Jaroslav Ptáček

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The aims of this study were to investigate the frequency of computed tomography (CT) examinations for paediatric patients below 15 y of age in 128 CT facilities in 28 developing countries of Africa, Asia and Eastern Europe and to assess the magnitude of CT doses. Radiation dose data were available from 101 CT facilities in 19 countries. The dose assessment(More)
The purpose of this prospective study at 73 facilities in 18 countries in Africa, Asia and Eastern Europe was to investigate if the CT doses to adult patients in developing countries are higher than international standards. The dose assessment was performed in terms of weighted computed tomography dose index (CTDIw) and dose length product (DLP) for chest,(More)
PURPOSE The aim of this work was to introduce a new algorithm for image reconstruction in bone SPECT and to compare its performances with a commercially available standard OSEM and resolution recovery (RR) reconstruction. MATERIALS AND METHODS The algorithm was built applying the Lucy-Richardson deconvolution adn logarithmic image processing to the(More)
18F-FDG PET/CT imaging is useful in patients with fever of unknown origin and can detect giant cell arteritis in extracranial large arteries. However, it is usually assumed that temporal arteries cannot be visualized with a PET/CT scanner due to their small diameter. Three patients with clinical symptoms of temporal arteritis were examined using a standard(More)
Two cases of successful detection of inflammatory foci using Tc-99m exametazime (HMPAO)-labeled leukocyte scintigraphy in premature infants were reported. Necrotizing enterocolitis was detected in a child with a body weight of 1.6 kg. Scintigraphy confirmed a neonatal osteomyelitis in the distal part of the leg of another patient weighing 2.2 kg. These 2(More)
BACKGROUND AND PURPOSE The aim of this study was to evaluate three different techniques used for stereotactic positron emission tomography (PET) image definition: (1) PET imaging with external stereotactic radioactive markers, (2) PET imaging without external stereotactic markers and subsequent coregistration with stereotactically defined imaging modality(More)
INTRODUCTION The aim of this study was to determine the optimal image matrix and half-width of the Gaussian filter after iterative reconstruction of the PET image with point-spread function (PSF) and time-of-flight (TOF) correction, based on measuring the recovery coefficient (RC) curves. The measured RC curves were compared to those from an older system(More)
A statistics-based approach to comparison of planar scintigraphic images is introduced to provide additional information to subtraction method. The proposed procedure leads to parametric images with better noise properties allowing subsequent statistical analysis. An example of an application of the technique is given using parathyroid scintigrams. The(More)
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