<p>There are two Gadolinium-based liver-specific contrast media for Magnetic Resonance Imaging on the market, Gd-BOPTA (MultiHance®, Bracco Imaging, Milan, Italy) and Gd-EOB-DTPA (Primovist®, Bayer Schering Pharma, Berlin, Germany). The aim of this study in two parts was to evaluate the dynamics of biliary, parenchymal and vascular enhancement using these contrast media in healthy subjects. Ten healthy volunteers were examined in a 1.5 T magnetic resonance system using three-dimensional Volumetric Interpolated Breath-Hold (VIBE) sequences for dynamic imaging with both contrast media – at two different occasions – until five hours after injection. The doses given were 0.025 mmol/kg for Gd-EOB-DTPA and 0.1 mmol/kg for Gd-BOPTA. The enhancement over time of the common biliary duct in contrast to the liver parenchyma was analyzed in the first study. This was followed by a study of the image contrasts of the hepatic artery, portal vein and middle hepatic vein versus the liver parenchyma.While Gd-EOB-DTPA gave an earlier and more prolonged enhancement of the biliary duct, Gd-BOPTA achieved higher image contrast for all vessels studied, during the arterial and portal venous phases. There was no significant difference in the maximal enhancement obtained in the liver parenchyma.At the obtained time-points and at the dosage used, the high contrast between the common biliary duct and liver parenchyma had an earlier onset and longer duration for Gd-EOB-DTPA, while Gd-BOPTA achieved higher maximal enhancement of the hepatic artery, portal vein and middle hepatic vein than Gd-EOB-DTPA. Diseases of the liver and biliary system may affect the vasculature, parenchyma, biliary excretion or a combination of these. The clinical context regarding the relative importance of vascular, hepatic parenchymal and biliary processes should determine the choice of contrast media for each patient and examination.</p><p> </p>

Cognitive diagnostic assessment (CDA) is a testing format that employs a cognitive model to, first, develop or identify items measuring specific knowledge and skills and, then, use this model to direct psychometric analyses of examinees item response patterns to promote diagnostic inferences. The attribute hierarchy method (AHM, Leighton, Gierl, & Hunka, 2004) is a psychometric procedure for classifying examinees test item responses into a set of structured attribute patterns associated with different components from a cognitive model of task performance. Attribute reliability is a fundamental concept in cognitive diagnostic assessment because it refers to the consistency of the decisions made in diagnostic test about examinees mastery of specific attributes. In this study, an adapted attribute-based reliability estimate was evaluated in comparison of the standard Cronbachs alpha using simulated data. Factors expected to influence attribute reliability estimates, including test length, sample size, model structure, and model-data fit level, were also studied. Results of this study revealed that the performances of the two attribute-based reliability estimation indices are comparable; however, the adapted index is conceptually more meaningful. Test length, model structure, and model-data fit were shown to impact attribute reliability estimates differentially. Implications to researchers and practitioners were given based on the simulation results. Limitations of the present study and future directions were also discussed. / Measurement, Evaluation, and Cognition

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

No description available.

Thèse d'exercice : Pharmacie : Nantes : 2003. Mémoire DES : Biologie médicale : Nantes : 2003. / Thèse : 2003NANT014P. Bibliogr. f. 152-157.

Thèse de doctorat : Automatique et traitement du signal : INPL : 2007. / Titre provenant de l'écran-titre.

Reproduction de : Thèse de doctorat : informatiques : Grenoble, INPG : 1989. / Titre provenant de l'écran-titre. Bibliogr. p. 145-149.

Thèse de doctorat : Recherche clinique, innovation technologique, santé publique : Strasbourg 1 : 2008. / Titre provenant de l'écran-titre. Bibliogr. 10 p.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006. / Bibliography: p. 160-174. Also available on the World Wide Web.

Reproduction de : Thèse d'exercice : Médecine vétérinaire : Toulouse 3 : 2009. / Titre provenant de l'écran titre. Bibliogr. f. 43-45.