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Showing 1 to 10 of 10 for “"OSEM"”.
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Development of stopping rule methods for the MLEM and OSEM algorithms used in PET image reconstruction
… of stopping rule methods for the MLEM and OSEM algorithms used in image reconstruction positron emission tomography (PET). The development of the stopping rules is based on the study of the properties of both algorithms. Analyzing their mathematical expressions, it can be observed that the …
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Applications of cone beam computed tomography in radiotherapy treatment planning.
… the Ordered Subsets Expectation Maximisation (OSEM) package used in this study is intended for fan-beam geometry, only the slices from the central plane of cone-beam were chosen. The projections were corrected for distance-dependent resolution and centre of rotation offset. When the number of …
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Ansätze zur Optimierung der Datenverarbeitung in der Positronen Emissions Tomographie
… 18-F-FDG die Tatsache aus, <br>dass der Glukosemetabolismus von Tumorzellen gegenüber dem von normalen <br>Zellen deutlich erhöht ist und FDG verstärkt angereichert wird. Zur <br>Bestimmung des Ausmaßes der Metastasierung von Tumoren erhalten die <br>Patienten in der Regel Aufnahmen des …
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Investigation of Quatitative Image Features From Pretreatment Ct and Fdg-Pet Scans In Stage Iii Nsclc Patients Undergoing Defintive Radiation Therapy
… when using similar reconstructions (e.g., 3D OSEM) (CCC = 0.93). The two FDG-PET features found to be prognostic were also able to isolate sub-cohorts of patients that demonstrated survival differences based on radiation dose.</p> <p>QIFs were found to provide additional prognostic information …
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Simultaneous ⁹⁹m̳Tc-MDP/¹²³I-MIBG imaging of neuroblastoma using SPECT-CT
… ordered-subset expectation maximization (MC-JOSEM) reconstruction algorithm has been been developed for simultaneous ⁹⁹m̳Tc/¹²³ imaging by Ouyang, El Fakhri, and Moore (2007). MC-JOSEM incorporates attenuation into a full system matrix to greatly improve image accuracy and include both primary …
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Development of Spect and Ct Tomographic Image Reconstruction
… the ordered-subsets expectation maximization (OSEM) algorithm. We also examined how rotational and translational sampling affects reconstructed image quality when constrained by total injected dose and scan time. We conclude the following: When reconstructing noiseless datasets, varying the …
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Evaluation of yttrium-90 positron emission tomography dosimetry
… The phantom study determined Siemens® OSEM-PSF algorithm, known as TrueX, with 2 iterations and 14 subsets had the optimal balance of noise and accuracy. Using this reconstruction algorithm, the PET images were found to accurately measure activity and calculated dose within 10% when …
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Reconstrucción de imágenes de tomografía por emisión de positrones de alta resolución mediante métodos estadísticos
… de reconstrucción desarrollado es de tipo OSEM (EM con subconjuntos ordenados) y se puede regularizar mediante un esquema MRP (Median root prior) de tipo generalizado. El esquema propuesto se completa con el método MXE (minimum cross entropy) con regularización mediante imagen anatómica …
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IMPROVING RESOLUTION IN WRIST SPECT WITH CONVERGING COLLIMATORS AND CT ANATOMICAL PRIORS
Wrist injuries account for over 750 000 visits to the hospital each year. Better imaging techniques are required to properly diagnose these injuries. Planar nuclear medicine offers a high sensitivity for fracture detection, but low specificity. Improving resolution could lead to better specificity. …
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On-board Robotic Multi-pinhole SPECT System for Region-of-interest (ROI) Imaging
… SPECT. The SPECT images were reconstructed using OSEM with up to 6 iterations. Images were evaluated as a function of gate by profiles, noise versus bias curves, and a numerical observer performing a forced-choice localization task. Even for the 20 mm tumor, the 49-pinhole imaging ROI was found …