data as an iterative dialogue between theory and data, which is guided by a particular ‘feeling with......Empirical insights are proven fruitful for the advancement of Philosophy of Science, but the integration of philosophical concepts and empirical data poses considerable methodological challenges. Debates in Integrated History and Philosophy of Science suggest that the advancement of philosophical...

  20. SPECT and PET in cerebrovascular diseases. SPECT und PET bei cerebrovaskulaeren Erkrankungen

    Knapp, W.H. (Herzzentrum Nordrhein-Westfalen, Bad Oeynhausen (Germany). Inst. fuer Nuklearmedizin)

    1993-02-01

    Investigations using recently emerged perfusion tracers for SPECT, Tc-99m-HMPAO in particular, and studies of local glucose metabolism and oxygen utilisation with PET have deepened our knowledge of the pathophysiology in development and in the sequel of stroke. Studies of local cerebral blood flow and cerebrovascular reserve capacity are indicated in case of neurological symptoms suspected to be caused by transient ischemic attacks or in case of significant narrowing of the cerebral arteries. PET investigations of local metabolism (at the present state) are indicated in patients with incompleted stroke or with infarction and extended ischemic border zone. The differential diagnosis between multi-infarct-dementia and primarily neurodegenerative dementias is facilitated, in some individuals, by the characteristic topography of reduced flow. (orig./MG).

  1. Empirically Exploring Higher Education Cultures of Assessment

    Fuller, Matthew B.; Skidmore, Susan T.; Bustamante, Rebecca M.; Holzweiss, Peggy C.

    2016-01-01

    Although touted as beneficial to student learning, cultures of assessment have not been examined adequately using validated instruments. Using data collected from a stratified, random sample (N = 370) of U.S. institutional research and assessment directors, the models tested in this study provide empirical support for the value of using the…

  2. An algorithm to estimate the volume of the thyroid lesions using SPECT

    Pina, Jorge Luiz Soares de; Mello, Rossana Corbo de; Rebelo, Ana Maria

    2000-01-01

    An algorithm was developed to estimate the volume of the thyroid and its functioning lesions, that is, those which capture iodine. This estimate is achieved by the use of SPECT, Single Photon Emission Computed Tomography. The algorithm was written in an extended PASCAL language subset and was accomplished to run on Siemens ICON System, a special Macintosh environment that controls the tomographic image acquisition and processing. In spite of be developed for the Siemens DIACAN gamma camera, the algorithm can be easily adapted for the ECAN camera. These two Cameras models are among the most common ones used in Nuclear Medicine in Brazil Nowadays. A phantom study was used to validate the algorithm that have shown that a threshold of 42% of maximum pixel intensity of the images it is possible to estimate the volume of the phantoms with an error of 10% in the range of 30 to 70 ml. (author)

  3. Brain perfusion ratios by 99mTc HMPAO SPECT utilizing a mean value of the visual cortex to the cerebellum ratio derived from normal subjects

    Sanchez Catasus, C.; Rodriguez, R.; Cisnero, M.; Palmero, R.; Diaz, O.; Aguila, A.

    2002-01-01

    Aim: Previous results shows that the cerebellum (CER) is the best reference to calculate relative indexes of perfusion (IP) by brain SPECT. However, it can not be used on patients with bilateral cerebellar hypoperfusion. In such cases visual cortex (VC) or an average of the whole brain activity is recommended (WB). VC and WB are less reliable than CER, making it difficult to compare SPECT scans that have been normalized with different values. Materials and Methods: To overcome this difficulty, we developed a method to calculate IP utilizing a reference value defined as (VC / ), where is the mean value of the VC/CER ratio derived from a normal database which was assumed to be constant. We called the value VC/ the 'Pseudocerebellum' (PCER). For clinical validation, we first tested statistically the VC/CER ratio on a group of 60 [ 99m Tc]-HMPAO SPECT scans of 20 normal subjects and 40 neurological patients with positive SPECT but without involvement of VC and CER. To demonstrate that IP PCER approx. IP CER , we calculated the mean value of the absolute differences CER - IP PCER vertical bar> on two groups of scans from subjects without involvement of VC and CER: 10 normal subjects (GI); and 40 patients (GII). Finally, using an indirect procedure the method was tested on a third group of SPECT scans of 30 patients with bilateral cerebellar hypoperfusion (G III). Results: The VC/CER ratio was approximately constant with gender and age at a 95% confidence level; CER - IP PCER vertical bar> was 1.22%±0.35 and 1.20%±0.42 for GI and GII, respectively. This is less than the within-subject replicability of the HMPAO SPECT studies; and thus demonstrated by an indirect approach that IP PCER is a valid procedure by which to evaluate relative perfusion on patients with bilateral cerebellar hypoperfusion and quantitatively comparable to using CER as reference region. Conclusion: The VC/CER ratio has very little inter-subject variability in individuals where these regions are not

  4. Methodology for Validating Building Energy Analysis Simulations

    Judkoff, R.; Wortman, D.; O' Doherty, B.; Burch, J.

    2008-04-01

    The objective of this report was to develop a validation methodology for building energy analysis simulations, collect high-quality, unambiguous empirical data for validation, and apply the validation methodology to the DOE-2.1, BLAST-2MRT, BLAST-3.0, DEROB-3, DEROB-4, and SUNCAT 2.4 computer programs. This report covers background information, literature survey, validation methodology, comparative studies, analytical verification, empirical validation, comparative evaluation of codes, and conclusions.

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

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

    1997-05-01

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

  6. A novel computer-assisted image analysis of [{sup 123}I]{beta}-CIT SPECT images improves the diagnostic accuracy of parkinsonian disorders

    Goebel, Georg [Innsbruck Medical University, Department of Medical Statistics, Informatics and Health Economics, Innsbruck (Austria); Seppi, Klaus; Wenning, Gregor K.; Poewe, Werner; Scherfler, Christoph [Innsbruck Medical University, Department of Neurology, Innsbruck (Austria); Donnemiller, Eveline; Warwitz, Boris; Virgolini, Irene [Innsbruck Medical University, Department of Nuclear Medicine, Innsbruck (Austria)

    2011-04-15

    The purpose of this study was to develop an observer-independent algorithm for the correct classification of dopamine transporter SPECT images as Parkinson's disease (PD), multiple system atrophy parkinson variant (MSA-P), progressive supranuclear palsy (PSP) or normal. A total of 60 subjects with clinically probable PD (n = 15), MSA-P (n = 15) and PSP (n = 15), and 15 age-matched healthy volunteers, were studied with the dopamine transporter ligand [{sup 123}I]{beta}-CIT. Parametric images of the specific-to-nondisplaceable equilibrium partition coefficient (BP{sub ND}) were generated. Following a voxel-wise ANOVA, cut-off values were calculated from the voxel values of the resulting six post-hoc t-test maps. The percentages of the volume of an individual BP{sub ND} image remaining below and above the cut-off values were determined. The higher percentage of image volume from all six cut-off matrices was used to classify an individual's image. For validation, the algorithm was compared to a conventional region of interest analysis. The predictive diagnostic accuracy of the algorithm in the correct assignment of a [{sup 123}I]{beta}-CIT SPECT image was 83.3% and increased to 93.3% on merging the MSA-P and PSP groups. In contrast the multinomial logistic regression of mean region of interest values of the caudate, putamen and midbrain revealed a diagnostic accuracy of 71.7%. In contrast to a rater-driven approach, this novel method was superior in classifying [{sup 123}I]{beta}-CIT-SPECT images as one of four diagnostic entities. In combination with the investigator-driven visual assessment of SPECT images, this clinical decision support tool would help to improve the diagnostic yield of [{sup 123}I]{beta}-CIT SPECT in patients presenting with parkinsonism at their initial visit. (orig.)

  7. A novel computer-assisted image analysis of [123I]β-CIT SPECT images improves the diagnostic accuracy of parkinsonian disorders

    Goebel, Georg; Seppi, Klaus; Wenning, Gregor K.; Poewe, Werner; Scherfler, Christoph; Donnemiller, Eveline; Warwitz, Boris; Virgolini, Irene

    2011-01-01

    The purpose of this study was to develop an observer-independent algorithm for the correct classification of dopamine transporter SPECT images as Parkinson's disease (PD), multiple system atrophy parkinson variant (MSA-P), progressive supranuclear palsy (PSP) or normal. A total of 60 subjects with clinically probable PD (n = 15), MSA-P (n = 15) and PSP (n = 15), and 15 age-matched healthy volunteers, were studied with the dopamine transporter ligand [ 123 I]β-CIT. Parametric images of the specific-to-nondisplaceable equilibrium partition coefficient (BP ND ) were generated. Following a voxel-wise ANOVA, cut-off values were calculated from the voxel values of the resulting six post-hoc t-test maps. The percentages of the volume of an individual BP ND image remaining below and above the cut-off values were determined. The higher percentage of image volume from all six cut-off matrices was used to classify an individual's image. For validation, the algorithm was compared to a conventional region of interest analysis. The predictive diagnostic accuracy of the algorithm in the correct assignment of a [ 123 I]β-CIT SPECT image was 83.3% and increased to 93.3% on merging the MSA-P and PSP groups. In contrast the multinomial logistic regression of mean region of interest values of the caudate, putamen and midbrain revealed a diagnostic accuracy of 71.7%. In contrast to a rater-driven approach, this novel method was superior in classifying [ 123 I]β-CIT-SPECT images as one of four diagnostic entities. In combination with the investigator-driven visual assessment of SPECT images, this clinical decision support tool would help to improve the diagnostic yield of [ 123 I]β-CIT SPECT in patients presenting with parkinsonism at their initial visit. (orig.)

  8. A novel computer-assisted image analysis of [123I]β-CIT SPECT images improves the diagnostic accuracy of parkinsonian disorders.

    Goebel, Georg; Seppi, Klaus; Donnemiller, Eveline; Warwitz, Boris; Wenning, Gregor K; Virgolini, Irene; Poewe, Werner; Scherfler, Christoph

    2011-04-01

    The purpose of this study was to develop an observer-independent algorithm for the correct classification of dopamine transporter SPECT images as Parkinson's disease (PD), multiple system atrophy parkinson variant (MSA-P), progressive supranuclear palsy (PSP) or normal. A total of 60 subjects with clinically probable PD (n = 15), MSA-P (n = 15) and PSP (n = 15), and 15 age-matched healthy volunteers, were studied with the dopamine transporter ligand [(123)I]β-CIT. Parametric images of the specific-to-nondisplaceable equilibrium partition coefficient (BP(ND)) were generated. Following a voxel-wise ANOVA, cut-off values were calculated from the voxel values of the resulting six post-hoc t-test maps. The percentages of the volume of an individual BP(ND) image remaining below and above the cut-off values were determined. The higher percentage of image volume from all six cut-off matrices was used to classify an individual's image. For validation, the algorithm was compared to a conventional region of interest analysis. The predictive diagnostic accuracy of the algorithm in the correct assignment of a [(123)I]β-CIT SPECT image was 83.3% and increased to 93.3% on merging the MSA-P and PSP groups. In contrast the multinomial logistic regression of mean region of interest values of the caudate, putamen and midbrain revealed a diagnostic accuracy of 71.7%. In contrast to a rater-driven approach, this novel method was superior in classifying [(123)I]β-CIT-SPECT images as one of four diagnostic entities. In combination with the investigator-driven visual assessment of SPECT images, this clinical decision support tool would help to improve the diagnostic yield of [(123)I]β-CIT SPECT in patients presenting with parkinsonism at their initial visit.

  9. A limitation of the split-dose method for evaluating rCBF changes using 99mTc-ECD and SPECT

    Odano, Ikuo; Takahashi, Makoto; Noguchi, Eikichi; Ohtaki, Hiro; Shibaki, Mitsurou; Kasahara, Tosifumi; Hatano, Masayoshi; Ohkubo, Masaki.

    1997-01-01

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

  10. Post traumatic brain perfusion SPECT analysis using reconstructed ROI maps of radioactive microsphere derived cerebral blood flow and statistical parametric mapping

    Gonzalez-Brito Manuel

    2008-02-01

    Full Text Available Abstract Background Assessment of cerebral blood flow (CBF by SPECT could be important in the management of patients with severe traumatic brain injury (TBI because changes in regional CBF can affect outcome by promoting edema formation and intracranial pressure elevation (with cerebral hyperemia, or by causing secondary ischemic injury including post-traumatic stroke. The purpose of this study was to establish an improved method for evaluating regional CBF changes after TBI in piglets. Methods The focal effects of moderate traumatic brain injury (TBI on cerebral blood flow (CBF by SPECT cerebral blood perfusion (CBP imaging in an animal model were investigated by parallelized statistical techniques. Regional CBF was measured by radioactive microspheres and by SPECT 2 hours after injury in sham-operated piglets versus those receiving severe TBI by fluid-percussion injury to the left parietal lobe. Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was identified at the voxel level using statistical parametric mapping (SPM. Results A significant area of hypoperfusion (P Conclusion The suitability of SPM for application to the experimental model and ability to provide insight into CBF changes in response to traumatic injury was validated by the SPECT SPM result of a decrease in CBP at the left parietal region injury area of the test group. Further study and correlation of this characteristic lesion with long-term outcomes and auxiliary diagnostic modalities is critical to developing more effective critical care treatment guidelines and automated medical imaging processing techniques.

  11. Salivary SPECT and factor analysis in Sjoegren's syndrome

    Nakamura, T.; Oshiumi, Y.; Yonetsu, K.; Muranaka, T.; Sakai, K.; Kanda, S.; National Fukuoka Central Hospital

    1991-01-01

    Salivary SPECT and factor analysis in Sjoegren's syndrome were performed in 17 patients and 6 volunteers as controls. The ability of SPECT to detect small differences in the level of uptake can be used to separate glands from background even when uptake is reduced as in the patients with Sjoegren's syndrome. In control and probable Sjoegren's syndrome groups the uptake ratio of the submandibular gland to parotid gland on salivary SPECT (S/P ratio) was less than 1.0. However, in the definite Sjoergren's syndrome group, the ratio was more than 1.0. Moreover, the ratio in all patients with sialectasia, which is characteristic of Sjoegren's syndrome, was more than 1.0. Salivary factor analysis of normal parotid glands showed slowly increasing patterns of uptake and normal submandibular glands had rapidly increasing patterns of uptake. However, in the definite Sjoegren's syndrome group, the factor analysis patterns were altered, with slowly increasing patterns dominating both in the parotid and submandibular glands. These results suggest that the S/P ratio in salivary SPECT and salivary factor analysis provide additional radiologic criteria in diagnosing Sjoegren's syndrome. (orig.)

  12. Subcortical aphasia and cerebral blood flow using SPECT

    Celsis, P.; Puel, M.; Demonet, J.P.; Bonafe, A.; Cardebat, D.; Viallard, G.; Pujol, T.; Marc-Vergnes, J.P.; Rascol, A.

    1985-01-01

    Possible cerebral blood flow (CBF) alteration in subcortical aphasia was investigated by single-photon emission tomography (SPECT). The results confirm the capsulo-striatal lesions and also point to the high rate of ipsilateral thalamic and cortical dysfunction. (author). 8 refs.; 1 fig.; 1 tab

  13. Cerebral fat embolism studied with MRI and SPECT

    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.)

  14. Radionuclide cisternography: SPECT and 3D-rendering

    Henkes, H.; Huber, G.; Piepgras, U.; Hierholzer, J.; Cordes, M.

    1991-01-01

    Radionuclide cisternography is indicated in the clinical work-up for hydrocephalus, when searching for CSF leaks, and when testing whether or not intracranial cystic lesions are communicating with the adjacent subarachnoid space. This paper demonstrates the feasibility and diagnostic value of SPECT and subsequent 3D surface rendering in addition to conventional rectilinear CSF imaging in eight patients. Planar images allowed the evaluation of CSF circulation and the detection of CSF fistula. They were advantageous in examinations 48 h after application of 111 In-DTPA. SPECT scans, generated 4-24 h after tracer application, were superior in the delineation of basal cisterns, especially in early scans; this was helpful in patients with pooling due to CSF fistula and in cystic lesions near the skull base. A major drawback was the limited image quality of delayed scans, when the SPECT data were degraded by a low count rate. 3D surface rendering was easily feasible from SPECT data and yielded high quality images. The presentation of the spatial distribution of nuclide-contaminated CSF proved especially helpful in the area of the basal cisterns. (orig.) [de

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

    Ishikawa, M.; Kobayashi, T.; Kanda, K.

    2000-01-01

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

  16. Clinical application of domestica manufactured BHP6601 SPECT

    Zhang Shuwen; Tian Jiahe; Liu Zilai; He Yijie; Shao Mingzhe; Zhang Jinming

    2005-01-01

    Clinical imaging of 150 patients with varying demand is carried out with BHP6601 SPECT manufactured locally, and the results are compared with that obtained by an E. CAM system manufactured by Siemens. The results show that BHP6601 had an acceptable and stable performance from a technical point of view. It offers a sufficient ability for organ imaging of clinical requirement. (authors)

  17. SPECT/CT: main applications in nuclear medicine

    Perera Pintado, Alejandro; Torres Aroche, Leonel A.; Vergara Gil, Alex; Batista Cuéllar, Juan F.; Prats Capote, Anaís

    2017-01-01

    SPECT/CT has represented not only the possibility of acquiring anatomical and functional images in one single study, but also a revolution for the clinical management of several diseases, taking the better of each one of these imaging modalities. The present work is aimed at presenting an overview of the most important applications of the SPECT/CT in the field of oncology, cardiology and neurology. New technological advances in the design of innovative solid state detectors and related equipment have had a positive effect on the performance of this kind of dual modality. This hybrid technique improves the sensitivity and the specificity of gammagraphic studies, as well as shortens the acquisition times and gives attenuation correction of co-registered images, which, in turn, makes their analysis easier. Some of the main applications for the study of oncological diseases are the following: localization and follow-up of different kinds of tumors, their metastasis and relapses, as well as the optimization of radiotherapy doses. This technique has been useful to evaluate the coronary artery disease allowing an adequate attenuation correction of images, the determination of calcium score, and performing angio-CT studies, according to the CT quality. SPECT/CT has also gained ground in the assessment of some neurological diseases. Conclusions: The introduction of new technological advances and radiopharmaceuticals thus predicting a more relevant place for SPECT/CT in clinical practice. (author)

  18. Ocular melanoma: Detection using iodine-123-iodoamphetamine and SPECT imaging

    Dewey, S.H.; Leonard, J.C.

    1990-01-01

    Uptake of iodine-123-iodoamphetamine has been demonstrated in malignant melanoma using planar imaging techniques and has been used to detect an ocular melanoma at 12 hr postinjection. Using SPECT technique, an ocular melanoma is identified in a 64-yr-old male at 1 hr postinjection

  19. Regional cerebral blood flow in SPECT pattern in Parkinson's disease

    Lenart-Jankowska, D.; Junik, R.; Sowinski, J.; Gembicki, M.; Wender, M.

    1997-01-01

    The purpose of our work was to compare the regional cerebral blood flow (rCBF) in SPECT examination in Parkinson's disease with (17 cases) and without (7 cases) dementia and in various clinical stages of the disease. The patients underwent SPECT examination 5-40 min after intravenous application of HMPAO (Ceretec, Amersham) with 740 Mbq (20 mCi) pertechnate 99m Tc. SPECT was performed with a Siemens Diacam single-head rotating gamma camera coupled to a high resolution collimator and Icon computer system provided by the manufacturer. The results were defined in relative values of ROI in relation to cerebellum. Patients with Parkinson's disease showed hypoperfusion in cerebral lobes and in deep cerebral structures including the basal ganglia. Regional perfusion deficit in SPECT was seen with and without associated dementia and already in early stage of the disease. Parkinson's disease is provoked by the lesions of dopaminergic neurons of the central nervous system leading to domination of extrapyramidal symptoms. There are many indications that also the neurotransmitters associated with cognitive functions as acetylcholine demonstrate some abnormalities. However, only in some cases of Parkinson's disease dementia is the dominating symptom. Our results of regional cerebral blood flow testify that in Parkinson's disease the dysfunction of the central nervous system is more diffuse than has previously been suggested. (author)

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

    Tonami, N.; Matsuda, H.; Ooba, H.; Yokoyama, K.; Hisada, K.; Ikeda, K.; Yamashita, J.

    1990-01-01

    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

  1. Topodiagnosis in Creutzfeldt-Jakob disease by HMPAO-SPECT

    Heye, N.; Farahati, J.; Heinz, A.; Buettner, T.; Przuntek, H.; Reiners, C.

    1993-01-01

    A 80-year old female presented with an early stage of Creutzfeldt-Jakob disease with clinical, neurophysiological and neuropathological findings suggesting a focal involvement of the brain. HMPAO SPECT disclosed asymmetries of regional cerebral perfusion, thus suggesting that it may be a further diagnostic instrument in this disease. (orig.) [de

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

    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.

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

    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%.

  4. Reduced contralateral hemispheric flow measured by SPECT in cerebellar lesions

    Sönmezoğlu, K; Sperling, B; Henriksen, T

    1993-01-01

    Four patients with clinical signs of cerebellar stroke were studied twice by SPECT using 99mTc-HMPAO as a tracer for cerebral blood flow (CBF). When first scanned 6 to 22 days after onset, all had a region of very low CBF in the symptomatic cerebellar hemisphere, and a mild to moderate CBF reduct...

  5. Leg 201Tl-SPECT in chronic exertional compartment syndrome

    Elkadri, N.; Slim, I.; Blondet, C.; Choquet, Ph.; Constantinesco, A.; Lecocq, J.

    2004-01-01

    Leg 201 Tl-SPECT in chronic exertional compartment syndrome Background: The chronic exertional compartment syndrome is one of the most frequent origins regarding leg pain due to sport training. The diagnosis can be established by invasive compartment pressure measurement. The aim of this study is to evaluate the role that could have 201 Tl-SPECT for patients with suspicion of compartment syndrome. Patients and methods: 51 leg 201 Tl-SPECT exams were performed (exercise - and rest without reinjection) in 49 patients; 28 had compartment syndrome confirmed by pressure measurement. About 100 MBq of 201 Tl were injected during exercise, when pain appeared or at least after 25 minutes exercise. We studied mean percentages of level uptake for each compartment, referred to the maximal uptake of both legs. Results: 47 compartments were concerned by compartment syndrome and 361 compartments were not. Scintigraphic patterns in compartments are reversible ischaemia (45%), uptake stability (36%) or reverse redistribution (19%); these patterns are not linked to compartment syndrome. However, there is a significant difference of rest 201 Tl level uptake between compartments with and without compartment syndrome and a significant correlation between muscular pressure measurement and rest level uptake. Conclusion: 201 Tl-SPECT shows that only ischaemia does not explain compartment syndrome. Moreover, it allows to predict pressure variation during exercise but it does not offer any interest in order to select patients for muscular invasive pressure measurement. (author)

  6. The role of SPECT in the evaluation of skeletal trauma

    Murray, I P.C. [Prince of Wales Hospital, Randwick (Australia)

    1993-02-01

    Single photon emission computed tomography (SPECT) has, in the last decade, established a critical role in routine diagnosis. Skeletal scintigraphy exemplifies the impact in improving detection of lesions by delineation of their site and size. The advantage of minimizing the superimposed radioactivity from overlying and underlying structures is typified by the readiness with which avascular necrosis of the femoral head can be identified by removal of the surrounding hyperaemia which masks the classical photopaenia. However, the ability to achieve an accurate image at a plane at a prescribed depth is most characteristically shown by the study of a vertebra, a bone of irregular contour and subject to a variety of pathological disorders at different sites within it. The various focal abnormalities resulting from these can be localized exactly, readily distinguishing, for example, those in the body from those in the natural arch. In particular, the alterations resulting from trauma, such as pars interarticularis stress fracture, are readily seen. Consequently SPECT has an indispensable role in the investigation and management of low back pain. However, the ability of SPECT to delineate abnormal accumulation has provided a new approach to the evaluation of knee pain, especially when acute such as that resulting from athletic injury, since the identification of the presence or absence of focal abnormalities can be critical to patient management. The frequency of these various disorders in which SPECT is so useful explains why the procedure has become such a routine high-volume examination in so many departments. (author).

  7. Skeletal scintigraphy and SPECT/CT in orthopedic imaging

    Klaeser, B.; Walter, M.; Krause, T.

    2011-01-01

    Multi-modality imaging with SPECT-CT in orthopaedics combines the excellent sensitivity of scintigraphy with the morphological information of CT as a key for specific interpretation of findings in bone scans. The result is an imaging modality with the clear potential to prove of value even in a competitive setting dominated by MRI, and to significantly add to diagnostic imaging in orthopaedics. SPECT-CT is of great value in the diagnostic evaluation after fractures, and - in contrast to MRI - it is well suited for imaging in patients with osteosyntheses and metallic implants. In sports medicine, SPECT-CT allows for a sensitive and specific detection of osseous stress reactions before morphological changes become detectable by CT or MRI. In patients with osseous pain syndromes, actively evolving degenerative changes as a cause of pain can be identified and accurately localized. Further, particularly prospective diagnostic studies providing comparative data are needed to strengthen the position of nuclear imaging in orthopaedics and sports medicine and to help implementing SPECT/CT in diagnostic algorithms. (orig.)

  8. [Elaboration of the SPM template for the standardization of SPECT images with 123I-Ioflupane].

    García-Gómez, F J; García-Solís, D; Luis-Simón, F J; Marín-Oyaga, V A; Carrillo, F; Mir, P; Vázquez-Albertino, R J

    2013-01-01

    Statistical parametric mapping (SPM) is a widely used produced for normalization of functional images. This study has aimed to develop a normalization template of (123)I-Ioflupane SPECT-imaging DaTSCAN(®), GE Healthcare), not available in SPM5, and to validate it compared to other quantification methods. In order to write the template we retrospectively selected 26 subjects who had no evidence of nigrostriatal degeneration and whose age distribution was similar to that of the patients in the usual practice of our Department: 2 subjects (7.6%) were 65 years (57.7%). All the studies were normalized with the T1-template available in SPM5 and an average image of the value was obtained for each voxel. For validation we analyzed 60 patients: 30 with idiopathic Parkinson's disease patients (iPD) with right involvement (66.83±12.20 years) and 30 with essential tremor patients (ET) (67.27±8.33 years). Specific uptake rates (SUR) of different striatal regions were compared after image normalization with our template and the application of a semiautomated VOIs-map created with Analyze v9.0 ((©)BIR, Mayo Clinic), against two quantification methods: a) manual adjustment of a ROIs-map drawn in Analyze, and b) semi-automated method (HERMES-BRASS) with normalization and implementation of VOIs-map. No statistically significant differences in the iPD/ET discriminatory capacity between the three methods analyzed were observed (p0,871, p<0,001). This difference was greater in patients with PD. Our study demonstrates the efficacy of our SPM «template» for (123)I-Ioflupane SPECT-imaging, obtained from normalization with «T1-template». Copyright © 2012 Elsevier España, S.L. and SEMNIM. All rights reserved.

  9. Testing non-rigid registration of nuclear medicine data using synthetic derived SPECT images

    Todd-Pokropek, A.

    2002-01-01

    Aim: Non-rigid registration is needed to build atlas data to make statistical tests of significance of uptake in nuclear medicine (NM). Non-rigid registration is much more difficult than rigid registration to validate since some kind of matching function must be defined throughout the volume being registered, and no suitable gold standards exist. The aim here has been to assess non-rigid methods of registration and deformation for NM to NM and NM to MRI data. An additional aim has been to derive good synthetic SPECT images from other NM and MRI data to be used after as reference standards. Material and Methods: Phantom and patient test images have been acquired for both NM and MRI, which are then used to generate projections, where the characteristics of the images are modified to change both signal and noise properties. These derived images are different in character but perfectly registered with the original data, and can then be deformed in a known manner. The registration algorithm is then run backwards to re-register the modified deformed data with the original images. A technique has been developed to assess the vector fields of the original deformation to the reverse non-rigid registration field. Results: The main purpose of this paper is to describe a methodology for optimising algorithms, not to develop the algorithms themselves. Two different algorithms based on optic flow and thin plate spline interpolation have been intercompared and in particular the constraints imposed tested. Considerable differences in matching can be observed in different regions for example edge and centre of brain. Conclusions: Quadratic distance between known makers is a bad estimate to use to assess non-rigid registration. A robust statistic has been developed which can be used to optimise non-rigid algorithms based on the use of synthetic SPECT reference datasets. While the task being tested is simpler than the real clinical task, it is the first essential step in the

  10. The need of appropriate brain SPECT templates for SPM comparisons

    Morbelli, S.; Altrinetti, V.; Piccardo, A.; Rodriguez, G.; Brugnolo, A.; Nobili, F.; Mignone, A.; Pupi, A.; Koulibaly, P.M.

    2008-01-01

    Statistical parametric mapping (SPM) is used worldwide to compare brain perfusion single photon emission computed tomography (SPECT) data. The default template within the SPM package used for SPECT image normalization includes images of a group of healthy subjects studied with 99m TcHMPAO. Since [ 99m Tc] HMPAO and [ 99m Tc] ECD have shown to distribute differently in SPECT studies, we formulated the hypothesis that comparing set of [ 99m Tc]ECD data normalized by means of a [ 99m Tc]HMPAO template may lead to incorrect results. A customized [ 99m Tc]ECD template was built with SPECT and magnetic resonance imaging (MRI) images of 22 neurologically healthy women. Then, two sets of subjects, i.e. a group of patients with very early Alzheimer's disease (eAD) and a matched control group, studied by means of [ 99m Tc]ECD SPECT, were chosen for comparisons. The same statistical approach (t-test between eAD patients and controls and correlation analysis between brain SPECT and a cognitive score) was applied twice, i.e. after normalization with either the default [ 99m Tc]HMPAO template or the customized [ 99m Tc]ECD template. In the comparison between eAD and controls, a cluster of difference in the posterior-cingulate gyrus of both hemispheres was only highlighted when using the customized [ 99m Tc]ECD template, but was missed when using the default [ 99m Tc]HMPAO template. In the correlation between brain perfusion and a cognitive score, the significant cluster was more significant and far more extended, also including the right superior temporal gyrus, using the customized [ 99m Tc]ECD template than using the default [ 99m Tc]HMPAO template. These data suggest the need of customized, radiopharmaceutical-matched SPECT templates to be used within the SPM package. The present customized [ 99m Tc]ECD template is now freely available on the web. (authors)

  11. Imaging fusion (SPECT/CT) in degenerative disease of spine

    Bernal, P.; Ucros, G.; Bermudez, S.; Ocampo, M.

    2007-01-01

    Full text: Objective: To determine the utility of Fusion Imaging SPECT/CT in degenerative pathology of the spine and to establish the impact of the use of fusion imaging in spinal pain due to degenerative changes of the spine. Materials and methods: 44 Patients (M=21, F=23) average age of 63 years and with degenerative pathology of spine were sent to Diagnosis Imaging department in FSFB. Bone scintigraphy (SPECT), CT of spine (cervical: 30%, Lumbar 70%) and fusion imaging were performed in all of them. Bone scintigraphy was carried out in a gamma camera Siemens Diacam double head attached to ESOFT computer. The images were acquired in matrix 128 x 128, 20 seg/imag, 64 images. CT of spine was performed same day or two days after in Helycoidal Siemens somatom emotion CT. The fusion was done in a Dicom workstation in sagital, axial and coronal reconstruction. The findings were evaluated by 2 Nuclear Medicine physicians and 2 radiologists of the staff of FSFB in an independent way. Results: Bone scan (SPECT) and CT of 44 patients were evaluated. CT showed facet joint osteoarthrities in 27 (61.3%) patients, uncovertebral joint arthrosis in 7 (15.9%), bulging disc in 9(20.4%), spinal nucleus lesion in 7(15.9%), osteophytes in 9 (20.4%), spinal foraminal stenosis in 7 (15.9%), spondylolysis/spondylolisthesis in 4 (9%). Bone scan showed facet joint osteoarthrities in 29 (65.9%), uncovertebral joint arthrosis in 4 (9%), osteophytes in 9 (20.4%) and normal 3 (6.8%). The imaging fusion showed coincidence findings (main lesion in CT with high uptake in scintigraphy) in 34 patients (77.2%) and no coincidence in 10 (22.8%). In 15 (34.09%) patients the fusion provided additional information. The analysis of the findings of CT and SPECT showed similar results in most of the cases and the fusion didn't provide additional information but it allowed to confirm the findings but when the findings didn't match where the CT showed several findings and SPECT only one area with high uptake

  12. Role of SPECT imaging in symptomatic posterior element lumbar stress injuries

    Debnath U

    2005-01-01

    Full Text Available Background : Diagnosis of stress injuries of spine is very difficult with conventional radiography. Methods : In a observational study, 132 subjects were recruited (between 8 and 38 years of age, who had lumbar spondylolysis or posterior element stress injuries. All these patients underwent clinical examination followed by plain X-rays, planar bone scintigraphy and SPECT (single photon emission computerised tomography. SPECT scans can identify the posterior element lumbar stress injuries earlier than other imaging modalities. As the lesions evolve and the completed spondylolysis becomes chronic, the SPECT scans tend to revert to normal even though healing of the defect has not occurred. The aim of the study was to determine the time lag after which SPECT imaging tends to be negative. We divided the patients into two groups, one SPECT positive group and the other SPECT negative group. Pre treatment background variables such as age, gender, back pain in extension or flexion, sporting activities, time of onset of symptoms, Oswestry Disability Index (ODI were used in a univariate logistic regression model to find the strong predictors of positive SPECT imaging results. Determinants of positivity versus negativity of SPECT were identified by discriminant analysis using multivariate logistic regression. Results : Seventy nine patients had positive SPECT scans whereas 53 patients had negative SPECT scans. Bilateral increased uptake was more common than unilateral uptake. Increased uptake at the L5 lumbar spine was more common (70% in SPECT positive group. Low back pain in extension was significantly more common in SPECT positive subjects. Active sporting individuals had higher probability of having a positive SPECT scan. The mean time lag from the onset of low back pain to SPECT imaging was 7 months in SPECT positive group and 25 months in the SPECT negative group. Multivariate analysis predicted that there is a significant difference in positivity of

  13. Life Writing After Empire

    A watershed moment of the twentieth century, the end of empire saw upheavals to global power structures and national identities. However, decolonisation profoundly affected individual subjectivities too. Life Writing After Empire examines how people around the globe have made sense of the post...... in order to understand how individual life writing reflects broader societal changes. From far-flung corners of the former British Empire, people have turned to life writing to manage painful or nostalgic memories, as well as to think about the past and future of the nation anew through the personal...

  14. Theological reflections on empire

    Allan A. Boesak

    2009-11-01

    Full Text Available Since the meeting of the World Alliance of Reformed Churches in Accra, Ghana (2004, and the adoption of the Accra Declaration, a debate has been raging in the churches about globalisation, socio-economic justice, ecological responsibility, political and cultural domination and globalised war. Central to this debate is the concept of empire and the way the United States is increasingly becoming its embodiment. Is the United States a global empire? This article argues that the United States has indeed become the expression of a modern empire and that this reality has considerable consequences, not just for global economics and politics but for theological refl ection as well.

  15. A correlation of clinical, MRI and brain SPECT in dementia

    Shelley, S.; Indirani, M.; Gokhale, S.; Anirudhan, N.; Sivakumar, M.R.; Jaganathan, K.

    2004-01-01

    Background: Dementia is a clinical syndrome characterised by acquired impairment in multiple neuropsycologic and behavior domains including memory, language, speech, visuospatial ability, cognition and mood/personality. Dementia produces deficits in perfusion reflecting decreased metabolic needs. Neuroimaging techniques help in determining whether the cognitive symptoms are organic and in which pattern of cognitive loss the patient may evolve. AIM: To differentiate various types of Dementia, based on the regional perfusion abnormalities seen in Brain SPECT and correlate this with Clinical and MRI findings. Material and methods: Patients suffering from memory impairment and memory loss were referred to our department for Brain SPECT as a part of work up for Dementia. They had undergone a detailed clinical examination, psychometry, mini mental status examination (MMSE), memory/cognitive testing and an MRI. Brain SPECT was done after injecting Tc 99m ECD (Ethylene Cysteinate Dimer ) and imaging after 45 minutes. The images obtained were reconstructed in a conventional way. The various patterns of perfusion abnormalities seen in the SPECT images was studied and correlated with MRI and clinical findings. The patients were thus classified as having Multi Infarct Dementia, Alzheimer's disease, Fronto-Temporal Dementia and Mixed variety. Results: Twenty One Patients were included in our study from February 2003 to February 2004. The mean age of the patients was 73 years ( 37 to 81). 15 were males and 6 were females. Out of 21 patients, 12 had Multi Infarct Dementia, 4 had Alzheimer's disease, 1 had Fronto- Temporal Dementia and 4 had Mixed variety. Conclusion: Brain SPECT aids in substantiating the clinical findings and in correlation with MRI helps in distinguishing various types of Dementia and thus has prognostic implications and helps in instituting early appropriate treatment to the patient. In our study, the majority of the patients have Multi Infarct Dementia

  16. Partial volume correction in SPECT reconstruction with OSEM

    Erlandsson, Kjell, E-mail: k.erlandsson@ucl.ac.uk [Institute of Nuclear Medicine, University College London and University College London Hospital, London NW1 2BU (United Kingdom); Thomas, Ben; Dickson, John; Hutton, Brian F. [Institute of Nuclear Medicine, University College London and University College London Hospital, London NW1 2BU (United Kingdom)

    2011-08-21

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

  17. Comparison of SPECT and whole-body planar imaging in radioimmunoscintigraphy with Tc-labeled antibodies

    Lacic, K.; Bokulic, T.; Lukac, J.; Dakovic, N.; Kusic, Z.

    1994-01-01

    The authors of some recent clinical studies suggested 20-24 hours SPECT imaging as a mandatory procedure in radioimmunoscintigraphy with Tc-labeled antibodies. The aim of our study was to compare whole-body (WB) planar imaging versus SPECT as well as 4-6 hours SPECT to 20-24 hours one. For this purpose we analyzed 33 lesions in 12 postsurgical patients with colorectal carcinoma. Each patient received intravenously 0.5-1.0 mg anti-CEA BW 431/26 murine monoclonal IgG-antibodies labeled with Tc-99m (814-1110 MBq). WB and SPECT imaging were performed at 4-6 and 20-24 hours post infusion. 20-24 hours WB scan imaged more 'hot' and less 'cold' lesions than 4-6 hours one. SPECT scan showed significantly more lesions than WB scan. 20-24 hours SPECT scan detected more 'hot' lesions than 4-6 hours SPECT. At the same time the number of 'cold' lesions decreased in 20-24 hours SPECT in comparison to 4-6 hours one. As a conclusion we can say that our results suggest a superiority of SPECT imaging in comparison to WB scan. Except that, in our opinion performing of a 20-24 hours SPECT scan in radioimmunoscintigraphy with Tc-labeled antibodies should be mandatory. (author)

  18. Comparison of SPECT and whole-body planar imaging in radioimmunoscintigraphy with Tc-labeled antibodies

    Lacic, K; Bokulic, T; Lukac, J; Dakovic, N; Kusic, Z [Clinical Hospital Sestre Milosrdnice, Zagreb (Croatia). Dept. of Oncology and Nuclear Medicine

    1994-10-01

    The authors of some recent clinical studies suggested 20-24 hours SPECT imaging as a mandatory procedure in radioimmunoscintigraphy with Tc-labeled antibodies. The aim of our study was to compare whole-body (WB) planar imaging versus SPECT as well as 4-6 hours SPECT to 20-24 hours one. For this purpose we analyzed 33 lesions in 12 postsurgical patients with colorectal carcinoma. Each patient received intravenously 0.5-1.0 mg anti-CEA BW 431/26 murine monoclonal IgG-antibodies labeled with Tc-99m (814-1110 MBq). WB and SPECT imaging were performed at 4-6 and 20-24 hours post infusion. 20-24 hours WB scan imaged more `hot` and less `cold` lesions than 4-6 hours one. SPECT scan showed significantly more lesions than WB scan. 20-24 hours SPECT scan detected more `hot` lesions than 4-6 hours SPECT. At the same time the number of `cold` lesions decreased in 20-24 hours SPECT in comparison to 4-6 hours one. As a conclusion we can say that our results suggest a superiority of SPECT imaging in comparison to WB scan. Except that, in our opinion performing of a 20-24 hours SPECT scan in radioimmunoscintigraphy with Tc-labeled antibodies should be mandatory. (author).

  19. Effect of STA-MCA bypass based on the motor activation SPECT

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

    1999-07-01

    The effect of STA-MCA bypass for ischemic cerebrovascular diseases (CVDs) on pure motor function using motor activation SPECT was evaluated and analyzed, and this effect with the resting cerebral blood flow and reserved capacity was compared. Motor activation SPECT were carried out on 22 cases with STA-MCA bypass for symptomatic ischemic CVDs. All motors activation SPECT using the finger opposition task on the affected side were performed before bypass, at 1 month, and 3 months after the bypass. Visual inspection was used to determine whether the result of the motor activation SPECT was as negative or positive. The activated region was detected anatomically precisely by superimposing the SPECT on the MRI. Before this study, the same examination was performed on normal controls. In controls, 91% showed the activated area on the sensorimotor cortex after the finger opposition tasks. Before bypass, the resting SPECT revealed reduction of cerebral blood flow (CBF) on the affected side in all cases. All cases also showed a disturbed response to acetazolamide (ACZ). Nine cases were positive in the motor activation SPECT. One month after bypass, the resting CBF increased in 11 cases. Seven showed preoperative positive motor activation. Fifteen cases were positive in the motor activation SPECT. Three months after bypass, 20 cases showed improvement in the resting CBF, and 19 cases were positive in the motor activation SPECT. Ten cases were negative in the preoperative motor activation SPECT. At one month after surgery, ACZ activation SPECT was performed in 12 cases. Five showed improvement of the response to ACZ. At 3 months after surgery, 8 of 12 cases treated with ACZ activation SPECT showed improved response to ACZ. In most of the cases, improved response to ACZ could be seen after response to motor activation improved. STA-MCA bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT. (K.H.)

  20. Effect of STA-MCA bypass based on the motor activation SPECT

    Kawaguchi, Shoichiro; Uranishi, Ryunosuke; Sakaki, Toshisuke; Imai, Teruhiko; Ohishi, Hajime

    1999-01-01

    The effect of STA-MCA bypass for ischemic cerebrovascular diseases (CVDs) on pure motor function using motor activation SPECT was evaluated and analyzed, and this effect with the resting cerebral blood flow and reserved capacity was compared. Motor activation SPECT were carried out on 22 cases with STA-MCA bypass for symptomatic ischemic CVDs. All motors activation SPECT using the finger opposition task on the affected side were performed before bypass, at 1 month, and 3 months after the bypass. Visual inspection was used to determine whether the result of the motor activation SPECT was as negative or positive. The activated region was detected anatomically precisely by superimposing the SPECT on the MRI. Before this study, the same examination was performed on normal controls. In controls, 91% showed the activated area on the sensorimotor cortex after the finger opposition tasks. Before bypass, the resting SPECT revealed reduction of cerebral blood flow (CBF) on the affected side in all cases. All cases also showed a disturbed response to acetazolamide (ACZ). Nine cases were positive in the motor activation SPECT. One month after bypass, the resting CBF increased in 11 cases. Seven showed preoperative positive motor activation. Fifteen cases were positive in the motor activation SPECT. Three months after bypass, 20 cases showed improvement in the resting CBF, and 19 cases were positive in the motor activation SPECT. Ten cases were negative in the preoperative motor activation SPECT. At one month after surgery, ACZ activation SPECT was performed in 12 cases. Five showed improvement of the response to ACZ. At 3 months after surgery, 8 of 12 cases treated with ACZ activation SPECT showed improved response to ACZ. In most of the cases, improved response to ACZ could be seen after response to motor activation improved. STA-MCA bypass is useful not only for resting CBF but also for pure motor function based on motor activation SPECT. (K.H.)

  1. Usefulness of isoproterenol stress thallium-201 myocardial single photon emission computed tomography (SPECT)

    Watanabe, Shigeyuki; Ajisaka, Ryuichi; Masuoka, Takeshi

    1990-01-01

    Twenty patients complaining of chest pain were referred for isoproterenol stress thallium-201 myocardial single photon emission computed tomography (ISO-SPECT). The findings were compared with those obtained from isoproterenol stress ECG testing (ISO-ECG) and exercise SPECT (EX-SPECT). Isoproterenol was iv injected in a dose of 0.02 μg/kg/min. The amount was continuously increased until limited by chest pain, ST depression, and/or determined heart rate criteria. The patients were scanned immediately and three hours after giving isoproterenol. Transient hypoperfusion was regarded as myocardial ischemia. Washout rate, obtained from circumferential profile analysis on the short axis SPECT images, was expressed by Bull's eye display. Fifteen patients with angiographically significant stenosis of 75% or greater were diagnosed as having coronary artery disease (CAD). The other five patients had normal coronary artery (NC). In diagnosing CAD, ISO-ECG and ISO-SPECT had a sensitivity of 80% and 92%, respectively. Because the NC group had negative findings for redistribution on ISO-SPECT, the specificy of ISO-SPECT seemed to be high. For multi-vessel disease, redistribution on ISO-SPECT tended to underestimate coronary lesions. The underestimation was, however, corrected by calculating washout rate. For evaluable 11 patients undergoing concurrent EX-SPECT, ISP-SPECT was equivalent or superior to EX-SPECT in diagnostic sensitivity. None of the patients had severe side effects of isoproterenol, except for some having arrhythmia. The results indicated that ISO-SPECT is a safe, high sensitive diagnostic approach that is comparable to Ex-SPECT. (N.K.)

  2. Topodiagnosis in Creutzfeldt-Jakob disease by HMPAO-SPECT. Topodiagnostik der Creutzfeldt-Jakobschen Krankheit durch HMPAO-SPECT

    Heye, N. (Neurologische Klinik, St. Josef Hospital, Bochum Univ. (Germany)); Farahati, J. (Klinik und Poliklinik fuer Nuklearmedizin, Essen Univ. (Gesamthochschule) (Germany)); Heinz, A. (Neurologische Klinik, St. Josef Hospital, Bochum Univ. (Germany)); Buettner, T. (Neurologische Klinik, St. Josef Hospital, Bochum Univ. (Germany)); Przuntek, H. (Neurologische Klinik, St. Josef Hospital, Bochum Univ. (Germany)); Reiners, C. (Klinik und Poliklinik fuer Nuklearmedizin, Essen Univ. (Gesamthochschule) (Germany))

    1993-02-01

    A 80-year old female presented with an early stage of Creutzfeldt-Jakob disease with clinical, neurophysiological and neuropathological findings suggesting a focal involvement of the brain. HMPAO SPECT disclosed asymmetries of regional cerebral perfusion, thus suggesting that it may be a further diagnostic instrument in this disease. (orig.)

  3. Skeletal scintigraphy and SPECT/CT in orthopedic imaging; Knochenszintigrafie und SPECT/CT bei orthopaedischen Fragestellungen

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

    2011-03-15

    Multi-modality imaging with SPECT-CT in orthopaedics combines the excellent sensitivity of scintigraphy with the morphological information of CT as a key for specific interpretation of findings in bone scans. The result is an imaging modality with the clear potential to prove of value even in a competitive setting dominated by MRI, and to significantly add to diagnostic imaging in orthopaedics. SPECT-CT is of great value in the diagnostic evaluation after fractures, and - in contrast to MRI - it is well suited for imaging in patients with osteosyntheses and metallic implants. In sports medicine, SPECT-CT allows for a sensitive and specific detection of osseous stress reactions before morphological changes become detectable by CT or MRI. In patients with osseous pain syndromes, actively evolving degenerative changes as a cause of pain can be identified and accurately localized. Further, particularly prospective diagnostic studies providing comparative data are needed to strengthen the position of nuclear imaging in orthopaedics and sports medicine and to help implementing SPECT/CT in diagnostic algorithms. (orig.)

  4. Machine learning models for the differential diagnosis of vascular parkinsonism and Parkinson's disease using [123I]FP-CIT SPECT

    Huertas-Fernandez, I.; Benitez-Rivero, S.; Jesus, S.; Caceres-Redondo, M.T.; Martin-Rodriguez, J.F.; Carrillo, F.; Garcia-Gomez, F.J.; Marin-Oyaga, V.A.; Lojo, J.A.; Garcia-Solis, D.; Mir, P.

    2015-01-01

    The study's objective was to develop diagnostic predictive models using data from two commonly used [ 123 I]FP-CIT SPECT assessment methods: region-of-interest (ROI) analysis and whole-brain voxel-based analysis. We included retrospectively 80 patients with vascular parkinsonism (VP) and 164 patients with Parkinson's disease (PD) who underwent [ 123 I]FP-CIT SPECT. Nuclear-medicine specialists evaluated the scans and calculated bilateral caudate and putamen [ 123 I]FP-CIT uptake and asymmetry indices using BRASS software. Statistical parametric mapping (SPM) was used to compare the radioligand uptake between the two diseases at the voxel level. Quantitative data from these two methods, together with potential confounding factors for dopamine transporter availability (sex, age, disease duration and severity), were used to build predictive models following a tenfold cross-validation scheme. The performance of logistic regression (LR), linear discriminant analysis and support vector machine (SVM) algorithms for ROI data, and their penalized versions for SPM data (penalized LR, penalized discriminant analysis and SVM), were assessed. Significant differences were found in the ROI analysis after covariate correction between VP and PD patients in [ 123 I]FP-CIT uptake in the more affected side of the putamen and the ipsilateral caudate. Age, disease duration and severity were also found to be informative in feeding the statistical model. SPM localized significant reductions in [ 123 I]FP-CIT uptake in PD with respect to VP in two specular clusters comprising areas corresponding to the left and right striatum. The diagnostic predictive accuracy of the LR model using ROI data was 90.3 % and of the SVM model using SPM data was 90.4 %. The predictive models built with ROI data and SPM data from [ 123 I]FP-CIT SPECT provide great discrimination accuracy between VP and PD. External validation of these methods is necessary to confirm their applicability across centres. (orig.)

  5. Empirical Evidence from Kenya

    FIRST LADY

    2011-01-18

    Jan 18, 2011 ... Empirical results reveal that consumption of sugar in. Kenya varies ... experiences in trade in different regions of the world. Some studies ... To assess the relationship between domestic sugar retail prices and sugar sales in ...

  6. Defying Intuition: Demonstrating the Importance of the Empirical Technique.

    Kohn, Art

    1992-01-01

    Describes a classroom activity featuring a simple stay-switch probability game. Contends that the exercise helps students see the importance of empirically validating beliefs. Includes full instructions for conducting and discussing the exercise. (CFR)

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

    Armstrong, Ian S; Hoffmann, Sandra A

    2016-11-01

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

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

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

    2003-12-21

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

  9. We need more empirical investigations and model validation for a better understanding of crime. Comment on "Statistical physics of crime: A review" by M.R. D'Orsogna and M. Perc

    Ribeiro, Haroldo V.

    2015-03-01

    Since the seminal works of Wilson and Kelling [1] in 1982, the "broken windows theory" seems to have been widely accepted among the criminologists and, in fact, empirical findings actually point out that criminals tend to return to previously visited locations. Crime has always been part of the urban society's agenda and has also attracted the attention of scholars from social sciences ever since. Furthermore, over the past six decades the world has experienced a quick and notorious urbanization process: by the eighties the urban population was about 40% of total population, and today more than half (54%) of the world population is urban [2]. The urbanization has brought us many benefits such as better working opportunities and health care, but has also created several problems such as pollution and a considerable rise in the criminal activities. In this context of urban problems, crime deserves a special attention because there is a huge necessity of empirical and mathematical (modeling) investigations which, apart from the natural academic interest, may find direct implications for the organization of our society by improving political decisions and resource allocation.

  10. Development of advanced industrial SPECT system with 12-gonal diverging-collimator

    Park, Jang Guen; Jung, Sung-Hee; Kim, Jong Bum; Moon, Jinho; Han, Min Cheol; Kim, Chan Hyeong

    2014-01-01

    Industrial single photon emission computed tomography (SPECT) is a promising diagnosis technique to investigate the dynamic behavior of process media. In the present study, a 12-gonal industrial SPECT system was developed using diverging collimators, and its performance was compared with those of hexagonal and 24-gonal systems. Of all of the systems, the 12-gonal type showed the best performance, providing (1) a detection-efficiency map without edge artifacts, (2) the best image resolution, and (3) reconstruction images that correctly furnish multi-source information. Based on the performance of the three different types of configurations, a SPECT system with 12-gonal type configuration was found most suitable for investigating and visualization of flow dynamics in industrial process systems. - highlights: • Industrial SPECT provides the dynamic behavior of multiphase industrial processes. • The present study compared performance of various industrial SPECT systems. • The 12-gonal SPECT system with diverging-collimator provides the best performance

  11. Study of cerebrovascular diseases and SPECT with 99mTc HMPAO

    Collazo de la Maza, A.; Borron Molinos, M.; Barroso, E.

    1997-01-01

    Thirty eight patients with Cerebrovascular disease, that had suffered a Thrombotic brain infraction, demonstrated by Computed electroencephalogram or Brain Mapping (BM) and Computerized Tomography (CT) were investigated with '99' '9' 'm' Tc HM-PAO brain SPECT. Their ages ranged from 37 to 73 years old, 18 males and 20 female. Some of them were followed up with these diagnostic methods. The acquisition and processing of the SPECT studies were donw with a SOPHY DS7 Gamma Camera. The results showed that the global diagnostic sensibility of the SPECT was 79%. The sensibility of SPECT in the Acute stage was 75 %, CT 57% and BM 92%. In Steady stage we found a high positivity of SPECT with 83 %, Ct 66% and BM 66%. In the Recuperation Stage SPECT was 77%, CT 66% and 45%. Some phenomenon like the Luxury Perfusion and Diaschisis were studied and it is possible to found some prognostic relation

  12. Cortical region of interest definition on SPECT brain images using X-ray CT registration

    Tzourio, N.; Sutton, D. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot); Joliot, M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot INSERM, Orsay (France)); Mazoyer, B.M. (Commissariat a l' Energie Atomique, Orsay (France). Service Hospitalier Frederic Joliot Antenne d' Information Medicale, C.H.U. Bichat, Paris (France)); Charlot, V. (Hopital Louis Mourier, Colombes (France). Service de Psychiatrie); Salamon, G. (CHU La Timone, Marseille (France). Service de Neuroradiologie)

    1992-11-01

    We present a method for brain single photon emission computed tomography (SPECT) analysis based on individual registration of anatomical (CT) and functional ([sup 133]Xe regional cerebral blood flow) images and on the definition of three-dimensional functional regions of interest. Registration of CT and SPECT is performed through adjustment of CT-defined cortex limits to the SPECT image. Regions are defined by sectioning a cortical ribbon on the CT images, copied over the SPECT images and pooled through slices to give 3D cortical regions of interest. The proposed method shows good intra- and interobserver reproducibility (regional intraclass correlation coefficient [approx equal]0.98), and good accuracy in terms of repositioning ([approx equal]3.5 mm) as compared to the SPECT image resolution (14 mm). The method should be particularly useful for analysing SPECT studies when variations in brain anatomy (normal or abnormal) must be accounted for. (orig.).

  13. 123I-IMP single photon emission computed tomography (SPECT) study in childhood epilepsy

    Hara, Masafumi; Shimomura, Osamu; Kojima, Akihiro; Izunaga, Hiroshi; Tomiguchi, Seiji; Hirota, Yoshihisa; Taku, Keiichi; Miike, Teruhisa; Takahashi, Mutsumasa

    1990-01-01

    N-isopropyl-p[ 123 I]-iodoamphetamine (IMP) single photon emission computed tomography (SPECT), X-ray computed tomography (X-CT) and magnetic resonance imaging (MRI) were performed in 18 children with idiopathic seizures. In children with idiopathic seizures SPECT identified abnormal lesions in the highest rate (50%) compared with X-CT (11%) and MRI (13%), but the findings of SPECT poorly correlated with the foci on electroencephalography (EEG). Idiopathic epilepsy with abnormal uptake on SPECT was refractory to medical treatments and frequently associated with mental and/or developmental retardation. Perfusion defects identified on SPECT probably influenced the development of the brains in children. IMP SPECT is useful in the diagnosis and medical treatment in children with seizures. (author)

  14. Attenuation correction of myocardial SPECT images with X-ray CT. Effects of registration errors between X-ray CT and SPECT

    Takahashi, Yasuyuki; Murase, Kenya; Mochizuki, Teruhito; Motomura, Nobutoku

    2002-01-01

    Attenuation correction with an X-ray CT image is a new method to correct attenuation on SPECT imaging, but the effect of the registration errors between CT and SPECT images is unclear. In this study, we investigated the effects of the registration errors on myocardial SPECT, analyzing data from a phantom and a human volunteer. Registerion (fusion) of the X-ray CT and SPECT images was done with standard packaged software in three dimensional fashion, by using linked transaxial, coronal and sagittal images. In the phantom study, and X-ray CT image was shifted 1 to 3 pixels on the x, y and z axes, and rotated 6 degrees clockwise. Attenuation correction maps generated from each misaligned X-ray CT image were used to reconstruct misaligned SPECT images of the phantom filled with 201 Tl. In a human volunteer, X-ray CT was acquired in different conditions (during inspiration vs. expiration). CT values were transferred to an attenuation constant by using straight lines; an attenuation constant of 0/cm in the air (CT value=-1,000 HU) and that of 0.150/cm in water (CT value=0 HU). For comparison, attenuation correction with transmission CT (TCT) data and an external γ-ray source ( 99m Tc) was also applied to reconstruct SPECT images. Simulated breast attenuation with a breast attachment, and inferior wall attenuation were properly corrected by means of the attenuation correction map generated from X-ray CT. As pixel shift increased, deviation of the SPECT images increased in misaligned images in the phantom study. In the human study, SPECT images were affected by the scan conditions of the X-ray CT. Attenuation correction of myocardial SPECT with an X-ray CT image is a simple and potentially beneficial method for clinical use, but accurate registration of the X-ray CT to SPECT image is essential for satisfactory attenuation correction. (author)

  15. Mnemonic activation by SPECT; Activation mnesique en TEMP

    Migneco, O.; Darcourt, J.; Benoit, M; Malandain, G.; Thirion, J.P.; Robert, Ph.; Vidal, R.; Desvignes, Ph.; Benoliel, J.; Ayache, N.; Bussiere, F. [Universite de Nice Sophia-Antipolis, INRIA (France)

    1997-12-31

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

  16. SPECT-CT bone scintigraphy in cancer patients

    Sergieva, S; Alexandrova, A.; Nikolova, N.; Dimcheva, M.; Baichev, G.

    2012-01-01

    Full text: Introduction: SPECT-CT study allows the precise correlation between functional and morphological data on the same image. Methods: Whole body bone scan (WBBS) is a diagnostic modality still firmly established as a valuable tool to assess skeleton abnormalities. CT is an imaging method for characterizing destruction of the bone spongy lesions, their consolidation or calcium accumulation. This fact allows differentiation of the osteolytic metastases from the osteosclerotic and mixed lesions and also from degenerative ones. Whole body bone scan followed by SPECT-CT scanning increases the accuracy of the study and potentially accelerates the diagnosis of the patient based on a single imaging session. This is especially important in cancer patients. Results and discussion: After retrospectively review of WBBS and SPECT-CT fused images 141 bone lesions in 89 pts were analyzed The skeletal findings with previously uncertain character were classified as definitely benign, indeterminate or definitely malignant. 1. 47 (33%) of all lesions in 36 pts could be correlated with benign degenerative findings on SPECT-CT images. 5 (3%) lesions in 3 of these pts were indeterminate on the SPECT-CT images. They were localized in the area of articulation parts and corpus of the thoracic vertebra and ribs. After additional MRT examination and 6 months follow-up these changes were considered degenerative: osteopathy changes and presence of spondyloarthrosis and osteochondrosis; compression fractures due to advanced osteoporosis. These pts were with prolonged chormono/chemotherapy; chronic inflammatory disease of the coxofemoral articulation, coxarthrosis, aseptic necrosis of the femoral head and postoperative sacroiliitis; post-traumatic fractures or surgical intervention; hyperplastic degenerative lesions in the skeleton and asymmetrical pelvic bone structures due to M. Paget. 2. 41 (28,1%) single osseous metastatic spots (up to 3 foci) were scanned in 31 pts. 3. 13 (10

  17. Optimization of SPECT calibration for quantification of images applied to dosimetry with iodine-131

    Carvalho, Samira Marques de

    2018-01-01

    SPECT systems calibration plays an essential role in the accuracy of the quantification of images. In this work, in its first stage, an optimized SPECT calibration method was proposed for 131 I studies, considering the partial volume effect (PVE) and the position of the calibration source. In the second stage, the study aimed to investigate the impact of count density and reconstruction parameters on the determination of the calibration factor and the quantification of the image in dosimetry studies, considering the reality of clinical practice in Brazil. In the final step, the study aimed evaluating the influence of several factors in the calibration for absorbed dose calculation using Monte Carlo simulations (MC) GATE code. Calibration was performed by determining a calibration curve (sensitivity versus volume) obtained by applying different thresholds. Then, the calibration factors were determined with an exponential function adjustment. Images were performed with high and low counts densities for several source positions within the simulator. To validate the calibration method, the calibration factors were used for absolute quantification of the total reference activities. The images were reconstructed adopting two approaches of different parameters, usually used in patient images. The methodology developed for the calibration of the tomographic system was easier and faster to implement than other procedures suggested to improve the accuracy of the results. The study also revealed the influence of the location of the calibration source, demonstrating better precision in the absolute quantification considering the location of the target region during the calibration of the system. The study applied in the Brazilian thyroid protocol suggests the revision of the calibration of the SPECT system, including different positions for the reference source, besides acquisitions considering the Signal to Noise Ratio (SNR) of the images. Finally, the doses obtained with the

  18. {sup 67}Ga-SPECT/CT with a hybrid system in the clinical management of lymphoma

    Palumbo, Barbara; Sivolella, Silvio; Palumbo, Renato [University of Perugia, Nuclear Medicine Section, Department of Radiological Sciences, Perugia (Italy); Palumbo, Isabella; Liberati, Anna Marina [University of Perugia, Internal Medicine and Oncology, Department of Clinical and Experimental Medicine, Perugia (Italy)

    2005-09-01

    The purpose of this study was to investigate the added value of co-registered fusion imaging using a hybrid system in patients with lymphoma. Twenty-four lymphoma patients underwent {sup 67}Ga-SPECT/CT using a hybrid tomograph consisting of a dual-head, variable-angle gamma camera and a low-dose X-ray tube. Results were compared with those of SPECT alone. Forty-five lesions were identified by SPECT alone, while 49 were detected by SPECT/CT. Forty out of the 45 lesions observed on SPECT were confirmed as lymphoma, but five were due to other causes (thoracic aorta blood pool activity, sialoadenitis in the submandibular gland, bowel activity, rib fracture and bone marrow activation due to radiotherapy). SPECT/CT identified nine more neoplastic lesions compared with SPECT alone: four areas of radiopharmaceutical accumulation were observed in para-aortic lymph nodes, three in the spleen, one in the liver and one in para-iliac lymph nodes. In five cases, SPECT/CT provided additional anatomical information over SPECT alone. In four patients, four large areas of {sup 67}Ga uptake (one mediastinal, two supraclavicular and one para-aortic) were better characterised; in one subject uptake was localised in the seventh thoracic vertebra only by SPECT/CT. Hybrid imaging provided additional data in 13 patients (54.2%), thus inducing oncologists to reconsider the therapeutic approach in eight subjects (33.2%): unnecessary treatment was avoided in four (16.6%) while therapy was altered in another four (16.6%). SPECT/CT hybrid system is able to provide information not obtained by SPECT alone. It allows the anatomical localisation of lymphoma and physiological radiopharmaceutical uptake, facilitates the diagnosis of tumours located in the abdomen (subdiaphragmatic lesions) and provides information that may cause a change in therapeutic strategy. (orig.)

  19. Recovered neuronal viability revealed by Iodine-123-iomazenil SPECT following traumatic brain injury

    Koizumi, Hiroyasu; Fujisawa, Hirosuke; Kurokawa, Tetsu; Suehiro, Eiichi; Iwanaga, Hideyuki; Nakagawara, Jyoji; Suzuki, Michiyasu

    2010-01-01

    We evaluated cortical damages following traumatic brain injury (TBI) in the acute phase with [123I] iomazenil (IMZ) single photon emission computed tomography (SPECT). In all, 12 patients with cerebral contusion following TBI were recruited. All patients underwent IMZ