Purpose: To calculate organ S values (mGy∕Bq-s) and effective doses per time-integrated activity (mSv∕Bq-s) for pediatric and adult family members exposed to an adult male or female patient treated with I-131 using a series of hybrid computational phantoms coupled with a Monte Carlo radiation transport technique.
Methods: A series of pediatric and adult hybrid computational phantoms were employed in the study. Three different exposure scenarios were considered: (1) standing face-to-face exposures between an adult patient and pediatric or adult family phantoms at five different separation distances; (2) an adult female patient holding her newborn child, and (3) a 1-yr-old child standing on the lap of an adult female patient.
Diagnosing bone infection in its acute early stage is of utmost clinical importance as the failure to do so results in a therapeutically recalcitrant chronic infection that can only be resolved with extensive surgical intervention, the end result often being a structurally unstable defect requiring reconstructive procedures. [(18)F]-FDG-PET has been extensively investigated for this purpose, but the results have been mixed in that, while highly sensitive, its specificity with respect to distinguishing between acute infection and sterile inflammatory processes, including normal recuperative post-surgical healing, is limited. This study investigated the possibility that alternative means of acquiring and analyzing FDG-PET data could be used to overcome this lack of specificity without an unacceptable loss of sensitivity.
View Article and Find Full Text PDFMultiple myeloma (MM) is an incurable plasma cell malignancy of the bone marrow. MM has 3 components: diffuse marrow infiltration, focal bone lesions, and soft-tissue (extramedullary) disease. The hallmark biomarker in blood or urine is a monoclonal immunoglobulin, the monoclonal protein.
View Article and Find Full Text PDFEur J Nucl Med Mol Imaging
March 2011
Purpose: PET perfusion imaging with (82)Rb is a powerful tool for evaluating coronary artery disease (CAD). Little is known about normal patterns or significance of (82)Rb lung distribution in the setting of heart disease. Herein, PET/CT hybrid imaging was used to obtain insights into the frequency and potential radiomorphologic correlates of altered (82)Rb distribution.
View Article and Find Full Text PDFJ Exp Psychol Hum Percept Perform
February 2011
The relationship between interference and facilitation effects in the Stroop task is poorly understood yet central to its implications. At question is the modal view that they arise from a single mechanism-the congruency of color and word. Two developments have challenged that view: (a) the belief that facilitation effects are fractionally small compared with interference effects, or nonexistent altogether; and (b) the finding that interference and facilitation effects are inversely correlated.
View Article and Find Full Text PDFBackground: Larval mosquito habitats of potential malaria vectors and related species of Anopheles from three provinces (Gyeonggi, Gyeongsangbuk, Chungcheongbuk Provinces) of the Republic of Korea were surveyed in 2007. This study aimed to determine the species composition, seasonal occurrence and distributions of Anopheles mosquitoes. Satellite derived normalized difference vegetation index data (NDVI) was also used to study the seasonal abundance patterns of Anopheles mosquitoes.
View Article and Find Full Text PDFF18-fluorodeoxyglucose positron emission tomography (FDG-PET) is a powerful tool to investigate the role of tumor metabolic activity and its suppression by therapy for cancer survival. As part of Total Therapy 3 for newly diagnosed multiple myeloma, metastatic bone survey, magnetic resonance imaging, and FDG-PET scanning were evaluated in 239 untreated patients. All 3 imaging techniques showed correlations with prognostically relevant baseline parameters: the number of focal lesions (FLs), especially when FDG-avid by PET-computed tomography, was positively linked to high levels of beta-2-microglobulin, C-reactive protein, and lactate dehydrogenase; among gene expression profiling parameters, high-risk and proliferation-related parameters were positively and low-bone-disease molecular subtype inversely correlated with FL.
View Article and Find Full Text PDFPurpose: Myocardial perfusion imaging with (82)Rb PET allows for ECG-gated studies to be obtained early after radiotracer injection, capturing ventricular function close to peak pharmacologic action of dipyridamole. This is different from gated SPECT and may potentially provide additional diagnostic information. We sought to identify potential correlates of the PET-derived ejection fraction response to vasodilator stress.
View Article and Find Full Text PDFPurpose: Misalignment of low-dose-CT used for attenuation correction (AC) may cause artifacts in cardiac-PET-CT. The aim was to evaluate incidence and severity of misalignment and its quantitative effects on regional myocardial (82)Rb-distribution.
Methods: Rest/dipyridamole (82)Rb-perfusion-PET-CT studies of 92 consecutive patients were analyzed for misalignment.
Unlabelled: The accuracy of myocardial perfusion SPECT improves with attenuation correction. Algorithms for attenuation correction in hybrid SPECT/CT systems have the potential for misregistration of emission and transmission scans because CT and SPECT are obtained sequentially. Misregistration will influence regional tracer distribution and may reduce diagnostic accuracy.
View Article and Find Full Text PDFAltering voltage-gated ion channel currents, by changing channel number or voltage-dependent kinetics, regulates the propagation of action potentials along the plasma membrane of individual cells and from one cell to its neighbors. Functional increases in the number of cardiac sodium channels (Na(V)1.5) at the myocardial sarcolemma are accomplished by the regulation of caveolae by beta adrenergically stimulated G-proteins.
View Article and Find Full Text PDFWe investigated the parameters of involuntary word reading in the Stroop task in 7 experiments. Experiments 1-4 varied response modality and the presence of congruent word trials in a test of the claim that presenting a Stroop color word with only one letter in the target color eliminates the Stroop effect. Experiments 5 and 6 addressed the roles of spatial attention and orthographic processing as possible mechanisms behind the reduction of Stroop effects with the single-letter format.
View Article and Find Full Text PDFIn Stroop color naming, color targets were accompanied by a color word or a color word plus a neutral word that reduces or "dilutes" the Stroop effect. Abrupt-onset cues called the focus of attention to one stimulus or another. Cuing influenced the size of the Stroop effect but never eliminated it.
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