ABSTRACT
OBJECTIVE: Amyloid imaging clinically is usually reported as positive or negative, and the role of amyloid topography has not been studied before. To evaluate in a clinical setting the regional distribution patterns of C-Pittsburgh compound B (C-PIB) and the fluorine-18-fluorodeoxyglucose (F-FDG) uptake in patients with mild cognitive impairment (MCI), we designed this study. METHODS: We studied 81 consecutive MCI patients, 64 amnestic (A-MCI) and 17 nonamnestic (NA-MCI) by C-PIB and F-FDG PET/computed tomography, by visual analysis. PIB retention was classified according to the regional distribution into the following patterns: A (frontal, lateral temporal, basal ganglia and anterior cingulate) and B (global retention). F-FDG images were considered positive only if temporoparietal hypometabolism consistent with Alzheimer's disease was observed. RESULTS: In 42 of the 64 A-MCI, C-PIB was positive. Twelve of the 42 positive A-MCI showed an A-pattern, all F-FDG negative, and 30 a B-pattern, 10 F-FDG positive and 20 F-FDG negative. Of the 17 NA-MCI, C-PIB was positive in three and F-FDG was positive in one. The different proportion of C-PIB positivity in A-MCI and NA-MCI was highly significant (P<0.001). CONCLUSION: Two different C-PIB patterns were observed in MCI patients and for the A-pattern, glucose hypometabolism consistent with Alzheimer's disease is highly unlikely. These findings may contribute towards a better selection of patients for future potential treatments and also to optimize the use of F-FDG-PET/CT.
Subject(s)
Cognitive Dysfunction/diagnostic imaging , Cognitive Dysfunction/metabolism , Glucose/metabolism , Positron Emission Tomography Computed Tomography/methods , Adult , Aged , Aged, 80 and over , Alzheimer Disease/complications , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/metabolism , Amnesia/complications , Amnesia/diagnostic imaging , Amnesia/metabolism , Amyloid beta-Peptides/metabolism , Aniline Compounds , Brain/diagnostic imaging , Brain/metabolism , Carbon Radioisotopes , Cognitive Dysfunction/complications , Female , Fluorodeoxyglucose F18 , Humans , Male , Middle Aged , Radiopharmaceuticals , ThiazolesABSTRACT
18F-Fluoro-2-deoxy-D-glucose (F-FDG) PET/CT acquisition is generally performed 60 min after injection. The normal biodistribution pattern of F-FDG includes activity in the aortic territory due to blood pool activity, which could interfere in the diagnosis of aortic diseases by overlapping the wall uptake. The aim of the study was to evaluate the change over time of F-FDG uptake by the aortic wall and the activity in the lumen in a control population and to establish normal reference values. This prospective study included 15 control patients (mean age: 58.2 years). PET/CT was acquired 60 min (early scan) and 180 min (delayed scan) after an F-FDG injection at a dose of 7 MBq/kg. A visual and semiquantitative analysis of the F-FDG aortic wall uptake was carried out, and lumen activity and the aortic wall to lumen ratio [target-to-background ratio (TBR)] were determined. In the visual analysis all patients showed F-FDG activity at the aortic territory at 60 and 180 min. The pattern of uptake at 60 min was diffuse in all 15 patients (100%), without delineation of the aortic wall uptake; however, at 180 min the uptake pattern of the aortic wall changed to lineal in 14 patients (93.3%). The aortic wall maximum standardized uptake value decreased from 2.07±0.34 to 1.7±0.46 during the delayed acquisition (P=0.0279) and the lumen maximum standardized uptake value decreased highly significantly (1.99±0.35 vs. 1.36±0.32, P=0.0001). Therefore, TBR also increased highly significantly from 1.04±0.06 to 1.25±0.16 (P<0.0001). The high decrease in blood pool activity from 60 to 180 min provides a better delineation of the aortic wall uptake, which corresponds to the normal pattern at that time. The TBR increased significantly at 180 min, and 1.25±0.16 is suggested as the threshold for diagnostic purposes, especially for the diagnosis of vasculitis.
Subject(s)
Aorta/diagnostic imaging , Aortography/methods , Fluorodeoxyglucose F18 , Image Processing, Computer-Assisted/methods , Multimodal Imaging/methods , Positron-Emission Tomography/methods , Tomography, X-Ray Computed/methods , Aorta/metabolism , Aortography/standards , Biological Transport , Female , Fluorodeoxyglucose F18/metabolism , Humans , Image Processing, Computer-Assisted/standards , Male , Middle Aged , Multimodal Imaging/standards , Positron-Emission Tomography/standards , Reference Values , Time Factors , Tomography, X-Ray Computed/standardsABSTRACT
FUNDAMENTO: A través de la televisión se pueden reforzar los estilos de vida que afectan a la salud. En los últimos años han proliferado series juveniles con gran audiencia entre los adolescentes sobre la influencia de las serie s televisivas en sus estilos de vida. DISEÑO: Se trata de un estudio cualitativo, en el que se ha empleado la técnica de los grupos focales, realizado en marzo del 2000 con la participación de 32 adolescentes de dos poblaciones de la comarca de la Axarquía en Málaga. VARIABLES: Se analizó la influencia de las series televisivas sobre: drogas , sexualidad, sexismo, alimentación, ejercicio físico, violencia y conducción de vehículos. RESULTADOS: Los adolescentes de estos grupos piensan que las series tienen influencia en sus vidas. Analizaron las ideas de violencia, que lesatraen, los contínuos cambios de parejas en algunas series, la publicidad de bebida s alcohólicas, la ausencia del deporte, el "machismo" o la presencia de tabaco. CONCLUSIONES: Se propone la intervención de padres y madres, profesores y enfermeras para lograr un espíritu crítico en los chicos ante la avalancha d e mensajes televisivos y reivindicar la incorporación de mensajes de educación para la salud en las tramas de las series (AU)
