45 Thus, the fundamental measurement of decline from premorbid levels may be possible with functional neuroimaging. If confirmed in future studies, this capability may overcome all factors currently confounding clinical diagnosis: regardless of the patient’s language skills, educational background, or age, we may be able to define how much their brain function has declined from what, was, for each individual patient,

normal levels. This decline may well be a better predictor of progression or medication response than current clinical symptomatology. Conclusion We have reviewed the recent, literature on neuroimaging diagnosis of AD. As in any conclusions based on a literature review or meta-analysis, Inhibitors,research,lifescience,medical the possibility of a publication bias must be considered. It is possible that unsuccessful imaging studies (ie, those reporting low diagnostic accuracy) are not published, due to reservations by authors or editors. It is also possible that, imaging papers tend to be submitted to specific journals, with Inhibitors,research,lifescience,medical publication Selleck Camptothecin policies different, from those of other, more purely clinical, journals. Finally, some papers may have been published in journals not indexed by Medline. Thus, further

consideration of our conclusions must be bound by the nature of the material and its Inhibitors,research,lifescience,medical limitations. Our interpretation of this literature offers two main conclusions. First, that the variability Inhibitors,research,lifescience,medical of diagnostic accuracy is considerably lower than that of clinical diagnosis. In particular, while neuroimaging cannot improve the best clinical diagnosis findings (which are close to 100%), the lowest accuracies

reported for imaging are considerably higher than the lowest accuracies reported for clinical diagnosis (Figure 2) . Thus, imaging can serve to significantly improve the lower bounds of diagnostic accuracy. Second, we propose that imaging adds unique information to the diagnostic process that may not be available by any other methods. This information may be especially pertinent in certain clinical situations, discussed above. Both clinical Inhibitors,research,lifescience,medical criteria and imaging procedures are continuously evolving, and they need to continue to be used together for further evaluation. While MRI appears to be superior overall in this material (Figure 2), the current work was not designed to compare Oxymatrine the relative merits of various imaging modalities. Studies that employ more than one imaging modality are rare but. useful, and more need to be conducted. For example, De Santi et al41 compared PET-derived glucose metabolism and MRI-derived volumetric measures in temporal lobe structures. They concluded, overall, that neocortical (middle and superior temporal gyrus) measures were more accurate than hippocampal structures, and that functional PET measures were superior to MRI findings in discriminating AD from normal controls.