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Research Interests: Engineering, Computer Science, Algorithms, Image Processing, Medical Imaging, and 15 moreComputed Tomography, Magnetic Resonance Imaging, Medicine, Image Quality, Humans, Image Reconstruction, Attenuation Correction, Magnetic Resonance, Artifacts, Ct Scan, Image Enhancement, Attenuation, Iterative Reconstruction, maximum likelihood estimate, and imaging system
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The expression status of human epidermal growth factor receptor 2 (HER2) in cancer predicts response to HER2-targeted therapy. Therefore, its accurate determination is of utmost importance. In recent years, there has been an increase in... more
The expression status of human epidermal growth factor receptor 2 (HER2) in cancer predicts response to HER2-targeted therapy. Therefore, its accurate determination is of utmost importance. In recent years, there has been an increase in research on noninvasive techniques for molecular imaging, as this method offers the advantages of a more accurate determination of HER2 status without the need for multiple biopsies. The technetium-labeled single-domain antibody RAD201, previously known as 99mTc-NM-02, has been shown to be safe for use in breast cancer imaging with reasonable radiation doses, favorable biodistribution, and imaging characteristics. Methods A total of six HER2-positive, heavily pretreated patients with different cancer types aged between 42 and 69 years (5 women and 1 man; the median age of 55.5) have been examined. In six of seven scans, the patients were administered 500 ml of Gelofusine® solution (40 mg/ml) for radiation protection before the tracer injection (434 ±...
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Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur dynamischen Zuordnung mobiler Endgerate (E1, En) zu einer von mehreren Basisstationen (B1, B2, Bm) in einem digitalen Hausnetzwerk. Das Verfahren ist dadurch gekennzeichnet,... more
Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur dynamischen Zuordnung mobiler Endgerate (E1, En) zu einer von mehreren Basisstationen (B1, B2, Bm) in einem digitalen Hausnetzwerk. Das Verfahren ist dadurch gekennzeichnet, dass es verteilt auf jeder Basisstation (B1, B2, Bm) autonom ausgefuhrt wird. Die Basisstationen messen zu diesem Zweck die Verbindungsstarken zwischen ihnen und den in ihrer Reichweite befindlichen Endgeraten (E1, En) und teilen die so gewonnenen Messwerte in einer Rundsendung allen anderen Basisstationen mit. Alle Basisstationen konnen dann aufgrund der gewonnenen globalen Informationen nach einem vorgegebenen Algorithmus, zum Beispiel einer Zuordnung des Endgerates zur grosten Verbindungsstarke unter Berucksichtigung einer Hysterese und eines Schwellwertes, eine Zuordnung von Endgeraten zu Basisstationen berechnen. Sofern die neu berechnete Zuordnung sich gegenuber der bestehenden Zuordnung geandert hat, sendet eine Basisstation ein handover-Komman...
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Quantitative accuracy and thus diagnostic precision in Emission Tomography is impaired by the inherent random characteristics of the data acquisition leading to statistical image noise. Edge preserving spatial variation regularized... more
Quantitative accuracy and thus diagnostic precision in Emission Tomography is impaired by the inherent random characteristics of the data acquisition leading to statistical image noise. Edge preserving spatial variation regularized iterative image reconstruction approaches require case-specific control parameter adaptation for optimized contrast-vs-noise tradeoff. For MLEM reconstruction, we propose and evaluate iRDF which automatically adapts RDP edge preservation parameters according to local image noise and PET data characteristics. In order to distinguish between clustered noise spots and small tumors, we introduce hot-spot artifact correction. The proposed method was evaluated using NEMA IQ phantom data as well as clinical patient data. After initial iRDF base parameter tuning, results showed that iRDF maintained similar image quality regardless of statistics without requiring manual parameter tuning, in contrast to e.g. RDP. With NEMA-IQ phantom data, local image variance was ...
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L'invention concerne un systeme de detecteur qui fournit des informations d'imagerie au bord d'un scintillateur. Le dispositif de detecteur fournit des informations completes et une resolution de signal amelioree. Des SiPM... more
L'invention concerne un systeme de detecteur qui fournit des informations d'imagerie au bord d'un scintillateur. Le dispositif de detecteur fournit des informations completes et une resolution de signal amelioree. Des SiPM peuvent etre utilises a la place des PMT pour assurer la couverture geometrique du scintillateur et une resolution spatiale ameliorees. Avec ces systemes de detecteur, la resolution spatiale peut etre inferieure a 2 mm. En outre, l'epaisseur globale du detecteur peut etre sensiblement reduite, et la profondeur de la resolution d'interaction se trouve egalement amelioree.
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... WIECZOREK AND GOEDICKE: ANALYTICAL MODEL FOR SPECT DETECTOR CONCEPTS ... D. Efficiency-Resolution Trade-Off There is a general relation between the efficiency and the spa-tial resolution that can be accomplished by use of a specific... more
... WIECZOREK AND GOEDICKE: ANALYTICAL MODEL FOR SPECT DETECTOR CONCEPTS ... D. Efficiency-Resolution Trade-Off There is a general relation between the efficiency and the spa-tial resolution that can be accomplished by use of a specific de-tector, showing that ...
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Research Interests: Engineering, Computer Science, Algorithms, Image Processing, Medical Imaging, and 15 moreComputed Tomography, Magnetic Resonance Imaging, Medicine, Image Quality, Humans, Image Reconstruction, Attenuation Correction, Magnetic Resonance, Artifacts, Ct Scan, Image Enhancement, Attenuation, Iterative Reconstruction, maximum likelihood estimate, and imaging system
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Three-dimensional dosimetry based on quantitative SPECT/CT has potential advantages over planar approaches, but may be impractical due to acquisition durations. We combine one SPECT/CT with improved quantification of multiple planar... more
Three-dimensional dosimetry based on quantitative SPECT/CT has potential advantages over planar approaches, but may be impractical due to acquisition durations. We combine one SPECT/CT with improved quantification of multiple planar scintigraphies to shorten acquisitions. A hybrid 2-D/3-D quantification technique is proposed, using SPECT/CT information for robust planar image quantification and creating virtual SPECTs out of conjugate-view planar scintigraphies; these are included in a 3-D absorbed dose calculation. A projection model simulates photon attenuation and scatter as well as camera and collimator effects. Planar and SPECT calibration techniques are described, offering multiple pathways of deriving calibration factors for hybrid quantification. Model, phantom and patient data are used to validate the approach on a per-organ basis, and the similarity of real and virtual SPECTs, and of planar images and virtual SPECT projections, is assessed using linear regression analysis. Organ overlap, background activity and organ geometry are accounted for in the algorithm. Hybrid time-activity curves yield the same information as those derived from a conventional SPECT evaluation. Where correct values are known, hybrid quantification errors are less than 16% for all but two compartments (SPECT/CT 23%). Under partial volume effects, hybrid quantification can provide more robust results than SPECT/CT. The mean correlation coefficient of 3-D data is 0.962 (2-D 0.934). As a consequence of good activity quantification performance, good agreement of absorbed dose estimates and dose-volume histograms with reference results is achieved. The proposed activity quantification method for 2-D scintigraphies can speed up SPECT/CT-based 3-D dosimetry without losing accuracy.
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Abstract. Quantitative SPECT as well as simultaneous acquisition of multiple isotopes with SPECT in the clinical field, although clinically interesting, are still limited by reconstruction artifacts and computing power. As a considerable... more
Abstract. Quantitative SPECT as well as simultaneous acquisition of multiple isotopes with SPECT in the clinical field, although clinically interesting, are still limited by reconstruction artifacts and computing power. As a considerable step in this direction, we have implemented an efficient reconstructor with variance reduced Monte-Carlo-simulation in the forward and/or backward projection of an OS-EM iteration. Apart from a quantitatively accurate scatter estimation the integrated MC simulation allows us to include all effects that are relevant for the multiple isotope task. The reconstruction problem is explicitly formulated as a combined maximum-likelihood estimation for all unknowns in one step and implemented efficiently on the basis of the OS-EM algorithm using the Effective Scatter Source approach. The algorithm has been evaluated on simulated as well as measured phantom data. Two isotopes (Tc99m, Tl201) were tested on the voxelized NCAT phantom and evaluated quantitativel...
Quantitative SPECT as well as simultaneous acquisition of multiple isotopes with SPECT in the clinical field, although clinically interesting, are still limited by reconstruction artifacts and computing power. As a considerable step in... more
Quantitative SPECT as well as simultaneous acquisition of multiple isotopes with SPECT in the clinical field, although clinically interesting, are still limited by reconstruction artifacts and computing power. As a considerable step in this direction, we have implemented an efficient reconstructor with variance reduced Monte-Carlo-simulation in the forward and/or backward projection of an OS-EM iteration. Apart from a quantitatively accurate scatter estimation the integrated MC simulation allows us to include all effects that are relevant for the multiple isotope task. The reconstruction problem is explicitly formulated as a combined maximum-likelihood estimation for all unknowns in one step and implemented efficiently on the basis of the OS-EM algorithm using the Effective Scatter Source approach. The algorithm has been evaluated on simulated as well as measured phantom data. Two isotopes (Tc99m, Tl201) were tested on the voxelized NCAT phantom and evaluated quantitatively. In addi...
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Quantitative SPECT imaging of In is of growing importance in nuclear medicine applications like patient-specific radionuclide dosimetry. In this study, the quality of a Monte-Carlo based model of the imaging chain from nuclear decay to... more
Quantitative SPECT imaging of In is of growing importance in nuclear medicine applications like patient-specific radionuclide dosimetry. In this study, the quality of a Monte-Carlo based model of the imaging chain from nuclear decay to detection in a gamma camera is investigated. Important characteristics like the camera point spread function (PSF), the phantom attenuation and scatter effects are compared between simulation and experiment. The model shows a good agreement to the actual measurements and allows for further use in the development of quantitative SPECT reconstruction which will be mandatory for future oncology.
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Respiratory motion, which typically cannot simply be suspended during PET image acquisition, affects lesions' detection and quantitative accuracy inside or in close vicinity to the lungs. Some motion compensation techniques address... more
Respiratory motion, which typically cannot simply be suspended during PET image acquisition, affects lesions' detection and quantitative accuracy inside or in close vicinity to the lungs. Some motion compensation techniques address this issue via pre-sorting ("binning") of the acquired PET data into a set of temporal gates, where each gate is assumed to be minimally affected by respiratory motion. Tracking respiratory motion is typically realized using dedicated hardware (e.g. using respiratory belts and digital cameras). Extracting respiratory signalsdirectly from the acquired PET data simplifies the clinical workflow as it avoids to handle additional signal measurement equipment. We introduce a new data-driven method "Combined Local Motion Detection" (CLMD). It uses the Time-of-Flight (TOF) information provided by state-of-the-art PET scanners in order to enable real-time respiratory signal extraction without additional hardware resources. CLMD applies...
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... Andreas Goedicke, Herfried Wieczorek, Henrik Botterweck, Wolfgang Eckenbach, Ling Shao, Member, IEEE, Micheal Petrillo, Member, IEEE, Jinghan Ye ... We tried FBP with Ram-Lak, Shepp-Logan, Cosine, Hamming or Hann filter, and... more
... Andreas Goedicke, Herfried Wieczorek, Henrik Botterweck, Wolfgang Eckenbach, Ling Shao, Member, IEEE, Micheal Petrillo, Member, IEEE, Jinghan Ye ... We tried FBP with Ram-Lak, Shepp-Logan, Cosine, Hamming or Hann filter, and statistical methods, Maximum Likelihood ...
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Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in (18)F-FDOPA brain-PET, with a special focus on... more
Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in (18)F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches. Four PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated (18)F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPML). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (Ki) was assessed. Main differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPML (PUT < 30%) and highest for FSL (PUT > 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of Ki for CN and PUT was clearly improved by PVC. The regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical structure of interest. Caution is recommended in subsequent interpretation of Ki values. The possible different change of activity concentrations due to PVC in both target and reference regions tends to alter the corresponding TACs, introducing bias to Ki determination. The accuracy of quantitative analysis was improved by PVC but at the expense of precision reduction, indicating the potential impropriety of applying the presented framework for group comparison studies.
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... Andreas Goedicke, Herfried Wieczorek, Henrik Botterweck, Wolfgang Eckenbach, Ling Shao, Member, IEEE, Micheal Petrillo, Member, IEEE, Jinghan Ye ... We tried FBP with Ram-Lak, Shepp-Logan, Cosine, Hamming or Hann filter, and... more
... Andreas Goedicke, Herfried Wieczorek, Henrik Botterweck, Wolfgang Eckenbach, Ling Shao, Member, IEEE, Micheal Petrillo, Member, IEEE, Jinghan Ye ... We tried FBP with Ram-Lak, Shepp-Logan, Cosine, Hamming or Hann filter, and statistical methods, Maximum Likelihood ...